View Full Version : Motor Efficiency Mod

01-26-2005, 03:42 AM
Ever noticed how big the Epoch motor magnets are compared to the rest of the motor? I started playing around and found that one Epoch magnet will pick up more weight than two stock Mini-Z motor magnets. With more voltage and current like on a slot car track or in a larger car that would be great but the Epoch’s battery and ESC have to really work just to get the motor moving. So how about weaker magnets for your Epoch not stronger.

New Mod Warning: As far as I know nobody else has tried this yet, so don’t rush into it expecting that it will work for everyone, it worked for me and as yet thats all I can say. But if you are not willing to accept the consequences of failure don’t try it until a few more adventurous soles try it and like it first.

Motor Efficiency Mod (Weaker magnets for your Epoch not stronger.)
For smoother operation at the low end and more speed at full throttle try thinning the magnets buy 0.75 to 1.0 millimeters.

Step1: Unsolder the motor leads, and remove the motor.

Step 2: Disassemble the motor. On the side of the motor that does not have the diode use a very small jewelers straight slot screwdriver of knife to pry the frame away from the end cap while pulling that side of the end cap up. Then carefully remove the armature and set it aside.

Note: Before removing the magnets I recommend you use something to mark their positions, since they must go back on exactly as they come off. I simply borrowed some of my wife’s nail polish painting one side of each magnet and a little of the frame a different color.

Step 3: Remove the magnets. Lay the frame and magnets flat on a work surface and insert the edge of a hobby knife between the magnet and frame, then using a small weighted implement such as a pair of pliers strike the back of the knife blade separating the magnet from the frame. Repeat the procedure for the second magnet, and be careful.

Step 4: Sand or file 0.75 to 1.0 mm off of the back of the magnets (red area on diagram).

Note: It is vitally important to keep everything exactly even and level, not only must both magnets be the exact same thickness, but also each side must be exactly the same thickness as it’s opposite.

For me 200 grit wet (the gray stuff) sand paper placed on a level metal surface worked best. I stuck the magnets together and rotated them often making sure each side stayed exactly the same thickness as I sanded, moving the magnets not the sandpaper. Use a damp paper towel to clean the filings off the magnets as you work. Do not hurry take your time. And remember it is better to remove too little than too much.

Step 5: Re-glue the magnets to the frame, in the exact same position and polarity that they were to begin with and reassemble the motor. Your can manually center the magnets but it will work much better if you let the motor center the magnets for you. To do this use a slow drying adhesive such as “Power Poxy” all purpose adhesive, it dries very slowly if you do not press it down too hard. Once the motor is assembled hold it so the shaft points up while powering the motor with 2 AA batteries the opposing magnetic fields will center the magnets exactly. This will of course require a considerable amount of patience on your part but the end result is well worth the effort.

Step 6: Reinstall the motor, and race.