Motor Management

Chances are that if you have been in this hobby for a while you have gained a collection of parts. Especially motors. Good chance you also have some that look almost identicle, but have different specs. So how do you tell the differance?

Here we have 3 motors that all look the same, except for the one on the end I modified the mount on to make it lighter, just ignore that part. These are all AX 1806n motors. What if I told you that each motor was different? How can you tell what their Kv rating is when there is no makings on the motor? Some come with stickers on them, but stickers fall off. Then what? What if there was some system to keep that information on the motor without sickers or other markings that could be damaged in a crash or banged up in storage?

There is. For any of you who have played with electronics, good chance you've played with resistors. Resistors use a color system to mark their rating. Most use a 4 band system, some use 5. Both systems use the same color to number system, and end in a metalic color. The first 2 bands are just numbers, the 3rd is the "Multiplier", or how many zeros to add. The last band is tolerance, or how close the rateing of the resister is to its marking. Lets apply this system to our 3 motors with a bit of colored heat shrink.

So what do these colors mean? The motor on the left we have Red, Brown, Red, Motor (I am useing the motor as the last band to know what way to read the code). So if we go back to our little chart and add the numbers to the colors we get 2, 1, 00. So that means the first motor is 2100kv. We do the same for the second motor and we get 2500kv, and the third is 2900kv.

Here we have a KEDA 2730 motor. acording to the color code, its a 3000Kv motor (Orange = 3, Black = 0, Red = 2 0's). Now this is all well and good for motors rated with 100kv incroments, but what about some of the motors that have more "accurate" ratings?

Here we have a C20 motor with 4 color bands. Now I mentioned that some resistors use a 5 band system. So here we have "5" bands (motor being the last band). Red, Black, Green, Black, Motor. Going back to our chart we get 2, 0, 5, 0. So this is a 2050kv motor.

What about slower speed motors? Same thing. Lets say you have a 750kv motor? You would need to use Purpler, Green, Brown, Motor. 930kv? White, Orange, Brown, Motor.

Where to get these multi colored heat shrinks? It can be hard to find some colors of heat shrink. The material I am useing is made by a company called Ico-Rally. They sell their heat shrink in packs of a given size in 6" lengths and each pack has alsmot every color of the rainbow in them. You may find it at a local electronics store or simply do a search online for ICO-Rally.

If you wish to not bother with the color code system, there is the option of tracking down heatshrink with numbers printed on them. These can be a bit harder to find, but some aftermarket can part companies make number heat shrink for marking spark plug wires. The issue here is the size of the heat shrink. There is a nice little kit made by a company called Context Engeineering and they sell a kit with all different sizes of numbered heat shrink. Part #TT74902.

I hope this helps you guys keep you motors organized. This should be really good for you multi-rotor guys. Have fun.