What are some common lift gear ratios for tall lifts such as DR4B. I am thinking a 5:1 for torque would be ideal, but I am not sure.
After scrounging the internet, it seems like 1:7 is the way to go.
Why do you need a 1:7? The cones are extremely lightweight, unless you plan on lifting mobile goals with it as well?
Yeah but keep in account that the movable goals need to be lifted in order to bypass bumps to be placed into zones. Movable goals are about 3.7ish lbs
I’m thinking of doing a 1:7 with speed internals. Should get the job done and will be able to lift the mobile goal if necessary.
Double Reverse Four Bars lift at twice the speed and half the torque of a single four bar, so your gear ratio seems a bit too aggressive for lifting the goals.
The way I made mine lifts the exact same way a 4-bar would
Well this gear ratio is just a little faster than 5:1 with torgue motors if you convert the 1:7. It is with speed motors, so converted to speed with torque motors = 7 / 1.6 = 4.375, so ratio = 4.375:1.
I think that though with enough rubber bands you would be able to lift them fine.
If you have a 1:7 with torque, tensioned with bands for speed, it should be fine I would think. If it’s too slow, I would consider going to 60’s or keeping the 1:7 with high speeds. We’re not allowed to test yet so we’ll figure out in a few months.
What does “tensioned with bands for speed” means? As far as I know, one put rubberbands to make a counterweight for the lift.
More or less that.
Did anyone think about a 1:5 with high speed internals and rubber bands?? That might be enough because its not that much weight and this ratio will be a lot quicker.
That’s actually what I was thinking, if 4 HS motors with a 1:5 external gearing could lift a bunch if starstrucks…
meta prediction:
2 motor turbo 7:1 dr4b
who needs torque
I know that. I want my lift to be fast, but still hold a lot. That’s when rubber bands come in
I feel like this might be a bit too aggressive, but it’s worth a try. The issue with this might end up being that you have so many rubber bands that the arm struggles to come down rather than go up. I have actually seen a few robots that struggled to lower their arm because of the intense amount of rubber bands.
Ok. I just wanted to point out that they are pretty close to the same ratio, so if one doesn’t work the other might be a good choice without sacrificing too much.
Wouldn’t it make more sense to take 2 motors of the lift and use them elsewhere? Make a 2 motor linear lift to just pick up mobile goals maybe, that way you get speed for cones and torque for mobile goals. Then do a 1:5 on the lift.
Is it possible to do an effective/efficient DR4B with only 2 motors?
Maybe not a 2 motor 1:5, but a 2 motor 1:7 should be easily doable. Teams in skyrise lifted 12+ times as much weight with 4 motor 1:7s.
I still feel that 2 motors would be too little if you wanted to make it very durable and fast.