Threading a shaft

Mark_Wrathall

I see there has been some discussion about cosmetic threading, but I am only interested in a normal drawing representation of a shaft thread on a normal production drawing. I have a university assignment to prooduce a drawing of a spindle shaft, and can't see a way to create the thread on the shaft unless I draw each line into the drawing.

Is it not possible to assign a thread to a shaft in the model, and have this automatically draw the root diameter lines per ISO 6410?
https://ww3.cad.de/foren/ubb/uploads/AndreySCA/Gewinde.jpg

Jake_Rosenfeld

@Mark_Wrathall I actually think I misread your post. You're looking for thread indications on the shaft, not the hole. Correct?

If this is the case, we don't currently have a way to do this, but you could use the thread creator to create actual threads on your shaft:
https://cad.onshape.com/documents/6b640a407d78066bd5e41c7a/w/4693805578a72f40ebfb4ea3/e/f8aea9e5c33e02eab0854a4f

Please raise an improvement request from the "Improvement request" section of this forum so that we can prioritize work of thread indicators on shafts.

Jake_Rosenfeld

@Mark_Wrathall

Are you using the "Hole" feature to create your holes? Does this not provide what you need?

https://cad.onshape.com/documents/45a627679c685e7736438b6f/w/a8b3eed233d3b0ff316441ca/e/0c4508ad82e0e9912e20df13
https://cad.onshape.com/help/Content/hole.htm

Jake_Rosenfeld

@Mark_Wrathall I actually think I misread your post. You're looking for thread indications on the shaft, not the hole. Correct?

If this is the case, we don't currently have a way to do this, but you could use the thread creator to create actual threads on your shaft:
https://cad.onshape.com/documents/6b640a407d78066bd5e41c7a/w/4693805578a72f40ebfb4ea3/e/f8aea9e5c33e02eab0854a4f

Please raise an improvement request from the "Improvement request" section of this forum so that we can prioritize work of thread indicators on shafts.

Mark_Wrathall

Thanks Jake. Correct, it is a shaft, not a hole. A pictorial thread doesn't help,as it is for a Uni assignment, and compliance with ISO drawing standards is a criteria it will be marked on.

Mark_Wrathall

I raised an improvment request.

david_fisher985

I have a similar kick, only my request to show the threading on the shaft comes from my manager. I appreciate that I can create an actual thread using the helical sweep, but engineering groups tend to be conservative about this. I once saw a drafter take a lambasting for illustrating a beautifully rendered sagging chain on a pipe cap.  It was regarded as a showy waste of time.  The same goes for perfectly pictorial threads.  The convention is to have the major thread diameter shown as an object line and the minor diameter shown in fine dashed (or Phantom) lines.  The effect is much like the one already provided on the hole callout in plan view.  The actual representation of the minor thread need not be a scaled distance from the major thread, but
pictorially spaced about .03" (on paper) away parallel to the major diameter.

ALSO, while a centerline IS provided as a tool in the drafting system, a phantom line IS NOT. The phantom line is an essential tool for providing a sense of adjacent geometry without confusing it with the principal part the design.

ifan_lappage537

This feature would be perfect for education too, even if you could draw an arc in the drawing to represent the thread on the end view.
Preferably just be able to click a shaft in the part studio and assign it a thread (not rendered in 3D) that would produce the correct 2D representation in a drawing

TillysInteriors

@Jake_Rosenfeld Please could we get an official update on thread drawings like @david_fisher985 shows above?

I'd like a threaded rod in a drawing without the cosmetic thread representation.

nick_papageorge073

In 20 some years of engineering, I can probably count on one hand how many times I’ve seen the actual thread drawn on a part and shown in a drawing. It’s almost never done. We’ve even made custom screws and not drawn the thread. Just call it out with a note. 

Jake_Rosenfeld

@Clive_Reynolds

I don't have any update for you, but sending in a support ticket requesting the behavior will help us to prioritize the work. 

Ste_Wilson

@Jake_Rosenfeld
To be fair its a 190 vote feature request hanging on from 2017...
https://forum.onshape.com/discussion/6857/external-cosmetic-thread#latest

Hfrossard

nick_papageorge073 said:

In 20 some years of engineering, I can probably count on one hand how many times I’ve seen the actual thread drawn on a part and shown in a drawing. It’s almost never done. We’ve even made custom screws and not drawn the thread. Just call it out with a note. 

I guess it depends on the industry. 
In 10 yeatrs of engineering, I've seen it countless times.

andy_nias

How many votes are needed to get this shifted? I've never seen an actual thread drawn out on a drawing as it would be very confusing, that's why there are standard drawing symbols. I don't sketch an actual toilet/shower/sink/radiator/window when I'm doing a floor plan. Every other piece of CAD software I've used has this capacity so it would be really useful for onshape to add this feature. Threaded holes in onshape aren't shown with the actual thread so it's clearly possible...
I have a ready supply of people to vote for it if that will make a difference. I'm fed up with fudging drawings by adding sketches.

S1mon

Schematic external threads were added recently https://forum.onshape.com/discussion/19404/improvements-to-onshape-november-1st-2022/p1

There are FeatureScripts to create actual thread geometry for those of us who like to see that. 

https://forum.onshape.com/discussion/4867/new-featurescript-thread-creator/p1

Mark_Wrathall

Thanks for getting to that request. Lucky I didn't wait till now to hand in that assignment
While the thread undercut is a good start, there are norms for those as well, as if you are doing this to prevent the stress concentration, you will probably use one of the DIN 509 options.
Mark