# Is it okay for the mobile goal manipulator to have 1:1 gear ratio?

I am using a four bar for my mobile goal manipulator. Does the four bar need to be geared so it has 5:1 or 7:1 gear ratio or can it just have a 1:1 gear ratio?

It depends on how many motors you are using and how much movement the four bar has to do but I would recommend a 7:1 or 5:1 gear ratio to have enough torque to lift the mobile goals as they are quite heavy.

I would definently not recommend 1:1 as I tried that. I required 4 motors on strength and they still needed rubber bands.

It also depends on the lever arm, some people are using rack and pinions for the lift and then you might consider making it faster than 1-1. But some people are using 6 or 8 inch bars on their four bar and you would need a gear reduction. There is more to it than just the gear ratio.

IMO you don’t need a mogo lift to be that fast. I think you’ll find that you don’t need any more than 2 motors for a mogo lift. A 1:1 ratio would either need lots of rubber bands or lots of motors.

I tried it you need 4 motors and rubber bands

This person was able to do it with a 1:1 gear ratio and only two motors.

Yes but how many successive lifts can it do without stalling out? In a match you need to be able to reasonably and safely do 2-4 mobile goals with 4+ cones. In skills you may need as many as 8 successive mobile goals sometimes with a cone or two on each.

Good point.

Please do not do a 7:1 ratio for the mogo, its only ~3.7 pounds. 5:1 is slow enough already, but if you have an external stacker, it is probably better to go with 5:1 since you will be intake mogos with cones on them. If you have an internal, 3:1 is faster and works just as well.

That is very usefull to know
I wish this thread started 3 weeks ago before I rebuilt robot and made a 1:1 with 4 motors plus rubberbands it might have worked better

lol ben

Who’s Ben?

triple b as in BBB he does rubix as in cubes and i guess likes math
@BBBcube3.14

That is all true minus the last bit. It might be a strong subject but i don’t care too much about it.

I’m using a 1:5 ratio with one motor. Works great.

That’s what seems to be working the best for everyone

Albeit my arms are only ~2.5” long
The lift arms are only ~2.5” long. Not mine.

inches? That seems, very(x10) short

Well it’s better than centimeters