Quote:
Originally Posted by Finnster
Here is your setup as I understand it right?
Give or take a few mph for tire size, you are at a 22:1 FDR. That's really really low if I've got the gears right. Proper gear should be 15-17:1 I would say. I had my 1100kv on 8S geared 13:1 before and was faster than 40mph on 28K rpms in a Revo (w/ smaller tires of course.) This is a 60mph setup, not a 40.
The reason the motor heated up so much was b/c of the low gear. Efficiency is quite low w/ low motor loads, plus the rpms and voltage will be higher than what is listed. This is evidenced by the 160F motor temp at 5F ambient. Inside that little furnace the magnet was prolly 200F+.
Now as far as Medusa's specs, they also list the motor as 1100W. Your setup will easily pull twice that (say 120A at 21V+2500W.) Remember these are plane motors. You can do high rpms in a fast moving plane that draws a fairly steady amount of power. Not the peaky power cars do. 2500W->300W---> 2300W--->brake-->2500W--100W, etc all in a few secs. Now a medusa can prolly handle it, but everything else needs to be setup just right as well or its asking for trouble.
IDK and don't care what TRX lists for gearing. The above is true. Now the inside gets very hot, high rpms...boom goes the magnet. You can see it came right off the shaft. Now maybe it was just faulty anyway, and had nothing to do with the setup. I had a Neu that did the same w/o warning and never got above 120F. The mag isn't wrapped, so it smacks the coils and you have one fubared motor.
If thats the speed you want I would drop voltage or kvs. Its like having a 500hp supercharged v8 and leaving it in 2nd gear bc you don't want to go too fast while you are flooring it. It just isn't gonna last
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your quite bit right....as i read i was undergeared again....!!???but i dont want to make some top speed....i just want to race on my snow track without issue....so 42000 rpm its ti high for this motor....???on 6 cell i have a good run time...low temps ...motor(neu),esc and lipo...8 cell its to heavy,,,