3 Motor Gear Box For Fast Base

My team and I have been wondering how to apply our last 2 motors to our robot (currently have 4 base, 2 arm, 1 claw, 2 mogo). We want to add them to our base and increase our drive speed. Currently we have 4 high speed motors directly connected to each wheel with no external gear ratio. If anyone knows how to create a 3 motor gear box for fast speed to where I can attach to the back of my robot and run a chain to our robot’s front wheels. The gear box can utilize any 3 of motors (standard, high-speed, turbo). I appreciate all feedback and thoughtful responses. (PS: if there is already a thread nearly related to my post can you please link me)

Team 461B

Might want to reconsider your means of lift. An arm won’t get you far. Otherwise, add two to your drive.

People say arm and they mean whatever kind of lift they have, not necessarily 1-bar or 2-bar.

It really depends on how much space you have. Since your robot is completely built you may not have space in the right places to fit a gear box. Posting a picture of just your drive will get you much more helpful responses.

Last season we did a 36T:36T:36T gear box with a sprocket on the middle gear. The sprocket drove two more sprockets; one for the front wheel and one for the back wheel. We had many issues in the beginning with the chain snapping bc we had too much/too little tensioning. Since all the wheels depended on the chain for power, if the chain broke then the entire side of the drive wouldn’t have power. After a lot of trial and error, we finally got the tensioning, but it was not elegant. Another team that we were close with wanted to make a similar drive, so we suggested that they hook up at least one wheel per side to the gear box directly so even if the chain snaps at least one wheel per side receives power.

You might want to consider doing a pair or motors and a single motor— instead of all three combined— per side so you have more flexibility.

We are using a 2 motor 1 bar chain bar with a 3:5 gear ratio. We can score 6 cones max at a very fast rate. We plan to add to the ability to stack higher if it is needed, but I’m sure at any tournament we can alliance with a high stacking robot while we finish 3 other mobile goals with 6 cones each.

We have enough space to accommodate a gear box. I was quite vague with my description early but we want a drive train that utilizes 6 motors to drive at a relatively fast speed.

You could consider a simple rack-and-pinion or elevator lift in order to expand that capability.

Yes we are working on some designs but our main priority before our tournament Saturday is to get a faster base.

Chain extra drive motors together, then. (See attached).

My team did this type of design on our starstruck bot and it was really fast.

Red = sprockets
blue = chain
black = c-channel/wheels
purple = motor

doesn’t the speed of each motor change because their mounted to different sized sprockets on the drive?

they shouldn’t because the ratio is still 1:1

you sure cause that is a 1:2 ratio with a motor on each. That means one rotation of one motor is twice for the other?

So this is what’s weird (I didn’t expect any mind to be paid to the sprocket size, sorry). We only could find 4 sets of turbo gears, so we have 4 motors that are turbo (directly on the shafts with wheels) and 4 high speed motors chained to these with a 3:2 ratio, so the math works out.

I see , sorry for pointing that out i was just weirded out by it