Dr4b not lifting

Heeeeelp. My dr4b has 2 motors and is rubber branded but it won’t lift! I’ve seen other teams with 2 motor dr4bs that lifted. Is there something wrong with the way I’m doing it?

Rdit: thanks!

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The small gear connected to the motor has to be in between the large gears because the two large gears are spinning towards the middle. You want them to be moving the same direction. Hope this helps!

I mean the lift works, and it lifts, the motors just dont have enough power to open the lift all the way. Do you think it is a construction or coding issue?

try using rubber bands?

How many?
And taranmeyer dont show up lol

enough till it lifts

How many do u use?
20 chars

depends on what im lifting. 4-10 seems reasonable

The twelve tooth pinion seems to be in the right place so that shouldn’t be too big of a problem unless the bars touch the axle it’s on before the DR4B can go all the way up. For rubber banding, a big part of it depends on the triangle you use. With our triangle, our team uses about 5 doubled up rubber bands on each side. Also be sure that the rubber band triangle is helping the lift go up and not pushing it down.

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Also, you could try lifting with your hands to see if everything moves without the motors.

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How tight are those screw joints?
An what is this for?


if those motors are 200 RPM, then your gear ratio is a bit too high. I had a very small 2 200 RPM motor 1:5 DR4B with really reduced friction and it was pretty weak. I can’t imagine your lift would work with that gear ratio. try gearing it 1:7, but even that might not be enough.

Ah so some specs:
Both lift motors are geared for 100 rpm. The 12 tooth gears turn the 60 tooth gears.

Thing is the lift can barely even lift it’s own weight. And to answer your question, that bar on the side is to stabilize the lift so it doesn’t wobble

Edit: I’ve already made sure the acrew joints are loose enough

is the lift able to go all the way up with your hands? something could be stuck so its better to test it without motors first.
edit: looks like the bar may be the issue…

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Yes the lift goes all the way when I use my hands.
The bar also doesn’t touch the lift at all, so I dont think that’s the problem.

Is the motor speed related to output torque in anyway? If I remember correctly my speed is set to 50%

set it to 100% and see what happens

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Uh yeah motor output speed is definitely related to output torque


I think that explains a lot lol

Motor output speed is inversely proportional to output torque. Not sure if setting the output command as motor RPM would be the best strategy here to solve the issue