Messages

8691

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.

8692

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.

8693

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.
         

8694

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.

8695

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.

8696

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.

8697

Tangent Corner / 'BIG' CNC

« on: March 20, 2009, 06:54:15 AM »

I spotted this on Flickr - it is just about the biggest CNC I have seen - how about you ?.

Tweakie.

8698

General Mach Discussion / Re: Motor "Sometimes" goes in Wrong Direction while Tuning

« on: March 18, 2009, 01:30:20 PM »

Hi Jamie,

No other suggestions, sorry.

Incidentally do the motors have sufficient torque ?. (can you stop them with little force when they are rotating).

Tweakie.

8699

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

« on: March 18, 2009, 11:39:29 AM »

Thanks Dave.

This is the big advantage of making things for yourself - the boss doesn't moan at you when you don't get it right first time.

Tweakie.

8700

General Mach Discussion / Re: Motor "Sometimes" goes in Wrong Direction while Tuning

« on: March 18, 2009, 07:34:54 AM »

Hi Jamie,

As Hood said earlier have you tried changing the direction signals from active high to active low (or visa versa) ?. This is under Configuration, Ports & Pins, Motor Outputs.

Tweakie.