When we were designing I remember someone telling me we were limited to two fisher price motors. Now I’m going through the rules and I can’t see anything that limits using fisher price motors. Am I missing it??
Also, If anyone can help me think of a way to speed up our mechanism that currently is using a globe motor, the standard gearbox and the gates belting that came in the kit, I would appreciate it.
I dont know where the rule is (prob in KoP section), but you are only permitted 2 FPs.
EDIT: It is listed in the KoP Checklist, as 2 motors. I am 100% positive you are only permitted 2 FPs.
Unfortunately, I havent used those belts and stuff in the kit before, so I cant help you there.
<R60> Items specifically PROHIBITED from use on the ROBOT include:
Electric motors and/or servos different from, or in addition to, those in the Kit Of Parts, with
the exception of those specifically permitted by Rule <R59>.
Electric solenoid actuators (note: electric solenoid actuators are NOT the same as pneumatic
solenoid valves – the latter are permitted, the former are not).
You got 2 in the KOP so you can use 2, no more than that.
I’m probably not the best person to answer your question regarding globes, but I think I can ask some questions that may help others answer it better.
What are the “bands in the kit”? The surgical tubing bands? The Gates belts?
Could you gear it differently? If using the gates belts, use different size pulleys on one end or the other?
What other motors do you have available (or which ones are already on your robot, whichever is easier)
What does the globe interface to, a sprocket, a pulley, a spool, etc.?
Try using a banebots RS550 motor. There are a whole selection of gearboxes
. If you are currently at a regional and cant order one, ask other teams what banebot gearboxes they have
one other option is to remove the gearbox on the globe and replace it with a modified banebots gearbox or modified dewalt gearbox or modified fp am planetary gearbox. This isnt a simple fix but despite to many peoples knowledge the globe motor is actually a pretty useful motor once the gearbox is removed. i beleive its around 11000 rpm. however i am not 100% sure this is legal but i see no specific reason why it wouldnt because your not modifing the motor just the gearbox. we are currently facing a similar issue with our robot but we still have the two fp to use if we need too.
Mcmaster doesnt sell the same kind of belt as gates belt in the kit . Since gates isnt a distributer, we got our extra belts from motion industrials who were very helpful and provided a product that was not stocked at there location the same day.
Our team actually disassembled the globe motor transmission and took out a stage. We started out using these for our rollers to grab the ball, but they were too slow. Upon the removal of a stage, they are much faster and work very well for their purpose
Removing a stage is going to require shortening the ring gear on the outside of the transmission or removing the planet gears of a stage and locking the Sun/Carrier of one stage to a later stage. Neither is incredibly difficult, but it will take some time. The important thing to remember however is that this isn’t going to net you any increase in power. Your mechanism will move something like 3-5 times faster (I haven’t looked at the guts of a globe yet) but it will also only provide one-third to one fifth as much torque. You might have better luck speeding up your mechanism by attaching a banebots RS-550 or RS-540 to it, if you have them available. if you’re using all 4 CIMS, 2 FPs, and both BBs, then you’ve effectively exhausted your supply of high powered motors and you’ll simply be left with globes, window lifts, etc. However, if I recall the progression of motors correctly, the van door motor often ranks just a bit higher than the globe for power.
The team I used to work with did this. All we did was mill off a stage on the ring gear (the casing), and index 3 holes into the casing. Pull a stage out, slap it back together, three screws/roll pins in, and you’ve got a 400rpm Globe motor. Quite useful, actually.
294 designed a 2.5" roller to to be driven with a belt reduction. they now realized that is a lot slower than it should be (considering on 973 we have them 1:1 to a 5" roller) they want to fix it. They don’t have the belt available to switch ratios, and can’t simple switch the two pulleys.
We/they have 3-4 globes to try this out on and if we can find a way to do it at the regional it’d be the easiest way to fix this issue.
Removing a gear stage is probably your best bet, then. The smartest move would be to remove a stage and have the machine shop mill or lathe down the ring gear to make it shorter. The quickest way, however, would be to remove the planets from a stage and weld that stage’s sun gear to that stage’s planet carrier/ the next stage’s sun gear. As long as you clamp everything up straight and true, this should work just fine. If you’ve got a Globe to burn, I’d try this first for a quick fix.
We have a spare Globe motor lying around our shop somewhere that I’ll take a look at next time I’m in there. Can anyone elaborate on exactly how to take out out a stage without welding, milling, or anything that uses anything more than basically hand tools?
We dealt with that issue a couple of years ago. We milled down the casing on the gearbox of the globe by .25". We then pulled out the one level of planetary gears and increased the speed to something like 450rpm if I remember correctly. We did all the stats on it and have it in the shop somewhere. You do lose the proportional amount of torque however.
A few mentors on 254/968 decided welding the two stages and grinding off the gears would be a good method. They did it to one of their own, but didn’t end up using it so they just let us use it. Worked out great for us and it only took the Ames Fabricator 20-30 minutes.
You have to press the pins into the body of the gearbox. You will feel them release/drop in when they get deep enough. Then it is just a matter of pulling them apart (should not require any force)
I can’t think of any sane way of dropping a stage without welding, milling or some such. If you’re in a real crunch, I’d just make all the preparations for welding two stages together and plan on being first in line at the Machine Shop on Thursday morning. I suppose if you’re attempting this on the stage right out of the motor then you could try degreasing the pinion on the motor and the carrier above it and fusing them with JB-Weld or some industrial strength metal-metal epoxy, but I wouldn’t want to think of that as more than a temporary solution, to be replaced with a more permanent solution when you have access to a welder. You might have more success at it if you try this with the next stage up from the motor and simply degrease the gears and fill the entire stage with JB-Weld or some such, and then dremel off the teeth of the planet gears and any excess JB weld so the whole mish-mash spins freely inside the ring gear. This would atleast spread out the load a fair piece. That’s the only method I can think of aside from hack/chopsawing the ring gear to length or mechanically munging up the planets so they don’t spin and stay fixed around the sun.