Standard motors externally geared vs turbo motors

Are their any downsides to externally gearing standard motors for speed instead of using turbo motors?

Always gear internally when you can. External gearing can cause unnecessary friction.

@8283 Despite the friction, if you had an external gear ratio that was equivalent to the internal ratio of turbo motors. It would technically go the same speed, right? (Not accounting for the friction)

I don’t think it’s possible to get a 1:2.4 gear ratio with vex gears, but if you used a 3:7 gear ratio with strength motors, ignoring friction, your robot would be nearly as fast as if you were using turbo motors.

Also it’s worth noting that all internal gears are a huge reduction from the actual speed of the motor. If you had an external ratio equivalent to torque you’d be doing a lot of unnecessary work. For example, let’s say you need a shaft turning at ~240rpm. The internal speed of the motor could be something like 1000rpm, reduced to 240 in a turbo motor. If you used a torque+external, it’d have to be first reduced to 100, then back up to 240.

you are able to get a 2.4 gear ratio with sprockets and chain, but the down side is there that there is most likely going to be more friction when you externally gear the motors. Internally gearing the motors is more efficient.

Yeah, as stated above you can use sprockets and chain to achieve nearly the 1:2.4, but there will be more friction as well, so it’s undesirable. If avoidable, don’t do it. The ratio can be achieved through a 6-tooth green sprocket and gray 15-tooth sprocket available in the tank tread kit. This will give you a 1:2.5, which isn’t quite perfect but I’m pretty sure it’s as close as you can get.

@536 Xavier Robotics I believe the low strength sprockets include a 10t sprocket and a 24t sproket