Drivetrain Debate

Our Drivetrain is currently and 4 motor direct H drive. We are debating making a 2 motor chain drive so we can free up two motors for things such as a ring collection system to score rings on home MOGOs. We don’t have access to pneumatics, so we are stuck there. Would a 200rpm 2 motor drivetrain be able to carry a 15-18 pound robot up the ramp with 1-2 goals?

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2 200 rpm motors to carry up 1-2 towers up the bridge would require a hefty gear ratio. However I have seen teams use a tank tread drive go up the bridge with much more success. In my opinion a bad drive train and rings is worse than a good drive train without rings especially this year were speed is king.

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This is what my team was thinking. I agree with this.

Absolutely not. I can confirm from experience that 4m can barely get a bot up the ramp with two goals. Doing so with two motors would not be feasible. Before I obtained pneumatics I had a fairly successful bot with 4m 257 on 4in omnis, 1m 100 rpm 1:7 lift, 1m 100 rpm clamp, 1m 600rpm ring mech, and 1m 20 rpm tilter.
With this setup I was able to barely park with two and often times found myself unable to park in matches because my motors were starting to heat up.
I would recommend doing a 4m 200-257 rpm drive on 4in wheels if you want a chance at making it up the ramp (no guarantee without 6m drive).

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Alright. We can make it up the ramp with traction wheels in the front, and omnis in the back. We can only get up if we have 2 goals to hold us down.

What is your motor distribution?

If you can already make it up the ramp I would recommended taking a motor from somewhere else on your bot for a ring mech.

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Make a 4motor 200rpm drive with a 1motor 600rpm intake with a 1motor lift 1:7 100rpm with a 1motor locking clamp and a 1 motor rear tilter. Best way to go if you don’t have pneumatics.

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I would caution you against using anything less than 4 drive motors. Most teams use at least 4 and many use 6. With only 2 you will likely not have enough drive torque.

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This is what we have, except we have a two-motor lift. We are not sure on how to make the 1 motor lift. We can try though.

2 motor 4-bar, 4 motor drivetrain, 1 motor clamp, one motor tilter.

we use a 1:7 on a 100 RPM motor for our lift. The thing i will mention is that you have to have space to run an axel to both of your arms. I strongly do not recommend 2 motor drive.

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We use 1 motor 1:5. You don’t need two.

This is the best picture I can get. I don’t know the distance between the two poles. So both arms need to be powered?

You could probably get away with a one motor four bar

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Run an axel al the way across so both sides are driven. Then use rubber bands so that the tension In the rubber bands pulls the arms together so it takes less energy and force fron the motor to lift it

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This is what I was beginning to think.

I have had 2 motors for a few weeks at the beginning of the year and when we switched to 4 motors, it was a great choice. I have no idea how your robot performs, so I can’t say what is best for your bot, but for us, it was one of the best decisions we could have made.

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Just use 4 motor drive then one for 4-bar, one for ring intake, one for back lift

Teams will frequently use a center motor / gear assembly and T off of that to the arms. This alleviates the stress and twist on long axles.

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Do you have a picture of this? We are not sure how this would be done?