Contra Rotating CR50L Brushless Outrunner Motor inc Radial Motor Mount

• Overall
• Quality
• Value

Customer Rated

Jan 13, 2012

I finally got around to finishing the prop setup and got the rear bell to run a little more true. While the rear bell still does not run completely true, after about 1/8 throttle it runs smooth as silk. Please refer to my first review and my thread on RCG for what I believe to be the things that need to be done so that this motor can be run safely.



My setup for this motor is two Super Simple 100A ESC's and Zippy 25c 5000mah 6s batteries. The SS ESC's have always been reliable for the price for me and that is why I used them. Here are the numbers under load after 15 seconds WOT.



23 volts

65 amps

~3kW total power



I don't have thrust numbers but once the plane is on her feet I will get some and post them. So far it is looking good for the money; you just have to be willing to put a little time and effort in to the motor. Either way, it is a decent alternative to the only other motor of this type and size available that is more than 3x the money.

• Overall
• Quality
• Value

Customer Rated

Nov 15, 2011

I ordered this motor to go in an ESM Spitfire. I think the contra-prop spitfires are some of the nicest looking planes around, and with this motor it was finally doable for a decent price. The only other CR motor of this size is three times as expensive.



My first impressions of this motor were not very good. It looked good coming out of the bag but when I went to turn the rear bell the magnets were rubbing against the stators. That was honestly the only thing wrong with the motor that I could see other than there was no glue in between the magnets. I have heard of many HK motors throwing magnets so that needed to be rectified as well.



To fix the rubbing I simply took some wet/dry sandpaper and sanded the stators by hand until the magnets did not rub. This honestly only took about an hour of work. Fixing the magnets took a little more time but was not too difficult. I simply filled each gap with JB Weld.



The last thing I did was change the bearings and added a thrust bearing similar to the ones used on helicopters so the bearing on the front bell was not taking any axial force. I also made a new shaft out of 6mm tool steel but only because I wanted to use a collet adaptor for the front. There is nothing wrong with the original shaft, it was just too short.



I have not done a full run-up yet but I did post a video in the video tab of a short test I did the ot