Author Topic: Final Depth Increment Bug  (Read 2772 times)

Offline Bob La Londe

  • CNC Jedi
  • *****
  • Posts: 4442
  • ^ 8.5 pounds on my own hand poured bait.
    • View Profile
    • CNC Molds N Stuff
Final Depth Increment Bug
« on: July 21, 2024, 20:59:28 pm »
This is fairly well documented that CamBam will on its own ignore the final depth increment and even ignore the depth increment if the last pass is numerically small. 

I think it may be an artifact of the fact that the author thinks natively in metric and I work in standard inch mode.  There are other things where this has been found to be the case, and I think it may in part be related to the resolution and stepover bugs I have commented on in 3D machining. 

In any case CamBam will often ignore the final depth increment and the depth increment plunging directly to the full depth of cut if the amount is small.  If the number is .005 that is quite insignificant if working with a base unit of 1mm, but it's enough to be a nice finish pass when the base unit is 1 standard inch. 

MOPS ARE FREE is the expected rallying cry here, but they really aren't.  They are almost free.  They do take time to setup.  Two instead of one probably is not significant, but often you may be applying the MOP to multiple elements of geometry.  If you need to profile 30 elements instead of 1 then instead of creating one MOP you "can" create 2, but you double your travel time between cuts.  For one or two elements it may not be a big deal if they are close together, but if they are scattered across the work envelope of the machine you are throwing away machine time.  To make your code more efficient instead of creating 1 MOP for your 30 elements you are creating 60.  Now the time in CAM starts to add up. 

It's well known, but I don't know if it is part of the documented bug list or not.  I don't know if documenting things matters anymore either, but I am hoping it does. 





Getting started on CNC?  In or passing through my area?
If I have the time I'll be glad to show you a little in my shop. 

Some Stuff I Make with CamBam
http://www.CNCMOLDS.com

Offline dh42

  • Administrator
  • CNC Jedi
  • *****
  • Posts: 7378
    • View Profile
    • Cambam V1.0 French Doc
Re: Final Depth Increment Bug
« Reply #1 on: July 21, 2024, 21:28:32 pm »
Hello BoB

Yes this bug was still reported for CB 0.98 (#7)

https://cambamcnc.com/forum/index.php?topic=4508.0/index.php

https://cambamcnc.com/forum/index.php?topic=4506.msg32765/index.php#msg32765

https://cambamcnc.com/forum/index.php?topic=5356.0/index.php

http://www.atelier-des-fougeres.fr/Cambam/Aide/Bug_report.html

For your example (profil1) the trick of using 0 for depth increment is working but maybe not sufficient for the job you've to do ...

Quote
I don't know if documenting things matters anymore either, but I am hoping it does.

I hope too, Hopefully one day Andy will find time to work on CamBam again.

++
David
« Last Edit: July 21, 2024, 21:36:17 pm by dh42 »