Thread Modelling - lead in chamfer

[dannyspitz]

Hi,

I'm trying to model both exterior and interior threads but have an issue with the lead in and out chamfers. if i model the chamfers (60Deg x 0.5mm) on the surface the thread will not extend throught the chamfer to give a useable thread but if i model the thread surface with square edges to the end of teh thread i end up with a sharp edge with no lead in chamfer which is not standard practice and can lead to a razor sharp edge. 

Aany ideas on how to extend the thread "cut" beyond the length of the face as would happen when machining and hence why undercuts are used?

[Anonymous · Accepted solution]

Thanks Mark,

Tried your method but now having issues with adding the chamfer in the
correct distance and angle direction! Getting frustrated with F360 as simple
stuff that¹s been available on 10 year old ³professional² CAD sw isn¹t
available.

Think I¹ll create a cutting part for the mating partsŠ more time wasted!

Regards,

Danny

[HughesTooling]

I've done a couple of tips threads on this, here's the links.

http://forums.autodesk.com/t5/post-your-tips-and-tutorials/chamfer-threaded-rod/td-p/5946660

http://forums.autodesk.com/t5/post-your-tips-and-tutorials/how-to-chamfer-modeled-threaded-holes/td-...

Mark

[PhilProcarioJr]

I have found if you create the chamfer first on the end then add the threads, then drag the chamfer after the thread operation on the timeline it fixes this issue.

Been meaning to bring this up with the devs as really it's a bug but I forgot about it until reading this thread.

[Anonymous]

Phil, Your tip works great on a lead-in end chamfer. Thanks!  However this method fails when I try to apply it on an undercut chamfer.  Please see attached PDF.  Btw, both chamfers were defined the same way. Any tips on how to fix this?  Thanks!

[PhilProcarioJr]

@Anonymous

Like this?

[Anonymous]

@PhilProcarioJr

Yes, That's it almost exactly.  Thanks!  I was modeling a M-F Hex stand-off and I started from the hex body.  You're way is much simpler. Much appreciated.

IMHO though, it seems like Fusion not being able to properly handling a chamfer on the end of a thread (without special tricks) is a bit of a bug.  But then again, I wouldn't be learning so much without having to learn these tricks so it's all good.  Cheers!