How many Amps???

[opus444]

Hey guys.. I'm almost done with my Chopped up TXT.. I'm going to be running a 600 gear box with the standard 55 turn lathe motor. I was thinking about saving some weight by running some light batts.

I do a lot of flying also and have a 3s pack of light polys that I can draw 30 amps out of before they blow up... Here's the question.............. With the motor gear box set up that I plan on running............ How many amps do you think that motor will draw. I was thinking that considering the massive gear ratio it wouldn't draw all that much. I do know that when you stall an electric motor that in theory amprage will go out to infinity. That's only in theory though. So how many amps would it all draw???? Does anybody know???????

Thanks for any help,

Todd..

[BENDER]

Moved to Electronics, so the electrcal engineers we have here will see it.

[Ace]

I think a lathe motor prolly draws 5 amps max.

I heard someone measured a stalled lathe motor at 4 amps...

Two in a clod run 45 to an hour on 3000milliamphour packs. 45 minutes would be 3/.75=4 amps average for two motors.

One lathe motor geared down on a 600 reduction would draw less.

I'd say 5-10 amps max is a low estimate

[JohnRobHolmes]

but stalled out it would draw much more. i would bet it could hit 30 amps. an easy way to find out is to take an ohmmeter and measure the resistance. amps x ohms = volts. so 11.1 volts with a 30 amp max would give you .37 ohms (minimum) for the motor. if it dropped below that the amp draw would increase. i just measured 4.5 amps at 6 volts when stalled. i then measured .5 ohms, which is wrong. i trust the amps more than the ohms. my batteries werent fresh, so the amp draw could be too low from that.

using my data you could infer that (if amp draw is correct) that 11.1 volts would give you about 8.5 amps stalling current. if my ohm data is correct then you would get slightly over 22 amps stalled.

if you are worried about your batts, put a quick blow 25amp fuse inline with the battery.

[opus444]

Thanks for all the help guys.. I was thinking it would be some were in the 20 amp range, but just wanted to check.. I like the thought of running a fuse in the middle of it all.. I never thought of that.. I figure I might as well go for a 30 amp fuse and get the most out of my batts as possible..

Again thanks for all the help..

Todd...