I've been messing around with a 48" I beamer electric (with a planform based on a shrunken Imitation), and I'd been having problems with line tension, I figured I'd been flying to slow.

I originally had a 10x5R on there and it was ok line tension but it was slow and I wanted more. Being relatively skint at the moment I didn't want to shell out for a new motor, so swapped the prop to a 10x7(normal) and the line tension dropped away even further!

The addition of a new motor (same can size but an increase from 900kv to 1200kv) I went back to the 10x5R and she was fairly singing along.

Just goes to show, a high PRM, low pitch setup is really the only way to go.  Considerng the price of a new motor was around $29 AUD, and a prop is half that, there's a lot to be said for getting a motor to swing the prop at the speed you want, rather than trying to get the motor you have to work.

As much as this is probably re-inventing the wheel, hopefully this may stop someone else from going down the path that I did.

John, I actually was using a 4s pack!

Sometimes I think I'm too smart (or dumb depending on how you look at it) for my own good.

I'd seen that RSM had been supplying NTM 32-36A motors as a .35 replacement. AS it happened I had one of these lying dormant in one of my drawers and decided to build a plane around it. The 35-36A comes in different KV ratings and now in hindsight, I think RSM was probably selling one with more kv's than the one I had (900).

At any rate, it was a learning curve and the 35-36A now resides in a powered sailplane so all is not lost!

As Andy said he did the testing for me on the NTM motor. After a lot of flights we decided not to continue to offer that motor. It had nothing to do with the actual performance of the individual motor. The decision was based upon the variations in quality we found within the same motor from NTM.

Remember, we wanted to use a 3 cell battery coupled with a 11X 5.5 prop with this size of model so we had to be able to obtain the same performance when we sent out a power system. Some of the NTM motors would work great and some motors simply would not work consistently. For that reason we looked for and found a much better motor where we did not experience the inconsistencies due to manufacturing tolerances in the motor.

That is why we no longer supply the NTM 3536 motor in our .35-.40 (glow equivalent) power systems. Please do not take any of the comments above as a suggestion that the NTM motor is not good. If you are fortunate enough to obtain one of these that meets the specifications then you will have a very decent motor for your ECL system. If you experience what we did when you purchase a number of these NTM 3536 motors you will just have to take your chances.


I hope that this is of assistance.

Eric Rule