MechMate CNC Router Forum

Go Back   MechMate CNC Router Forum > Personal Build Histories > Construction started, but not cutting yet
Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Reply
 
Thread Tools
  #31  
Old Mon 29 June 2009, 16:29
andyclarkecncuk
Just call me: andy
 
bristol
United Kingdom
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
Attached Images
File Type: jpg IMG_0559.JPG (57.3 KB, 727 views)
File Type: jpg IMG_0560.JPG (36.2 KB, 724 views)
Reply With Quote
  #32  
Old Mon 29 June 2009, 19:22
Doug_Ford
Just call me: Doug #3
 
Conway (Arkansas)
United States of America
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.
Reply With Quote
  #33  
Old Mon 29 June 2009, 22:55
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
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.
Reply With Quote
  #34  
Old Sun 05 July 2009, 08:11
andyclarkecncuk
Just call me: andy
 
bristol
United Kingdom
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
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
Attached Images
File Type: jpg IMG_0578.JPG (49.2 KB, 669 views)
File Type: jpg IMG_0580.JPG (44.2 KB, 667 views)
File Type: jpg IMG_0581.JPG (32.6 KB, 665 views)
Reply With Quote
  #35  
Old Sun 05 July 2009, 10:24
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Great work Andy!

Yeah, we need to summarise that proxy thread - it is too daunting now.
Reply With Quote
  #36  
Old Sun 05 July 2009, 17:41
Doug_Ford
Just call me: Doug #3
 
Conway (Arkansas)
United States of America
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.
Reply With Quote
  #37  
Old Sun 05 July 2009, 23:31
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
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 . . . )
Reply With Quote
  #38  
Old Mon 06 July 2009, 01:45
Kobus_Joubert
Just call me: Kobus #6
 
Riversdale Western Cape
South Africa
Send a message via Yahoo to Kobus_Joubert Send a message via Skype™ to 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.
Reply With Quote
  #39  
Old Mon 06 July 2009, 04:58
javeria
Just call me: Irfan #33
 
Bangalore
India
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!
Reply With Quote
  #40  
Old Mon 06 July 2009, 10:21
bradm
Just call me: Brad #10
 
Somerville(MA)
United States of America
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.
Reply With Quote
  #41  
Old Mon 06 July 2009, 10:40
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Quote:
Originally Posted by bradm View Post
. . . 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?
Reply With Quote
  #42  
Old Mon 06 July 2009, 11:24
bradm
Just call me: Brad #10
 
Somerville(MA)
United States of America
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.
Reply With Quote
  #43  
Old Mon 06 July 2009, 12:44
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
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.
Reply With Quote
  #44  
Old Mon 06 July 2009, 13:43
hennie
Just call me: Hennie #23
 
Roodepoort JHB
South Africa
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.
Reply With Quote
  #45  
Old Tue 07 July 2009, 02:20
andyclarkecncuk
Just call me: andy
 
bristol
United Kingdom
Thanks all for the info,
I think i will get her cutting and then see how i get on.
Thanks Andy
Reply With Quote
  #46  
Old Mon 10 August 2009, 03:42
andyclarkecncuk
Just call me: andy
 
bristol
United Kingdom
She Moves

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
Attached Images
File Type: jpg IMG_0583.JPG (52.9 KB, 552 views)
File Type: jpg IMG_0584.JPG (57.4 KB, 546 views)
File Type: jpg IMG_0585.JPG (62.5 KB, 550 views)
Reply With Quote
  #47  
Old Mon 10 August 2009, 04:34
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
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.
Reply With Quote
  #48  
Old Mon 10 August 2009, 05:07
andyclarkecncuk
Just call me: andy
 
bristol
United Kingdom
Thanks Gerald, Eye sight is not what it used to be!
Reply With Quote
  #49  
Old Mon 10 August 2009, 05:47
sailfl
Just call me: Nils #12
 
Winter Park, FL
United States of America
Andy,

Good work and the machine looks great.
Reply With Quote
  #50  
Old Mon 10 August 2009, 09:01
lumberjack_jeff
Just call me: Jeff #31
 
Montesano, WA
United States of America
That's a beautiful looking piece of machinery. Very well done!
Reply With Quote
  #51  
Old Mon 10 August 2009, 10:06
domino11
Just call me: Heath
 
Cornwall, Ontario
Canada
Andy,
Very Nicely done!
Reply With Quote
  #52  
Old Tue 11 August 2009, 02:01
andyclarkecncuk
Just call me: andy
 
bristol
United Kingdom
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
Reply With Quote
  #53  
Old Tue 11 August 2009, 02:38
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
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]

That thread is thoroughly confusing at first, but there is a calculator at about post #27.
Reply With Quote
  #54  
Old Tue 11 August 2009, 03:08
andyclarkecncuk
Just call me: andy
 
bristol
United Kingdom
http://www.worldofcnc.com/images/Com...e%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
Reply With Quote
  #55  
Old Tue 11 August 2009, 03:36
andyclarkecncuk
Just call me: andy
 
bristol
United Kingdom
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
Reply With Quote
  #56  
Old Tue 11 August 2009, 03:57
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
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
Reply With Quote
  #57  
Old Tue 11 August 2009, 03:58
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
It me much longer to get it!
Reply With Quote
  #58  
Old Wed 12 August 2009, 11:39
Belli
Just call me: Greg
 
Johannesburg
South Africa
Setting step/unit

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.

Greg
Reply With Quote
  #59  
Old Wed 12 August 2009, 12:12
andyclarkecncuk
Just call me: andy
 
bristol
United Kingdom
Thanks Greg, That is really usefull.
Andy
Reply With Quote
  #60  
Old Thu 13 August 2009, 04:33
andyclarkecncuk
Just call me: andy
 
bristol
United Kingdom
My First cuts

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.
Attached Images
File Type: jpg IMG_0586.JPG (32.7 KB, 425 views)
File Type: jpg IMG_0588.JPG (39.0 KB, 428 views)
Reply With Quote
Reply

Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Anyone in UK Beds Bucks Herts pcsiltd Introduce yourself and start planning 3 Fri 05 June 2009 13:43
Cutting in the UK! Electrical noise problem solved! - Darwen, UK Barrie MechMates already cutting 5 Fri 01 May 2009 09:25
New UK member........but with a twist GBCSL Introduce yourself and start planning 17 Fri 24 April 2009 01:36
Looking for someone in UK to build for a friend Arthur Ransom Archives 1 Fri 10 August 2007 10:13
All UK Members - UK lee underwood Construction started, but not cutting yet 0 Wed 21 February 2007 09:44


All times are GMT -6. The time now is 10:40.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.