Reversing a Hacker Style Brushless Motor 20-22L.

Written on November 12, 2009 – 6:54 pm | by bluehash |

The Hacker Style Brushless(20-22L) motor finds a very common use in Quadcopters. Unfortunately the only way to mount the motor on a frame is to reverse the shaft so that the mounting holes can be used for what they were meant for..mounting.

dontenorio69 has a very helpful video on how to do this. The same process is detailed below, but with pictures:

  • The Hacker Style comes with all mounting hardware as well as some spares including an extra circlip, in case yours goes flying when you try to pop it out.
  • First remove the circlip from one end of the shaft. Then loosen the grub screw from the other end. After this, the rotor and armature should separate. There is a tiny washer near the circlip end inside the motor. Keep this safe in case you need it later. Yo will not need it again for the reversal.
    Circlip RemovalSeparate Parts.
  • With a thin ended screwdriver, hammer the shaft out. It will take a few tries to get out.
    Thin ended screwdriver.Shaft Removal.
  • Once the shaft pops out, reverse it and hammer it back in, so that there is enough shaft left for the circlip to clasp on. The following iluustrations will make this clearer.
    Shaft Removed.Shaft Reversed.Shaft Reversed and Inserted.Brushless_Hacker_Style_Outrunner_20-22L_Shaft_Circlip
  • Now it’s time to cut the shaft so that the prop adapter fits easily. The shaft will be too long for the adapter to fit. You can cut it with a Dremel using cut-off discs made specifically for cutting metal.
    Shaft Too Long For The Prop Adapter To Fit.Dremel Cut Off Wheel Used To Cut The Shaft.
  • Before cutting the shift, remember to tape off the motor holes to prevent any metal shavings to go inside the motor. The simplest way is to make a mask from scotch tape.
    Motor Mask Using Scotch Tape.Cut Off Shaft.
  • Fully assembled motor with 10×4.7 APC prop.
    Motor Shaft Reversal Complete.

Related Posts

11 Responses to “Reversing a Hacker Style Brushless Motor 20-22L.”

  1. Anurag says:

    surely it was a useful stuff,especially for quadcopter enthusiasts(cause mounting a motor is real challenging task for them)…..

  2. luc says:

    I just got my motors in, but why not just cut the axle on the bottom end ?
    Mine have a piece sticking out the bottom, like in your pictures. Top end is OK for mounting the prop.
    So I was just thinking, why not change anything, and just cut the bottom part with a dremel disc?
    Thanks for the very clear instructions


  3. bluehash says:

    Luc, that is a good idea! Wonder why I never thought about that.
    Were you able to build what you were going for?

  4. RocketRay says:

    All very Good but i cant get that funny circlip(C-Clip) on whatever i do, tell us how to get it both off and on cuz i cant do it GRRR

    • bluehash says:

      I used a nose plier. To put it back on, align the cir-clip on the groove and press it in with the nose plier. Home this helps.

  5. jordicamu says:

    Great tutorial. By chnace, any of you have any idea where to find the bearings for this motor?
    I have six motors waiting for them.
    Thank you in advance

  6. Paul says:

    I don’t think it’s advisable to hammer a shaft in to the motor, there’s a good chance that the shaft may bend slightly. It needs to be pressed into position in a manner which ensures that the motor and shaft stay in alignment and the force being applied to the shaft is in line with the shaft. I use a drill press.

  7. Paul says:

    I forgot to mention that the other reason to use a drill press or something similar is that the force being applied needs to be no greater that that required to start the shaft moving into the motor where as striking with a hammer applies a much greater pulse of force than necessary over a much shorter time period. You could also use a vice to press a shaft into a motor.

    • bluehash says:

      Hi Paul, Thanks for your comments. You are absolutely right as not having to hammer the shaft out, but I did not have anything close to a drill press at my disposal. Thanks for the tip. I’ll keep this in mind the next time I dos such a thing.


Welcome to my place on the web. I note down anything interesting most of them relating to my experiences, Tech, To-dos, How-tos and various hacks. Most of my time is spent in tinkering around with hardware, building robots and working with DSPs.More

Want to subscribe?

 Subscribe in a reader Or, subscribe via Email

Add to Technorati Favorites
Find entries :