Closeup of coil winder showing newly installed nylon bearings.

Changes To The Coil Winder

I added nylon bearings to the motor coupling side of the rotating shafts to reduce shaft wobble.
This will also make the construction of the motor couplings less critical.

Because of the large existing holes in the wood I used nylon spacers around the nylon bearings. I roughed up the nylon surfaces to be glued and used a 5 minute two part epoxy to bond the parts together and then to the plywood.

I put the rotating shafts in place before the epoxy set to make sure the alignment and position of the bearings were correct.

Closeup of bronze motor coupling. Closeup image of coupling side nylon bearing.

In the left image above is one of the new coupling side nylon bearings. To the right is the old setup using the motor coupling to support the rotating shaft.

Closeup of threaded rod aluminum spacer being used as bearing surface.

The spacer for the coupling was locked in place on the threaded rod with a brass pin. Now I am using an aluminum threaded spacer further in on the threaded rod to use it as a bearing surface inside the nylon bearing instead of using it as a spacer inside of the motor coupling.

I wrapped plumbers Teflon tape around the threaded rod than rotated the aluminum spacer over the tape and into position. The Teflon tape helps to center the spacer on the threaded rod and holds the aluminum spacer in place. Some epoxy or other adhesive can also be applied to secure the spacer.

Stepper motors mounted on standoff to accommodate newly added bearings.

With the new bearings I mounted the motors on 1 1/2" standoffs to allow room for the couplings between the motors and the newly added nylon bearings.

I also moved the plywood winder side in by about 1 1/2" to adjust for the new motor mounting so I could continue to use my existing threaded and brass rotating shafts.

The bronze couplings to the right were the latest change I made to the coil winder right before adding the motor coupling side bearings.
These couplings are pretty good but after adding them I realized that adding bearings to the motor side was the way to go as opposed to continuing the try to perfect inexpensive homemade couplings.

The remaining wobble in the rotating shafts is caused by the brass and threaded rods not being straight. Improving the couplings and adding bearings (bushings) to both sides has made this obvious.

Latest version of the Automatic Coil Winder with coupling side bearings added.

Coil Winder Construction Ideas

Use two stationary guides for the moving stage as opposed to one guide and the rotating threaded rod. The guide rail(s) from an old ink jet printer or scanner would probably work well.

With bearings on the coupling side of the rotating shafts, couplings can be made from something as simple as rubber hose, such as automotive or lawn equipment fuel line.

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