Thread Maker v4.1

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KurtF
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Re: Thread Maker v4

Post by KurtF »

Well I'll be. I just confirmed this; ThreadMaker4 isn't compatible (is potato) with the release version 0.19 FC. Apparently, FC19 doesn't like one of my sketches being 4 mm (or any non-0 distance) off the deck. FC20 handles it with no problem.

So, Greentree, if you can get by without tapered threads, here is the prior version, which is based on good old-fashioned CSG cylinders, instead of a loft between 2 sketches. The V1 ThreadMaker was done on FC19, so I expect V3.1 will do fine unless/until you update FC.
ThreadMaker3.1.FCStd
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greentree
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Re: Thread Maker v4

Post by greentree »

Kurtf, thanks for your quick reply and for investigating!

For this application, I specifically interested in NPT threads. Useful for many things, in this case mounting microcontrollers and sensors in cheap PVC environmental housings.

I will install FC 0.2 and it sounds like that will fix the problem.

I'll let you know my experience.

Thanks again!
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KurtF
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Re: Thread Maker v4

Post by KurtF »

greentree wrote: Sun May 01, 2022 1:28 pm I will install FC 0.2 and it sounds like that will fix the problem.
Ok, hang on. Fixing TM4 in FC19 is easier than I thought. I was just playing with it when you posted. You don't have to upgrade your FC (unless you want to anyway). To fix TM4 in FC19:

1) Dbl-click the additive loft in the Ext Bevel Base body. This launches loft task panel.
2) Click the Add Section button (task panel).
3) Click Model Tab to get to Tree View, then click on the sketch Sketch001R2.

Ale-poof! It's fixed. Close task panel and to the same steps to Int Bevel Base (SketchIntR2).

This is still strange though... I Open V4 in FC20, and both sketches are under the additive loft, just as I left them. Open in FC19, and one of those sketches "jumps out" of the loft feature, causing it to fail. But after I put the sketch back under the loft in FC19, and save it/re-open it... no more jumping sketch problem (no is potato!).

Ah. Morning coffee's kicking in. All I have to do to fix the source is apply the fix here and save it in FC19, then re-post it. No new version required (nothing actually changes that I can see in the FC doc for this). Yay.

Ugh. Further testing shows that the prior TM versions don't load correctly in V19 either. I saw errors about Part::PrismExtension extension not found, plus it took a couple of minutes to "Import project files...". No doubt v19 is choking on v20 file format. Sorry to say, you'll need to upgrade FC to 20 after all, for TM with NPT. Potato soup.
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KurtF
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Re: Thread Maker v4

Post by KurtF »

FreeCAD v0.19 compatability has been restored, Captain. See the top post for details and version 4.1.

However, the Ext Thread Body still breaks in this one particular version (0.20.27422) when you apply thread taper. But later versions of weekly build seem to work fine. Greentree, if you upgrade your linux from weekly builds, you'll get 28774. Based on 2 prior 20.x builds testing great with tapered threads, I have high confidence that you won't have any trouble. Later on, I'll upgrade myself and check it out. Thanks for the potato report!
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Re: Thread Maker v4.1

Post by greentree »

KurtF, I've been bogged down in other aspects of the project and am just now getting back to this CAD design component.

I've downloaded and done a test run making 3/4" NPT threaded parts (int and ext chamfer) with TM4.1, on the standard ubuntu-issued FH 0.19.

It seems to be working just fine -- hooray!!

I will update when I have more experience with it.

Thanks again for this, it is very useful in my project and I'm sure for many other people!
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KurtF
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Re: Thread Maker v4.1

Post by KurtF »

Good. Glad to hear no is potato.

I need to give you one more update... the spreadsheet notes show the slightly-wrong taper angle for NPT. The correct value is 1.7899 (I had gotten 1.7833 from a typo in Wikipedia).

But even with the slightly wrong angle, I printed a fitting to connect a 120psi oil pump with 1/2" NPT to M18 straight threads. So far, no leaks. :-)
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Re: Thread Maker v4.1

Post by greentree »

Great, I will make that correction. Thanks!

Impressive the printed part works in a high PSI application!
Workshop_Notes
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Re: Thread Maker v4.1

Post by Workshop_Notes »

KurtF wrote: Mon May 16, 2022 4:11 am I need to give you one more update... the spreadsheet notes show the slightly-wrong taper angle for NPT. The correct value is 1.7899 (I had gotten 1.7833 from a typo in Wikipedia).
On the thread taper, instead of a decimal angular value, it might be better to input the diameter reduction per unit length from the thread specification documents and then calculate the angle (e.g. Wiki gives the half angle as arctan(1/32) ).

How easy would it be to extend this to other v-thread profiles? If you were able to add the Whitworth thread form (55 degree included angle and rounded roots and crests), it will allow you to do ISO tapered pipe threads, which use this thread form. ISO pipe threads are just a metricated version of BSP threads (taper is the same as NPT).

Other v-profiles that might be a bonus if the cost of doing them is minimal are 80 degree (for PG threads) and 47.5 degree (for BA threads).
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Re: Thread Maker v4.1

Post by KurtF »

Hello, Workshop.

You caught me in the middle of studying thread standard documents. There's an overload of material, and many overlapping and overarching standards. You also caught me in the middle of writing python code to replace this sketch-driven solution. So to keep the project size manageable, I'm focusing on what I hope are the most commonly used standards for ISO and NPT "thread-users":

ISO 68-1M Profile Standard.
ASME B1.13 Thread Standard, which specifies ISO 68-1 profile.
ASME B1.20.1 Tapered Thread Standard, which also specifies 68-1 profile.

Currently, ThreadMaker generates 68-1M profile with flat root. Macro version will have rounded root checkbox.

Workshop_Notes wrote: Sun May 22, 2022 7:18 am On the thread taper, instead of a decimal angular value, it might be better to input the diameter reduction per unit length from the thread specification documents and then calculate the angle (e.g. Wiki gives the half angle as arctan(1/32) ).
I hadn't thought of that, specify taper ratio instead of taper angle. Is this what thread-using engineer types will find most intuitive? Presently, I handle taper in the dialog box, with 2 buttons (ISO) and (NPT) to pre-populate the taper input box with standard values.

Workshop_Notes wrote: Sun May 22, 2022 7:18 am 80 degree (for PG threads) and 47.5 degree (for BA threads).
What's a PG? And a BA? My macro code is designed to accept plug-in profile routines, as I already have 2 for flat or rounded root. So if there's popular demand and application... it can be done!
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KurtF
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Re: Thread Maker v4.1

Post by KurtF »

Threads by ThreadMaker!

Oil Pump Is Potato.jpg
Oil Pump Is Potato.jpg (531.19 KiB) Viewed 2015 times

This is the 120 psi pump, which failed after about 2 hours of use way beyond it's temperature range (and that of it's warped rubber elements). So my attempt to prolong the life of my transmission with a chemical spray pump failed. It leaked like a sieve, but the threads never leaked. Yay! Sort of.

That bit of oil you see pooled in the motor housing just beneath the spindle was never supposed to be there. Pump seals blew. But to be honest, thread only handled 120 during the first half hour of use. Max pressure degraded down to about 40 psi before I pulled it out and got my first quote on tranny replacement: over $5,000 (not a great prospect for a 20 yr old car).

M14 to NPT0.5 Oil Pump Fitting.FCStd
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