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Unread 30-11-2014, 04:54
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asid61 asid61 is offline
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AKA: Anand Rajamani
FRC #0115 (MVRT)
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Re: pic: Finally Done!

Quote:
Originally Posted by JorgeReyes View Post
I think it might be a smart idea to 3D print the side plates, that way you don't have to use all your grant money machining something that might not work
I highly recommend against this.
3D printing does not hold the required tolerances for work such as bevel gears, particularly plastic 3D extruders. The printers normally found in FRC are NOT suitable for work such as this, plus they have a "step" of 0.003" vertically; you will end up with a lot of slop in your gear train. You have to double or triple stack the tolerances due to the existence of side plates.
Not to mention press fits with bearings is barely possible, as a decent press fit in plastic may weaken or destroy the frame during pressing due to the layering (depending on the printer).
Plus, you still have to do heavily loaded tests to make sure that it can hold up due to the plastic and layering.

Now, some actual questions:
1. What is the final weight of this gearbox without motors?
2. What is your reasoning for going with a bevel gear setup?
3. What advantages does this design hold over 192's gearbox design from 2014? I still haven't seen a shifting gearbox design that beats theirs in terms of weight or size.

20fps is too fast. You can limit the top speed in software for the driver, but your acceleration will be very poor with only 4 cims. Seeing as you are running bevel gears, would it be possible to add a 3rd cim sticking stright up?
Your final gear reduction looks like it can be reduced to a much smaller/better ratio. Top speed for a 4 cim drive shouldn't hit above 17-18fps if you want to optimize distance/time. OC it depends on the game, but it would be a very rare game that requires 20fps on four cims.
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