Just Checking In and Catching Up #44 - Delhi India

[aniljangra]

Hello Everyone,

First of all Thanks to Gerald for providing such a good plans and to all the members here to make the process so easy (seems to be :p ).

After about a month of reading reading and reading today I decided to break the bad habit of thinking and START.

Well, ordered the laser parts and belt/pulley/bearing etc for reduction to start with.

As I'm not able to import anything, so everything is going to be locally sourced or DIY (including DIY BOB, Drives, Power Supply, Rails, V-Rollers etc etc)

This is going to be a slow build because, i get only weekend to work on this.

Thanks again... and please ignore if the language as this is the first time I'll be writing/posting anything on fourm.

[javeria]

Hi Anil - you can get BOB from www.sunrom.com, I have one of his BoB's and it seem to work ok - you will have to build a small relay circuit to get the router on/off or can also use a SSR directly -

In meena babzaar old shops (near Jumma masjid) have a lot of steppers, take a multimeter with you and chk for any N34 motors , see which coils show a resistance of around 0.2 to 3 ohms??? and just tie them together - if the motor shaft locks then you may have a good motor, if not just get some new ones, but they are pretty expensive locally.

if you want I can import and provide you the motors and drives from HK, let me know.

I suggest not going with DIY drives - been there done that - suffered a lot!

Have fun in your build -

RGDS
IRfan

[DMS]

Hi Anil,

Welcome.
You can also find capacitors, control boxes, carbide tools etc. at dirt price. Just check them before purchasing. There are two shops in mid of Meena Bazar having thousands of steppers.
You can get double sided tape, proxies,heat shrink tubes, lugs, almost all control box related item and cables from Bhagirath place. If you are going to build controller just check Girish Radio for parts opposite which is also capacitor shop where you can get new one at much higher price. (I got one from Meena B at 80/- still working flawless)
I know you already own cnc so there is really no need to say what you can get in Delhi ;)
Enjoy
Sharma.

[aniljangra]

Hi Irfan,

Actually I already have few Nema34 motors (bought from meena bazaar of course), i got them some time back to convert my mini Drill/Mill to CNC.
Thanks for the tip for quick checking motors, will do that today.

I,ve designed PCBs for Drive and will be testing this weekend. (look avrstmd.com), For now i don't forsee any problem because its using AVR and LMD18245 (3A 55V DMOS).

If there is any problem, I'll upgrade the motors as well as drive from HK.

I'll surely ask you to do that for me as i had bad experience in past with customs when i tried to get some ICs.

Thanks a lot for offering help.
Anil

[javeria]

Oh Anil - u already have a cnc - is that DIY too?

the driver looks similar to PICstep, I hate the LMD18245 being priced so high (INR 1950 for each). did you get a current price on the LMD, are there any substitutes, ??? for the full bridge MOSFET drivers??

RGDS
Irfan

[javeria]

Where in Delhi are u located - I was in Delhi for 6 months during 2005-06, it was fun time staying in delhi -but I did hate the vast temperature differences.

RGDS
IRfan

[aniljangra]

Irfan, Yes the other one is also DIY but small, buit it to rub (etch mill) PCBs for prototyping.

Thanks Sharma for the kind advice, i didn't get you (you got it for Rs 80.).
Please look at my above post for the Drive I am planning to use.

I seriously don't think it won't work as I have used LMD18xxx in past with my own desing it works great.

Anyway We'll see.

By the way Sharma, I have heard of your name already !! Trying to remember ...

[javeria]

Rs 80 for a used 10000uF 100V cap - sharma so you took my advice ah! :D

G' suggests not to go for em - need to be careful with those - may just blow up.

RGDS
IRfan

[aniljangra]

Where in Delhi are u located - I was in Delhi for 6 months during 2005-06, it was fun time staying in delhi -but I did hate the vast temperature differences.


I am near Dwarka, you are welcome the next time you are here.

You know the funny part is I made the other CNC when I was in Bangalore in the past. Actually I did my B.E (Electronics & Comm) from Hubli.

[DMS]

Rs 80 for a used 10000uF 100V cap - sharma so you took my advice ah
I tried hi and low for good caps and I found largest cpacity (size) only there ;}
Well so far so good.

[aniljangra]

INR 1950 for each !!!:eek: Its very high, try following link ..

http://in.farnell.com/jsp/search/browse.jsp;jsessionid=QHT2DLQULAP50CWNBBSLYFQ?N=0&Ntk=gensearch_001&Ntt=lmd18245&Ntx=&suggestions=false&ref=globalsearch&_requestid=83206

I also need few, let me know if you also want, we can order combined, for 10+ its Rs 802.

I'll go with G regarding Caps, I have blown many in my life and now afraid of doing that again :)

[javeria]

ya sharma me too - the bottle caps are so expensive and the small (polyester) high valued ones are mostly sleeved under rated ones - so I go with the used ones too - but this is valid only here in India -

Rest of the world please ignore :D LOL

[javeria]

no Anil - I tested a leadshine drive and I am very satisfied with it, so have decided to go with it-

i am more inclined to get a machine running with properly matched things - having mismatched things takes a year or two out of what you want to achieve - believe me.

RGDS
Irfan.

[DMS]

Ani

My sincere advice get gecko 203, bulletproof. I also tried lot of other things and gave up with (thankfully) Irfan's help. Any other steppers will work.
I also could not import, so got help of others.

[aniljangra]

Thanks Sharma,

Taken .. I'll go with gecko, but I'll rather do mechanical first and test it.

Mech. is something I am bit afraid of as I havn't done such big thing before :(

[javeria]

Do it like John's build here - and you can read my thread again to avoid any mistakes :D

http://www.mechmate.com/forums/showthread.php?t=1610

[aniljangra]

Thanks for pointing to that thread, Nice bolted version, good for me as I move a lot, approx 1 house shift in a year:)

[aniljangra]

After lots of phone calls, at last i found someone to make me Rack/Pinions and ordered :

6 pcs of 4'-6" length module1 racks (2 for each side of x, 1 for y and last to make z), and 5 pinions 24 tooth (one extra).

Hope these are done as I expect. (Is the 24 right number ? because maker came up with that doing some calculations i am not aware of :confused: )

Hope I have now enough posts and i can put some photos ! (I read somewhere that you need minimum posts for that)

[javeria]

I think you are on the right track - what price?

[aniljangra]

INR 5700 for the racks and INR 500 for 5 gears.
Total 5700+500=6200 (Approx USD 135)

[javeria]

thats a very good price

[aniljangra]

Got Laser cut parts and rack/gears. Laser parts don't match the drawings (pdf prints) :confused: I suspect parts are cut from old dxf files. Can someone please go through the pics and confirm if it looks OK or i need to take care of anything in particular because of this !!

[aniljangra]

This is first weekend worked on build, first part is rollers, some pics of the process ...

[aniljangra]

Grooves are 90 deg to best i could do with my limited abilities.
Rollers are 47 mm dia instead of 46mm.
Gerald, does that increase of roller dia changes anything and need to be compensated elsewhere in design ? Thanks

[aniljangra]

Sorry to bother you again G', 3 of the bearings do not roll smooth after pressing into v-tyres. Thea are not stuck but more friction than others. Is this a matter of concern ?

[Gerald D]

Laser parts don't match the drawings (pdf prints) :confused: I suspect parts are cut from old dxf files. Can someone please go through the pics and confirm if it looks OK or i need to take care of anything in particular because of this !!

Give me an example of where PDF does not match dxf?

3 of the bearings do not roll smooth after pressing into v-tyres. Thea are not stuck but more friction than others. Is this a matter of concern ?

As long as the wheels will roll (and not slide) over the rails, it will be okay.

Rollers are 47 mm dia instead of 46mm.
Gerald, does that increase of roller dia changes anything and need to be compensated elsewhere in design ?

That is no problem

[aniljangra]

Thanks Gerald for looking into, for now i noticed :
- on page 1020451BA there is a slot but its missing on mine.
- on 1030420WA it shows 2 slots, none on mine.
- on page 1030422BD shown a tab that says 35mm, Bend 45 deg up. This tab is missing on mine.
-What makes 1020451BA/1020452BA different ? i tried looking at parts but could not make out. May be I'll know when i weld those. Thanks

[Gerald D]

- on page 1020451BA there is a slot but its missing on mine. The purpose of this drawing sheet (from 2007) is purely to show the bend position and amount. The number/shape of holes is not relevant. The holes are defined on 1020451PC which has a note that the slots were deleted April 2008.
- on 1030420WA it shows 2 slots, none on mine. Similar situation as above.
- on page 1030422BD shown a tab that says 35mm, Bend 45 deg up. This tab is missing on mine. The tab is shown in ProfilesBends30Jun08.zip (http://www.mechmate.com/forums/attachment.php?attachmentid=1676&d=1214853734) (the most current version from June last year)
-What makes 1020451BA/1020452BA different ? They are cut from two different shapes of steel, and they are bent in different directions. Your 1020452 shape is visible in the photos, but the bend is to the wrong side.

The small errors that you have are not fatal. You can use the parts. You will have some small problems fitting switchbuttons and getting the right position for the cable carrier.

[aniljangra]

Thanks, now i can move without worry.

[javeria]

Ah anil - you seem to be progressing well - and a lot of electronic stuff u do there - so what are the other things you do????

I think you will very soon have your mechmate running!

RGDS
Irfan

[aniljangra]

Thanks Irfan, It may not be running soon considering it took 2 days to do just the rollers. And i don't want it to be as i am enjoying every bit :)

Electronics is my hobby, but still do small one off uC based development if someone asks me in free time.

[aniljangra]

Irfan, is the gas spring available easily. Where you got yours, cost/ part number etc. ?, thanks

[javeria]

Anil - I just put a normal spring just INR 35 - working great for me

[aniljangra]

Picked a 19"x4"x3/8" tool steel piece for making z-slide.
6940

Tried using normal HSS endmill and within one minute the bit was gone. There was no other way than to use carbide for this so made this flycutter with carbide insert i had and it worked :)
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First surfaced both sides with shims wherever needed.
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Chips are very very hot and burn everything it touches !!
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Next pass, surfaced both sides, directly bolting plate to mill bed.
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Somehow in photo the marks are highlighted but actually the surface is smooth.

Next is squaring the plate sides !! Can anyone suggest how to do that as i don't have any clue on how to clamp the plate on sides ?

Till I find a way to clamp the plate on side, i need to move on to other thing :)

Made eccentric bushings and prepared pinion gears.
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6939

[aniljangra]

Forgot something, the plate thickness after milling both side is 8mm. I assume it good to be more than 6mm ?? please correct me if i am wrong, thanks

[javeria]

good progress anil

[aniljangra]

Made parts for reduction, Chopper's version, thanks Chopper :o
6953

Checking for fit, everything looks fine till now..
6952

Don't have a welder right now, so making all the parts ready till i am ready to borrow or buy one.

By the way, 2 slots for motor mounts are missing as the milling bit broken (already one drill bit and two milling bits are gone), need to learn a lot more about !!

[DMS]

Hi Anil,

Vow fast progress,
If you are using these steppers, then these are only about 300 oz-in (2.5V-4.6A).
HSS bits even doesn't work on MDF, no match for carbide. I am using all carbide bits.

[Castone]

Great job Anil !

[aniljangra]

Thanks Leo :)

[aniljangra]

If you are using these steppers, then these are only about 300 oz-in (2.5V-4.6A)

Yes Sharma, the one seen in picture is about 300 Oz-in but I am not going to use it on X/Y axis (may be Z only). Below is the one I am going to use for X/Y.
6954

Anyhow, I have these so i am just going to use them and later replace them for better performance if needed.

[aniljangra]

Nothing interesting to report this time as I am in the process between BBB (Beg/Borrow/Buy) for the welder. So to kill time, browsed through plans again and found missing parts that I could do and then assembled & tested motor drive.
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One drive tested ..
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Worked without smoke so started assembling more of them ..
6958
Five more in the making, total 6 as I make smoke sometime :)

[domino11]

Anil,
You are making your own drives. Nice. Did you do the board layout yourself?

[DMS]

What's the total cost of one driver ?
As far as welding is concerned ? I got cheap welder at INR 1800 and learned welding, and my MM is still holding :)

[chopper]

Next is squaring the plate sides !! Can anyone suggest how to do that as i don't have any clue on how to clamp the plate on sides ?

I have a suggestion, drill and attach your tube to the back of the plate
and then put the tube in the vise and machine the sides....I think that would make it easy to do and keep things square since you could machine both sides with out taking it out of the vise....
thanks for the shout out about the belt drives...
//chopper

[bradm]

Are those LM18200 H-bridges on that driver? Of the 55V 3A limit variety?

[aniljangra]

I have a suggestion, drill and attach your tube to the back of the plate and then put the tube in the vise and machine the sides....
I think that would make it easy to do and keep things square since you could machine both sides with out taking it out of the vise....
//chopper

Ah cool, all this time i was only thinking how to get the plate held vertically, never thought it could be milled sideways in horizontally as well (though I did that few times it didn't clicked this time), so dumb of me :p

[aniljangra]

Are those LM18200 H-bridges on that driver? Of the 55V 3A limit variety?
Those are LMD18245, yes same 55V 3A .

You are making your own drives. Nice. Did you do the board layout yourself?
Heath, I did the layout myself (in Eagle) as I wanted single sided boards.

[aniljangra]

Initially thought I'll be working only weekends on MM but I find myself working a bit almost daily after getting back from work :) must be addiction sort of .. Finally squared all edges of z plate today
6970
DRO to rescue for drilling ..
6971
Drilling complete, 2 dowel holes are drilled 5.5 mm and reamed to 6mm
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Gerald, my plate thickness is little more than 8mm, is it better/worse than standard 6mm ? If needed i can skim/grind the face opposite to countersunk to get it to correct thickness. Thanks

[chopper]

the thickness of the plate wont matter as long as the angles on the side are ground or machined to the correct angle so the V wheels fit that is all that matters.
//chopper

[aniljangra]

Thanks Chopper, for that matter it applies to all rails not just z-plate. As we are on this I have another doubt about grinding using skates, if the grinding plates are not bent to correct angle the final output is going to suffer ? I am not yet on that stage but I don't find any discussion on setting the angle correctly !! or it does not matter somehow ?

[chopper]

Thanks Chopper, for that matter it applies to all rails not just z-plate. As we are on this I have another doubt about grinding using skates, if the grinding plates are not bent to correct angle the final output is going to suffer ? I am not yet on that stage but I don't find any discussion on setting the angle correctly !! or it does not matter somehow ?

there are several ways to do it, you can use a scrap piece and check the angle,
or you can grind the rails and check the angle as you go ( you will be making many passes to get to the end so you will have time to make adjustments as you go ) and adjust the angle to match your wheels, either way will work, also if the angle is not exactly the same as the wheels it wont be a big deal as long as they are consistently the same over the length of the rails, but the closer to the correct angle the better...when grinding what I did was set the grinder up and take a pass of each side of the rail to form the V and then adjust the height and repeat, you will see the V start to form
and when it gets large enough you can set one of your wheels on the rail to check the angle, then you keep grinding until you have about .020 thousands of an inch flat left on the top of the rails you will need to check the specs on that number to be sure I am going by memory and I could be wrong on the .020
//chopper

[aniljangra]

Thanks, so the way is to adjust as you go and visually. I thought there was a was to do it instrumentally that I might have been missing :)

Chopper what do you mean by ".020 thousands of an inch" !! that seems to be nothing (.02 / 1000 = 0.00002 inch), maybe a typo, I'll check it while I am at that step. Thanks again

[chopper]

you will need to check that measurement in the plans I thought it was .020 ( this is the flat on the top of the rail not the angles you will be grinding you do not grind the rails to a complete point)
but it could be .040 or so....
also if you are using the skate that comes with the laser cut kit which is the same one I used there are adjusting screws on the skate to adjust the angle.
I measured mine visually, but if you have an instrument to measure the angles with I would use that. it has been a while since I built my machine and I cannot remember the angle I think it was 90 degrees if that is the case you can measure it with a square, or you could make up a measuring device of your own but it still ends up being a visual thing, and that is why I used the V wheels
//chopper

[aniljangra]

Thanks chopper, yes it make sense to use roller for checking.
Made last part for belt drive, the shaft and tested for fit (don't have welder yet so just clamped together everything), everything seems to fit nicely.
6996
Note : the motor in pic is just for tests and not going to use for MM :)

[chopper]

looking good.....
I tried to make the design simple so it is easy to build,
looks like you have it mastered, I am interested in feed back when you are done on the belt drives to see how you like their performance.
//chopper

[aniljangra]

I haven't them welded yet !! I feel these are going to work fine chopper. I am sure going to report the outcome.

[aniljangra]

Ordered the steel for table today and going to get it tomorrow so as to keep me busy this weekend.
All steel is uncut, full lengths of 20 feet except main beams (3"x8") because those were only available in 40 feet a length.

My plan is to cut it using chopsaw or cutoff wheels with grinder. Lets see if that's achievable or I have to get someone with flame cutter later.

With this the real fun begins and the part I am most afraid of ..

[aniljangra]

Tried to assemble the grinding jig but the wheel does not fit, its too big ! My grinder is 5", is the jig designed for only 4" grinder ? Am i not doing it correctly or do I rush for a 4" grinder :confused:
7013
7012

I knew it, this part is not fun !! :p

[aniljangra]

After looking at related threads, realized my mistake. The jig will only take 4.5" grinder !! Tomorrow go and search for 4.5" grinder.

[javeria]

Anil - kindly PM me the details of your timing pulley ( spec and cost)

RGDS
Irfan

[aniljangra]

Irfan, PM sent

[aniljangra]

Gerald please help, while welding Y-Car, I end up with gap on both sides where bent part of 10 30 422 meets 10 30 455, pictures below. I think the 51 deg angle is not bent fully, please guide me what to do with the gap !!
7086
7085

Meanwhile I keep cutting and preparing steel for the table...
7087

[Gerald D]

Just push the thin plate closed with 2 fingers and weld it . . . .while the thick plate stays vertical.

[aniljangra]

Thanks Gerald, but I am not able to move it by hand, its hard (mine was cut from 3mm thick as the laser company didn't had 2mm plate in stock). Foolish I am, tried to fix by blow of hammer and the gap widened :o .

[Gerald D]

Then you need to apply force with a clamp. Once you make the first small weld, check it all for square again. You can put a spacer block (or even the spider) in the center and then put clamps right across both sides and pull them in together.

[aniljangra]

OK, great, I'll get clamps of that size and try, Thanks a lot

[aniljangra]

Another problem I created is missing table offset w.r.t beams while welding main beams to cross members, Luckily not yet welded table legs so going to grind open the welds for re-welding. Any other option do I have other than opening and re-welding ??

Its not that I was not aware of offset but I was so focused on aligning/leveling/centering everything that I even centered the table and beam :)

[aniljangra]

Table Welding completed today :) No photos for this as I work in small room and not able to capture the whole table with my camera.
7193

Welding was not that hard, I guess the rail cutting & grinding is the harder one :p

[Claudiu]

Hi Anil,

good work till now. I think everybody leaves the rails till the very end. Me too.
Good luck with your build

Claus

[aniljangra]

Thanks Claus, I don't have space so now as the table is done, somehow I have to cut and grind the rails on it, in fact everything now on is going to be done on MM table as It already filled up all the space.

[aniljangra]

Started with next major part, the Rails (with of course skate method). For me the only option is to do it inside and the only working space I have is MM table. Here is my setup for cutting..
7264
The only thing I had and can trust for flatness was this Granite tabletop :), got the permission to use it with a promise that the first thing MM is going to do will be a tabletop.
7265

Only a small portion cut and its all mess inside already ..
7266

[Gerald D]

Check for fire risk . . . . that table on the right looks like it has some rags, paper & chemicals on top or underneath? It will also be easier to clean up if you clear all the stuff off the table first.

[aniljangra]

Thanks Gerald, I am clearing all that stuff now before going any further. Anyone reading this please take all the care and do it outside in open ( I had to do it this way as I don't have other option)

[aniljangra]

Cutting of angles to 28mm completed, next going to level and smooth the top of the rails flat a bit with grinder and then grind V :)

Used 10 discs because could not utilize the whole discs as the angles were 65mmx65mm. One tip to add here (may be its already said) is to level and get the disc parallel to cutting surface, otherwise disc is caught in groove and may break and wear fast.
7272

I was lucky enough to just cut all of them with what i had (10 discs) as you can see i had to break last a little part of rail as the last disc was not enough to cut through :)
7273

In t1st pic, look how small my lathe looks in comparison to MM table

[DMS]

So you consumed all discs we purchased :)
Just to add I got another bigger pulley from M. bazar.
You also need to check angle for v cutting.
(Note - I was with Anil on 23.11.09 together we explored market)

[aniljangra]

So you consumed all discs we purchased :)
We purchased only 5 that day, I needed another 5 and got them later :), Yes I had a thought about the angle before and asked the question in this thread, will keep in mind to get the angle match rollers to best i can, thanks for reminding.

[aniljangra]

Wondering today how fast time passes while working on MM, its been a month since started MM build :)
Well, little more progress as the rails grinding completed, no pics for this :( but yes a nice pic of grinding a little V on hand as a reminder to be more cautious and respectful with steel & machines.
7376

Moving on to gantry, drilling the pilot in flat bar, y-rail and gantry tube all in one go by clamping together.
7374

And finally a welded gantry:D, small twist but seems fine.
7375

No, room is always not as dirty as its is now :eek: this is a pic from last month when I started the build.
7378

And Yes I do have a lot of help available :)
7377

[Claudiu]

Hello Anil,

sorry about that V-Cut in your hand. As a doctor I usually have always a medi kit around, but I think it will be cured by the time I arrive!:)

Greetings
Claus

[Gerald D]

See, tapping threads is child's work . . . :)

[aniljangra]

Correct Gerald :)
By the way I am using a small 300W drill to tap all threads and its working fine for me. Though 300W is far less power than required but still its faster than doing manually.

As a doctor I usually have always a medi kit around, but I think it will be cured by the time I arrive!:)
Claus

Your are right, It already started healing already and you might not notice it by the time you arrive :)

[gixi]

What can I say : Welcome to the club... A few months ago I cut my self with the grinder. During the construction process I was electocuted, cut, burned, etc. But all was left behind when MM start to make dust and chips :).
Claudiu its right : medical kit its a must in a workshop :D.

[Gerald D]

Avo Marius, you were cut, burned and electrocuted and you havn't sued the owner of the MechMate site for all these injuries? :(

[javeria]

They got out ALIVE - and that was enough for them not to complain :D

[aniljangra]

Getting out ALIVE is THE problem (for Gerald), DEAD can't complain :)

[aniljangra]

Gantry set on the X-rails finally..
7425

and being tested for smooth ride
7426

please check for the Y-car orientation w.r.t gantry, the first pic below is taken from 0,0 corner(0,0 closer to camera).

Yes, X-rails hangs over beams because of wrong offset calculation again by me :( , Need to weld a piece there before closing ends of beams.
7423
7424

[padmanaabha]

Great work Anil. All the best. Waiting to see the machine working. Is our Mini Router working? If yes post me a picture of the same.

[Gerald D]

Anil, the orientation is correct.

[vishnu]

Hi,

Good Progress, Love see them Blue.

Vishnu

[aniljangra]

Anil, the orientation is correct.

Thanks Gerald for confirming quickly.

Great work Anil. All the best. Waiting to see the machine working. Is our Mini Router working? If yes post me a picture of the same.

Thanks Pady :), We discuss only the BIG machine here, I'll send you pics of other machine in mail.

Hi,
Good Progress, Love see them Blue. Vishnu
Thanks Vishnu, Paint job will be soon :)

[J.R. Hatcher]

Anil I don't think you need to do any to the overhanging rails. My next machine will overhang about 4" with no support. J.R.

[Gerald D]

I agree with J.R. - those overhanging rails are really not a problem.

[gixi]

Avo Marius, you were cut, burned and electrocuted and you havn't sued the owner of the MechMate site for all these injuries? :(

Gerald it's too late for me to do that now when all my friends hear from me what a nice guy you are. But speaking seriously grinder could become a very dangerous tool when you are thinking at something else during the cutting process.

[aniljangra]

I agree with J.R. - those overhanging rails are really not a problem.

OK, then I'll go ahead and round and deburr the sharp corners/edges pf the rails and let them overhung.

[padmanaabha]

Sorry, I didn't know. Will be tracking your progress. Very eager to see the machine working.
all the best again.
Pady

[aniljangra]

Doing z-axis worked out to be most time consuming for me, most time gone towards beveling z-slide plate. Then there was a wild spider so it has to go under the cutter :)
7488
7489
And the z-axis test assembled, I am sure everyone is going to shout at me for another mistake ? Rack holes on wrong side of plate. Anyway after drilling another 2 holes for rack I will put dummy screws on these and the screw pattern will look symmetrical :D
OR can i simply use tape ??
7490
And it started looking familiar
7491
And nobody is going to comment on my ugly weld or I'll stop posting pics :o

[Castone]

Hey your almost there! soon you will be making chips fly and dont worry you always have to break a few eggs to bake a cake. It looking good.

[aniljangra]

Thanks Castone, The major part now (the part left is always major one) is finishing it all. All the deburring/cleaning/grinding/painting is a time consuming and never ending part :(

[Claudiu]

Hey Anil,

you have made nice progress with your build!

Don`t bother about bad welds, but never post anything with Led Lights...:D

Greetings
Claus

[aniljangra]

Claus, Thanks for the warning about lights :)

[aniljangra]

Belt drive plates joined today, ready for assembling after painting. Looks crude and not pretty as CNCed Alu. plates but I prefer weld over bolts somehow !
7532

[aniljangra]

Quick and sloppy paint job :)
7599

7600

7601

7602

7603

7604

7605

[padmanaabha]

Mechmate is all over the place, Anil. Can see how u r enjoying the progress. All the best.
Pady

[aniljangra]

Pady, Much fun still remains as it gets assembled and the electrical / electronics part done, so hurry up and pack up if you don't want to miss all that fun :)

[aniljangra]

Aligning the banana snake rails is no easy task, some pics taken during the process.
Using a thread, first fixed the point that were correct and then pushed or pulled the rails where miss aligned.
Pushing the at one point using clamp was simple
7681

Pulling the other way required more clamps :)
7677
7678
7679
7680

Then draw filed the points as needed and finally straightened and smooth using V block and sand paper.
7682

Checking and it passes :p (my criteria being not so stringent as others here)
7675

All Gantry wheels seems to sit without gap over the travel except 0,0 corner :( because rails is sharply bent and clamps doesn't seems to work on correcting such sharp bend.
7683
7684

And Gantry riding on rails...
7685

Now moving on to Y rails, hunting for holes in clamp strip..
7676

Its late today so final alignment of y-rails be done tomorrow, just a pic of y-car riding the (yet to be aligned) rails.
7686

Partially assembled the belt reduction plates, pulleys on all of them are smooth, that's a great relief :)
7674

By the way, had to undo and assembled these twice as I forgot to insert the belts first time. Anyone doing belt drives, don't repeat my mistake

[Claudiu]

Anil

You did a great job so far. Looking goood:)

[aniljangra]

Thanks Claus, I wish my build was as good as yours but as you can see I don't have patience like you :)

Look, I painted without even welding stop blocks, proxy, chain mounts etc, and I am sure I must be missing many more such things... :o

[Robert M]

Look, I painted without even welding stop blocks, proxy, chain mounts etc, and I am sure I must be missing many more such things...

What seems to rush you... :confused:
Make sure you at least have stoppers ( Stop blocks ) :eek:

[Claudiu]

Look, I painted without even welding stop blocks... :o

I also did not paint the last 10 inches of the rails to have my stop blocks welded at last. I wanted to get most travel so I waited with them until to the very last, to check most travel.

[aniljangra]

What seems to rush you... :confused:
Make sure you at least have stoppers ( Stop blocks ) :eek:

I don't mean to eliminate the stop blocks or proxies, Its just that I thought "the welding work is done so lets paint it :)".

[aniljangra]

My solution for connecting the sensors and buttons to BOB is to feed all the inputs to a control box riding on gantry (as discussed in past on this forum). Already drawn schematic in Eagle and doing the PCB, here is the rendering of the board (checking the size that can fit all those connectors :) )
Top edge there are 8 connectors for sensors, left edge is the power connector, right side the LEDs and bottom edge the connectors for buttons, probes and output to BoB)

Circuit diagram is also attached for someone to have a look at, I tried to keep it as simple as possible :)
7740
7739

Please (everyone :)) suggest if something is missing or not correct :

1. Take inputs from 8 NPN proximity sensors and combine them in one output to BOB. Four of them can be Home and other 4 Limit sensors. As all the inputs are ANDed, as many as required can be used and all other inputs can be left unconnected.

2. Eight LEDs to show the status of which one triggered the output. LED will be latched till reset.

3. Take Inputs from all three button stations and combine them in output to BOB. On each station there are 3 buttons a) Estop, b) Pause/Resume, c) Z-zero (we only need one button for Pause and Resume, though the controller will send output to 2 seperate line to BOB depending on the current state). All buttons are NO type

4. Take input from Touch plate (Active low) and Touch prob (Active high) and combine them together. ( As I haven't yet worked with Mach3, I am not sure of this combined probe/plate output can be further combined to the output from proxies or it need to be seperate output to Bob, please suggest ?). Anyway this is not going to affect H/W and can be changed in code anytime.

[javeria]

hmm need only three proximities to act as limit and home switches, on my machine I use only 3.

there is only one signal required for the Z tool zero probe,

[aniljangra]

Ok, I'll reduce the number of proxy inputs to 4.

Also while browsing thread on this topic I found the answer to my other question "Z-zero can be combined to other inputs ..."

So now there will be 2 inputs one N/O and one N/C from Probe/touch plate and there will be no separate output ( these will be combined in series with the output that is used for proxies).

Also noticed that there need to be an option for a seperating one of the output from X proxy for auto squaring, so there will be a jumper for this selection.

So now a smaller chip can be used. I'll draw a new schematic today. Thanks

[paniken]

I am Hari pradeep from kerala India.Can you give me prices for Hong Kong motors and drives if you are importing for me

[aniljangra]

Updated as :
- Number of proxies reduced to four.
- Jumper added for routing one proxy output to separate pin for auto squaring.
- Probe output combined with other proxy outputs.
- E stop is directly routed to BoB input, other buttons goes via controller.
- Smaller chip and smaller board.
Here is placement view, next to route the PCB and program uC.

7750

Suggestions are welcome as I usually rush and miss things :)

Already got one suggestion to take thermistor input from spindle for early warning for high temperature before VFD shuts it down due to overheating, thus the work can be paused and resumed later. So saved one pin on controller for that, now searching for thermistor specs ?? (don't have spindle yet). I guess its some kind of NTC !!

[aniljangra]

Got some missing electronic parts for drives and fixed heat sinks. All of them tested good with motor attached. As small parts of kitchen table project sort of went well. :). I made 6 of them just in case i blow up one or two dring testing but it all went well.
7775

[javeria]

looking forward to see them zip zap and zoom the mechmate

[Claudiu]

Anil, respect. You are a real electronics Guru.:)

[aniljangra]

Claus, making few circuits don't make you guru :)

Moving on to MM, the pic shows the way I managed to get rails seated on those twisted gantry tubes, as shims were not working I laid some welds on top of tubes across the length and using tightened wire, level and a flat slab grind off the high points.
7829

Just to add, the rails were removed and then the welds were laid on top of tubes.

[aniljangra]

Few items from recent shopping :)
7830

7831

7832

7833

7834

7835

[aniljangra]

And progress so far ..
7836

7837

7838

7839

7840

7841

[aniljangra]

Wiring started, pictures of whats done so far ...
7842

7843

7844

7845

7846

7847

Still need to get Teflon washers for motor mounting and pivot points. Also wiring need more tiding up and most probably all of the MM need another coats of paint :) Thanks for looking, Anil

[javeria]

great work

[DMS]

I like Red and White.

[aniljangra]

Thanks Sharma, I hope its allowed :)

Here is final piece, the Z-slide mounted, I was waiting for the motor for Z but couldn't resist and mounted the old round motor for now :)
7858

And now back to control box and wiring.

[aniljangra]

After encouragement from fellow member, decided to post pictures of my control box (Biiiig one :)).
7942
Green is power indicator and other 2 red are to indicate 2 relay outputs, spindle and dust collector.
7947
7945
7946
7942
7940
7941
7949
And hand made Bob till PCB is ready, for testing
7948
Transformer has 3 tap so that motor voltage can be tweaked.
7950

Plate where all ground wires terminates
7944
It look fine except bad paint job done by me as usual :)
7943

[Robert M]

Nicely going ANIL….
It sure looks like you’re very close to a rolling day!
Wishing you all the best and a smooth final tuning !!
Amicalement, Robert ;)

[DMS]

Cool man !!!
Now start making dust and get first 2010 #

[Claudiu]

Good Job ! Take care to have the control box cleaned out of any wire pieces lying around, thy make beautyful sparks!!!
Happy New Year!

[aniljangra]

Thanks Robert, Sharma,

Hope to qualify for first # of 2010 :)

[aniljangra]

Good Job ! Take care to have the control box cleaned out of any wire pieces lying around, thy make beautyful sparks!!!
Happy New Year!
Right Claus, it gets a vacuum cleanup after wiring done. Wish you and all here a happy new year.

[aniljangra]

Wishing all at MM forum a Happy new year 2010 :)

Got Logos printed, will paste them today and do a pen test as I don't have spindle/router yet.

[padmanaabha]

Go Roaring Anil. All the best. Happy New Year to one and all at the Forum too.

[Castone]

Way to go. Lets see those pen marks!

[aniljangra]

My telephone (internet) was down last few days and could not update.
After pen marks (in first pic, those marks are supposed to be roadrunner :)), I moved on and installed a die grinder I had in place of spindle and finally it makes dust..

First few final shots with logo pasted
7994
7993

Z-proxy is mounted directly on spider plate, a bit off center, It works fine.
7995

Quick change mount works great, and here is die grinder in place..
7996
7997

Broken my first router bit in MM, my mistake instead of typing -0.1, typed -1.0 for the Z and the machine happily plunged exactly 1 inch without a strain :)
7998

Now using a broken drill bit for testing :)
8001

And look at the dust, huurreey...
8000

Here is closeup, size is approx 12 inch, rapid 400 ipm, feed 50 ipm, broken drill bit approx 1 mm.

7999

[Claudiu]

Yippie !!!:D:D:D
Congrats for the first MM # in 2010 !!!
Nice Carvings...

[aniljangra]

Thanks to Gerald, Claus, Leo, Pady, Irfan, Robert, Sharma, Chopper and all the members for looking at my build, not good looking but it works :D:D:D

I'm sorry if I forgot to mention any names, no disregards please :)

[Gerald D]

Well done Anil!

[KenC]

Great job Anil! Congrats!

[aniljangra]

Thank you Gerald for the #44 :D
Thank you Ken. Need to do the PCB for BoB today as I am still using my handwired board.

[gixi]

Well done ! I presume you have the same feeling when you see that monster who was a few month ago just some metal bars, wires and now is moving.

[sailfl]

Anil

Congratulations on #44.

[DMS]

Isn't feelings are such that when we see newborn ?
Congratulations on first #2010
Welcome to growing Indian MM club.
And don't worry about broken bits, now we have good (cheap) source, don't we ;)

[aniljangra]

Well said, the feeling is exactly same :)

[domino11]

Congratulations Anil! :)

[Kobus_Joubert]

Well done Anil...let the real fun begin....

[Castone]

I am very happy for you Anil. You have done a great job on your machine.

[hennie]

Enjoy , and well done Anil

[aniljangra]

Thank you Kobus, Leo, Heath, Hennie and everyone, I got ideas for executing bits and pieces from almost everyone's thread :)

[normand blais]

Félicitation Great for you 1 instead of .1 not as bad as 5 instead of .5 happy pole vaulting

[quadtech]

Anil, Congrats! Great work, and done really quick too.
So #33 and #44 are in India. Perhaps someone here
will get #55 too :-)

Do post some technical details of your homebrew
driver board and BOB.

[Rad Racer]

Nicely done Anil, congratulations on #44.

[aniljangra]

Thank you Wayne.

Anil, Congrats! Great work, and done really quick too.
So #33 and #44 are in India. Perhaps someone here
will get #55 too :-)

Do post some technical details of your homebrew driver board and BOB.

Thanks, Pieces keep on fitting in as you move along, its a nice design just get started and in no time you will be moving fast :)

I am doing a controller board for managing all inputs from proxy and switches and redoing the BoB to add an intellegent charge pump (uC based so that it never missfires on noise) and including a PWM to 1-10V for spindle control from mach on same chip.

I'll update as soon as I test them and send the design/code to anyone interested.

[riesvantwisk]

Thank you Wayne.
intellegent charge pump (uC based so that it never missfires on noise)

Anil,

I was thinking the same, however would not a simple bandpass filter be enough? Then EMC2 or MAch3 just needs to put out a specific frequency.
That said, I am not sure how the current implementation is of the CP on the PMDX122 is, does the flip frequency matter?

I did notice that EMC2 puts out a very low (2-4hz??) frequency for the CP, I am not sure what will happen if that is increased.

Ries

[jhiggins7]

Anil,

Great build and a wonderful job documenting the build. :) Congratulations on Serial #44, the first Serial # of 2010 just as you had hoped!

The Updated Builder's Log is here (http://spreadsheets.google.com/ccc?key=0AttqjIPMBEXKcExveGc4d3U0V25zQmMyX1U1eUVhU Xc&hl=en).


Please let me know the "cutting" dimensions of your MechMate for the Builder's Log. Also, please review your entry and provide any changes you would like.

[aniljangra]

Thank you, I was just waiting for you :)

For log cutting dimensions are 2500x1220, Entry look fine, if you can please update the comment section as "Belt reduction per Chopper design, DIY Drives & BoB"

BoB yet to be completed as PCB is not yet ready but right now I'm using a DIY handwired BoB.

Thanks again

[aniljangra]

Anil,

I was thinking the same, however would not a simple bandpass filter be enough? Then EMC2 or MAch3 just needs to put out a specific frequency.
That said, I am not sure how the current implementation is of the CP on the PMDX122 is, does the flip frequency matter?

I did notice that EMC2 puts out a very low (2-4hz??) frequency for the CP, I am not sure what will happen if that is increased.

Ries

Ries, A small 8 pin uC is cheaper than few passive components :) moreover think of this as a band pass digital filter with added hysteresis. Hysteresis can be smaller for ON and a bit longer for OFF so that a glitch in CP pulse train don't send a stop signal.

For PWM to 0-10v conversion, of course a simple passive network will do and that's exactly I am thinking of doing.

I'll do some testing on both and post the results.

[jhiggins7]

Updates completed, here (http://spreadsheets.google.com/ccc?key=0AttqjIPMBEXKcExveGc4d3U0V25zQmMyX1U1eUVhU Xc&hl=en).

Again, great job, Anil.:)

[jhiggins7]

Anil,

Like "quadtech",

...Do post some technical details of your homebrew
driver board and BOB.

I'm also interested in additional details of your DIY drivers and BoB. I'm familiar with the AVRSTMD.COM site.

You mentioned Gerbers. Would you be willing to share your Gerbers?

[aniljangra]

John,

Don't know if I should post the files here so I am PMing you the Egale files for the Drives, Change as you like and generate Gerber or anything you want :). Fell free to ask if I missed anything. Download free version of Eagle, the PCB is within the limits of free version.

I'll post my version of BoB with CP and PWM as well soon. Also there is a controller board that rides on gantry for taking inputs from proxy and buttons in progress, will be done and shared soon, thanks for the interest.

As the real work is done on weekends so my progress is slow :)

[aniljangra]

Thought of testing for backlash by milling the contours of pcb tracks.
8044
Roughness is due to me not using proper bit but a broken drill bit as cutter and high feed rate of 100 ipm, whole thing milled in 34 seconds flat :D. See for yourself the capability of MM :D, perfect usable PCB can be produced with proper bit and feed.

May be if I can get a bit I'll do the BoB and cntroller board for MM on MM itself :)

Note : I still need to put the spoil board and surface it.

[aniljangra]

Can anyone using VFD with 0-10v speed control unit confirm that a input with about 500mv ripple will work on VFD ?

I tested a simple RC network today and its producing DC 0-10V with a ripple of 500mV from PWM signal at 1500Hz.

How far can we increase the PWM freq from Mach ?

[bradm]

Anil, I'm running off a PWM signal and a simple RC network; never bothered to measure the ripple. The first shot used a very small capacitor, and it showed up as a random small speed variance at the spindle (I had the VFD display the spindle freq). I upped the capacitance until the variance went away.

Assuming that your VFD linearly allocates the 0-10v across 0.0-400.0hz ( mapping to 24000 rpm), it's 10v divided into 400 (or 4000) levels, so 25mv (or 2.5mv) per level, with each level representing 60rpm (or 6 rpm). 500mv ripple could represent up to 1200rpm or 20hz variance, assuming that the VFDs sampling of the control signal was worst case timing with no hysteresis. Real world variance would likely be less; mine was about 3hz before I fixed it.

I suspect you'll want to increase your capacitance a bit, but testing will show you what you need to do. The down side of too much capacitance would be a VFD that was slow to respond to control signal changes.

[aniljangra]

Thanks Brad, I guess there is bit of hysteresis or averaging or both built into VFDs so don't want to increase cap too much slowing the response time.

That's exactly the reason I asked for how much high Mach can reliably put out PWM freq (assuming 25Khz kernel freq).

Whats your PWM base freq set at ?

[bradm]

I'm using EMC2, not Mach3, and the setting I'm using is 50hz (I just triple checked this, I'm using the pwmgen module for EMC2). Practically speaking, the physical limits of spindle accel and decel are far greater than even lots of capacitance here, as long as you don't use a spare power supply filter cap :). 1500hz should be more than enough.

[aniljangra]

Thanks Brad for confirming the freq, you are right about the response time in practical world :) I'll increase the cap value to get the ripple down. Bad news is my DSO died suddenly for no reason :(, I suspect the grinding dust from rail grinding got in and shorted something inside.

[Gerald D]

I can't remember what a DSO is?

[aniljangra]

Sorry Gerald for the confusion, "Digital Storage Oscilloscope" is not a part of MM, thats the reason you don't remember :)

[quadtech]

Hope the scope issue turns out to be something
simple like a fuse.

Can you get the LMD18245T locally?

[aniljangra]

Quad, I got LMD18245 from farnell (http://in.farnell.com), you need 2 of them for each drive. Micro-controller is also available on same site.

[aniljangra]

Kobus asked if its possible to do isolation milling on MM, I did trail and here is the proof that its surely possible.
8057

Note that I am using broken drill for milling, so the isolations are wide and the actual track/pad width looks small. But with actual bit the output is a usable PCB as all tracks are intact :)

By the way this is the actual PCB for MM to combine all inputs.

[Kobus_Joubert]

And with Vectric V-Carve pro I can do the PECK Drilling of the holes at the same time.

[aniljangra]

Kobus, Eagle generates a NC file for drilling as well. I didn't bother to complete the milling and do drilling as its just a test, for you :D

[jhiggins7]

Anil,,

Your PCB looks good...even with the limitations you talked about. Thanks for showing us more of the capabilities of the MechMate.

I know you may be busy with getting your spindle working and that you have a "day job" to attend to, so this discussion may need to be delayed...BUT, I'm very interested in your experience with the Open Circuit AVRSTMD drivers.

First, could you confirm the specifications of the stepper motors you are using? I believe you are using the 3.5 amp, 4.5 volt, 450 oz-inch HOLD, Superior Electrics for the X and Y and a 300 oz-inch for the Z. Is this correct? What current setting are you using on the AVRSTMD? Also, what voltage are you running the stepper motors at?

Next, I'm wondering about mid-band resonance. I don't believe the AVRSTMD driver design has mid-band resonance compensation. On the other-hand, ALL of the Geckodrive stepper motor drives have mid-band resonance compensation. So, do you notice any problems with your MechMate that would be the result of mid-band resonance issues? I'm no expert, but I believe the effects would be strange noises and even stalls or lost steps.

Finally, I'm wondering about heat. The AVRSTMD uses some significant heat sinks. It appears that your drivers are mounted on metal stand-offs directly to the back of the enclosure. Do you notice any heat build-up inside your enclosure? Did you vent your enclosure? Do you use any circulation fans? I don't see any vents or fans in the pictures of your enclosure.

[aniljangra]

Thanks and first of all let me make it clear that I wanted to avoid Geckos because of cost (my whole set of drives cost me about the cost of one 203 :)) and believed that if motors are chosen and connected correctly 3Amp limit of drivers chips (LMD18245) is enough for MM.

I am running chips at 2.5 Amps with single coil on x and y and series connected coils on z (because z motor is 4.6 amps).

You won't believe but only Y motor is 450oz-in and all other motors are approx 300 oz-in and I am comfortable at running any axis rapid at 500ipm without loosing steps (of course you can't cut at 500ipm anyway).

I have not noticed any mid-band problem till now, I guess motors accelerate fast enough through the region. May be I need to run slow enough to notice the oscillations. (whats the accel you are using ?)

I've multiple taps on transformer so that I can get 45, 50, 60 volts, I tested drives on 45 and 50 volts.

Though I use large heat sinks on my drives (because I already had many of those laying with me), I think smaller will do, after-all its a DMOS device unlike 298 which generates lot of heat.

I don't have a fan but I have ventilation holes right above the drives, not visible in pics because those are covered by keyboard sitting above them :)

Computer CPU is generating more heat than these drives :), Its winter season so I am not installing the fan right now, may when its hot I'll add one.

I guess you already know, PICstep is another similar option available for drives using LMD18245.

[jhiggins7]

Anil,

Thanks for taking the time to respond to my questions. I appreciate the thoroughness of your response.

I'm planning to build a second MechMate. So, I'm wondering about using the AVRSTMD drives. I think I can build them for $20-30 each.

Keep up the great work! And please continue to share your results with us.

Two more questions. Have you "sensed" the temperature of the drives during operation of the MechMate (like touch them or nearly touch them or measure them with one of these (http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96451))?
Same question for the motors?

[aniljangra]

I don't have device for temp measurement, but I can touch them.

Motors are only slightly warm.

I can say that its worth to give it a try as you can build 4-5 of them for the cost of one Gecko and in case you feel you need to upgrade, you can use them for Y,Z,A etc and just but Gecko for X.

I'll do a temp measurement circuit as I get time and do the measurements on drives, inside box and motors.

Also again, do look at picstep as well.

[jhiggins7]

Thanks again, Anil. I'll be interested in your observations once you get your spindle working and start using your MechMate for long cutting sessions.

For temperature monitoring, I purchased a temperature probe like this (http://cgi.ebay.com/Digital-Thermometer-Temperature-Sensor-LCD-Display_W0QQitemZ170377985801QQcmdZViewItemQQptZLH _DefaultDomain_0?hash=item27ab51bf09)from Ebay and mounted it in the front panel of my enclosure. I attached the probe end to the driver heat sink.

I'm going to build at least one AVRSTMD. and check it out.

I've programmed both PIC and AVR. I find AVR simpler to program, so I'll go with the AVRSTMD for now.

I also notice that the Geckodrive G250 (which is the module used in the G540) is only $61 each and it can handle 3.5 amps and 50 volts. It also has the mid-range resonance compensation that I mentioned in an earlier post.

Keep up the great work Anil. Your build is an inspiration.:)

[aniljangra]

Thanks you John and good luck for you next MM.
Installed the spoil board and tried to set gantry at 90 deg to X, not yet done but will do next week as its I think its off more than that can be fixed by shimming the gantry wheels. Need to adjust the Y rails first on gantry tubes a bit before shimming the gantry wheels.

For now before surfacing the spoilboard, wanted to spoil it a bit so here is the cartoon file again :p

8107

[aniljangra]

My first attempt at 3D on MM ..
8145

Sorry for the bad pictures I always post, my handycam don't do better than this on stills :( , Next time may be I'll try video.

[aniljangra]

I'll be interested in your observations once you get your spindle working and start using your MechMate for long cutting sessions.

John, the last 3D job is 12x12 inchs approx and took about 50 mins using 4mm ballnose cutting about 0.5" deep in single pass with stepover = d/7 at 150 ipm.

Only Z drive seems getting hot (still touchable) in that an hour time, I think because :
- its the last one in the row, far away from vetilation
- Z motor is 4.6 amp and the coils are connected in series (more inductance)
- and of course its the one doing most work in 3d job :)

I think with a fan blowing air on drives will be sufficient for any cutting job.
Will keep updating as I go :)

[jhiggins7]

Very nice work, Anil. Love the lion's head.:)

I wish I could lend you my Temperature gun. I understand from this Forum that the stepper motors can run safely at 80 degrees C. I think that would feel really hot to the touch...you couldn't hold your hand on the motor.

When you cut the lion's head, what was your driver temperature like?

[aniljangra]

My cam seems to get better pics in daylight, here is again same pic.
8147

John,

Motors run cool with no sign of heating up, all of them only just warm.

While cutting, as mentioned earlier only Z-driver seems to heatup (still can hold hand on it), all other drivers were normal (just warm), Can't give you exact temp figures as not measured, but can say 3 drivers and all motors were warm similar to a Hard Drive running in computer. (may be about 30 deg C)

I'll connect the Z motor as single coil and It'll cool down the driver as other in system. I feel Z is heating up due to very high inductance of Z series connected coils.

John, even with it heating up there was no problem as electronics can run at that temp safely.

[javeria]

congrats again - you seem to be doing it very very well

[jhiggins7]

Thanks, again, Anil.:)

Really great work. Thanks for the feedback on your motors and drivers. Hope all continues to go well for you.

[KenC]

Nice work Anil.

[aniljangra]

Thanks you all, Irfan, Ken & John.
Now I need nice files to continue cutting :D

[aniljangra]

Amazing, how tilte of my thread changes automatically :p:D:D

[Claudiu]

good job, Anil.

[aniljangra]

Thank you Claus,

Finally got PCBs done and my BoB and controller for proxies and switches installed on MM. Now I can ref home and use the switches finally :)

The charge pump on Bob is done using a tiny micro-controller and same way a controller riding on Gantry takes all inputs from proxies and buttons and combine them to BoB output.

The BoB with charge pump and a simple PWM to 0-10v.
8294

The Controller for proxies and switches, the LEDs show the status of Proxies, on estop all LEDS turns on to show if any of the estop button pressed.
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Back side of board is all mess with all wires coming to connectors.
8296

[javeria]

great work

[KenC]

Fantastic! Wish I know how they work.

[vishnu]

Hi Anil,

Thats a nice BOB, keep us updated on the perfomance

Vishnu

[aniljangra]

Thanks you Vishnu/Irfan :)

Fantastic! Wish I know how they work.
Ken, Don't understand what you mean ?

If you want to know how its working for me, then yes these seems to be working fine for me :), for now. I'll test it with VFD when I get the spindle and report.

If you want to know how its programmed (ts simple stuff anyway), then for controller on Gantry :
samples all switches continuously and whenever any of "start" buttons is pressed it, it makes "start" output high. same way for "pause" buttons.

Proxy and estop inputs are sampled every millisecond, on estop input the estop line is made low and all LEDs are put on to show the event.

On any of proxy input the proxy output is made low and corresponding LED On to show the status.

(Proxies are not sampled continuously along with buttons, but every millisecond so that the homing sequence is repeatable every time exactly)

On BoB, there are buffers on inputs and outputs with the addition of a simple RC network to convert PWM to 0-10V signal for VFD.

and for Charge pump, there is a tiny micro-controller that counts pulses from CP pin every 10mS (for a frequency in the range of 6KHz to 13Khz), if the pulses are found in the range 10 times successively the outputs are enabled.

Same way on enabled outputs the CP signal has to miss for 10 successive times before the outputs are disabled.

In turn thats 100mS before the outputs are enabled/disabled on valid/invalid signal. I'm sure it won't act on noise with all this :)

By the way, can mach use same input for z-zero sequence as the other proxy inputs ? If yes, then the z-zero input can be combined as well, also the same 2 buttons when pressed together can initiate the z-zero sequence !!!

[KenC]

Anil, Thank you for your detail explanation of the working principle. I'll have to spend some time understanding it.
Woulkd you kindly elaborate the RC tank convert the PWM analog signal? Does the PWM signal comes in the form of pulse train or bit stream? I am having the idea that the PWM is a Psudo Analog signal...

[aniljangra]

PWM as the name suggest is pulse train of varying pulse widths. For low value the on time is less compared to off time, same way for higher value the on time of pulse is grater than the off time. So if you just average the pulses you will get an analog signal (of course in the range 0-5V).

To get 0-10v output you need to amplify it. I used a transistor to shift the level of pulse to 10v and then averaged.

[KenC]

Now I can see much more clearer. Thanks

I'm so happy!

[aniljangra]

As usual, again showing a PCB done on MM :)
This time made few adapters for surface mount parts for my electronic prototype work.

This pic is interesting because of the sizes involved on smds parts, this pcb is milled using 0.2mm bit and note the track width is only 0.1mm. (calculate that in inches :) )
8355

Some tracks are exact width but some are a little wider, Is that backlash ??
Also noticed that the pattern is consistent on all of them

[Gerald D]

Ouch! that thing is only 1" square! Okay, while the tracks are supposed to be 0.1mm [0.004"] wide, some are twice as wide as others, range probably about 0.05mm [0.002"] to 0.15mm [0.006"], which means you are holding an accuracy of +/- 0.05mm [0.002"]. That is too technical, and it tells us nothing . . . .

Did you always go in the same direction around each pad/track? If you go clockwise around, you will get wider tracks than if you went anti-clockwise, because of the flex in the cutting bit.

[jhiggins7]

Anil,

Well, .1 mm is about 4 mils (.004 inches). Not bad. Nice work.:)

I think I see the pattern...the lines are thicker on the left of the adapter picture...is that what you are seeing? I have no idea why it happens.


Were all the adapters you cut usable? I mean, were any of the signal lines too thin or "open"?

[Gerald D]

John, you posted the same time as me. I wasn't aware that 0.004" was called 4 mils.....I would have said 4 thou. ??

[jhiggins7]

1 mil = .001 inches or 1 thou. See here (http://en.wikipedia.org/wiki/Thou_(length)). I'm no machinist, so I just used the term as something I'm familiar with.

I'm also aware that a "extra fine" PCB trace width is one or two mils. So I was letting Anil know that the achievement of 4 mils using a CNC router was rather remarkable.

[aniljangra]

Did you always go in the same direction around each pad/track? If you go clockwise around, you will get wider tracks than if you went anti-clockwise, because of the flex in the cutting bit.

Hmm, I did not think about the flex in bit, I reran the file again (in slow motion :)) and noticed that all but 3 tracks on top left are milled clockwise !! But don't think its the cause in my case.

Sorry I forgot to mention that I used 30 deg V bit and closely zooming in the picture found that the depth is increasing from left to right, causing the isolation widening and track shrinking. (try zooming the pic to see what i mean)

(It must be level of the table or PCB that is fixed with double tape, even may be the level of my rails that's causing depth variation).

John, tested the continuity and the PCBs are very much usable :)

[aniljangra]

1 mil = .001 inches or 1 thou. See here (http://en.wikipedia.org/wiki/Thou_(length)). I'm no machinist, so I just used the term as something I'm familiar with.

I'm also aware that a "extra fine" PCB trace width is one or two mils. So I was letting Anil know that the achievement of 4 mils using a CNC router was rather remarkable.

Thank you John,
This measurement stuff is confusing in PCBs even more as the track and components are usually measured in mils (fraction of inch) and thickness of copper on PCB in microns (fraction of mm) :)

[javeria]

what ipm did you get this done pal

[Gerald D]

Thanks John, I hadn't taken notice of "mils" before.

Anil, my first thought on the varying widths was V-cutter depth, but I read your post twice: "this pcb is milled using 0.2mm bit" Well, I had to believe you had a very thin flexible bit! :)

[aniljangra]

Very slow Irfan :)

Feed rate was 20 ipm but it was scaring to see the rapid moves in between with small bit.

[jhiggins7]

I zoomed the picture. I can't see the depth of the groves. But your explanation of the problem cause makes a lot of sense.

Keep us posted. This is a very interesting development.

[aniljangra]

Anil, my first thought on the varying widths was V-cutter depth, but I read your post twice: "this pcb is milled using 0.2mm bit" Well, I had to believe you had a very thin flexible bit! :)

Correct Gerald, I too gone back and read it again, the smallest I have till now is 0.6mm used for rubout sometime. :) (to mill away the excess copper between track)

[riesvantwisk]

Anil,

for me this looks like an interference pattern like a moiré pattern, I have seen this a lot when I was working in the pre-press industry. This happens when the required design doesn't match your machines capabilities in such a way that sometimes the machine decides to add a extra step, or removes an extra step.

You can test this by creating a pattern of lines witj increasing distance.

So make a line of 4 mill thick and 10mm length (sorry I don't think in mils anymore... metric rules) spacing 2 mil apart and stack 20 orso on top of each other.
Then next to that use teh same 4 mil line, 10mm wide but with 3 mil spacing.
Then next to that use the same lines, but with 4 mil spacing. If you print this a pattern should appear of thicker and thinner lines and even if you stick enough on top you can even see a wave ....

Was I clear?

I think this is the problem....

Ries

[aniljangra]

Right, That was one of my thoughts and as I pulled up the freq/step calculator, can see that my full step resolution is .094mm, very near to the resolution (0.1mm) we are working.

Though the micro-step resolution is 10 times more, still there will be rounding off errors. And I think even if there was no rounding off error, the micro-step position is not held up as accurately as fill step position.

[Gerald D]

I have this nagging belief that the micro-step position is not held at all, but the smart people tell me that it is. If I am really bored one day, I could test it.

[aniljangra]

No more boring small PCBs this time :)

This is one of the two-parts divider ...
8384

This is how I plan to use it, the upper part is yet to be done..
8385

Measure 2.5' x 5' approx, used 3mm end mill cutting 2mm per pass at 80ipm. Total four passes in 8mm thick mdf and total time to cut about 3 hours.

[javeria]

please do a duco finish on that one - also probably enforce it with sheet of cast acrylic on bothside or on one side and yes email me the file :)

[Gerald D]

Talking of cast acrylic, how about casting acrylic (various colours) into the cutouts?

Nic job Anil!

[Kobus_Joubert]

I like I like well done

[aniljangra]

Thanks Gerald for the cutout idea, wish I had that earlier :(
I did not keep the original vectors and just have the outlines now. I think the cutouts won't fit exactly if I work reverse from outlines now.

Something to remember in future, to keep copies of file from each step as you design.

[normand blais]

Hi
mil might come from french( millième ) thousand ,we say the same like 4 mill but :)with the french accent. Nice divider acrylic would be great !

[Gerald D]

Anil, I am thinking of pouring a liquid into the openings. Something like this: http://www.creative-resins.co.uk/lamresin.htm

[Claudiu]

Very nice divider, how long did you cut on this one. CV or exact stop?

[KenC]

Must get my MM running.... must get my MM running... must get my MM running...

[aniljangra]

Nice song Ken :)

Anil, I am thinking of pouring a liquid into the openings. Something like this: http://www.creative-resins.co.uk/lamresin.htm
Yes thats a possibility, need to find out the availability and price.

Very nice divider, how long did you cut on this one. CV or exact stop?
Claus, total a little less than 3 hours with CV on.

[aniljangra]

Other part of the divider done, need some finishing on other side.
8395

Used (snapped) 4mm endmill, total time 4 hours.

[javeria]

good snapping :)

[jhiggins7]

Anil,

Great work. Very impressive.:)

What's "snapping"? I'm sorry if I should already know this.

I was wondering if you are monitoring the temperature of the Drives and Motors. Since you have "Open", DIY built drives, their performance "under load" is of interest to some of us that are considering using them as well.

[aniljangra]

Last 2 jobs were about 2 and 4 hours respectively. I noted that the drives were getting hot (but nothing that can't hold finger over it).

The temperature was samilar for 2 hours or 4 hour job, so I think that's max it can go irrespective of the time after a initial period.

I mounted the fan blowing air over them and how they run cool :)

[Gerald D]

John, look at the text just below the pic. . . . I think snapped means "broke" :)

[javeria]

did you not choke to the dust of that mdf, i heard that ur machine is now locked forever in the room you built it in :D

[aniljangra]

I want to do something for dust but don't have space for anything more, at least for now I'll continue as it is with masks :(

I can remove a wall if I want it out :), I was advised to do a bolted design but as I said earlier I like welded stuff somehow.

John, look at the text just below the pic. . . . I think snapped means "broke" :)

You guessed it right Gerald , sorry John if that's not correct English :)

[javeria]

hey get the eureka forbes vacuum cleaner thats like 8k I think and get a 12 inch industrial exhaust fan - almonard brand is 2k

remove a wall- what do you have hinges on em :D

RGDS
Irfan

[domino11]

Nice work on the PCB Anil! A lot of guys that are doing pcb work seem to have jigs that they can surface right before they cut the pcb to make sure everything is flat as of that day. They also will raise up the work so that the Z has as little extension and less flex as possible.

[Jason Marsha]

Anil,
Excellent work.

I thought I was the only person that used the corridor as storage for my MDF and plywood sheets :D , it sends the others in the house crazy.

You may want to experiment with a slower speed like 40 inches/min but with a single 8mm plunge, that will reduce your cut times significantly and save your bits.
With a 2mm plunge you will cut one path four times and with MDF being very abrasive on tools it may lead to premature failure.

What brand bit are you using?
Is it a spiral upcut?

If possible post a closeup pic of your bit.

I have used Whiteside spiral upcut 3.175 mm and 6.35 mm diameter bits and they have worked well.

Jason

[Rad Racer]

Anil - Claus,

I really like the dividers you guys are making.....very detailed design. What software did you use for the design work?

[aniljangra]

Nice work on the PCB Anil! A lot of guys that are doing pcb work seem to have jigs that they can surface right before they cut the pcb to make sure everything is flat as of that day. They also will raise up the work so that the Z has as little extension and less flex as possible.
Heath, thanks for the tips. Anyhow I did the PCB job on MM because my other small machine is in not in functional state. I need to make some space for that and make it functional again to do pcbs )(thats was the reason it was made :))

Anil,
Excellent work.

I thought I was the only person that used the corridor as storage for my MDF and plywood sheets :D , it sends the others in the house crazy.
You may want to experiment with a slower speed like 40 inches/min but with a single 8mm plunge, that will reduce your cut times significantly and save your bits.With a 2mm plunge you will cut one path four times and with MDF being very abrasive on tools it may lead to premature failure.

What brand bit are you using? Is it a spiral upcut? If possible post a closeup pic of your bit.

I have used Whiteside spiral upcut 3.175 mm and 6.35 mm diameter bits and they have worked well.
Jason
Jason, I only had worked in metal before and I am just starting with wood/mdf stuff.
The bits I have are 4 flute carbide meant for metal work, I'll try if I can get (as you said) "spiral upcut" bits. Also will try your suggested strategy of low speed with more pluge next time :). Still learning..
84308431

Anil - Claus,

I really like the dividers you guys are making.....very detailed design. What software did you use for the design work?
Wayne, I use Corel, that's the only one vector program I have a my work. In fact any vector program can be used, you just want node editing and weld/combine features.

[Gerald D]

Anil, those 4-flute metal cutting bits are not designed for drilling in the z-direction (the center of the bit has no cutting edges)

However, the 2-flute metal cutting bits can usually drill. And they have bigger space between the "blades" for clearing the sawdust out.

By far the most common cutter we use for MDF is the 2-flute solid carbide bit from the shop that sells to the metal cutters. ;)

[normand blais]

4 flute cutter need to move faster or rotate slower so it dont end up rechopping chips into dust and creating heat and wear. Also a 1/4 inch step down only wear the first quarter inch of the cutter even going 2 '' down

[KenC]

4 flute cutter need to move faster or rotate slower so it dont end up rechopping chips into dust and creating heat and wear. Also a 1/4 inch step down only wear the first quarter inch of the cutter even going 2 '' down

Pardon my ignorant, what is the advantage of the wear pattern?

[Gerald D]

If you make two passes at a 1/4" deep....compared to one pass at 1/2" deep

The deep, low number of passes gives you double the bit life because you are only make half the number of passes. But the bit is worn for the last 1/2" inch.

[normand blais]

1/4 inch dull and 1 3/4 sharp on 2 inch flute cutter

[aniljangra]

wow, good info here to learn from.

I'll probably get my spindle in few days and can then experiment with more plunge, right now my die grinder seems overworked with high plunge or high feed.

[aniljangra]

Had to redo this part of divider as the old one was not approved ;)
8481

[javeria]

beautiful

[jhiggins7]

Beautiful. But, I thought the other one was beautiful as well.:D

How about some close-ups of the cuts so we can see the cut quality?

[aniljangra]

John, I knew you would be the first one to ask for closeups ;), other one was also good but my customer (you know who !!) is more demanding :)

8482
Some manual cleaning of back side needed, i think again because I haven't surfaced the table yet.

8483
8484
8485

And below is the cutout part from the center of divider.
8486

[jessyjames]

Great job. I love seeing your screens. I must say that surfacing your table will dramatically improve your quality of parts produced. When you are able you should definitely make it a priority to do so as you will reap the benefits of it. Keep up the great work and make the "Boss".... happy..

James

[hennie]

Anil what is the thickness of your mdf? as the thinner your board gets the more difficult it is to get a good cut as there is a lot of flex in the board itself.Try cutting a full sheet of 3mm mdf compared to 16 mm thick.

[jhiggins7]

Very nice. Very clean. I don't see any chatter marks. Congratulations.:)

I think we can declare your DIY Drives and BoB a wonderful SUCCESS!:)

[quadtech]

Really nice work - inspiring for a slow one still in the info
gathering stage.
Anil, what motors are you using, and how
much did they cost? I think you got used ones?

[KenC]

Nice & smooth cut, good job!

[quadtech]

Anil,

I reread this thread, and found the pic of your motor
in post 41.

http://www.mechmate.com/forums/showthread.php?p=32175&postcount=41

Thanks
Prasad