Re: 2005 FP Pinion
 

We've got another pair of

74550-0642
TD034701
13 tooth pinion
Haven't measured resistance.

We really need to get this cleared up soon because we've all got to buy some gears and sprockets and we need the correct torque/power/speed data...

Re: 2005 FP Pinion
 

Dr. Joe, did you measure it already, or is this a calculated value?

Re: 2005 FP Pinion
 

Just checked our FP motors.
13 tooth
74550-0642
TD034701
Made in China

Joe P
Team 647 Shoemaker Cyberwolves

Re: 2005 FP Pinion
 

I will try to get to this over the weekend. Sadly, the power supply I need to do this is back here at Delphi and the parts are in Pontiac (about 1/2 hour away).

Joe J.

Re: 2005 FP Pinion
 

Checked ours, 13 teeth
Read the Friday Email about the Typo in the kit for the FP's. I also had the kids measure the free speed with the transmission. 144 rpm, battery fully charged, fuse, no victor. which is no surprise as last years was 130 same conditions.
Cheers
Tom Cooper
1227

Re: 2005 FP Pinion
 

Here are a couple measurements on our 2005 Fisher Price Motor

13 teeth; 1/2" O.D. pinion

Part ID# 74550-0642
Code: TD034701


Measured RPM*:
24,500 @ ~12V (voltage approx)
12,000RPM @ 6.0V
-11,600RPM @ -6.0V (reverse direction)
* Measured using R/C airplane hobby tach & transparent disc w/stripe


Motor Resistance**:
0.069 - 0.074 ohms

**Measured with 10A current source; 4 point measurement of 0.69-0.74 V while turning rotor between fingers

Calculated stall current from above:
162 - 173A (12V/0.069ohms; 12V/0.074ohms)


All these measurements agree well enough by those provided by Paul Copiola at

http://www.chiefdelphi.com/forums/sh...ad.php?t=32442

-David

Re: 2005 FP Pinion
 

To take this question to the next level;

Does anyone know or want to hazard a gues as to what the pressure angle is on the gears used in the FP transmission?

Matt B

Re: 2005 FP Pinion
 

20° (at least, that's what the old ones were). The new gears look like they have the characteristic "sharp" teeth, so short of taking measurements, I'd definitely say that that's what they are.

Re: 2005 FP Pinion
 

From history, I'd say you are pretty safe in saying it is a 20 Degree Pressure angle.

They typically use standard DP and pretty standard gears (no enlargements or thickening of teeth, etc.).

Joe J.

Re: 2005 FP Pinion
 

So is this 32 DP like the others?

Re: 2005 FP Pinion
 

Definitely. And I tested the mesh today with some good quality 20° PA gears, and I'm even more confident that nothing has changed.

13 T, 32 P, 20° PA