Is anyone there? need Dewalt help

Here is DeWalt's marketing thing on the subject.

http://www.dewalt.com/us/cordless/powerrating/

Unit Watts out (UWO) is their rating for the (presumably sustainable)maximum power output at the chuck of the drill. You can read about it..their explanation is basically technically correct.

Yes, max torque is related. The maximum power in a permanent magnet DCmotor system occurs at half the maximum speed when the system is loadedwith half the maximum torque.

1hp = 746 watts, DeWalt's DC900 36V drill is claimed to be 750 watts,close enough so let's call it 1 HP ok? Their max RPM is 400. So 200 RPMis the half-way point.

1HP = 200RPM*Tmax(in-lbs)/(24*5252)

Tmax = approx 630 in-lbs

The equation I used is known equation for relating power (HP) to RPMand torque (in ft-lbs..I added in the factor of 1/12 to account for thein-lbs to ft-lbs conversion).

By the way DeWalt make some bold claims about other manufacterers' drills.

For example they claim the 18V Lok Tor by Milwaukee puts out 390 UWOcompared to their DC988 model listed as 420 UWO. Yet I have readinformation from Milwaukee's own independent tests that claim the LokTor drills faster 2 9/16" self-feeds AND more self-feeds per batterythan that very DeWalt model.

This was posted on Milwaukee's Tool Talk forum (when it existed). Ibelieve the Milwaukee official said that DeWalt averaged 7.2 secondsper hole while the Milwaukee averaged 6.4 seconds per hole. I make beoff slightly but I do remember it was around a 1 second difference.Plus the Milwaukee apparently drilled 28 holes per batt where dewaltwas 25.

Your math is correct very good . I Have my master in electrical and do load counts , R factors , and sizing for application use on some really big motors , ..... Huge . The math is still the same from a
dc fractional motor to the big Westinghouse 400 horse power motors used in foundry, mining application. The only real difference is three phase power calculations vs 12v power supplied or EMF , ONLY A COMPLIMENT