Messages

31

General Mach Discussion / setting machine coordinates to zero??

« on: October 22, 2006, 08:59:24 PM »

ok here is my problem, I load mach 3 up with a program and then turn my cnc controller on. Both current position and machine coordinates are all zero, i then machine a part. If i move the axis to set the datum for another part and zero x & y then the machine coordinates are no longer zero and when it is done it returns to machine zeros which is a pain?? how can i zero the machine coordinates without rebooting everything? cheers

32

Tangent Corner / Re: HELP!! does anyone know about floating heads for engraving??

« on: October 16, 2006, 06:09:41 PM »

Due to the construction of my machine (extruded aluminium frame) I have problems with thermal expansion and contraction of the bed so even if I surface skim my vacuum table it changes slightly. Even the smallest change can make a big difference to the engraving with high and low spots especially when you only want to go 0.1mm deep. I did think about a PTFE collar riding on the work to provide the constant depth but then I though the removed material would get in the way if not properly extracted?? I think they use springs.. A sketch from someone in the know would be great!! Mark

33

Tangent Corner / HELP!! does anyone know about floating heads for engraving??

« on: October 15, 2006, 09:40:58 PM »

I want to make a floating head for my cnc router to give a constant depth. does anyone have any ideas on how to make one of these or how they work,. Cheers, M

34

General Mach Discussion / Re: Z axis moves on its own in program/jumps steps

« on: October 08, 2006, 05:36:18 PM »

Think I solved the Z axis problem. I was reading an old post with kinda the same problem and it suggested switching the Z axis step and direction to low active in ports and pins. So before I took a big sledgehammer to the whole shabangle I gave it a try and hey presto it worked. Not even a twitch now!! It reversed the direction so I went into homing/limits and reversed it in there...I am well chuffed I dont have to buy a new PC just yet 

35

General Mach Discussion / Re: Z axis moves on its own in program/jumps steps

« on: October 07, 2006, 07:43:35 PM »

Im defo going to bed in a minute  Thanks for the offer hood but it is a slimline dimension 5150c computer and doesn`t take the normal size pci parallel port cards as I have tried to get hold of one before.. Will try a few things with the axis then go from there. Cheers, Mark

36

General Mach Discussion / Re: Z axis moves on its own in program/jumps steps

« on: October 07, 2006, 07:06:39 PM »

Im from the UK and its just gone midnight, guess I should really go to bed but it is a Saturday!! Will try swapping the Z & Y over tomorrow, dnt think my neighbours will be too impressed if I light it up now  Thanks for the help, will let you know how I get on

37

General Mach Discussion / Re: Z axis moves on its own in program/jumps steps

« on: October 07, 2006, 06:56:40 PM »

You mean reverse the Z axis into the Y axis on the controller? My X axis is driven by 2 stepper motors..I have kinda been having the problem with the Z axis twitching away from the word go.. The people I got the machine from aren`t really much help on technical problems and im not the best at speaking German hehe   I figured I could try my new dell desktop as the driver test is perfect (it is not on the laptop) but it doesn`t have a parallel port!! Mark

38

General Mach Discussion / Re: Z axis moves on its own in program/jumps steps

« on: October 07, 2006, 06:45:21 PM »

It is running windows XP home edition, version 2002. service pack1 

39

General Mach Discussion / Re: Z axis moves on its own in program/jumps steps

« on: October 07, 2006, 06:38:15 PM »

Not sure if I have shielded wires on step and direction Brian . How could I tell if I had a problem with noise? Is there a simple test? CNC router was new a few months ago from these guys (www.cnc-step.com) Seems like a well built proffesional piece of kit with CE approval and the like. The software that came with it was awful so I got mach3 which is fantastic to use . I have tried adjusting the acc/vel & pulse width but to no avail.. Dedicated laptop what I run it from is an intel celeron 2.4 processor with 192Mb of ram. Not sure if this is sufficient or not? Cheers

40

General Mach Discussion / Z axis moves on its own in program/jumps steps

« on: October 07, 2006, 12:42:32 PM »

This is really becoming a problem for me  When im running a program the Z axis will move -ve direction and miss steps on its own + make a horrible sound. Once I left it for a few seconds and it had gradually jumped 10mm down into my vacuum table (not good) but still showed correct depth on readout. This happens nearly every program I run. Dont seem to have problems with X & Y steps jumping! I am running it all from a compaq presario 2100 (could this be the problem) Any help would be most appreciated. Cheers, Mark