Just Checking In and Catching Up #44 - Delhi India
 

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.

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

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.

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

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

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

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 ...

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

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.

I tried hi and low for good caps and I found largest cpacity (size) only there ;}
Well so far so good.

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

http://in.farnell.com/jsp/search/bro...equestid=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 :)

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

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.

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.

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 :(

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

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

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)

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

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

thats a very good price

Got some parts
 

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 !!

Little progress with rollers
 

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

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

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 ?

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

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

That is no problem

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

- 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 (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.

Thanks, now i can move without worry.

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