This is the part in question:
http://www.mcmaster.com/#catalog/115/1157/=uvbih
The 1/4 to 3/4" spider coupler that I was going to use to attach my steppers to the threaded rod.
Now the 3/4" end comes keyed and works fine, but the 1/4" does not.
My question is, should I just look to find couplers that ARE keyed, or would it be possible to hunt down some tool to key these pieces myself. I have absolutely no practical experience in this field.
Thanks for your help guys.