Flycutter Facing

Here's the place for discussion related to CAM/CNC and the development of the Path module.
dubstar-04
Posts: 393
Joined: Mon Mar 04, 2013 8:41 pm
Location: Manchester, UK
Contact:

Flycutter Facing

Postby dubstar-04 » Mon Aug 27, 2018 5:57 am

I am trying to setup a facing operation using a flycutter, However I can't seem to get the tool path I would like (File attached).

This is the tool path using a 6mm Endmill:
Facing-6mmRougher.png
Facing-6mmRougher.png (313.51 KiB) Viewed 397 times
Tool path using a 70mm diameter flycutter:
Facing-Flycutter.png
Facing-Flycutter.png (261.2 KiB) Viewed 397 times
Tool Library:
ToolLibrary.png
ToolLibrary.png (76.46 KiB) Viewed 397 times
What I would like is the tool to lead in from the y direction and move across the part in a single move. I'm guessing that I am having trouble as the tool is a larger diameter than the part width?

FreeCAD Info:

OS: Ubuntu 18.04.1 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.14016 (Git)
Build type: None
Branch: master
Hash: 5f63f9f23f10640b613cd894ed529eaf69a04aec
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedKingdom (en_GB)
Attachments
TortureTest2.FCStd
(658.88 KiB) Downloaded 9 times
mlampert
Posts: 1304
Joined: Fri Sep 16, 2016 9:28 pm

Re: Flycutter Facing

Postby mlampert » Mon Aug 27, 2018 4:42 pm

dubstar-04 wrote:
Mon Aug 27, 2018 5:57 am
What I would like is the tool to lead in from the y direction and move across the part in a single move. I'm guessing that I am having trouble as the tool is a larger diameter than the part width?
That's correct, PathArea doesn't generate a Path if the tool doesn't fit inside the area to be processed. Also, PathArea doesn't generate single sweeps, it needs to make a loop.

Edit: What you can do is make Stock bigger than the tool and use Stock as the boundary for MillFacing
dubstar-04
Posts: 393
Joined: Mon Mar 04, 2013 8:41 pm
Location: Manchester, UK
Contact:

Re: Flycutter Facing

Postby dubstar-04 » Mon Aug 27, 2018 5:06 pm

mlampert wrote:
Mon Aug 27, 2018 4:42 pm
dubstar-04 wrote:
Mon Aug 27, 2018 5:57 am
What I would like is the tool to lead in from the y direction and move across the part in a single move. I'm guessing that I am having trouble as the tool is a larger diameter than the part width?
That's correct, PathArea doesn't generate a Path if the tool doesn't fit inside the area to be processed. Also, PathArea doesn't generate single sweeps, it needs to make a loop.

Edit: What you can do is make Stock bigger than the tool and use Stock as the boundary for MillFacing
Thanks for the reply. Changing the stock doesn't seem like a very elegant solution.

IMO this should just work like it does for smaller tools. I would of though that facing with a flycutter is pretty common practice.

Is it worth filing a bug for this?
cahlfors
Posts: 62
Joined: Tue Jan 24, 2012 8:27 pm
Location: Sweden

Re: Flycutter Facing

Postby cahlfors » Mon Aug 27, 2018 6:27 pm

It is not a bug - just missing functionality. For now, we have to accept it. I think I have seen a feature request for that or something similar.
If redefining the stock is not a good solution for you, you could create a helper object instead. In this case, just a slab with the necessary width to let you generate a path for your flycutter. It will not generate the single pass you desire, but it will get the job done. It is the same issue with face mills.
FreeCAD-daily/Ubuntu or Mint
Mendel 3d-printer/pronterface
HeeksCAM
LinuxCNC
Optimum BF20L mill
mlampert
Posts: 1304
Joined: Fri Sep 16, 2016 9:28 pm

Re: Flycutter Facing

Postby mlampert » Mon Aug 27, 2018 7:01 pm

dubstar-04 wrote:
Mon Aug 27, 2018 5:06 pm
Thanks for the reply. Changing the stock doesn't seem like a very elegant solution.

IMO this should just work like it does for smaller tools. I would of though that facing with a flycutter is pretty common practice.

Is it worth filing a bug for this?
I wasn't aiming at elegant, my bar was as low as "is it possible". I agree about your comments and I think you should enter an issue as a feature request - so we don't forget about it.
dubstar-04
Posts: 393
Joined: Mon Mar 04, 2013 8:41 pm
Location: Manchester, UK
Contact:

Re: Flycutter Facing

Postby dubstar-04 » Mon Aug 27, 2018 7:41 pm

mlampert wrote:
Mon Aug 27, 2018 7:01 pm
dubstar-04 wrote:
Mon Aug 27, 2018 5:06 pm
Thanks for the reply. Changing the stock doesn't seem like a very elegant solution.

IMO this should just work like it does for smaller tools. I would of though that facing with a flycutter is pretty common practice.

Is it worth filing a bug for this?
I wasn't aiming at elegant, my bar was as low as "is it possible". I agree about your comments and I think you should enter an issue as a feature request - so we don't forget about it.
Thanks for taking the time to reply. I understand your perspective, TBH coding single pass facing ops would be simple enough by hand so that would probably be my approach, while we have a nice UI and some amazing tools it would be nice if we could work to extend them to cover more use cases hence report here:

https://www.freecadweb.org/tracker/view.php?id=3570

Thanks,

Dan
mlampert
Posts: 1304
Joined: Fri Sep 16, 2016 9:28 pm

Re: Flycutter Facing

Postby mlampert » Mon Aug 27, 2018 8:38 pm

Thanks, that's great.