thread milling?

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freman
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Re: thread milling?

Postby freman » Sat Jul 10, 2021 3:44 pm

sliptonic wrote: Wed Dec 09, 2020 2:18 pm The threadmill operation will require a threadmill tool. This is brand new stuff so there isn't one in the example toolbits.

It looks like phpbb won't let me attach a toolbit (.fctb) So I can't give you mine but here's the contents.

Code: Select all

{
  "version": 2,
  "name": "threadmill",
  "shape": "thread-mill.fcstd",
  "parameter": {
    "Crest": "0.100 mm",
    "Diameter": "5.000 mm",
    "Length": "50.000 mm",
    "NeckDiameter": "3.000 mm",
    "NeckHeight": "20.000 mm",
    "ShankDiameter": "5.000 mm"
  },
  "attribute": {}
}
Just scanning back on the thread, I noticed this.

I've hit this kind of problem and usually rename it as .txt or something the dumb filters will accept. Just put a note to warn folks what is going on.


Where can I find the thread milling op ? I don't seem to see it anywhere. Do I have a recent enough build? Thanks.

OS: Fedora 34 (Thirty Four) (LXQt//usr/share/xsessions/lxqt)
Word size of FreeCAD: 64-bit
Version: 0.20.24847 (Git)
Build type: Release
Branch: master
Hash: 20e756306d9aa624fcbf465f0345d721673ce720
Python version: 3.9.4
Qt version: 5.15.2
Coin version: 4.0.0a
OCC version: 7.5.0
Locale: English/United Kingdom (en_GB)
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sliptonic
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Re: thread milling?

Postby sliptonic » Sat Jul 10, 2021 5:30 pm

Path->Specialty Operations->Threadmill.

I think it's an experimental. I've never used it because I don't have any threadmill tools. It's mlampert's baby.
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freman
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Re: thread milling?

Postby freman » Sat Jul 10, 2021 6:50 pm

Hey cool, it works. I'll have to try to knock up a test tool.

Maybe at least this would be a good way to start a thread good and vertical , cut half the depth and then finish by hand with a proper tap.
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JoshM
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Re: thread milling?

Postby JoshM » Sat Jul 10, 2021 9:55 pm

I just got a newsletter the other day and learned that thread forming tools move but do not cut metal. The threads are stronger because of this, and there are no chips generated.
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sliptonic
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Re: thread milling?

Postby sliptonic » Sat Jul 10, 2021 10:09 pm

Hmm. That doesn't sound right.

A tap or die is a manual thread forming tool and it produces chips. Here's a video of a threadmill in action and it's producing chips. Not a lot, but definitely producing chips.

https://youtu.be/ggo24jmlpWA?t=390
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JoshM
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Re: thread milling?

Postby JoshM » Sat Jul 10, 2021 10:32 pm

Hey Brad. It’s weird to me too. Here’s the link. Am I conflating two different tools?

https://www.harveyperformance.com/in-th ... tterJune21
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sliptonic
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Re: thread milling?

Postby sliptonic » Sat Jul 10, 2021 11:14 pm

It looks there's a specific class of threading tools that do this forming vs cutting action. Conventional taps and other tools have flutes and produce chips. these don't but can only be used on certain materials. Definitely a very different tool from a thread mill.

Interesting stuff. Today I learned.
GeneFC
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Re: thread milling?

Postby GeneFC » Sat Jul 10, 2021 11:33 pm

JoshM wrote: Sat Jul 10, 2021 9:55 pm I just got a newsletter the other day and learned that thread forming tools move but do not cut metal. The threads are stronger because of this, and there are no chips generated.
I have been using those for several years. For CAM purposes they are just ordinary taps. Not at all the same as thread milling.

I do not have the capability for rigid tapping, so they are used manually.

Gene
bmsaus4ax
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Re: thread milling?

Postby bmsaus4ax » Sun Jul 11, 2021 12:31 am

sliptonic wrote: Sat Jul 10, 2021 3:01 pm
bmsaus4ax wrote: Sat Jul 10, 2021 11:30 am

You want to use the existing threadmill .ui file but with your own macro code?
Yes that was the intention, to learn how the whole process works.
Yes, it's possible. The .ui file contains no logic of its own so you can just load it and get a reference and then do anything you want with it.
I was looking to add the external selection option rather than rebuild the .ui ( the panels directory not being available in a pre-built version)
Look closer at the PathThreadMillingGui.py file for how the controls are set up and responded to.

That said, I agree with freman. Getting a local build set up isn't too difficult.
I think the object obj.___ properties are my snag at the moment, still learning how to navigate Python and the FreeCAD environment.
Not knowing what amongst the vast number of things I don't know, is the thing I NEED to know, is a big hurdle at present.
Is there a really simple operation within Path ( as far as the .ui and ..GUI.py interoperation are concerned ) that I can study as an example?

I need to upgrade my system to do local builds; for the one successful one I did, I could not get OCL to integrate. I know I don't need it for threading but I have been just sticking to the Appimage.
bmsaus4ax
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Re: thread milling?

Postby bmsaus4ax » Sun Jul 11, 2021 12:45 am

freman wrote: Sat Jul 10, 2021 6:50 pm Hey cool, it works. I'll have to try to knock up a test tool.
The cheapest tool is an internal threading bar with an insert.
You need separate internal "IR", and external "ER" inserts for the respective operations.

Or grind up separate internal and external HSS tools if you make your own in a standard boring bar. ( for the helix angle)