Quote Originally Posted by uncle_bob View Post
The adapter / coupler that attaches the Acme rod to the stepper ( = collar on the bottom?) is the main problem with this approach. If it does not line up the center of the motor shaft with the center of the threaded rod, you are right back to troubles. That is where getting an integrated stepper / rod really shines (there is no possibility of offset). Depending on where you buy the parts, it may actually be just about as cheap. It gets the couplers out of a very crowded part of the printer andmakes the conversion easier.
I contemplated using integrated stepper motors with the 8mm acme thread. However, I couldn't find a company that sold them in the proper length for a decent price. After searching for a few weeks, I thought about the assembly of the integrated stepper/acme thread and realized the mounting for the motor would need to be modified. If you recall you first install the motor bracket getting it straight and in the proper place. You then have to tilt the motor in just the right way to slide it up and into position.

Using a integrated motor/thread system wouldn't work in this manner. To do this, I have two options, the first would be to CNC out one side of the aluminum bracket, so I can slide the motor and threaded rod in easily. The other option would be to print a bracket that can warp over time.

So I decided to go the easy route and use the flexible collars. However, I have plans to install the following couplers: https://www.amazon.com/Wangdd22-Coup...o+8mm+coupling

This will make the Z Axis nearly as rigid as the integrated motor/thread, while making it easy to install.

I will put my files up on Thingiverse sometime soon for those who want them. They are only a prototype and I plan on changing things are time progresses.