Machsupport Forum
Mach Discussion => Mach4 General Discussion => Topic started by: crevalle1 on March 16, 2019, 08:53:37 PM
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New to the forum and this is my first post...
We just bought a new BOSS 5x10 CNC router with Mach4, HiConn Integra motion controller, and LeadShine drives/servo motors.
Factory support is a bit...limited.
It cuts straight lines no problem, but arcs, circles, and continuous arcs are very jerky and rough.
You can visibly watch and feel the gantry "lurch" in the Y axis, but the X axis appears very smooth.
We can rule out mechanical issues I think...the machine is new and has no binding or worn parts.
We can rule out the bit...we get the same issues with no material on the table and no bit in the spindle.
We can rule out feed speeds...we get the same results at 10ipm and 100ipm.
We are cutting poly/HDPE with a 3 flute upcut spiral by the way.
It's almost as if Mach4 is ignoring CV...it is most definitely turned on in the software. But whether we change to the slider from 5 degrees to 189 degrees, we seem to see no change in cut quality.
The problem is also perfectly repeatable...we get the same lumps and bumps at the same points every time which would seem to rule out noise in the machine. (We have a hefty earth ground on the machine right through the slab and 10' down)
Any ideas as to where else to look?
I'm attaching a copy of the G code file and some pics of both internal and external radii in 1/2" poly. WE tried making 4 passes to see if that would improve cut quality, but no luck.
Thanks for your help!
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Hi,
I don't have a solution but maybe an idea for a test that might narrow it down.
I'm wondering if the Y axis stepper driver is faulty or perhaps is executing full steps whereas the X axis is executing microsteps.
To test that idea can you change the Y and X axes? By this I mean that the step/dir signals from the nominal X axis
pins of the BoB be hooked to the Y axis driver and stepper. The X axis driver and stepper would be hooked to the current
nominal Y axis step/dir pins.
If this is feasible without permanently damaging circuit boards it represents a simple test that can aid the determination
of the logical cause of the fault.
Craig
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Hmm...I can check into this but I'm still pretty sure this is a software issue.
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Hi,
I'm still pretty sure this is a software issue
That may be so, in which case the test I've suggested will have a negative result, which will tell you as much as a positive
result. Currently 'Im pretty sure' isn't worth squat as evidence.
Craig
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10-4. I understand.
I should mention however that there are 2 Y axis drives. A master and slave.
The odds of both being faulty are pretty small. If one were bad, we would have seen it show up with a lot of other symptoms including poor straight line cutting.
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Hi,
The odds of both being faulty are pretty small. If one were bad, we would have seen it show up with a lot of other symptoms including poor straight line cutting.
Very true....so don't bother with the test. Good luck.
Craig
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When your troubleshooting never rule Anything out. This is from a guy who made a lot of money fixing other peoples problems, and machines. I am sure Craig has done a lot of the same.
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Hi,
This is from a guy who made a lot of money fixing other peoples problems, and machines. I am sure Craig has done a lot of the same.
Made a living from it for forty years.
Craig
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Hi,
This is from a guy who made a lot of money fixing other peoples problems, and machines. I am sure Craig has done a lot of the same.
Made a living from it for forty years.
Craig
:) I thought so.
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Hello,
If you haven't already, you should check out the CV Wizards. Go to Wizard>Select Wizard and you'll see a few different options to help you get everything tuned up and running smoothly. They are fairly self-explanatory and have good instructions included in the wizards themselves.
Best wishes,
Bryanna
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FOUND IT!!!
OK, for whatever reason, CV was NOT activated. We had to add a G64 to the front of the program to activate it.
After that, smooth curves!
I have since added the G64 to the initialization line in the Mach setup screen. I thought checking the Constant Velocity button would do this?
We are still monitoring this, because randomly, CV has turned itself off again.
We can manually add the G64 to the program when we see this and all is well.
Not sure what happened to turn it off though...
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You might need to increase the "Lookahead" lines from the default of 200.