2012 KoP motor part numbers

[Ether]

The 2012 KoP lists motor part numbers (http://www.chiefdelphi.com/forums/attachment.php?attachmentid=11284&stc=1&d=1325976541)

AM802-001A

am-9012

am-9014

I was assuming these were AndyMark part numbers, but when I searched the AndyMark web site, these part numbers were not recognized (see attachments).

What up?

[Joe Ross]

I think am-9012 and 9014 should be am-0912 and 0914

http://www.andymark.com/product-p/am-0912.htm
http://www.andymark.com/product-p/am-0914.htm

The am-0255 page references AM802-001A

[Ether]

I think am-9012 and 9014 should be am-0912 and 0914

http://www.andymark.com/product-p/am-0912.htm
http://www.andymark.com/product-p/am-0914.htm

The am-0255 page references AM802-001A

Thanks Joe.

I'm updating my motor calculator for the 2012 KoP motors.

[Ether]

The AndyMark web site lists the following specs for the PG71 (am-0914) motor:

84 rpm & 1.3 amps @ 12V no load

6.8 ft-lbf & 11.3 amps @ 11.6V stall


Extrapolating the stall from 11.6V to 12V would give:

6.8*(12/11.6) ft-lbf & 11.3*(12/11.6) amps @ 12V stall


Assuming max power occurs at half speed and half torque would give:

half speed = 84/2 = 42 rpm

half torque = 6.8*(12/11.6)/2 = 3.52 ft-lbf = 675.3 oz-in

max watts = (42 rmp)*(675.3 oz-in)/1352.3 = 21 watts


The web site says max power is 130 watts (see attachment).


Somebody please check my math?

[Richard Wallace]

I think your math is correct.

Peak mechanical power (at half of free speed and half of stall torque) is about 21W.

Electrical power would be about 70W under those conditions.

I don't have access to my team's motors right now, but after the Monday meeting I will take them to the lab, and try report dynamometer test results on Tuesday or Wednesday.

---------

Edit: It appears that this gearmotor is aimed at replacing the old-favorite Globe transfer case gearmotor, which had more than twice the stall torque and about the same free-speed. That motor could develop about 80W peak mechanical power, if I recall correctly.

[Ether]

after the Monday meeting I will take them to the lab, and try report dynamometer test results on Tuesday or Wednesday

fantastic. thanks.

[Kevin Sevcik]

3.52 lbf-ft * 1.356 N-m/lbf-ft = 4.77 N-m
42 rpm * 0.10472 (rad/s)/rpm = 4.4 rad/s

4.77 * 4.4 = 21-ish.

Your math checks, so I'd guess there's a problem with the specs somewhere. Probably the listed max power. The input power at half torque is about 73W. So at max power it's either 30% efficient, or 178% efficient. I know which side I'm putting my dollar on....

[Ether]

Thanks Joe.

I'm updating my motor calculator for the 2012 KoP motors.

Done. http://www.chiefdelphi.com/media/papers/2432

[John]

This has the maximum power as 18.28 W.

http://www.usfirst.org/sites/default/files/uploadedFiles/Robotics_Programs/FRC/Game_and_Season__Info/2012_Assets/Motor%20Info_0.pdf

[Ether]

This has the maximum power as 18.28 W.

http://www.usfirst.org/sites/default/files/uploadedFiles/Robotics_Programs/FRC/Game_and_Season__Info/2012_Assets/Motor%20Info_0.pdf

On that chart, the AndyMark part number is listed incorrectly.

It should be "am-0914" not "am-9014".

Also, if you go to the AM website for am-0914, you will see that the specs listed there differ greatly from the FRC chart.

[Kevin Thorp]

Does anyone know if the AndyMark PG-71 gearmotor (am-0914) can take a side load?

The Globe gearmotor of similar design could not.

[nickcvet89]

Hey, can a Globe motor be used this year? Also, does anyone know where I can get a spec sheet on it? Thanks