Big Black Motors

[Joe Johnson]

They are made by Chiaphua. They are used in Atwood Mobile Power Jacks. All models of power jacks use the same motor and the same gear cluster mating with the motor (the very one in the kit -- thanks to Atwood -- this makes a very nice addition to the kit just a bit easier to use). The jacks are available at most RV centers, in stock. Cost is $150-200 or so based on the model and the markup of the dealer.

Atwood Mobile Power Jack



Specs should be out soon but as I recall, the numbers are 2.2N-m stall torque. 107Amp stall current, 5500RPM free speed, ~2 Amps free current (all @ 12V).

The output gear is VERY non-standard. It is a 36 Diametral Pitch, 9 tooth, enlarged, 25 degree pressure angle gear. Actual data should be out soon.

The gear that mate with it is a 44T gear (4.888:1 ratio). The center distance will have to be slightly enlarged from nominal I think, though I am not sure of the exact value -- it should not be too fussy. The smaller gear clustered with this gear is a standard 32 D.P. gear

By the way, it was touch and go getting these beauties in the kit. I have been working with Chiaphua for months to get these babies in the kit, it almost didn't happen. In the end, Chiaphua gave us a good price, I BEGGED my management for some funding to cover most of the price and then I BEGGED FIRST to kick in the balance of the funds to seal the deal.

I am very happy that we ended up getting these in the kit. I hope that they work out well for all teams.

Joe J.