Advices on FP Motor

[David Guzman]

I'm from team 1251 and we are trying to make prototypes on drive trains to learn about them and come up with a good design during building season. We haven't work with the FP motors and I will like to hear from some people with experience. What are the good things and bad things of usings this motors? How are the more efficient? And so on, any advise and experiences will help.

Thanks for all your help.
David Guzman
Team 1251
2004 All Star Rookie Team Award at UCF Regional

[Mike Betts]

Dave,

Beware of breaking teeth off the final two stages if using the FP transmissions.

[Arefin Bari]

hey dave,

there are bunch of threads about the fisher price motors...

here is one... '

good luck...

[Solace]

a single lesson learned from 2004.

Do not use FP motors in your drive train unless you are comfortable basking in the aroma of sizzling plastic.

[Elgin Clock]

Originally Posted by Solace

a single lesson learned from 2004.

Do not use FP motors in your drive train unless you are comfortable basking in the aroma of sizzling plastic.

I remember that smell @ the Jersey regional. I thought the stands were on fire or something.
I guess I was upwind of it.

[JVN]

• The FP motor windings have insulation that gives off a distinctive odor when combusted.
• The magic white smoke leaves these motors much easier than most.
• The motor will burn before the 30A breaker trips.
• Gear down to reduce motor load accordingly.

Seriously...
Try to keep these motors from EVER running at stall while drawing 12V. This will minimize their strain over the course of a match, and prevent them from smoking.

If you EVER stall these motors during a pushing match...
... hope you have some spares ready.

[Tytus Gerrish]

:wiffs the air: Smells like... fisher Price,

[Al Skierkiewicz]

The FP motors are really pretty strong motors but like any of the motors we use there are some flaws. FP's need to be run at the RPM they were designed for. Low RPM on these motors spells disaster as the fan that pulls colling air through the frame is very inefficient. At low speeds the heat from the motor will melt the fan (which is just pressed on the armature shaft) and it will stop working altogether. Remember that this motor is designed to power a drive around kids car in almost continuous duty until the batery dies, without failure. Keep the RPM up, and the motor ends unobstructed to allow cooling air to flow through and you should have no problems. Stall current is above 90 amps, so more than 100 watts can be dissipated in that little package.

[David Guzman]

Thank You every one for your input. From what i have heard, it isnt very reliable to use them in the drive train. What has your team used them for? How did it go?

[Al Skierkiewicz]

Originally Posted by David Guzman

Thank You every one for your input. From what i have heard, it isnt very reliable to use them in the drive train. What has your team used them for? How did it go?

Dave,
I should add that we have used FPs for many years in our drives including our 2003 Championship winning design. They are as reliable as anything in the KOP if used as intended.

[Mike Betts]

I will not be as harsh on the motors as others in this thread. They are powerful and compact actuators. We have used the FP motors in quite a few key applications over the years (we have avoided using the FP gearbox since the first year). I don't think that we have ever failed a motor.

Prolonged stalling of any DC motor is something we try to avoid by design. Beside heating effects, the larger motors (drill, CIM, van door) will trip circuit breakers and the smaller (window, seat) will rapidly slow (internal PTC resistor). All of these are undesirable in a competition robot...

Another note: I usually inspect the FP motor wires where they attach to the motor rather carefully. I have found the integrity of the connection at that point to be lacking...

[David Guzman]

Ok now im confused because firt John V says that the motors will burn before the 30 amp breaker trips. However Al says that their stall current is over 90 amps. I don't know if im understanding correctly but if the motor burns before it trips the 30 amp circut breaker then that would mean that it would burn before it gets to its stall current?