Thread Mill

Here's the place for discussion related to CAM/CNC and the development of the Path module.
meme1111
Posts: 2
Joined: Tue Aug 06, 2019 10:24 pm

Thread Mill

Postby meme1111 » Sun Dec 29, 2019 1:53 pm

hello, can you tell me if it is possible to generate a path with this type of cutter?
phpBB [video]

I thought of helix but the entrance to the forum is not central.
thank you
chrisb
Posts: 24420
Joined: Tue Mar 17, 2015 9:14 am

Re: Thread Mill

Postby chrisb » Sun Dec 29, 2019 6:09 pm

Hi and welcome to the forum!

Path workbench does not respect the tool geometry directly, but you can use the helix operation to create a path. It is especially easy if you model the outer diameter of the thread as in the attached example.

In the example I want to create a path for an M16x2 thread:
- I modeled a hole of 16mm
- the tool has a diameter of 8mm, that's what I specified in the tool table
- I selected the inner wall of the hole
- I created a helix path with stepdown=2mm
Snip macro screenshot-274776.png
Snip macro screenshot-274776.png (4.56 KiB) Viewed 340 times
Please note that the model does not show the thread correctly. If you use the hole feature in PartDesign workbench for an inner thread, then you have to adjust the diameter of the tool
Attachments
threadM16.FCStd
(15.92 KiB) Downloaded 10 times
m0n5t3r
Posts: 105
Joined: Fri Feb 03, 2017 2:55 pm

Re: Thread Mill

Postby m0n5t3r » Sun Dec 29, 2019 8:04 pm

the only issue with this method is the retract (it's on the edge, so it will be a single use cutter :P)

I guess you'll need some code / macro to generate the thread and retract correctly, or some gcode postprocessing
meme1111
Posts: 2
Joined: Tue Aug 06, 2019 10:24 pm

Re: Thread Mill

Postby meme1111 » Sun Dec 29, 2019 9:12 pm

thank you chrisb. I think what he says m0n5t3r is correct, in this way the elix of the tool slams on the edge without entering. I have no idea how to intervene in the gcode :roll:. However I will give it a try.
chrisb
Posts: 24420
Joined: Tue Mar 17, 2015 9:14 am

Re: Thread Mill

Postby chrisb » Sun Dec 29, 2019 9:14 pm

You are right. It would make a good feature request to add a property "retract in center".
herbk
Posts: 1801
Joined: Mon Nov 03, 2014 3:45 pm
Location: Windsbach, Bavarya (Germany)

Re: Thread Mill

Postby herbk » Sun Dec 29, 2019 10:21 pm

Lead In/Out dressup dosn't work at a helix path to...
Gruß Herbert
mlampert
Posts: 1463
Joined: Fri Sep 16, 2016 9:28 pm

Re: Thread Mill

Postby mlampert » Sun Dec 29, 2019 11:25 pm

I have a change that does exactly this - it however depends on the new ToolBit changes. Those are merged but need verification and I didn't want to add an feature that depends on some basics which might get kicked out, or change significantly.
chrisb
Posts: 24420
Joined: Tue Mar 17, 2015 9:14 am

Re: Thread Mill

Postby chrisb » Mon Dec 30, 2019 1:04 am

mlampert wrote:
Sun Dec 29, 2019 11:25 pm
Those are merged but need verification
What should we test?
mlampert
Posts: 1463
Joined: Fri Sep 16, 2016 9:28 pm

Re: Thread Mill

Postby mlampert » Mon Dec 30, 2019 6:00 am

chrisb wrote:
Mon Dec 30, 2019 1:04 am
mlampert wrote:
Sun Dec 29, 2019 11:25 pm
Those are merged but need verification
What should we test?
A new approach to Tools, ToolLibraries and ToolControllers:
https://forum.freecadweb.org/viewtopic.php?f=15&t=41026