By Mike Pfeiffer (MARCEE)
Note: Mike did this for us as a demo at a club meeting. It only takes him about 15
minutes to make this conversion and he says a first timer can do it in about 30 minutes.
The Magnetic Mayhem is a great motor for the price, but the bushings are really a weak
point -- I wore out the front bushing after only a few flights in a direct drive
configuration. The bushings do last longer in a gear-drive configuration.
- Obtain Two (2) 1/8" I.D. X 3/8" O.D. bearings (available from Tower Hobbies,
or most hobby stores that handle R/C cars and trucks. Approx. $4-$5 per pair.
- Scribe a line on the end cap and case so that they can be reassembled in the correct
- Use a Dremel tool with a cutoff wheel to cut approx. half-way through the locking tabs
which hold the end cap to the case.
Alternate #1 -- Some have just drilled
1/16" holes in the tabs and used music wire inserted in the hole to bend out the
Alternate #2 - Some have just held the motor firmly and struck the motor
shaft squarely against a piece of wood and have found that the tabs bend themselves out of
- Remove the metal shavings from the case using masking tape.
- Remove the brush springs and pull the brushes out of the holders (no need to remove the
screws holding the brush shunts).
- Use a small screwdriver to pry the tabs up and remove the end cap. Note; there will be
one of two small spacers on the shaft or stuck to the back of the bushing -- do not lose
- Remove the armature from the can -- Watch for spacers on the front shaft also -- see
step # 6.
- Use a vice and the appropriate sized punch to press out the bushings.
- Use a 3/8" diameter dowel or brass tubing to press in the rear bearing.
- Wrap cardboard of similar around the dowel/tubing to center it in the motor can to press
in the front bearing. Mike used a small piece of magic mending tape to hold the bearing to
the dowel to get it started. Once started, he pulled the dowel out and removed the tape
and then using the dowel proceeded to finish pressing in the front bearing.
- Reassemble the motor ensuring that the shaft spacers are in the correct location.
- If the motor or brushes are new, turn the end cap to neutral timing, secure with tape
and run the motor for approx. 15 minutes to break in the brushes.
- Turn the end cap to the factory setting and bend down the locking tabs. Apply a small
amount of CA to the end cap to ensure it does not come loose.
Note: This is also an excellent opportunity to re-time a forward rotation motor for
reverse rotation (the forward rotation motors are usually available from Tower's stock,
but the reverse ones are frequently back ordered). The timing as factory set seems to be
correct for most applications, so I would not recommend changing that.