Messages

1

General Mach Discussion / Re: dro and gcode don't match

« on: July 22, 2011, 09:45:46 AM »

Looks like you were right on with your answer Al.  I learned something new as well by single stepping through a job.  When you stop a job the gcode stops at the next line to be executed, not the last line that executed.  Everyone else probably already knew that, but I didn't. 

When I compared the DROs to the line before where it stops, the gcode and DRO are either right on or off by a tiny amount.  Exactly like you would expect based on resolution limits.

So much to learn with Mach!  Good thing I enjoy learning new things.  Mach keeps me really happy in that respect.

Thanks again for the help.

Ed

2

General Mach Discussion / Re: Large Toolpath and Mach Pauses every couple hundred lines

« on: July 22, 2011, 09:41:01 AM »

Hood, you are a life saver.  Turning off the toolpath display solved the problem. 

Maybe I'll get this job done before the weekend!!  Woohoo!!!

Thanks a bunch.

Ed

3

General Mach Discussion / Re: Large Toolpath and Mach Pauses every couple hundred lines

« on: July 22, 2011, 07:51:24 AM »

Hi Hood.  Thanks for the suggestion.  I'll give that a try first thing this morning.  I sure hope it works.

Ed

4

General Mach Discussion / Re: dro and gcode don't match

« on: July 22, 2011, 07:48:26 AM »

Hi Al - Thanks.  That sounds like a reasonable explanation.  I'm going to single step through a job when I get a chance and see if that's what looks like is going on.


Ed

5

General Mach Discussion / dro and gcode don't match

« on: July 21, 2011, 11:16:24 PM »

While trying to fix another issue I happend to notice that the dro doesn't match the gcode when I stop the program during a run.  They are all off by a small amount.  A search of the web only turned up a suggestion to check backlash settings.  I have backlash compensation turned off so I don't think that's my problem.

I did some air runs of old jobs and now see that those files had dro / gcode mismatch as well.  The pieces cut fine, but I cut artwork not jet engine components and I don't measure the finished project. 

Is this normal behavior for Mach?  Is a setting(s) I should be checking?

Thanks.

Ed

6

General Mach Discussion / Large Toolpath and Mach Pauses every couple hundred lines

« on: July 21, 2011, 11:08:45 PM »

I have a large rotary toolpath with about 1.2 million lines of gcode.  When I run the file Mach3 pauses for a couple of seconds every couple hundred lines of code.  As a test I deleted a bunch of the code so that I only have the first 10,000 lines in the file.  Lines 1 to 10,000 are exactly the same as the first 10,000 lines of the large file.  This smaller file runs perfectly with no pauses.

I have look ahead set to 200.  Looking at diagnostics I don't see any indication that the machine is overloaded.  It's a pretty fast computer.

I see that the limit for Mach3 is 10,000,000 lines of code.  I'm nowhere near that.  Any suggestions on what I should be looking at to get rid of these pauses?  It's a 12 hour job if it runs smoothly.  The pauses will add a lot more time.  Not to mention the problem of having the bit turn in place every couple of inches while Mach is doing whatever it's doing while it pauses.

Thanks.

Ed

7

General Mach Discussion / Re: Rotary + CV + G00 = Clunk

« on: July 05, 2011, 01:29:04 PM »

By the way, I should have mentioned that I'm running Version 3.042.020 of Mach.

Ed

8

General Mach Discussion / Re: Rotary + CV + G00 = Clunk

« on: July 05, 2011, 01:16:48 PM »

Hi Bill - with earlier tests I ran (before I tried Ian's suggestion) I found that leaving "Set Stop CV on Angle >" unchecked I didn't run as smooth as I did with it checked.  Do you have a rotary axis?  My problem only happens when I run with the A Rotary axis involved. 

If I run the exact same toolpaths in x, Y, z instead of x, A, z they run without the clunking problem.  (The clunking isn't coming from A (I triple checked).)

It really seems like Mach goes crazy with the acceleration on those G00 moves when doing rotary work.  Ian's suggestion of the dwell before the G00 move seemed to keep Mach from overaccelerating on the following G00 move.  I've looked all over for an option somewhere that might address this, but I just can't find anything.

Ed

9

General Mach Discussion / Re: Rotary + CV + G00 = Clunk

« on: July 05, 2011, 01:08:36 PM »

Summary of trying Ian's suggestion for "G4 P0":

Returned to my original settings:

A = 18810 vel and 3151 accel
X = 200 vel and 50 accel
z = 200 vel and 50 accel
CV = on
Set CV Dstance Tolerance = not checked
Set Stop CV On Angle > = not checked

Ran a quick test putting a "G4 P0" between lines 680 and 690 (in my OP).  Clunking gone.  Didn't have time to check and see how the overall results compare to my previous solution (motors tuned down and cv options on) for overall speed and quality of cut.  I'll run some test cuts tonight.

If the "G4 P0" turns out to be a better solution, I'll have to figure out how to insert them.  Not sure I can adjust my post processor to do it.  I can probably write my own post post processor to add them (there are a bunch of them needed), but it would sure be easier if there were an option to check in Mach 3 somewhere that would have the same effect as inserting those "G4 P0" codes.

Anyway, thanks for the lead on another possible solution.  I'll keep working on it.

Ed

10

General Mach Discussion / Re: Rotary + CV + G00 = Clunk

« on: July 05, 2011, 11:41:36 AM »

Hi Ian - If I just switch off CV, then I get really jerky movement on toolpaths with arcs.  With CV on and the settings I am now using I get smooth movement.  So it is still having some effect with those settings.

But I'm willing to try other things to see if I can solve the problem in another way that gets my speeds back up a bit.

I'll try your suggestion on G4 P0 later today and report back on what happens.

Thanks for the suggestion.

Ed