pic: 3d printed 1/2 inch hex shaft to arm part
 

Re: pic: 3d printed 1/2 inch hex shaft to arm part
 

Be careful when you put torque on it.

Depending on the type of printer you have the plastic may split around the hex.

Do you have sharp corners around the points of the hex?

Re: pic: 3d printed 1/2 inch hex shaft to arm part
 

What do you mean by sharp corners?

Re: pic: 3d printed 1/2 inch hex shaft to arm part
 

Any corner that isn't radiused.

Re: pic: 3d printed 1/2 inch hex shaft to arm part
 

On the part, I'm not sure. I will soon post an image from INVENTOR PRO.

Re: pic: 3d printed 1/2 inch hex shaft to arm part
 

I would definitely round the base of the hex extrusion to add some strength. Besides that, looks great!

Re: pic: 3d printed 1/2 inch hex shaft to arm part
 

This is a great example of a part that didn't need to be 3D printed. A wide variety of off the shelf hubs combined with a simple plate gusset would do the job much better, with far less risk of failure. Optionally you could broach your own part from solid, but most teams don't have a hex broach.

The hub around the hex should probably be thicker if you keep this plastic.

Re: pic: 3d printed 1/2 inch hex shaft to arm part
 

Yeah, I did do both of those things on a later model, but I don't have the file on my computer for some reason. IDKY.