And we have movement in the UK as well! - Bristol, UK

[andyclarkecncuk]

Hi, Andy here from the uk, downloaded the plans last week and now im ready to start building. Is there anybody here in the uk building one?
Thanks Andy

[mphel]

Hi Andy,
I think there are a few being built and at least one up and running. I've made a start, got all the steel, wheels (Rick- superior Bearings) Laser cut parts (M-Machine Metals- Darlington) most of the electricals, motors and rack/pinion on order.
I can give you a few pointers for uk specific items but the plans explain everything and the things that don't add-up on the first read will become much easier with the parts on a bench in front of you!
Good luck...
Mark.

[andyclarkecncuk]

Hi Mark, How much did the laser cut parts cost? also where did you source the rack from?
Thanks Andy

[mphel]

I think the Laser cut parts were about £250 but i think they were the first set they had cut and were treated as something of a loss leader, so they may be more now. If you speak to David Armstrong at M-Machine, he'll sort you out, he was very helpfull with mine.
I have the rack and pinion on order from Marchant Dice,(Kevin Marchant) around £380 for a 8x4 machine.
Hope this helps.
Mark.

[andyclarkecncuk]

Thanks for the info Mark, Ive ordered the laser cut parts which should be here soon. How have you decided to do the vee rails?. I am thinking of going for the alu with the vee rails bolted to it but not sure where to source the rails from? Also what size table are you building?
Thanks Andy

[mphel]

Andy, I'm building 8x4 table, have ground the rails with the attachment supplied in the laser cut set. I wasn't quite sure what to expect but found that it worked very well, I ground all rails in around 3 hours and I'm happy with the results!

Mark

[andyclarkecncuk]

Hi, Andy here from uk,
I have a small joinery company and i have been intrested in a cnc router for along time but i have never really understood how they work which has always put me off.
A few weeks ago i came across this website and i am hooked :).

The main reason i have decided to build a mechmate is so that i can learn and understand everything about how it works.
I have designed my table to take 10' x 5' as i have enough room to accomodate it although i rarely use this size of board (norm 8'x4').

Anyway i ordered the laser cut parts last week and they have just arrived :) I am very pleased with the quality of the parts and bends and i can not wait to get started. I have ordered the steel which hopefully will be with me by the weekend.

Im very excited but also quite nervous as my welding skills and electrical knowelege are not the best but i do like a challenge.
I will keep you posted.
Thanks Andy

[Gerald D]

Have merged your two threads together - this could become the first documented UK build. :)

[domino11]

Welcome Andy,
Maybe you will be the first UK serial number!

[Alan_c]

Welcome Andy, enjoy the build.

Was in Bristol 2 years back visiting my sister in Horfield, nice town but just a bit grey for us sunny Saffers :)

[2e0poz]

Hi Andy

Paul from sunny Swindon here just up the road. I have just joined today so still looking around. I'm in the middle of collection parts for my machine and hope to use a lot of the ideas found here. Not sure on the size yet but keep in touch.

Paul

[andyclarkecncuk]

Just thought i would update on my progress, i have all the steel here ready, all the laser cut parts, gecko 203v x 4, pdmx 122, computer with mach3, enclosure, vee bearings, PK296AE-SG7.2 motors, LAPP cables, bolts etc.
All i need to do now is order the electrical parts and start putting it all together.
My wife is going away for 2 weeks to visit family on Saturday so i will have sometime to make some progress :).
I have also decided to grind my own rails as i brought unequal angle in 60x30x6 so just need to skim top edge and then apply angles (hopefully).
Anyway i will take photos and start posting next week once i work out how to post them.

P.s Just wandering if anybody has ordered steel and forgot to add on the extra 420mm?:):)

[Gerald D]

What luck to get 60x30x6 as standard! Don't to aim for the 28mm on the drawing.....just skim the top until you get a 1mm wide band in the center. (it will wider than 1mm, but off-center, carry on till you go 0.5mm over the center line)

[andyclarkecncuk]

Gerald,
I could not beleive it either! Also got parrallel flange steel so no need for tapered washers.
I think i may have overdone the sizes of the sections for the cross bearers and main frame, but at least if i get broken into it should still be there looking at me in the morning!.
The delivery ticket states .76 ton.

[andyclarkecncuk]

http://www.mechmate.com/forums/attachment.php?attachmentid=5076&stc=1&d=1246180867

[andyclarkecncuk]

http://www.mechmate.com/forums/attachment.php?attachmentid=5079&d=1246181306

[andyclarkecncuk]

http://www.mechmate.com/forums/attachment.php?attachmentid=5078&d=1246181306

[andyclarkecncuk]

http://www.mechmate.com/forums/attachment.php?attachmentid=5077&d=1246181306

[andyclarkecncuk]

Hi, sorry if the photos are a bit mixed up, not really sure how to attch them. The laser cut parts fit together so well but as you can see from the pic the two end plates are not a pair ie they are the same hand does this matter?
Thanks Andy

[andyclarkecncuk]

http://www.mechmate.com/forums/attachment.php?attachmentid=5080&stc=1&d=1246210356
http://www.mechmate.com/forums/attachment.php?attachmentid=5081&stc=1&d=1246210356

5080

5081

[Gerald D]

the two end plates are not a pair ie they are the same hand does this matter?

No problem if they are the same hand.

I can't figure out how you are getting these picture posting problems. Can you tell me what your recipe is, so that I can try and figure out where the problem lies?

Nice progress by the way!

[andyclarkecncuk]

Hi Gerald, Im using the "go advanced" them uploading them and then cutting and pasting the file?
Thanks Andy

[Gerald D]

Yes, you need the "Go Advanced" then "Upload", but no further cut/paste. After the upload, it is already attached to the post - look at the preview at that point. . . .

[andyclarkecncuk]

Ah.. Ok thanks. Lets hope i can operate this machine better than i can post pics:)

[bradm]

That picture of the laser cut steel seems a little odd to me:

You have a total of seven gantry stiffeners, and I'd expect three plus the one with the cable chain mount.

You have one of the two pieces of the skate.

I'd expect three of the four motor mounts to have a slot, not just two. Also, the ovals are in strange positions.

Are you doing some interesting customizations?

[MattyZee]

It looks to me like you ordered the entire list of parts, both economic and full options. Hence both versions of the gantry stiffeners, both motor mount styles etc.???

[MattyZee]

And as Gerald said, excellent progress! looking good.

[andyclarkecncuk]

Bradm, Yes the company i brought the laser parts from supply the full set then just dont use what you dont need. Maybe a bit wastefull. Also the other part of the skate was on the floor having the mounting holes welded as they did not fit any of my grinders.

It maybe a good idea to leave these holes and let the user drill there own to suit there grinder.

Thanks Andy

[andyclarkecncuk]

Its amazing how small the frame looks in the pics. It is huge!
Andy

[andyclarkecncuk]

Hi, I have not got a metal chop saw so this is how i have been cutting everything square. When it gets a bit worn i just true it back up on the crosscut. I also screwed a stop on the back for repetitive cuts.

[andyclarkecncuk]

I didnt get a great deal done today as work is busy but i did manage to fit bracing and also tidy up the ends of the channels.

Im not sure if i should drill for the rails and them disassemble and paint the main frame or just keep going and then disassemble at the end?
Seems to me that it could take quite sometime to shim rails and then have to do it again after painting?
Thanks Andy

[Doug_Ford]

BEAUTIFUL corner Andy! Great work.

I felt the same way so I left the rails in place and painted after I shimmed them. I didn't want to go through the shimming and straightening process again.

[Gerald D]

Ah, true British ingenuity & workmanship, in the mold of Rolls Royce . . . :)

Our sequence is to bulk paint before assembly / drilling / tapping / shimming and then to touch up scars at the end.

[andyclarkecncuk]

Hi, Here are a few more photos of the table with paint on.
I managed to grind the rails this week and im glad they are now done. The skate works great. I was a little worried how they would come out but they are perfect. Its better to angle the disk so it cuts down as if it cuts up the burr on the top edge can stop the skate moving freely. Also keep wiping down the sides of the rail stops the bearings getting tight.

One of the rails had a small kink in it about 50mm long which i did not notice untill i was grinding it then i could feel it with the skate. I filled the hollow side with chemical metal and sanded straight and ground the lump off the opposite side which worked well and saved me buying another lenght of angle.

Shiming bolted tables
Its amasing what you can do with a few shims!
One of my X beams had a bend in it about 3' from the end approx 2mm out.
When bolting the table back together after painting i placed shims in the bolted joints and ive managed to pull the beam straight. It does take alot of time to get it right but it is well worth it. You can adjust how much you want to bend it by adding or removing shims, easy to remove shims with a magnet if you find it bends too much when you retighten the joint.
Note this can alter the y dimention slightly.

Next week i plan to get the gantry and y car finished then start to look at the electrics:eek:
Ive been reading alot of posts on the proxies but it still is not very clear to me, so if anyone has any advise on how to go about wiring them please let me know.
Thanks Andy

[Gerald D]

Great work Andy!

Yeah, we need to summarise that proxy thread - it is too daunting now.

[Doug_Ford]

You are a true craftsman Andy.

I don't know if Gerald and Sean_D are using proxies on their new machines but for a long time they didn't have them. Since Gerald has been right about everything else, I took his word for it when he said I didn't necessarily need them. I've been running my machine for months and haven't felt like I needed them at all. However, I would like something that helps set the Z axis. Just haven't gotten around to adding it yet.

[Gerald D]

We are not using any switches at present, and not feeling a real inclination to actually fit some. (But the mounting brackets are in place . . . )

[Kobus_Joubert]

I have the same feeling....never needed it. You know where you will start, you know how big your material is, so I have never run off the rails or into clamps. Just takes some practice and a clear mind when setting up.
Further I agree with Dough, that a Z-Zero is helpfull since you do change from one bit to the next and have to Zero the z-axis in between a job.

[javeria]

Well we need inputs from the guys who have it as well - :)

I feel its worth the small investment - I particularly find use when there is a power outage and I need to rehome and restart -

really I don't know how I would do without them -

The Auto tool zero is such a great tool - - cannot do without it now!

[bradm]

My MechMate doubles as a work table in my shop when it's not in use. This makes the proxies valuable for re-zeroing the machine before use, because every use is essentially a re-commissioning of the machine.

If the machine were in constant use, I'd probably almost never use the proxies, although I'd definitely use the Z Zero plate. So I think I'd prioritize getting a work zeroing plate or fixture higher that getting the limit switch proxies going.

[Gerald D]

. . . makes the proxies valuable for re-zeroing the machine before use, because every use is essentially a re-commissioning of the machine. .

What would be your view on simply holding the gantry against the stops when switching on?

Having a z-zero touch plate, do you see a zero-ing purpose for a proxy on the z-axis?

[bradm]

My view is that using the hard stops is just as valid an approach, although slightly less sexy. With the proxies, the process is:

1) one double click, two keystrokes, one push button to turn on machine.
2) safety check for possible collisions with anything on the bed
3) four keystrokes to start the X and Y axis homing. Max execution time is about 20 seconds.

Is it worth the extra $$ and complexity just for this feature? For many, I suspect the answer is no from a logical viewpoint, but yes from a satisfaction standpoint. It's definitely more in the cupholder category than the rearview mirror category.

I do note that at least in my EMC2 based world, running past a proxy limit allows recovery purely in software, because the computer still knows where the machine is. Once you hit a hard stop, you're recalibrating.

I don't have a proxy on my Z-axis, and I see no purpose for one.

I think the common setup operation is to get a specific location in 3D space zeroed so that the physical machine and the program agree. Using the touch-off capabilities of a Z-zero circuit against one or more of three dimensions is a very nice way to do this, and it doesn't involve the proxies.

[Gerald D]

Brad, I was playing a bit of devil's advocate by bouncing those questions off you :)

One might have to move the gantry, y-car and z-slide a long way to get a home position before switch-on, so the switches would be a lot more convenient, no doubt about that. However, in our situation, the loss of a home reference is extremely rare, so the gantry moving is around about 3 times a year. I think the guys with switches do a homing at every day's switch on.

As far as Andy's question goes here in his thread, I would suggest that one mustn't see proxies as a very complicated hurdle. It is something that can be figured out a bit later.

[hennie]

I have bought the proxy`s but never installed them,when I am finished for the day I go to my 0 points and switch the machine off next morning at start up I just make sure that my z -axis hight is what it was the day before.

[andyclarkecncuk]

Thanks all for the info,
I think i will get her cutting and then see how i get on.
Thanks Andy

[andyclarkecncuk]

Well i have finally got her to move :).
Its a nice feeling after all that hard work to see it working.

I have the pk296aesg7.2 motors with the power supply supplying 75vdc to the geckos. I have wired them Bipolar series and they seem to be getting very hot. Do i need less voltage to wire them diffirently?.


I think now the learning starts!

Gerald, Thank you so much for making this machine a joy to build. It looks very daunting in the begining but once you study the plans and break it down it is very straight forward. Two months ago i had never welded, tapped a hole or knew what n/c or n/o meant!.

Thanks Andy

[Gerald D]

Well done Andy - it is the Industrial Revolution all over again! :)

What resistors did you fit to your Gecko's and did you double check the resistance values with a meter? They should be 20 kiloOhm for that motor as bipolar series.

[andyclarkecncuk]

Thanks Gerald, Eye sight is not what it used to be!

[sailfl]

Andy,

Good work and the machine looks great.

[lumberjack_jeff]

That's a beautiful looking piece of machinery. Very well done!

[domino11]

Andy,
Very Nicely done!

[andyclarkecncuk]

Thanks all of you, i am really pleased with it.
I am having some problems trying to set the steps per mm in mach3?
The steppers say 0.25 step so 360/0.25 = 1440 x 7.2 = 10368 steps per rev of pinion?
Pinion dia = 30 x 3.14159265 = 94.2477795
10368/94.2477795 = 110.0078967
I have entered this but it is not to scale? Have i missed something?
Thanks Andy

[Gerald D]

The pinion diameter is measured at half of the tooth height - it is not the outside diameter of the pinion. The accurate way is know the module number and the tooth count. See: Understanding & Selecting gear pinions - setting the steps per mm[inch] (http://www.mechmate.com/forums/showthread.php?t=239)

That thread is thoroughly confusing at first, but there is a calculator at about post #27.

[andyclarkecncuk]

http://www.worldofcnc.com/images/Commercial%20Grade%20Pinion.pdf
Thanks Gerald for the quick reply, The pinions im using are the snb1030 in the above link, sorry didnt know how to put page in.
Measurement Do = 30 which is what i calculated?
Thanks Andy

[andyclarkecncuk]

Ah got it now,
0.25 is the output shaft,
so 1440 steps per rev x 10 for gekcos =
14400/ 94.2477795 =
152.78874554
Thanks Andy

[Gerald D]

If you are feeding that motor/gearbox full steps, the output shaft would turn 0.25 degree for one full step. (The gearbox ratio factor is included in the 0.25 degree marking). (the error here is that the 7.6 factor should not be considered)

However, your Gecko does 10 microsteps for the motors one full step, so Mach has to feed 10x more steps to get the right movement. (a factor of 10 should be included)

Therefore:
The steppers say 0.25 step so 360/0.25 = 1440 x 7.2 x 10 = 10368 14400 steps per rev of pinion
Pinion dia = 30 x 3.14159265 = 94.2477795
1036814400/94.2477795 = 110.0078967 152.789

[Gerald D]

It me much longer to get it! :)

[Belli]

Hi Andy,

On the settings page of Mach (Alt-6) is a button above the reset button called 'Set steps/unit'. Click this button and you don't have to worry about any of the maths, Mach does it all for you.:o

Greg

[andyclarkecncuk]

Thanks Greg, That is really usefull.
Andy

[andyclarkecncuk]

Pics of my first cuts:)

Well i have finally managed to make my first cuts.
I was very nervous but all went well and i am pleased with the results :)

I think i need to play with the speed settings as it was great along the straights but when it got to corners it seemed to me that it was moving too fast?
This is the first time i have operated a cnc so its hard to know what is the norm.

Thanks Andy

Sorry the pics arnt great.

[jhiggins7]

Andy,

Wonderful!

The pictures give the impression that the areas around the letter "B" are raised. Is this an illusion? What ever it is, these are the best "first cuts" I've seen.

Nice work. Congratulations.:)

Now, slap some Logo's on her and request a Serial Number!:D

[andyclarkecncuk]

Thanks John, logos on the way.

Afew more pics this time painted mdf white so it shows up better.

Last photo shows a few flats on "B" i think it should of been cut with two passes as when i cut the smaller version it came out perfect.

Thanks Andy

[Doug_Ford]

WOW!!!! Beautiful graphic design. First class work.

[andyclarkecncuk]

Thanks Doug, Beautiful but unfortunatly not designed by me - free in v carve pro demo.

I was just reading your post in the motor tuning part, What did you mean by g's?.
When you set the velocity and acc in mach do you use this to control the speed or the feed speed on the main page?.

When i first set them i tuned them so they sounded good, when i jogged the amber leds on the geckos would light up but since i have set the settings slower as it seemed too fast.
Should i set them so they sound good then adjust the feed speed to the job im doing?
Thanks Andy

[Doug_Ford]

I believe Mach3's use of the term "G's" stands for gravitational pull. I didn't come up with it. Mach 3 has a window on the motor tuning screen that shows the Gs. You don't set the G's, I believe Mach3 calculates the G's based on your settings.

It has been a while since I tinkered with this stuff and hopefully someone will correct me if I'm wrong but I think those velocity and acel settings are for jogging. Jogging is when you aren't cutting but only performing a rapid move through the air. You set the feed speed with your CAM program and it is contained in the G Code you are using for your particular workpiece being cut. At least I set mine that way.

I left the X and Y axis jog speed settings as fast as the machine could handle. They will actually go a little faster than I have them set. Unfortunately, at the fastest settings, when I tried to jog the gantry from one end of the table to the other, after about four feet the motors started losing steps so I reduced the velocity setting. For the Z axis, I had to slow it down because I was having trouble accurately zeroing the Z axis. It moved too quickly. No matter how quickly I tried to press and release the page down button on my keyboard, the Z axis would jump down too far. Slowing down the velocity fixed that.

I hope I answered your questions. If I misunderstood you or failed to answer completely, let me know and I'll take another stab at it.

Doug

[andyclarkecncuk]

Thought i would update as i havent for a while.
I have been really busy at work so havent had much time to spend on mechmate but yesterday had time to cut this.

It is 250mm dia cut in 18mm mdf and took 2hr 20min.