Gear Ratio

We have a 3:1 gear ratio right now with a 12 tooth powering a 36 tooth which has a 12 tooth in the middle which goes up the vertical tower to lift the scissor. We want to increase the speed but still keep a lot of torque in it.

So would a 2:1 even make a difference noticeably? or what would be better.

Since we have built a huge mechanical mess of a robot, as in it is not fun trying to change things inside of the robot because it takes a long time and we don’t want to waste time if it won’t help it.

Whenever you want help with a robot its always much clearer to provide pictures as well as describing the problem.
To me it sounds like you want to increase the gear ratio, to something like 1:7 to give more torque rather than less.
But without seeing the robot it will be much harder for people to help or offer advice (myself included).

This is what we have.

My better photo won’t upload from my phone. Tell me if that works

I got the better photo now.

I’m going to guess that you want to find the best-suited gear ratio you can; in other words, you want to have the motors geared for as much speed as you can while still being able to lift.

From here you can make a pretty good guess of what gear ratio you need; but why not do the physics/math on it?

torque = radius x force

torque = torque of one motor (provided by VEX)number of motorsgear ratio

radius = length of the member you are trying to turn

force = weight of what you are trying to lift, so game objects, aluminum, steel, screws, motors, pneumatics, intakes, yourself, the field, etc. plus a 15-20 % safety factor. (mostly for friction and other things you might have missed.)

So now we can set up an equation and solve for your gear ratio. This is really pretty easy math.

And now you know the minimum gear ratio you need to lift whatever you want to lift.****

I think I did it right, I got 19.65/1 so basically 20:1 gear ratio. That seems quite large and slow.

hmm…this looks familiar, haha.

4149G Scissor Rack and Pinion

Also, we haven’t had much luck with it. The way we designed the lift didn’t work out well, so we actually changed our game play method. We only had the lift go up once…seen in the video below.

Video of Quarterfinal Match - 4149G Scissor Lift that Deploys and Stays Up

Haha I got inspiration from your first video you released. It’s been a pain trying to fine tune that lift (the friction on the slides is horrible). It’s not too slow but takes about 6 seconds to go up 3 feet. It’s worked great so far, we get around 32 points in a match w/o autonomous points just by ourselves doing pegs and cubes.

The only issue I have heard about the why you built yours, is that the chain can snap when it is expanding up.

Very happy to hear you saw our video! It’s always fun to know that people really do watch!

Regarding the chain snapping issue, we never had that problem. We played over 25 matches at various tournaments without any problems. It did take a lot of careful work to make sure then chain could expand without getting caught on anything and stayed on the sprockets. Of all our matches, I only recall one match that the chain deployment didn’t work correctly. (It didn’t break, just came off the sprocket)

That’s good to hear that you don’t have that problem!

Do you have the ability to do pegs or just cubes?

We could do skyrise sections also. We didn’t do any in that match because our partner wanted to do them.

If we only do the skyrise during a match, we can build the whole tower. But it takes the whole time. We are more efficient at cubes.

Edit: We are currently making a reveal video for fun. Hopefully will be out in a week or two. It will show how everything works.

That makes sense, and can’t wait to see the reveal! Hopefully I can do our teams reveal soon