I'm very close to completion,

I’m very close to completion, but I can’t seem to figure out how to connect my z motors to the threaded shafts. These are all of the parts I have left. the coupler work fine for the threaded shaft, but they do not clamp to the motors. I also don’t see any mention on what the middle 4 pieces are for.

The right three parts are for endstops. The left four parts are your z-couplers. IIRC you need to place a piece of silicone hose around either your threaded rod or your motor shafts and then clamp these over them.

Typically, you have use a tightfitting vinyl (or similar) tubing that covers the stepper motor shafts to provide grip/traction for the z couplers. Are the middle pieces some sort of Z axis stabilizers?

What 3D printer are you building?

It’s a Mendel Prusa i2. I guess it’s time to find some heatshrink

I have a PrintrBot but it’s the same idea.

http://www.thingiverse.com/thing:9622 Similar idea. Make sure it’s a tight fit for the heatshrink AND the couplers when you barely torque down the coupler screws (don’t crack your couplers!).

The middle pieces are the belt clamp(s) for the y-axis if i remember correctly.

looks like you may need a couple of sizes of vinyl tubing from the hardware store. the larger size will go over the m8 rod (or the rod can screw into it) and the same piece can also fit onto the motor shaft if you push the smaller vinyl tubing into the larger

The middle pieces are nut holders for the belt clamps, not really necessary. I dropped belt clamps all together and use zipties to fasten and tighten the belts.

the four pieces are on the far left are your z couplers

Just an FYI in case you do, as Jason warns, crack your couplers; a number of people here and on the various forums recommend aquarium tubing - not as a fitting aid, but as a full-on replacement for the z-couplers. So if you do lose one or both to cracking, you may be able to get going with tubing alone.

Personally, I haven’t tried it - I had issues with my printed parts due to over-tightening (I thought it was not gripping, but the z-motor not turning turned out to be badly crimped wires), though I was able to make it work even then. It made my prints very wavy though, and I ended up getting some aluminum z-couplers that have a built in spring cut into them. They are working pretty well, but I’ve kept the aquarium tubing in mind as a backup in case of problems.

thanks for the comments. z couplers are mounted and I am on to electronics!