Hello Guest it is October 16, 2019, 04:46:44 PM

Author Topic: Stragen events question  (Read 16095 times)

0 Members and 1 Guest are viewing this topic.

Offline NormB

*
  •  169 169
  • Norm
    • View Profile
Stragen events question
« on: January 17, 2010, 09:32:03 AM »
I am running G-Code developed by Vcarve things are ruining normal.  Someplace in the middle at the end most anywhere the Z axis just goes off in no mans land.  I can raise an inch or more ) is now 1" above the work piece and I am cutting in the air.  I stop the program and reset the Z to real 0 then back up and repeat the cut.  This is a real pain and I am not able to find what is happening.  Something is causing this but I have no idea what to look for.  X and Y axis are all fine only the Z is messed up for some reason. 

Any ideas what I can look for to eliminate this problem  It's hard to reset the Z in the middle of a run.  To say nothing of finding your place in the code to start from here.

Norm

Offline Hood

*
  •  25,855 25,855
  • Carnoustie, Scotland
    • View Profile
Re: Stragen events question
« Reply #1 on: January 17, 2010, 09:57:05 AM »
If you could attach the code and say where in that code that you are having issues, someone may see a problem there.

Hood

Offline NormB

*
  •  169 169
  • Norm
    • View Profile
Re: Stragen events question
« Reply #2 on: January 17, 2010, 10:30:17 AM »
That really is the problem, the same job one time it will run just fine no problems the next time multiple  Z Odysseus and then other times maybe only one issue it's just not consistant and that tell me it's not a code problem it's something in setup or a mechanical problem of some sort that when certain conditions are met off we go.  I just am at a total loss on this.

Offline NormB

*
  •  169 169
  • Norm
    • View Profile
Re: Stragen events question
« Reply #3 on: January 17, 2010, 10:32:46 AM »
Just for kicks I am attaching the code file so you can see.

Offline NormB

*
  •  169 169
  • Norm
    • View Profile
Re: Stragen events question
« Reply #4 on: January 17, 2010, 10:40:05 AM »
Oh yes, one more thing, My Z axis is set to move at 30 IPS is this too fast?  I guess as I think about this it's after a plunge of 1/8 single cut I see this happen, I can't say for sure it's every time though.  It will always catch me when I am not looking.  At this point I feel like I just can't leave the machine to do it's thing and move on to t=other things prepping the next job etc.

Offline Hood

*
  •  25,855 25,855
  • Carnoustie, Scotland
    • View Profile
Re: Stragen events question
« Reply #5 on: January 17, 2010, 11:07:24 AM »
Ok if its the same code which is OK one time but not another its a different matter.
30Inch per second? Mach uses inch per min but no matter what it is it will depend on your hardware as to whether its too fast or not. If its a stepper system then usually the problem will be seen when the Z is doing a rapid positive movement rather than a negative. That is not to say it wouldnt happen the other way as there may be factors in your machine that put more stress on the Z as it is moving negative or could even be you are doing only small positive moves at rapid but longer ones in a negative direction.
Try lowering the Acell a bit and see if that helps. The other thing to look at would be if the cutter is getting pushed into the collet but that is doubtful with your problem as you are talking 1".

Hood

Offline ger21

*
  • *
  •  6,288 6,288
    • View Profile
    • The CNC Woodworker
Re: Stragen events question
« Reply #6 on: January 17, 2010, 11:38:56 AM »
Cut your Z axis acceleration in half.

I had been running my machine for several months, and it had never lost position a single time. The first time I did a detailed 3D carving, within 10 minutes, the Z axis was above the part.

Lowered the Z accel by half, restarted the job, and it ran flawlessly for 2 hours until the job was done.

Bottom line, is that all jobs are different, and some put a higher load on the system.

And btw, my Z velocity is 30, and I lowered the accel from 10 to 5.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html

Offline NormB

*
  •  169 169
  • Norm
    • View Profile
Re: Stragen events question
« Reply #7 on: January 17, 2010, 03:08:33 PM »
Okay, I just5 got back in from the shop, cut the Accel in half to around 5-6 now started a job, same job posted cutting the S lost in space.  Head moves up an additional move looked to me "I actually caught it this time" then moved back down and began to cut in the air.  I am just not sure what can cause this sort of problem.  I checked the mechanical on the Z axis for ease of movement and it's fine no obstructions nothing.  I cut at least 7 jobs similar without a problem then all at once this starts and in the last four Jobs I have lost at least four pieces. 

Offline Hood

*
  •  25,855 25,855
  • Carnoustie, Scotland
    • View Profile
Re: Stragen events question
« Reply #8 on: January 17, 2010, 03:12:40 PM »
did you note where in the code it happened? was the Z meant to be moving at that point but just did a wrong move?

Hood

Offline NormB

*
  •  169 169
  • Norm
    • View Profile
Re: Stragen events question
« Reply #9 on: January 17, 2010, 03:14:20 PM »
I did run the driver test too.  I saw an occasional spike of around 60 once in a great while other than that totally flat.