Converting the Magnetic Mayhem Motor to Ball Bearings
By Mike Pfeiffer (MARCEE)
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 orientation.
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 tabs.
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 the way.
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 these!
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.