Hello everybody. Im a verteran member of my team 1561, the Roboducks. Although I have spent a lot of time on our previous robots, we never tried to use the fisher price motor. This hear we are thinking about using the fisher price motor, but do not know how to go about doing that. It would really help if anyone could tell us how you have used it in previous competitions and how you would go about hooking it up. Thanks in advance.
The Fisher Price motors are among the most powerful motors in the kit.
They are wonderful little power packs.
You have to be careful not to load the motor so that it runs too slow or the motor will fry but, that is pretty easily done. For the most part it just means picking a high enough gear ratio and not running the motors to stall if you are driving an arm or something against a stop.
I also am a big fan of using the FP motor but not the FP gearboxes. I think the Nothing But Dewalt Whitepaper is a good method. But unless you need shifting, I have come to believe that the Banebots transmissions are the easiest and best methods to get useful work out of a FP motor.
Read this thread: Fisher Price Motor Replacement Gearbox
for more good discussion around using Banebots transmissions with FP motors.
Joe J.
Hay ALL
Dumb Question, is one or two fisher price motor/gearboxes?
Check list said 1, we got 2 in the kit, or did I read the list wrong?
Geo.
P.S use a octagon drive adaptor, a hose clamp, and support the outboard shaft with a bearing.
Team Update #1 says the checklist is incorrect. Everyone received and we are alllowed to use two (2) Fisher Price motors/gearboxes.
EDIT: Lil Lavery beat me to it.
I have a question about calculating the max power of the Fisher-price motor. I made a spreadsheet to redo the motor data from the “Tips, Guidelines and Good Practices” chart so that all of the units were consistent (Nm for torque and rad/s for speed).
I keep getting calculations that are not even close to the information provided and when I went to do it by hand I encounter the same problem. So, for example, I was fairly certain that the fisher price max power should be attained like this:
max power = (torque at stall divided by two) times (free speed divided by two)
Pmax = (T0/2)*(Wf/2)
T0 = 417.7 mNm * (.001) = .4177 Nm
Wf = (15636 RPM * 2 * pi)/60 = 1637 rad/s
Pmax = (.4177/2)*(1637/2) = 171W, as compared to 387W published
Which is so off that I’ve rechecked my work multiple times but cannot find any error.
Also, regarding the octagonal drive adapters for the FP gearboxes (mentioned by George), where are those available for purchase?
I have a question about the bigger fisher price motors, the CIM FP801 (What my team calls the ‘pimp CIM’). It comes with a gear on it already, as well as that springy thing. we took the springy thing off and want to just use the motor with that gear already on it. so my question: what are the dimensions and specs of that gear? it has 16 teeth, i know that much, but if i want to fit a McMaster Carr Gear to it i will need to know more. a link to some specifications or some details would be greatly apreciated.
You’re right. See this post:
http://www.chiefdelphi.com/forums/showpost.php?p=552098&postcount=3
See this post:
http://www.chiefdelphi.com/forums/showpost.php?p=430361&postcount=21
(The “gear” is actually a belt pulley, and probably won’t interlock with other gears.)
thanks. i thought that didnt look like a spur gear…
So saturday we were trying to get it off because we didnt want it on there (the belt thing). we successfully got off the spring roller atachement in seconds. the belt thing was a disaster. we took off the black clip on top as well as the other shiny protective thing. then we took off the set screw that was ataching the belt thing to the output shaft. we couldnt think of anything else to unatach in order to get off the belt thing. so we pulled and yanked for an hour or so on the belt thing trying to get it off. that didnt work at all. next we tried to grind it. we have a nice picture of this somewhere actually, because we ground off about a third of the belt thing. since we could see about half of the shaft now, we grabbed the belt thing with some vice grips clamped to a table, and started hitting the output shaft with hammer hoping to coerve it into moving the entire motor assembly down while the belth thing stays still, thus moving it off. somehow, we managed to hammer the output shaft out the back of the CIM ruining it.
so thats the sad story of our pimp CIM. we are ordering another one because we need that motor. hopefully we can order it without that stupid belt thing, but i dont know. if we cant get it without, can someone who has successfully removed the belt thing post instructions on how to effectively remove it without damagint the CIM? thanks.
pictures to come i promise!
There have been many posts about it (searching is a wonderful thing), the pulley is held on with an epoxy adhesive that weakens greatly when heated. Last year we used a Bunsen burner to heat it, but other methods work fine. After the epoxy has been weakened it can easily be pried of with a screwdriver or pulled off with a gear puller.
The belt thing is glued on. To remove it you will need a gear puller an a small torch to heat the belt thing up to about 400 F. Attach the gear puller and put some tension on it. Begin heating the pulley. When it gets hot enough, you will be able to turn the gear puller very easily and remove the pulley. There is a thread discussing this from last year.
Definitely invest in a gear puller. We have a small one (for FP’s and similiar) and a larger one. It will save you much aggravation, not to mention motors!!!:). Mcamaster carries them and BB has a nice small one.