Revolve Feature Problem

I created a M6 screw thread by revolving a triangle around a cylinder. The M6 thread has a 1mm pitch and the core (cylinder) is 5mm. The triangle is 0.5mm high and has a base of 1mm. When I revolve this triangle around the cylinders axis with a axial offset of 1mm the body cannot be created. If I use as base 0.95mm which leaves a 0.1mm gap between the revolved triangles it will work but it is not correct. It appears the point to point or line to line contact with itself with the correct 1mm based prevents the system from creating the body. I attached the model file. M6.shapr (404 KB)

Greetings,

I took you file and made a revolve using your triangle with the 0.95mm base. I made the axial offset 1.90mm and when revolved at 2 revolutions (720°) it does not work. However, using the pencil, one can go beyond the 720° rotation and below, but not at 720°. It looks like an issue to me.

My example addresses your original issue if the base was 1mm with an axial offset of 2mm. Same issue.

-Mike

@JoeSch
Not sure if anything can be gleaned from this, it was created prior to the latest updates, and I would recommend forming Threads 10mm Diameter and then Transform > Scale to the desired size.
10mm converting to 6mm by Scaling to 60%:

https://discourse.shapr3d.com/t/generating-threads/6680

Greetings,

Irrespective of the fact that JoeSch wants to create a metric thread, the issue he points out is with the Revolve tool. I agree that it is an issue. Whether you revolved a triangle or a circle makes no difference.

I agree if one wants to make a custom thread and use Scale that is fine. If one wants a true screw thread then I would download one from McMaster-Carr.

-Mike

Could the issue be a bug? LOL

Best,

Tommy

yes (whispering)

BTW, happy Fathers Day y’all

Hi fellow-shaprs,

@Gelphyn @tommyn - You both know, that the thread-design has been an all-time favorite of me and the team proposed a threading-tool over a year ago…

Nevertheless - the problem is, that the revolved shape isn’t allowed to have overlapping points with itself. The only remedy is to cheat little bit with the measures - a pitch of 1mm will fail, but when entering 1.0001 mm everything’s fine. Or 360deg won’t work, but 360.00001 will…
Just alter the thread measured a tad and in endeffect you’ll get to your wanted thread.

@TigerMike the collection of McMaster-Carr is a great resource for standard-threads in standard sizes - but everything away from the beaten paths calls for a bespoke thread and this is why a threading-tool would come in handy.

Cheers Chris

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Hi Chris,

I agree completely. McMaster-Carr is fine for existing components although given the fact that you can download 3D files, they can be altered and modified to suit a custom application. And yes, a built-in threading tool would be a real plus.

Here’s an example of how I have downloaded and modified gears from McMaster. I can 3D print gears that are 32 pitch or greater. Depending on the size, I would shave the gear tooth profile by a few thousands (in simple terms, copy-rotate-intersect) to compensate for 3D printing tolerances so there is a little backlash on prototype printed parts. There are no serious loads involved, only function.

Regards, Mike

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