Messages

7671

General Mach Discussion / Re: Problem Testing motors off machine.

« on: March 27, 2009, 04:29:54 AM »

Hi Rick

A similar problem was posted recently and the outcome was that the motor connections were incorrect.

Tweakie.

7672

General Mach Discussion / Re: Newbie here... Have a huge issue wih MACH 3 AND I REALLY NEED HELP!!!

« on: March 26, 2009, 03:45:48 AM »

Following up on TP's posting you could also check for backlash in the leadscrew, leadscrew moving in the thrust bearing, leadscrew nutplate loose in it's mounting or anything else that has worked loose on the axis drive chain.

Tweakie.

7673

General Mach Discussion / Re: Newbie here... Have a huge issue wih MACH 3 AND I REALLY NEED HELP!!!

« on: March 25, 2009, 01:54:34 PM »

Just another thought - when you are converting your DXF files and using tool offset, if the AutoCad lines are not all joined and a small gap is encountered the offset can revert to the other side of the line. (I know what I mean here but I am not sure I have explained this very well). I think it is called joining polylines.

Tweakie.

7674

General Mach Discussion / Re: Newbie here... Have a huge issue wih MACH 3 AND I REALLY NEED HELP!!!

« on: March 25, 2009, 03:09:18 AM »

Hi Roberto,

As Brett has already said it sounds like missing steps to me. Remember that lost steps in one direction will become gained steps in the opposite direction. I suggest that you check for any binding on the axis travel as well as the leadscrews.

Tweakie.

7675

Show"N"Tell ( What you have made with your CNC machine.) / Re: 3d Machining

« on: March 25, 2009, 03:01:16 AM »

Nice work Ed.

Tweakie.

7676

General Mach Discussion / Re: write wizard

« on: March 24, 2009, 10:20:39 AM »

Hi Larry,

I know this is an old post but as Bob said "for those who follow"

Hello Everyone,

I found a post in the Mach1Mach2CNC group on Yahoo with the solution.

For those who follow...

You must select one of the direction buttons before clicking the Write button!

Bob

Tweakie.

7677

Show"N"Tell ( Your Machines) / Re: Laser cross hair tool position.

« on: March 23, 2009, 08:15:33 AM »

Another update. Just thought you may be interested in this.

I have added two buttons to the Mach screen one titled 'Laser ON/OFF' and used Scott's VB script to perform this function. The other button is titled 'Home to Laser' and uses the following script.

Xs=GetOemDRO(59) 'Xscale DRO
Ys=GetOemDRO(60) 'Yscale DRO

Xmove = -72.8719 * 1/Xs 'move distance adjusted for X scale factor
Ymove = 10.7156 * 1/Ys 'move distance adjusted for Y scale factor

DeActivateSignal(OUTPUT5) 'turn off laser

Code "G91 G0 X" &Xmove & "Y" &Ymove ' makes an incremental move the distances that you set
While IsMoving () ' waits while that happens
Wend

Code "G90" 'goes back to absolute moves

DoOEMButton (1008) 'zero X DRO
DoOEMButton (1009) 'zero Y DRO

As I use the DRO Scale settings to scale my engraving work to fit the size of the blank I have included a calculation to position the cutter relative to the laser irrespective of the scale settings.

Tweakie.
         

7678

General Mach Discussion / Re: configure drive for motors

« on: March 23, 2009, 06:36:02 AM »

Bill is right - it is better to purchase a ready made stepper controller.

The 4 wire bipolar stepper motors when operated in full step mode, in one direction, require current through one set of coils then for the next step current through the next set of coils then for the next step current is reversed through the first set of coils and so on.

The 5 wire unipolar steppers are a lot easier to drive from PICs because one wire is common + and the other wires are grounded in sequence to produce the rotation (there is no current reversal through the coils therefore only one switching transistor is required for each coil).

See the following Wiki.  http://en.wikipedia.org/wiki/Stepper_motor

Tweakie.

7679

General Mach Discussion / Re: OEM codes for buttons, DRO's and LED's

« on: March 23, 2009, 05:35:18 AM »

Thanks Hood for posting the .xls file. It has been most useful.

Tweakie.

7680

Show"N"Tell ( What you have made with your CNC machine.) / Re: Miser engine

« on: March 21, 2009, 03:00:36 PM »

Brilliant Vince. 
I think that letting it run a while will free everything up OK.

Tweakie.