How to model a screw-thread?

Steen_Winther

I want to model a screw-thread and am looking for sweep with revolve (a la SW) or maybe a helix, but I can't seem to find a way. Any suggestions?

rajendra_bhat

yes.. those are not available. hope onshape is getting them soon.

john_mceleney

Steen,

Are you actually trying to model the actual thread (helix) or are you looking for cosmetic threads? In case as Rajendra commented, this will be done in the future.

John

Ed_Danzer

Usually helix threads burn resources so I have always used a revolve for threads in SolidWorks and have never had a problem in manuals with people not knowing a threaded fastener. For large assemblies 1,000 + parts I have a configuration with the thread revolve suppressed.

rajendra_bhat

yes.. those are not available. hope onshape is getting them soon.

john_mceleney

Steen,

Are you actually trying to model the actual thread (helix) or are you looking for cosmetic threads? In case as Rajendra commented, this will be done in the future.

John

Steen_Winther

Yes John, I want to model the actual thread and also spiral springs and similar geometries. Hard to find a mechanical product without a spiral spring...
Cheers

Ed_Danzer

Usually helix threads burn resources so I have always used a revolve for threads in SolidWorks and have never had a problem in manuals with people not knowing a threaded fastener. For large assemblies 1,000 + parts I have a configuration with the thread revolve suppressed.

Steen_Winther

Hi Ed, I agree that a cosmetic thread with revolves looks good enough for most purposes, but I really need to be able to model a spiral spring. Can't use a line of rings as a substitute...

Ed_Danzer

I agree springs have to be modeled correctly and in some cases so do threads. We have several products with tapered threads, variable pitch threads and springs. Springs need to have different configurations for installed length and fully compressed in the assembly length.

kevin_quigley

Helix is critical. Moulded threads are in every product we do. We need to model them so we can 3D print them. Personally I'd prefer to see something like what Fusion360 does. SolidWorks is definitely not the standard bearer for modelled threads. FYI in Fusion I can import a SolidWorks file with a cosmetic thread and Fusion models it! Seriously impressive stuff.

FYI the best automatic thread generator I have used is on VX (or now called ZWSoft 3D).

Draw a thread profile. Choose the thread tool. Select the surface to add the thread to, choose the profile, set pitch, turns, etc, select lead in and out, root radii etc. bam. Done. Lets use that as the standard bearer.

len_1962

and with additive manufacturing threads must be modeled for printing.

Steen_Winther

Just wanted to let everybody know that I have finally figured out a way of modelling a spring using only Onshape. It's not particularly user friendly - or fast - but it's feasible. Take a look at how I made the (missing) spring in my carburetor for the Veco .19
The model is here: https://cad.onshape.com/documents/ce24e0cbec8e45c89735d148/w/c1c671cc5fc64bd69adef18e/e/d0a4b77fc2c6452db20a1c10

lougallo

@Steen_Winther Yes. I did this as a dynamic spring. More of a trick since this is not how spring are made but looks good for a demo. Here is a shot of it. I will see if I can rebuild or import in my model and share it.



I then hid the shaft and supports. It can get wonky pretty quick as well but visually looks good in small displacements.