Black & Decker Fisher Price Transmission

[team222badbrad]

Recently while at VCU our team was stuck with a problem.

One of our double stacked BaneBot transmissions bit the dust on practice day and that was when we really put them to the test.
http://www.chiefdelphi.com/media/img/799/799d3e2bf243ffd8b1adfeda8b5a2e5d_m.jpg

We did not have a replacement and because one transmission was not enough to power our ball pickup and shooter delivery system, we needed to find something if our second one decided to fail. We were forced to eliminate and modify some of our ball conveyors.

So we sent someone from our team to the Lowe's right down the street to find a 12 volt drill.

He came back withTHIS (http://www.blackanddecker.com/ProductGuide/Product-Details.aspx?ProductID=5470)

With a little tinkering and figuring how to get the drill apart, the Fisher Price motor was a direct drop in.

Unlike the Bane Bots, this little gearbox also has an adjustable clutch, a good feature to prevent motor burnout.

I did get this setup nearly ready to be placed on the robot if needed before the end of practice day; however, we have not done any testing to see how this gearbox may handle on a FIRST robot.

If anyone is interested in this gearbox perhaps I may make a white paper on how to tear it down and place the Fisher Price in it.

http://www.chiefdelphi.com/media/img/9d3/9d394c8b53ad8d5509d0d4e36d929533_m.jpg

[JAH]

That sounds pretty neat. I'd love to see a white paper on how you did it. It really seems that you guys are good at thinking on your feet which is a good quality for any team to have. Assuming that there isn't a ton of power put into it I'd assume it would be ok. Other drill transmissions have been used before, granted they were stronger, but this is a really neat idea and hopefully it will work. Post pictures at some point if possible! :]

[sanddrag]

Cool. Let's see some pictures. I wanted to get some $8 drills from Homier to try. By direct drop in, do you mean no change of pinion? If so, that would be incredible.

[team222badbrad]

By direct drop in, do you mean no change of pinion? If so, that would be incredible.

We had to remove pinions from Black & Decker motor and the Fisher Price motor.

We then had to press the B&D pinion on the Fisher Price and cut some of the shaft just as you would do to make them fit the Bane Bots.

[Dillon Compton]

What sort of weight are we looking at for one of these?

What is the reduction?

More pics?

I'd love a whitepaper.

[David Guzman]

I would also like to see a white paper. Does it have variable speeds?

[Greg Perkins]

What about Harbor Frieght (http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=47155) Drills? You can get various different voltage models (most are very cheap) and use the transmissions off of them. I think a 12v model is around $10 and you can get 18v ones too. Seems like the Johnson motor from the FP would adapt well to the drill gearbox.

[Don Wright]

Any idea on the gear ratio?

[team222badbrad]

Any idea on the gear ratio?

I do not have the gear ratio at this time, I am working on that.

I do know that the output of the drill with the stock motor is between 0-700RPM, but that does not mean a thing unless the stock motor and the FP motor RPM's are nearly the same.

This is only a one speed transmission with a 24 position clutch.

Perhaps a Harbor Freight drill would work the same but we didn't have one around.

I am not sure on the weight, but it is a bit more than the Bane Bots.

I would say between 1 - 2 pounds.

[Andy A.]

An instructor of mine worked at Black & Decker for several years developing assorted electronic 'tools' for the home and nonprofessionals (things like that drill would have been up his ally). From what he's told the class, black and decker pretty much takes the same motor/gearbox assembly and just crams it into what ever clamshell they need at the time. So I suspect this gearset lives in many products under the same brand.

I'll talk to him about this and see if he can find any 'real' information about this or other B&D transmissions. It may be possible to order the gearbox directly, or find the least expensive device it comes in. Maybe even find multiple ratios ala BaneBots.

As an aside, I like the XRP tranmission conversions. DeWalt being owned by B&D, could some of the B&D trannys from the 'firestorm' line be an alternative to the cronicly out of stock XRP? It seems all the firestorm sets are only 2 speed, so I don't see getting the exact same model happening. I've only done a very casual search for transmissions alone, and have not come up with anything.

I guess I'll grill my instructor and see if he has any info or can put me in contact with someone who does still at B&D.

-Andy A.

[team222badbrad]

Tonight I investigated the gear ratios.

I do not know how to calculate planetary gear ratios, so here are the #'s

The sun gear attached to the motor is a 9 tooth which meshes with 3 16 tooth planet gears and they mesh with a 42 tooth stationary ring gear.

These gearboxes have 2 stages the first set of planet gears is plastic, while the second set is metal along with the whole ring gear assembly.

The second stage is basically a repeat of the first stage with the sun gear attached to the planet carrier and in the last stage the planet carrier is the output.

Can anyone tell me how to calculate the gear ratio for this?

[teamtestbot]

Hey,

Most lower end and "common" drill gearboxes are 36:1, 9 tooth pinion, 18 tooth planets, and 45 tooth rings. This is the case with drills from Harbor Freight, Homier, and lower voltage Black & Decker and Ryobi. The reduction is (1 + R/P), so two stages of 6:1.

Those drill parts tend to be interchangeable, e.g. a B&D 9.6v will fit on the back of a Harbor Freight transmission.