View Full Version : chiaphua gear cluster
do any of you remember the number of teeth that was on the cluster gear for the chiaphua motor
Aaron Lussier
09-01-2003, 17:06
8 but this year the Chiapuha has a shaft not teeth why do ask?
Rob Colatutto
09-01-2003, 17:53
no, the chippy output was 8, the cluster was 32 (or 25, or somewhere around there)
sanddrag
09-01-2003, 19:30
You may be able to find it in last year's kit details here.
http://www2.usfirst.org/2002comp/kit_p_hlist.pdf Warning very large file.
sanddrag, no it doesn't list it on the file, but thanks anyway.......but do you think we will be able to order that cluster gear from the Chiaphua company again, or do you think it was customly designed for last year's competition?
The 2002 Chiaphua output shaft have 9 teeth. The cluster gear has 44 teeth on the input side, and 16 on the output side. The motor output shaft and input side of the cluster are some strange pitch size that I don't remember (I have the motor in front of me, but don't have my tooth guages with me). The output side of the cluster is 32 pitch, 1/2" face width.
Hope that helps.
-dave
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Y + AX^2 + B.... ehhh, whatever.
dlavery, yeah it will help a lot, thanks, if I can't find a place that have them in stock, but would you guys know where I can get those clusters again?? like from the Chiaphua company or something like that?
Ken Leung
11-01-2003, 09:52
Originally posted by The wheelman
8 but this year the Chiapuha has a shaft not teeth why do ask?
That's right. The output shaft on this year's CIM motor is a keyed shaft and not that weird gear last year. It will be illegal to use last year's chiaphua motor with the gear cluster on your robot this year.
why wouldn't you be able to use the gear cluster from last year, isn't it just a normal gear? and you're allow to use last year's Chiaphua motor according to the team update #2
Ken Leung
11-01-2003, 10:29
My mistake then.
However, the gear cluster was a huge pain to use last year. You might be better off with this year's keyed output shaft.
Ken L, that's alright......yeah I know there sort of a pain, but we bought two extra from last years, and for some reason we feel like last year's one is more powerful.......plus we're planning to use a similar gear shifting design posted by dlavery for team #116 :)
so anyway, do you guys think I would be able to get the gear clusters from CIM again?
Katie Reynolds
15-01-2003, 19:54
yeah I know there sort of a pain, but we bought two extra from last years, and for some reason we feel like last year's one is more powerful
Hey, send one of those my way! ;) We're using the cluster gear from last year too, and need a few of them. Anyway, I've got a question for all of you - what model is the Atwood Mobile jack that the CIM/cluster gear came from? I can't remember (and yes, I tried searching but did not find anything.) Thanks :)
- Katie
Katie, we should help each other than LOL, because I have no luck in finding those gear clusters yet, apparently the guy that designed the chiaphua motor last year, and probably the gear cluster that came with it as well, left the chiaphua company so we can't get any help from Chiaphua company. I think we might just need to use the specs that dlavery gave us and have it customly made
Katie Reynolds
16-01-2003, 17:06
Antonio
From what I've found, in order to get the actual cluster gear ... you have to buy the actual jack it comes in. So far the cheapest I have found the jack is $177 ... but that's a lot to pay for a little cluster gear! :eek: I'll keep in touch if I find anything else out.
- Katie
how do you do that?
because if worse comes to worse I guess we can buy it if it is necessary
Try Southwest Wheel on the web.
Jack complete for $212 shipping included.:]
Katie Reynolds
19-01-2003, 17:24
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
Originally posted by Katie Reynolds
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.
MRL180YTL2002
19-01-2003, 21:34
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 ;)
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.
Jeff Waegelin
22-01-2003, 09:08
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.
Ken Leung
22-01-2003, 13:11
Originally posted by Jeff Waegelin
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?
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
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.
Katie Reynolds
23-01-2003, 18:40
Here is the link to the jacks that we ordered: Atwood Lightweight Power Jack (http://www.rvsupplywarehouse.com/PowerJacks.html). This one costs $184.99 - but the shipping is free! :D
- Katie
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)http://http://skene.org/robots/CIM-gearbox-2a.jpg
Jim Meyer
26-01-2003, 19:13
Originally posted by Jeff Waegelin
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?
I'm pretty sure that was an OCCRA rule.
Originally posted by Dr.Bot
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.
If you don't have easy access to a machine shop, you can work on the 80-tooth gear yourself, but you have to do some prep first. The gear is hardened, and must be annealed before you can work it.
To anneal the gear, heat it in a torch flame until it is cherry red (around 1650 degrees F), then let it air cool. You should now be able to work with it easily. Once done, the gear will be too soft to use reliably, and will need to be re-hardened before you use it. To harden it, heat it again to cherry red. Rapidly quench it in water (OK) or oil (preferable). You want to plunge it straight in vertically (i.e. along the length of the piece), and not sideways, to make the stresses within the piece as even and consistent as possible. For the same reason, swirl the piece in the liquid in a figure-8 pattern, and not in a circular pattern, until it cools. This will ensure that fresh surfaces of the piece are exposed as it moves through the liquid, and makes the cooling as even as possible.
Once the piece has cooled down to about 100 degree F, the hardening step is done. The piece is nice and hard, but it is also brittle (with good tool steels, if you drop the piece on a concrete floor at this stage it will frequently shatter). You need to temper the piece to draw back the hardness of the surface material into a stronger, less brittle form, and relieve internal stresses. Take a file or some emery paper and scrape the surface of the piece to reveal fresh metal. You will need to evenly reheat the piece to the tempering stage, and then quench it again. While it is possible to do this with a torch, it is difficult. The easiest way is to heat it in a kitchen oven (I will leave it to you to determine if you want to ask before or after you do this), or even a small toaster oven. Depending on the alloy, you need to get the piece up to about 460 degrees F. At this temperature, this fresh exposed metal will turn a straw yellow color. Watch the color carefully - this is your best indication of when the steel has tempered. If it goes past yellow into brown or purple, it is too hot and you need to start over from the hardening step. Once it is straw yellow, take it out of the oven and requench it immediately. When it has cooled, you are all set.
This isn't a perfect process that you would use for large-scale production, but it is a reasonable small-lot method. Knife makers and blacksmiths have been using this technique successfully for ages. You will have a nice hardened piece that should stand up under the stresses your robot will see.
FYI, the first cluster from the jack (the one that was in the FIRST kit last year) can also be bored out and worked if you use the proper techniques. The material used in the first gear cluster is very hard. It also work hardens very easily. If you need to open up the bore to put the cluster on a larger shaft, use a TiN-coated drill bit, slow turning speed (~500rpm for a 3/8" bit), heavy feed rates, and LOTS of coolant. You want to get through the piece as quicly and smoothly as possible before it work hardens any more, otherwise you will be there all night.
-dave
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Y = AX^2 + B..... ehhh, whatever
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