atwood supplier
 

Try Southwest Wheel on the web.
Jack complete for $212 shipping included.:]

We wound up ordering two for $185 apiece (free shipping too! ;)) If you need to know where we got them from, I can post a link tomorrow morning. Let me know :)

- Katie

Wow, you must need them incredibly bad to buy two jacks just to get the gear cluster.

Here at S.P.A.M. we machine parts to assemble our own gear clusters. We have to as the great Gary Jones (chief designer of all our gearboxes and from what've been told instrumental in several Pratt & Whitney Engine designs) who contsantly generates a new gearbox type and then condenses it so its smaller than the year before and lighter (which helps with a 130 pound robot weight limit...not to mention shrinking weight budgets for certain components). You just might want to order the gears and manufacture the clusters yourself (if you haven't ordered them yet). It might be cheaper...oh and shear pins stink in regards to gearboxes....especially due to the various loads/forces that are put upon the shafts and gears themselves. That's why Gary, James, and I spent the first six hours (unfortunately I guess right on the time it would take to fix the gearbox....thank you my friends for being so understanding) of the 2002 Championship, from 7:00am-1:00pm, fixing it....and then we had to repair the gearbox (well one) between division and the championship finals. Shear pins as their name implies...shear. I believe this years design call for screws.

Katie, yes please could you post the link..........right now we're looking into a local gear store to see if they have those two different gears in stock and putting those together, but we don't know how expensive that might be, so we'll see how it is tomorrow ;)

Atwood Motors & parts
 

Katie,
Thanks for the input.
I would be interested in the name of the supplier.

More importantly, though, we need to know what's inside the jack.
In other words, we know the specs for the motor an cluster gear, but we do not know the description of the last gear in their gear train.
Our first two jacks are on order but we are badly behind in getting the rest of the gear train together and we are waiting to see what the jack looks like before we can go any further.

Can you describe for us the last gear in their train?

177 is cheap.

you get a motor and whole bunch of other gears, too. You could use the gears to build a new transmission. The full speed out of the Atwood gear box was about 40 RPM.

Is it legal to buy a jack and use parts out of it? I seem to remember an old rule against buying big things and using parts from them (i.e. buying a lawnmower to use the wheels). I guess it's a change for this year, but am I correct in saying that was a rule before?

There is a post in the FIRST forums which specifically allows the purchase & use of gearboxes.
This helps us because we have limited access to precision machining required to fabricate a transmission.
Prior to 2003, my understanding was the same as yours, that off the shelf assemblies could not be used unless they had the invoice marked "fabricated for team XXX' as part of the documentation.
Re: Atwood,
the repair part which includes the motor & gearbox costs more than the jack as a whole can be bought for on the internet and Atwood calls it a special order (read takes a long time to fill).
We haven't rec'd our jacks yet so we're still anxious to see which parts we can re-use. If we had it to do over, we'd just go ahead and use the new motor and fabricate a transmission, somehow. We do not have the cluster gears from last year to work with.

It is ok to buy a jack and use the Chiaphua motor and the gear cluster in it, as long as it was part of the kit. Last year people couldn't buy the gear cluster all by itself, so they were forced to buy the whole jack, which come with its chiaphua motor, so that wasn't too bad of a deal.

Its like the same with buying a hand drill, and use its drill motor, as long as its the same motor as the kit's, and you are only using the drill motor.

Don't get too excited after reading this:

We never used our atwoods last year, so id imagine we still have the gear clusters somewhere. IF the advisors let me, i would be willing to give them to a team that really needs them so you do not need to buy the entire jack. I'm not saying I can...but I will try

Cory

Atwood gearbox revealed
 

We got our jacks.
The motor for the Heavy Duty model is the same motor as used last year.
The gearbox is plastic, but heavy looking.
Inside, there is a second steel cluster gear which is quite useful. It has 80 teeth mating with the 16 tooth gear from the first cluster.
This cluster comes apart, and if you discard the clutch mechanism, you'll find that the 80 tooth gear has a 5/8" hole in it!
This results in a reduction of 24.4 to 1 from the motor and a free speed of 225 RPM!
It appears that we can use this to good advantage.

Be careful mounting the 80 tooth gear - it is very hard and difficult to machine. The best bet is to drill the face - I had this done at a machine shop. A carbide drill could probably do it. Cutting a broachway for key stock would be a real problem. I think a diamond file and careful hand work would be the only way.

Here is the link to the jacks that we ordered: Atwood Lightweight Power Jack. This one costs $184.99 - but the shipping is free! :D

- Katie

CIM gearbox using the stock molded plastic housing
 

It is possible to use the molded plastic gearbox housing provided in the kit in conjunction with the CIM motor as an alternative to the drill motor. If you use a 10 pitch, 30 tooth worm gear (Boston Gear pn G1061ARH), combined with a 1.25" pd worm (pn. G1066KRH :see bostongear.com for specs), you get a 1/30 ratio gearbox that should work well. You need to slide the pillow blocks that hold the motor-side drive shaft out a bit to compensate for the larger diameter worm gear. We are planning to do this for our front wheels.
See the image below.
Drawings are also online at:
http://skene.org/robots/cim.htm

(img)http://skene.org/robots/CIM-gearbox-2a.jpg(/img)