Topics

1

Third party software and hardware support forums. / Compatible servo drives

« on: June 13, 2010, 09:49:02 PM »

I'm reading a Mitsubishi servo drive manual that effectively says it has a step/dir mode is available for its inputs. 
Does anybody here have any experience in trying to use Mitsubishi drives in a Mach3 system?  Is there any reason why one of these drives couldn't/shouldn't be driven from Mach3's parallel port?

Are there any other major manufacturers whose products will accept step/dir inputs?

Also, does anybody know a way to use Parker-Hannafin Aries drives (analog inputs) and controllers with Mach3?

Do you know of anybody working on a simple, low-cost, open-source step-to-analog converter?

I'm aware of Gecko, Galil, DSPMC, K-FLOP/K-Analogue, but there really ought to be a way for us to utilize the surplus servo drives & brushless motors that sell on eBay for pennies on the dollar.

Regards to all...
Dave

2

General Mach Discussion / Need help with resonance problem

« on: November 04, 2009, 05:42:17 PM »

Hello all,

I've converted a Grizzly wood lathe to CNC by adding some scrounged actuators with step motors.  I'm having a problem with the Z-axis.  It gets a few steps out of sync with Mach3 and starts cutting where it shouldn't.  In a run of 15 minutes it gets off maybe as much as a dozen steps.  Computer is fine.  Electronics is fine.  These are my background and I wish the problem was here because I could deal with it.  It's not.  It's mechanical.

I slowed the Z-axis *waaay* down to speed of 25 and acceleration of 2 and the problem went away.  So, now I have to figure out how to identify the resonance and how to deal with it.  This is an area I have no experience in.  Can someone point me to a recipe or tutorial on how to identify, measure and compensate for resonance?  I'm hoping I don't have to do this by trial and error because that could take forever.

Now, there's a Lovejoy-style coupler between the step motor and leadscrew.  I'm suspicious of the rubber spider between the two halves.  Seems to me that this could exacerbate resonance problems.   The leadscrew is almost 30" long and at least 1/2" dia., pretty massive.  The stepper's 1/4" shaft looks puny next to the leadscrew, and it is probably twisting under the torque and contributing also.  Would a larger stepper with a more robust shaft help?

Any help will be appreciated.

Dave

3

LazyTurn / Is this a bug in LazyTurn?

« on: October 31, 2009, 08:54:42 PM »

Hi Rich et al.,

So, I sprung for the $175 and purchased the license to Mach3.  Solved the previous G-code garble problem.

I'm cutting a profile into wood.  I'm using three separate runs:
  1) cut the billet down from square to round,
  2) cut the desired profile into the billet,
  3) make a deep, parting cut.

Now, I used the same AutoCAD file for both run 2 and run 3.  I just made the parting cut deeper for run 3 and moved some surfaces up to the billet diameter so LazyTurn wouldn't waste time cutting the same areas again.  I didn't move any the location of the parting cut.  I just made it deeper for run 3.

I was very careful not to shift ANYTHING in AutoCAD.  Indeed, I can load the two runs alternately in AutoCAD and they perfectly overlay each other.  I also checked the positions of the vertical lines defining the shallow cut and the deep cut and their X values were identical.  Only the length of the lines, i.e. the Y ends, were different, to set the depth of the cut.

When I fire up run 3, it wants to make the parting cut about 2 mm farther out, i.e., about 2mm offset on the Z-axis, and out of position from where the shallow version of the cut was made in run 2.

Am I missing something here?  It looks like a bug in the program to me, but I'm hoping you'll have an explanation that I overlooked.

By the way, everything else is working well.  I'm very pleased with myself because the hardware I scrounged and assembled is performing just as I hoped.  Not a hint of chatter. Plenty of torque in the step motors.  I can re-run phase 2 over and over and it overlays the previous cuts perfectly.  Fun and amazing to watch.

I just can't figure out why LazyTurn is shifting the location of the parting cut.

Any ideas?

Regards,
Dave

4

Feature Requests / Zoom-in and Zoom-out

« on: October 29, 2009, 10:26:40 AM »

LazyTurn  zoom works in the opposite way compared to every other program I've used.  E.g., Adobe Acrobat Reader, zoom-in makes the image larger.  In LazyTurn it makes the image smaller.

Thanks,
Dave

5

Feature Requests / G-code line limit in the demo versions

« on: October 29, 2009, 10:21:47 AM »

When reaching the limit, Mach3Mill and Mach3Turn should generate a coherent error message.  I was just told, in a different part of the forum, that reaching the limit causes the bizarre behavior in the G-code list window.

And the documentation should spell out the demo-version limitations, perhaps in the installation section.  That's the first place I went looking for it.

Apparently Mach3Turn has a lower limit than Mach3Mill.  I was expecting a 500 line limit, based on what I'd read, and I wasted a lot of time finding and trying to figure out the bizarre behavior I was seeing.

6

General Mach Discussion / G-code window is different than file in Notepad

« on: October 29, 2009, 08:35:26 AM »

I've just added X and Z axes to a simple Grizzly wood lathe.  I'm successfully using Mach3 on a Dell Latitude D800.  By reading posts on the forum I was able to disable the services that were causing laptop trouble.  Everything appears to be working and I'm about ready start cutting, but the G-code list window is behaving strangely. 

I'm not sure where to post my questions about this.  My G-code file is 375 lines long, well within the 500-line limit.  The code displayed in the G-code list window doesn't match the file that I load.  The first couple hundred lines are right but then it starts repeating lines and omitting other lines.  When I run the code the system works perfectly until it gets up to the problem area.  Then it halts. If I hit the edit button, Notepad comes up and the file is perfect.  When I quit Notepad and go back to the G-code list window the bottom half of the file is still messed up.   Is this because it's unlicensed?  Is the code limit less than 500 lines for Mach3Turn?

Dave