Printing threads with Cura and Inventor

[stevekerikeri 1]

Hi.

I am having real problems getting threaded components to print on the Ultimaker 2 using Inventor as the CAD package to draw designs. Has anyone encountered the same problem. I am not an expert so it could be something really simple.

Thanks

Steve.

[neotko 1,417]

Maybe this can give you a starting point

https://ultimaker.com/en/community/19093-any-idiots-guides-to-modelling-threads

[owen 19]

What's the actual problem? Creating the thread, printing or getting them to screw together?

[stevekerikeri 1]

Hi. We seem to have found the cause of the problem. In Inventor it will model a thread really easily in a 3D design but when you output it it does not work. You have to go back to the old long way of drawing a spiral along with the shape of the thread and combine the two to form a 3D thread. It quick way of doing it is just for design purposes. It will show up on designs and drawings but does not print out as a thread. This is a real shame as this was the main reason we chose to use Inventor as it was simpler for kids at the school to use. Seems there is not an easy answer.

[Cadmonkey3D 0]

Hi,  I can create threads in Fusion and 3d print the parts good using Cura with our Ulitmaker 5s.  When I use Inventor to create the threads and convert it to a .STL file then use the Cura with our Ultimaker 5s,  the threads come out wrong.  I have included a pic.  You can see the shadows of the 2 orange pieces show the threads leaning to the left and not like the top sample straight up and down.

Is this a problem with .STL converter in Inventor?

 

[danielkrice 4]

Assuming Inventor works the same way as Fusion, make sure 'modelled' is ticked when creating the thread, otherwise it doesn't get exported as a thread when saving as a .STL

[geert_2 557]

I guess by "the thread leaning to the left" you mean that it is asymmetrical, like a sawtooth instead of a symmetrical triangle?

 

If this model is printed standing upright, maybe this could be caused by the edges of the overhangs curling up?

 

Some materials have a tendency to curl up on overhangs, due to the shrinking while cooling. Since a steep overhang is printed largely in the air, there is nothing to keep it down. See the photos below. Sometimes printing in very thin layers and as cool as possible might help. Sometimes thicker layers work better.

 

Sometimes the curling up can be so bad that the nozzle bangs hard into the model, and damages it or knocks it off the bed. See the test prints below, which I designed for testing these limitations.