Turbo Transmission or Fast Transmission

Hey all, Randam here!

I’ve created a pretty solid mogo transmission along with my drive train. The only problem is that it uses the small 3.25 inch omni wheels. The transmission functions exactly as wanted, but the 17% speed decrease worried me. Our team has found a way to make the transmission fit with bigger wheels, but it requires turbo motors to be geared down 3:1. This would makes us about the same speed as most robots. Should we make the switch, or do turbo motors stall too quick? I’m not sure because they would be geared down to a slower speed.

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I’m assuming this is for vrc because there are no mobile goals in iq.

by “turbo motors” do you mean v5 motors with 600 rpm cartridges?
if so, gearing down a 600 rpm motor 3:1 will make it theoretically identical in speed and torque to a 200 rpm motor. In reality there will be some power loss due to friction in the gears, but not a large amount, and you likely are going to be using gears anyways so it probably won’t make a difference.

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Yeah, 600rpm turbo, sorry for not stating that😅. But would there be an slower acceleration curve (compared to fast motors) as the turbos would have to rev up to max speed?

no because by changing the gearing your output will spin at 1/3 the speed and with 3 times the torque. Identical to the speed/torque of a 200 rpm motor. Which means your spinup time would ideally be the same.

In reality, it would probably be ever so slightly different for a lot of reasons (mostly friction) but not to the point where it would effect your robot if built properly.

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Why not just use the 200 rpm gear cartridge? You wouldn’t need the 3:1 reduction and you wouldn’t lose additional power to gear friction.

The way our transmission is built, we had to use small wheels. That makes our robot slower. But we could use the bigger omni wheels and a change of gears along with turbo motors. This makes the 600rpm go down to a 200 rpm drive. Transmissions can’t have the motors directly mounted to the wheels, there’s a gear box connected the motors to the wheels.

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If your 600 rpm is being geared down to 200 rpm, you can just use 200 rpm cartridges directly unless im missing something

It’s only being geared down because there is a gearbox linking the motors to the wheels. I’m using smaller wheels right now because they fit better. That makes a robot slower, even though I’m using 200rpms. To try to fix this, I want to swap it out with 4inch wheels. But then the transmission doesn’t fit cleanly. That means the sizes of the gears have to be manipulated to a 3:1 gear ratio. The original pinion gear on the wheel axel would be swapped with a 36 gear. The driver gear is still a 12 tooth pinion. That means the robot is 3x slower with 200 rpm motors, so I want to use the 3x faster turbos to negate this.

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I’m confused by what you mean by “transmission”. Do you mean a simple gear train, or one that uses a differential or pneumatics to switch gears? If you have the space, you could also consider going with a 600 3-7 for 257.

A better and more complicated version of this

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Motor sharing is a useful idea, but I don’t see where your gear train prevents using larger wheels. Aren’t those 4 inch wheels in the video?

Ok, let me reiterate. My design is a lot more complicated than this video, it was just an example. If you have a pinion gear on the axel where your wheel is mounted, you need to have a gear that is big enough to be mounted above the top of the wheel. Otherwise the axels will not be suspended on 2 sides.
image
Small Wheels allow enough clearance to fix this issue. I could use a bigger gear on the axel, but that messes with gear ratios.

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