Parts that screw together

[Anonymous]

I created a threaded hole (1/2"-13 UNC) and a threaded insert, using the Hole and Thread commands.  But when I 3D printed them, I got two smooth objects, no threads.  How do I create threaded parts that 3D print as threaded parts?

     joe

[Mark.Lancaster · Accepted solution]

@Anonymous

First you have to understand that Inventor is not actually making threads.  Its just a representation..  Actual modeled threads can impact your Inventor performance.   So you need to model them yourself or use the CoolOrange Thread Modeler.  In addition when 3D printing threads, you need to make adjustments so the male/female threads work together..

[Anonymous]

Thanks.  Performance is a non-issue.  I have two simple parts that need to screw together.  I will google for coolorange thread modeler.  I am using Inventor 2015.  I can model the threads on a bolt-and-nut model so I only have two small parts to print to get the parameters right, then use those parameters on my actual part.

[mslosar]

You may want to do a search here on 3D threads as a couple of people have explained how to do it properly.

Coolorange made great threads PDQ for me. However, they're not optimized for 3D printing. The created threads seemed to be flush so that threading them together just wouldn't work.

I've been using this: 

http://theoreticalmachinist.com/Threads_UnifiedImperial.aspx

and this:

http://www.practicalmachinist.com/vb/attachments/f38/124994-what-percentage-screw-threads-p1.jpg

to make threads based on the method i found in this forum: https://knowledge.autodesk.com/support/inventor-products/getting-started/caas/screencast/Main/Detail...

THough I don't recall the post it came from.

[swalton]

If you are mating two printed parts, you might look at using a different thread profile, like a ACME thread.  See https://www.stratasysdirect.com/resources/fused-deposition-modeling/

If you must use a UN thread profile to match conventional parts, consider running a tap/die over the printed thread to clean up any printing "issues".

[Anonymous]

Thank you.  That was an almost-perfect tutorial.  The problem was putting a head on the bolt, and requiring that the nut tighten up all the way to the top (that's not what I'm building, but it is a suitable explanation)  Everything that caused the thread to go up to the thread caused it to cut into the head, I solved this by adding a new drawing to the underside of the head, which had a circle centered on the shaft of the bolt.  I then extruded the coil into the head, then extruding the circle into the head.  It worked.  I could have solved this by not extruding the head until I had cut the thread, but the "head" (which isn't actually the head of a bolt, but an artifact that mates with a fixed-feature "nut") was extruded from the object that mates with the "base" of the project.

It also didn't cover how to make the matching "nut".  I think I worked that out but I won't have a chance to print that part until tomorrow.  Would there have been a good way to build an assembly that would simulated screwing the two parts together?

Anyway, thanks everyone.  The goal was to create a spool that helps keep 1/4" copper tape from uncoiling in an unseemly manner. https://www.adafruit.com/product/1128.  

joe

[mbystry]

There is a cheaters way for the lazy too. From time to time (more so for 3D printed parts) I'll download the male and female fasteners from McMaster-Carr and modify them into the parts I need/want. The threads are perfect every time...and I didn't have to model them from scratch or use the Thread Modeler add-on.

[DrStein99]

I agree it's also a good practice to use actual metal fasteners - if your going to consider the practice of designing professional assemblies eventually.  A 3d printed screw, nut, bolt, washer just sounds wrong.