Heavy DR4B lift

VEX V5 General Discussion Technical Discussion
#1

So our lift is made of aluminum. we have linear slides to pick up cubes. but the linear slides are weighing the lift down. we upped the power to 200% and is still no going high enough. i don’t have any pictures for you guys. just need some suggestions before the 7th of December.

Thanks.

#2

What are your gear ratio for the arm, how many motors are you using, do you have any rubber bands?

#3

Theoretically you can counter all weight of the lift itself with rubber bands

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#4

i am not sure for the gear ratio but we are using 2 motors on the lift and yes we are using rubber bands.

#5

we have 4ish rubber bands on each side.

#6

‘Not getting high enough’ indicates your bands aren’t pulling with a near-constant force, look up some of the methods for triangle banding to keep the bands a balanced force.

3 Likes
#7

Try to add more rubber bands. Which gears do you have where the motor is or do you have any at all?

#8

i will come back to you around 3:30 Thanks.

#9

Just keep giving my team and i great suggestions!!!

Thanks

#10

You can increase the gear ratio, shorten the arm if you want, remove parts not needed, reduce friction.

#11

our gear ratio is 84:12

#12

Lol there ya go

Your gears are backwards, your lift needs more torque. it needs to first power the small gear which then powers the big gear at a slower speed

#13

ya i miss said that, it is 12:84

#14

Why do you have linear slides to pick up cubes? a claw would be a lot lighter.

I think It’s actually supposed to be driven gear/driving gear, when talking about gear ratios.

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#15

this is our design.

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#16

oh, I would suggest making custom linear slides because they are much lighter than the steel vex ones. You should also use the 100 rpm torque cartridges.

#17

how do you go about making custom linear slides?

#18

You’ll probably need more if your lift isn’t working. Our lift is probably similar to yours and we have 8 per side.

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#19

I think your example proves my point…

They use 2:1 as an example where the motor rotates twice and the driven gear rotates once

Regardless, for this thread you’ll want little gear to big gear. Previously you stated big to little

#20

you can use standoffs and high strength bearing blocks. standoffs are just smaller than high strength shafts so it creates i slide. it works quite well