Re: [CAD_CAM_EDM_DRO] Re: Has anyone done one of the R/C motor spindles?

turbulatordude wrote:

>>a 175W motor, Kv 4300 rpm/v Kt 0.45 oz-in/amp. Maximum voltage is about 8.5v, so around 36kRPM max. For another $40 you can step up to a faster, more powerful motor.
>>
>>
>I get confused with all the numbers.
>
>Kv = rpm per volt, assume 8.5 vols, so 4,300 RPM times 8.5 = 36,550
>RPM max.
>
>then Kt = oz-in per amp.
>since it is a 175 wqtt motor, we can figure a 20 amp power supply.
>
>Using 20 amp, then 20 times 0.45 = 8.1 oz-in for a motor.
>
>( 36,550 x (8.1x.00521) ) / 5252 = 0.326 hp
>
>Somehow I think the numbers may be wrong, but if that is correct, then
>those motors have a LOT of power in a very small package.
>
>It is a shame the cost is so dern high.
>
>

Yep, they are very powerful, and they get very toasty.
The motor rating of 175W looks like 1/4hp to me, using a conversion
factor of 745w/hp.

The Hacker C50XL is good for 40A/60A (cont/peak) at 36v for almost
2HP/3HP in a package about 3 inches long and 1.5 inches in diameter, 15oz.
And all for the low, low price of $515 :)

Dave K