To post something very brief... I'm going to get on a bit of a soap box.
Not having information is better than wrong information. I've seen a few people in this post (and other posts recently as well) post things they "believe" to be true.. or that they're "pretty sure about" or this is "close enough to right."
I'm going to correct a bunch of mistakes written here in hopes that we can continue with something worthwhile... I'm just going to tell it how it is, don't be offended.
Here's the stats, all converted to English units, by me a while back.
Code:
Motor Name Free Speed Stall Torque Stall Current Circuit Breaker Torque at Breaker Speed at Breaker Power at Breaker
(RPM) (in-lbs) (A) (A) (in-lbs) (RPM) (HP)
Drill (1) 19,670 7.70 127.0 40 2.18 14190.5 0.491
Drill in High (2) 1,521 48.64 127.0 40 29.27 1041.9 0.484
Drill in Low (3) 450 319.95 127.0 40 103.35 308.3 0.506
Atwood / Chip / CIM (4) 5,342 21.68 114.0 40 7.61 3467.6 0.419
Fisher Price (5) 15,694 3.54 61.0 30 1.74 7980.9 0.220
Globe Motor with Gearbox (6) 104 180.00 18.5 30 180.00 0.0 0.000
Van Door Motor (7) 75 300.88 44 30 205.15 23.9 0.078
Window Motor (8) 86 83.19 24.5 20 67.91 15.7 0.017
(1) - 12 Volts motor curve. Stall specs taken at 40.4 Amps, and assumed linear relationship to approximate at 40 Amps
(2) - Free speed from Gearbox performance, at 11.98 volts. Stall torque estimated at same efficiency as free speed
(3) - Free speed from 2003 manual page 5 reference, stall torque estimated using speed ratio efficiency. No solid available data, hence cause of higher power in Low than possible. Accurate free speed data would help immensely.
(4) - 2004 Motor data from CCL Industrial Motor Limited sheet
(5) - All data taken from 2004 Johnson Electric Manufacturing Specs
(6) - All data taken from 2003 competition specs, adjusted to 12 volts from 10 volts, assuming linear relationship
(7) - All data taken from 2003 competition specs.
Okay, so there are the specs... now to correct/comment on some people's comments.
Quote:
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Well I belive the ships stall before the drills do. So there for i belive the drills have more power. For example. We run drills on one side chips on the other side. We only rip our belts(breco flex timing belts) on the drill side. That makes me belive that the drills are stronger then the chips or that the drills have a higher stall current.
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Stall current isn't related to power.... the max power in an ideal DC motor like the one's we're using is at half the stall (max) torque (and hence half the free speed). Power output = torque x angular velocity. This varies depending on the load to the motor. You often want to design such that you're gearing to get the most power out of your motors.
Something you need to consider is that the max power output of these motors is well beyond the Amp circuit breaker limit. I have already done the calculation at the breaker limit above so that you don't make the mistake trying to design around something that will trip breakers.
Good luck everyone!
Matt