View Full Version : Multiplex Permax 400 6 volt with 3 series LiPo?

09-30-2005, 04:42 PM
I'm assembling a Easy Glider that comes with a basic speed 400 brushed motor. Multiplex says they will have a brushless drop in replacement in November. I intend to buy it and use 3 series LiPo with it. How long do you think the stock motor will last on 3 series LiPo?
If I understand what I'm going to do I will get more power but shortened life. If I get 10 flight before November that will be good enough.
I do have a 2 series I could use but I've read somewhere that it would be under powered. Whats your experience with this motor on 2 series, 3 series?
:) Poof, Arc, Burn, Smoke, Flys good! :D

09-30-2005, 04:51 PM
It will be fine BUT....and it is a big but.....

You must prop down, or it will cook in short order. Prop it for 9amps and you should be OK. Since it is a glider you might want to gear it...


09-30-2005, 04:59 PM
It's geared already. I should have mentioned that. 3.3:1 I think. Folding prop with no markings on it. One blade is 4.5 inches from hub to tip. I wonder if the drop in replacement brushless Will use a different prop or be geared?

09-30-2005, 05:02 PM
Do you have a meter? You have a 9" prop, so I would try an 8x4 or 8x6 and see if you are around 9amps. You might be able to get away with a low pitch (fine for sailplane) 9", but you need to measure actually amps or you might cook it..

Remember that these motors are mass manufactured and cost about .$50 each to make some live a long life, but others die quickly. I feel good when I get 100-150 flights out of a s400 motor.


09-30-2005, 05:34 PM
I have a Watts-Up meter. I will measure it but the prop looks like something Multiplex came up with. I don't think the usual folding props from other vendors like Graupner or AeroNaut will attach to the hub. I guess I could get a new hub but I'll be changing the whole power system in November. I think I'll just run it till it burns. Hopefully I'll be around 9 amps. Will throttle management help?

09-30-2005, 05:46 PM
Hopefully I'll be around 9 amps.
It won't be!
Will throttle management help?
Yes it will, but I would grab another hub and use a smaller prop.

Since you have the meter just measure and see what you get....