F/P Gearbox Drums?

[Ricky Q.]

In the kit for a couple years at least we got plastic drums that meshed in with the Fisher Price Gearboxes...Hopefully some people know what I am talking about.

1) We are trying to determine if these can be purchased any where..Does anyone know?

2) Do any teams have any extras of them that they are willing part with/trade?

Thanks
Ricky

[jskene]

I am not familiar with this part, but we can make one for you if you want.

Our CNC guru, Paul, designed and built today an octagonal plug that pushes into the center hole on the gearbox. We bought a foot long piece of 3" diameter delrin to make this out of and only needed 0.6" so we have lots left.

Just let us know what outside shape you want and I'm pretty sure I can talk him into making one for you.

[Andrew Blair]

Actually, what's proven to be extremely successful for us has been to avoid the octagon entirely, and just turn an appropriate sized round slug that fits the hole. Flange it so it doesn't slip in the output shaft of the FP, and screw it down in between the slots of the output with some small screws- 5mm or 10-32 works great.

[sanddrag]

Not sure if they are the right ones, but they appear to be. check the right side of this page http://www.kidswheels.com/index.cfm?catid=5

[jskene]

Now that I see the photo :



I remember these adapters. They work fairly well. You need to run a 1/2" shaft through the gearbox hub to hold them on to the drum.

I still prefer our solution, shown below.

[Joe Ross]

Looking at the following diagram, I'd say the PN for the drum is PN 76960-2249
http://www.pickeringappliance.com/po...17F558683D.pdf

[Andrew Schuetze]

I wonder how usefull it would be to have a white paper or an adapter available from AM or IFI for these transmissions? We are using one on our robot for the first time in our seven season history because one of our mentors was able to CAD up an adapter that we printed in a Dimension 3D printer. It should be farily easy to modify our design which has a pocket for the lead screw nut to a common shaft type...

A bigger need is to have a solid mounting solution for the motor/transmission set-up. That is our next task

[JessR]

Go buy the the hub adapters - they are available from any Power Wheels dealer for $5 or less each.
The hub and transmission hole are about 7/16 dia. as I recall.
Drill it out to 1/2 inch and use a 1/2 inch shaft (aluminum is good)

To mount the transmission, locate it by mounting the shaft on two bearings or bushings, and use it as a torque arm transmission - the gearbox floats on the shaft, just keep the box from rotating. (you can for instance make a small plywood "box" that just accepts the gearbox, with cutout for motor, or just a single sheet that outlines the shape of the box).
You can drive a drum off the adapter, a sprocket, or drive a cam.
As you probably know, use it in applications where it will keep rotating and cool. Dont use the FP where it will stall often, the small motor will let out the magic smoke pretty quickly.
Good luck.

[dtengineering]

Another option is to avoid the FP gearbox entirely, and use a banebots gearbox. There are threads on CD devoted to adapting the FP motor to the BB planetaries, and while it is reported that the very high ratio BB gearboxes will shred themselves if you drive an FP all the way to stall we used a 5:1 on our shooter last year and it worked great. (The shred at stall issue isn't that big of a deal... remember that if you stall an FP it won't be around for long either... there are also threads here on "magic smoke".)

The FP with a BB planetary mount up just like the 64:1 Banebots motor in the KOP this year. Depending on your design it might be a quick and easy alternative to the plastic gearbox. Not that there is anything wrong with the plastic gearbox... I just wanted to make sure you were aware that alternatives are available.

Jason

[Justin M.]

Originally Posted by dtengineering

Another option is to avoid the FP gearbox entirely, and use a banebots gearbox. There are threads on CD devoted to adapting the FP motor to the BB planetaries, and while it is reported that the very high ratio BB gearboxes will shred themselves if you drive an FP all the way to stall we used a 5:1 on our shooter last year and it worked great. (The shred at stall issue isn't that big of a deal... remember that if you stall an FP it won't be around for long either... there are also threads here on "magic smoke".)

The FP with a BB planetary mount up just like the 64:1 Banebots motor in the KOP this year. Depending on your design it might be a quick and easy alternative to the plastic gearbox. Not that there is anything wrong with the plastic gearbox... I just wanted to make sure you were aware that alternatives are available.

Jason

It's not that easy. BaneBots has sold out of ALL 256:1 42mm gearboxes, leaving the highest gear ratio 64:1 availible. The included gearboxes are 124:1. It might be best to use the plastic ones for this season, they seem to be indestructible (despite being made of plastic), light, free, and have plenty of torque.