Adaptive Path/CAM Operation

Here's the place for discussion related to CAM/CNC and the development of the Path module.
dubstar-04
Posts: 257
Joined: Mon Mar 04, 2013 8:41 pm

Re: Adaptive Path/CAM Operation

Postby dubstar-04 » Wed Aug 29, 2018 9:05 pm

kreso-t wrote:
Not sure if you caught one of my previous posts regarding the adaptive path violating the model. See image:
Crash.png
Crash.png (130.79 KiB) Viewed 371 times
Does the tool need to retract to the clearance height during linking moves?
kreso-t
Posts: 103
Joined: Sat Aug 04, 2018 2:32 pm

Re: Adaptive Path/CAM Operation

Postby kreso-t » Wed Aug 29, 2018 10:08 pm

cahlfors wrote:
Wed Aug 29, 2018 7:48 pm
There definitely are. Not all tools are even able to plunge, like a face mill for instance. There is nothing in the center that can cut.

Also of interest here is to have the cutting area overshoot the outer boundaries. Hard to explain, but imagine you were cutting this by hand. Then you would not only start from outside of the stock, you would take a pass and proceed beyond it as well. That way you would leave no artifacts around the perimeter. Staying within the surface of either the stock or part would leave artifacts along the perimeter and especially in the corners as the tool would not cut clear all the way to the edge. Today, we manage this phenomenon by either faking the stock being bigger than it is, or by creating a helper object with a bigger surface. It would be so much easier if the function could handle this by itself.

Looking forward to using this function! Thanks a million for your effort! :D

Thx cahlfors,

I am not that much of an expert in machining and I would probably prefer to use the "MillFace" operation for face milling as is already provided in FreeCAD and it does also support that overshooting of the boundary shape (which seem to me important for this type of operation):
FreeCAD 0.18_027.png
FreeCAD 0.18_027.png (211.73 KiB) Viewed 366 times
in my understanding face milling is more about getting good surface finish by making shallow and consistent cuts so there you don't have to worry that much about the material removal rate, tool bending/deflections caused by excessive cutting forces, chip evacuation, etc. Therefore I don't see that adaptive would be primarily used for face milling (also those curved adaptive paths don't seem to contribute to surface finish, straight lines are probably much better choice). Adaptive paths I see more to be used for effective removal of material, and for finishing passes then to use other operations. It would certainly be possible to integrate all those things into single operation (so that roughing and finishing strategies can be performed all together) but not sure that's a good approach, cause you would loose much of the flexibility you get with separate operations each having it's dedicated purpose, then settings/configuration of such operation would be complicated to use, and also from development perspective it would be hard to implement and maintain.

K.
kreso-t
Posts: 103
Joined: Sat Aug 04, 2018 2:32 pm

Re: Adaptive Path/CAM Operation

Postby kreso-t » Wed Aug 29, 2018 10:11 pm

dubstar-04 wrote:
Wed Aug 29, 2018 9:05 pm
kreso-t wrote:
Not sure if you caught one of my previous posts regarding the adaptive path violating the model. See image:

Crash.png

Does the tool need to retract to the clearance height during linking moves?
Yes, it should retract, it's probably a bug, I will check it tomorrow

BR,
K.
kreso-t
Posts: 103
Joined: Sat Aug 04, 2018 2:32 pm

Re: Adaptive Path/CAM Operation

Postby kreso-t » Thu Aug 30, 2018 7:16 am

kreso-t wrote:
Wed Aug 29, 2018 10:11 pm
dubstar-04 wrote:
Wed Aug 29, 2018 9:05 pm
kreso-t wrote:
Not sure if you caught one of my previous posts regarding the adaptive path violating the model. See image:

Crash.png

Does the tool need to retract to the clearance height during linking moves?
Yes, it should retract, it's probably a bug, I will check it tomorrow

BR,
K.
Hi Dan,

I can't seem to reproduce this issue, with every settings I tried it always retracts. Do you maybe have this model saved with those settings that caused the problem?

Thx,
BR
kreso-t
Posts: 103
Joined: Sat Aug 04, 2018 2:32 pm

Re: Adaptive Path/CAM Operation

Postby kreso-t » Thu Aug 30, 2018 7:18 am

kreso-t wrote:
Thu Aug 30, 2018 7:16 am
kreso-t wrote:
Wed Aug 29, 2018 10:11 pm
dubstar-04 wrote:
Wed Aug 29, 2018 9:05 pm
kreso-t wrote:
Not sure if you caught one of my previous posts regarding the adaptive path violating the model. See image:

Crash.png

Does the tool need to retract to the clearance height during linking moves?
Yes, it should retract, it's probably a bug, I will check it tomorrow

BR,
K.
Hi Dan,

I can't seem to reproduce this issue, with every settings I tried it always retracts. Do you maybe have this model saved with those settings that caused the problem?

Thx,
BR
OK, got it now. I will correct that.

BR,
K.
kreso-t
Posts: 103
Joined: Sat Aug 04, 2018 2:32 pm

Re: Adaptive Path/CAM Operation

Postby kreso-t » Thu Aug 30, 2018 5:10 pm

kreso-t wrote:
Thu Aug 30, 2018 7:18 am
kreso-t wrote:
Thu Aug 30, 2018 7:16 am
kreso-t wrote:
Wed Aug 29, 2018 10:11 pm
dubstar-04 wrote:
Wed Aug 29, 2018 9:05 pm
kreso-t wrote:
Not sure if you caught one of my previous posts regarding the adaptive path violating the model. See image:

Crash.png

Does the tool need to retract to the clearance height during linking moves?
Yes, it should retract, it's probably a bug, I will check it tomorrow

BR,
K.
Hi Dan,

I can't seem to reproduce this issue, with every settings I tried it always retracts. Do you maybe have this model saved with those settings that caused the problem?

Thx,
BR
OK, got it now. I will correct that.

BR,
K.
This should be OK now.
dubstar-04
Posts: 257
Joined: Mon Mar 04, 2013 8:41 pm

Re: Adaptive Path/CAM Operation

Postby dubstar-04 » Thu Aug 30, 2018 11:27 pm

kreso-t wrote: This should be OK now.

I will have a test over the weekend.

Thanks for all your effort on this!!
kreso-t
Posts: 103
Joined: Sat Aug 04, 2018 2:32 pm

Re: Adaptive Path/CAM Operation

Postby kreso-t » Fri Aug 31, 2018 8:52 am

dubstar-04 wrote:
Thu Aug 30, 2018 11:27 pm
kreso-t wrote: This should be OK now.

I will have a test over the weekend.

Thanks for all your effort on this!!
Thanks Dan also to you for your testing efforts and suggestions.

I'll see what can be done about this outside-in approach over the weekend.

BR,
Kresimir
cahlfors
Posts: 61
Joined: Tue Jan 24, 2012 8:27 pm
Location: Sweden

Re: Adaptive Path/CAM Operation

Postby cahlfors » Fri Aug 31, 2018 11:09 pm

kreso-t wrote:
Wed Aug 29, 2018 6:59 pm

FreeCAD 0.18_024.png
Overshooting the boundary is equally important here, as in face milling. Just don't overshoot into the material! :o
FreeCAD-daily/Ubuntu or Mint
Mendel 3d-printer/pronterface
HeeksCAM
LinuxCNC
Optimum BF20L mill
kreso-t
Posts: 103
Joined: Sat Aug 04, 2018 2:32 pm

Re: Adaptive Path/CAM Operation

Postby kreso-t » Sat Sep 01, 2018 4:48 pm

dubstar-04 wrote:
Wed Aug 29, 2018 8:54 pm
...
This would definitely be useful the test part for example:

Screenshot from 2018-08-26 20-13-24.png

This would benefit from starting machining from outside the stock and working inwards. That is what the HSM adaptive code would do.

Thanks,

Dan
Hi,

Added a preliminary version of outside-in clearing. It works only if "Outside" cut region is chosen. The previous way is still default and you heave to uncheck the "Force clearing inside-out" option if you want outside-in clearing.
There are still some potential improvements to all this, as currently the algorithm only takes into account the geometry you select + the stock geometry, it does not evaluate the cross sections of the whole model (i.e. to avoid regions that are part of the model body, so user have to be careful about the selection he/she makes).
FreeCAD 0.18_031.png
FreeCAD 0.18_031.png (327.06 KiB) Viewed 204 times
I also removed that "Process holes" option, as it does not seem to be needed now when you can select edges, and it seemed confusing.
FreeCAD 0.18_032.png
FreeCAD 0.18_032.png (223.12 KiB) Viewed 178 times
BR,
K.