Originally Posted by Glacier Girl
Hmm, don't know if I believe the motor specs.
300 watts divided by 18 amps is 16.666666
So to get 300 watts at 18 amp draw, it would need 16.67 volts. That's 4S power, and specs say 2 to 3S
???
Anyhow, I ran the motor specs on MotoCalc. 3S with a 9x6.
16.7 amps, 24.0 oz thrust, and prop speed of 47 mph, so approx 40 mph airspeed.
Approx 109.5 watts.
So at best 50 watts per pound for your set up.
Basic trainer set up at best I'd say............
OK - I own up !! My post was a little misleading .... sorry on purpose ... I needed confirmation of what I found .....
I too noted the mis-calculation in the specs when I first bought ... and is why I upped the ESC from 20A to 30A for a start !
I fitted the motor to my ME109 of approx 600gr and it was WOW out of sight .... but not so WOW as I thought it would be.
My present motor develops about 100W, is spec'd at 160W and actually with Wattmeter is reasonably truthful in it's advert. A turnigy motor.
This RC Timer - when I found it wasn't quite the Rise out of hand as I expected ... was put on Wattmeter and I got afluctuating max 120 - 130W reading on a 8x7 prop. I had a 30A ESC, 35C 2800mAH 3S LiPo connected all with good connectors. I was not amused !! On scales - it pulled 590gr thrust. (I suspend model from beam by tail, zero a digital scale - then open throttle ... weight then displayed is thrust ....)
I do have another motor that I'm looking at with a rep'd 2.5Kg thrust level ...
http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT
My reasoning is that if I assume ratings to be 2x what we get in practice - then I won't go far wrong.
Again I apologise for the subterfuge .... honest it was in a good cause !
AND I certainly will look at the motors suggested by you guys and
dolls !
