Messages

41

Mach3 and G-Rex / GREX and Wierdness

« on: April 23, 2007, 06:01:03 PM »

Hello all, my system has been acting kinda strange and I am NOT sure where or what the problem is. I have a Grex and It is hooked up to this machine that I am building, this machine is pretty bizarre and basically NOT what Mach was built for but Hey Its motion control right!?  Anyways, I have a Blank screen setup because this control is pretty wierd and I have OEM Buttons to Job My Axis (Specifically A) and they work just fine, but my hotkeys for the a axis dont work, and when I send GCODES like G00 A0.0 The motor will run to the point of startup and then stop, but then it will not respond to any further g codes.... it just ignores them..... any suggestions/pointers?

Mike

42

Mach3 and G-Rex / Re: GRex motor tuning and general configuration ?

« on: April 23, 2007, 05:54:32 PM »

Nope, just struggling with this day in and day out for the past couple of weeks so it is all fresh in my head.. give it a few more weeks and I wont remember a thing!

43

General Mach Discussion / Re: Challenge question regarding Homing & Limit Switches

« on: April 23, 2007, 05:51:32 PM »

I am starting to think I may have to go PLC or microcontroller for the home.......

44

General Mach Discussion / Re: Challenge question regarding Homing & Limit Switches

« on: April 23, 2007, 04:17:55 PM »

Poppa Bear, That looks like a pretty skookum Breakout board with some great features but I am not sure if it will solve my problem. I have 4 Separate motors on 2 of my Axis's which need to home properly.. so I need some way of disabling each motor as it hits home because they all share the same Step and DIR outputs and then re-enabling them to jog off the home/limit. Unless I am mistaken in what that particular breakout board will do, I dont think it gives me anything over what I have already. Basically pretend for some bizarre reason your x and Y axis have 4 motors on each and you need to be able to re-sync them back to home so they all line up... I know its sounds really bizarre but its what I have to deal with.... But thanks for the link looks like some great stuff there!

Mike

45

General Mach Discussion / Re: Abnormal condition

« on: April 23, 2007, 03:29:19 PM »

Thanks guys, it does tell you what the problem is when you clck on it....very handy... however, I have a strange problem, it may be my screens or it may be my GREX.. but after clearing the abnormal conditions the system doesnt move the axis still. I can jog using the oEM screen jog buttons but NOT the HOTKEYS and any G move moves it to its "home" position but nothing after that... and the ref A Axis doesnt do anything.... Any clues?

Mike

46

General Mach Discussion / Re: Challenge question regarding Homing & Limit Switches

« on: April 23, 2007, 01:06:55 PM »

Brett, Got your message, I will try and contact you most likely this afternoon. Hopefully thats convenient.
Mike

47

General Mach Discussion / Abnormal condition

« on: April 23, 2007, 01:05:45 PM »

Hello again  What does the Abnormal condition LED indicate? I am trying to test out some of the hardware I have connected and I can jog my A Axis fine but when I enter in a G00 A1.0 it moves to A 0.00 according to the dro but it doesnt move anywhere else after that. The only thing I can see is that I have this abnormal condition LED flashing. The Axis has also NOT been REF'd home as I have yet to put the switches in for that. But I was curious as to what condition that LED indicated was NOT normal, I cant seem to find any info in the Wiki and was hoping someone could satisfy my curiosity.

Mike

48

General Mach Discussion / Re: Challenge question regarding Homing & Limit Switches

« on: April 23, 2007, 10:55:54 AM »

Brett, That is the direction I have been trying, I have 4 Limit/Home switches with adjustable positions so we can get whole length dialed in. My challenge is in designimng the homing code and creating the bypass circuit to re-enable the motors after they have hit thier respective limits. I am also waaay over my inputs and outputs on this system, I think I will just have to bow down and put together a preliminary I/O handler using a Microcontroller or PLC... I do have a Modbus MODI/O but I havent set it up yet.....trying to get the fundamentals worked out first.
Any suggestions on a simple enable bypass which will allow me to re-enable all 4 motors? I was thiinking of using a set of relays linked to the limit switches to control the motor enable and limit info and the 5th relay to bypass the motor enables. Or is that getting too complex? My first inclination is allways to put together a microcontroller board customizzed for my application but I wanted to keep this system servicable by the average shop floor guy, relays are pretty straightforward arent they?
Mike

49

General Mach Discussion / Re: Challenge question regarding Homing & Limit Switches

« on: April 21, 2007, 10:00:55 PM »

Scott, All 4 of these motors are moving together, they will all share the step and dir signals from the grex. The motors position a 50' long "jig", and initially they will not be positioned correctly in relation to each other. Once Synced up they should never loose position but I want the system to correct any problems that may occur should a belt break or something jam one of the motors. Basically its like having a single controller controlling 4 Machines(for this axis). Does that make sense? If I have a single limit switch then all 4 will move together but only the one with the limit will be correct in relation to the home position the other motors may be out of position. All suggestions and questions are welcome. Sometimes the dialogue can trigger the solution or pehaps someone else out there has done something similar, a different perspecitive is allways welcome

50

General Mach Discussion / Challenge question regarding Homing & Limit Switches

« on: April 20, 2007, 02:20:08 PM »

Hello all, I am currently working on an automation project and since I love MACH3 and happened to have a GREX sitting on my shelf we decided to use the GREX for the motion control of this little project. My question/problem is thus: I Have 2 Unique Axis's each of these axis has 4 Stepper Motors and a limit switch for each motor. The 4 Motors all share a step and direction signal. I need to be able to "HOME" these motors. The simple solution has been forwarded by a respected colleague who suggested homing them to a hard stop but I am not sure how MACH3 would "know" then that they are homed. I am looking for an elegant reliable solution but I have a tendancy to OVERTHINK these problems and end up chasing my tail. All suggestions would be welcomed.
 I had thought to wire the 4 limit switches in series so that when ALL the motors have tripped the limit switches I get a limit signal, but I need to disable the motors as they trigger the limits so they dont move past the limit... again simple to do, but How do I get MACH to RE-ENABLE the motors after the limit has been triggered? It seems that the Homing process is embedded in MACH so I cant Modify it, I suppose I could write a Modified "probing" macro and use the limits as the probe switch, but is it possible to have 2 separate probes?..... O Hey theres my tail! 
Thanks in Advance

Mike