So… What successful winch designs did your team use to pull your robot off of the ground? CAD/drawings would be highly appreciated, but descriptions of your systems would be great as well!
For context, over the weekend, my team (7486) competed at the Miami Valley Regional and got destroyed (57/60…). Our robot just wasn’t finished (extreme lack of collaboration and teammate inclusion), wasn’t well-built, and we hadn’t done any prototyping or had any practice whatsoever. IMO, it was the 2nd SZN curse; we completely over-extended ourselves and tried to tackle everything in the game with limited funding and we didn’t use all of our manpower. Our intake and shooter were both shoddily built, but we were able to fix those, but our hang mechanism… Yikes! We were never able to successfully hang and our entire robot is just scuffed in general.
We had two 18-inch pneumatic pistons on either side of our robot that were stored in a downward position. The pistons were connected to each other by a churro and were subsequently moved to a vertical position, extended, and then we drove the robot forward so that the hooks (which were on the ends of the pistons) would be above the bar. The pistons would then be unextended and we would use a ‘winch’ to attempt to pull our robot off of the ground. The ‘winch’ consisted of a Toughbox Mini with 2 CIMS acting as the winch motor (the gearbox/motors caused us several problems), a ratchet that fit around the hex shaft, and some laser-cut wooden disks which ‘blocked off’ the part of the hex shaft that the paracord wrapped around. The paracord was attached to the pistons.
We are most likely going to be completely scrapping this design and replacing it, so I would prefer that you discuss your team’s successful winch design instead of proposing possible solutions regarding our current system’s issues.
(We only signed up for the MVR, but one of the teams who won the MVR offered us their spot at Buckeye… Still waiting for FIRST to get back to us on Monday…)
Thanks for everything!
The design many teams have used is to use constant force springs to extend their climber, and then ratcheting down the robot with a winch, often with a telescoping tube-style climber. This has worked fairly well for us, although we wished we had a little more extension height after LAN. You will need either three stages or some other method of getting the extension amount you need. We opted for a flip solution that is fast and effective.
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Do you know what teams have used this design? I am going to try to find a video of it in action. Also, what motors/gearboxes/gear ratios did teams use for their winch mechanisms (our ToughBox had lots of troubles…) and what do you mean by ‘flip solution’?
Our team did regret not having a centered telescoping box tube ‘elevator’ and we wouldn’t have used the pistons if they weren’t free (FIRST Choice).
Thanks!
We have a big spool attached to to a motor (i think a redline?) and on the other end, a ratchet. Theres a hole slit in the spool where the strap comes out (replacing/repair will be very hard but we do not think the strap will break), with the other end of the strap at the top of the hook.
To extend above, we have 80/20 bars with paracord rigged continuously. This is basically an elevator with no carriage. One end of paracord is connected to the innermost bar, while the other is secured into another winch. There are 2 videos of our climb on our instagram
Thanks! I am slightly confused by your climb, requiring 2 winches… Can you further explain?
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1293 ran two of these, one on each side for fear of grazing the ground since we were mounting them very off-axis. As it entered Palmetto:
- RedLine A motors at 80:1 (20:1 57 Sport, 4:1 HD Kickup Box from FIRST Choice)
- Surgical tubing instead of the extension springs (easier to tune and interface with if you’ve got someone with knot-tying experience–we have many people with a scouting background)
- Otherwise, stock.
As of the end of Palmetto, it has a few changes:
- Replaced the strap with a couple runs of paracord after it detached from the hook
- Chopped up some Allen wrenches to help keep the hook seated in the PVC pipe
- Turns out that one hook can get us up. But if you’re only doing one climber and powering it like we did, I’d still do two motors into the gearbox on principle.
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Instead of powering the elevator both ways (extend and retract), we retract by winching up the strap you can see in the newer video. You can also see the elevator slowly drop due to weight and gravity (this does not affect us that much so we’ll leave it be). When the black strap winches and shortens, the blue paracord just goes limp and loose.
It’s essentially 1 winch for the strap and 1 winch for the paracord
Oops, we kinda ‘overlooked’ the EveryBot’s climber…
That is actually a really cool design, and I think that we’d probably have to run two of them as well!
Thanks!
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Okay, that makes a lot more sense, and that actually seems like an EPIC design. I wish that we would’ve incorporated a strap, but quite honestly, we don’t really know anything about winches… We definitely should’ve reached out to CD before the MVR, but we weren’t planning on even using a winch until a few days before our competition when our original design didn’t work whatsoever!
When does 1665 compete?
W3 and W4 at NYTR and NYSU
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I’ll have to watch! Thanks for the help.
Us, 3647, and 4414 have the same climber. I’ll DM you a video of it deploying to protect a student’s privacy.
We PTO’d off our drive gearbox to climb, whereas 4414 is using 2 Falcons to climb. I mean, you can use any motor to climb so long as you’re willing to trade off time (power = work / time).
You’d generally want to use a somewhat custom gearbox to climb, but if those are out of reach then you could for sure go for something like a WCP single speed gearbox or a 57 sport gearbox. I would NOT use a versaplanetary to climb
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Our hook is shot up with a parallel bar lift and two pistons - one for when the bar is balanced, both for when it’s tilted away from us. Then we drive into the bar and drop the arm so it’s just the hook and paracord resting on the bar. Finally, we use a Neo with a 20:1 Versaplanetary gearbox and ratchet kit to winch ourselves up. It’s a fast, reliable climb, with the only issue so far being the hook falling off the bar occasionally due to its center of gravity being a little far back.
For our climb we used a 3 stage versa planetary gearbox. We use a ratchet and pawl to keep ourselves up after our robot is disabled.
Same here, but we use two so we can offset weight one side or the other on two independent hooks.
Looking at some of your matches you seem to be a tall bot. I think this simplifies your design constraints a lot. First you need to either prioritize funding or time. If you want to give more time to test design changes then I would go with the GreyT elevator with climber hooks as done in WCP CC I believe 6814 also had this style of climber at LAN this year. If you want to prioritize funding then I would go with the Every bot climber. Both are very reliable if done correctly.
Yeah, I would say that we are ‘tall’ but IDK if we can even be considered a ‘bot’! Our main downfall this year was that our Engineering Lead basically only allowed 2-3 people to build the robot, and those 2-3 people where the Engineering Lead’s friends and didn’t have any FRC experience. I would show up to our meetings and just sit there, waiting for something to do, and whenever I, or anyone else who was excluded, would ask to help or to start our own projects, they would say that ‘there was nothing to do’ and that ‘everything was under control’ even though it obviously wasn’t.
If we do compete at Buckeye, I will try to be as involved as I possibly can and will try to get everyone else who doesn’t get to work on the robot as much as they want to help. Hopefully these 4 weeks will actually be productive, as most of our team was literally embarrassed by our turnout. It was a great learning experience, and if we cannot compete at Buckeye, I hope we will have some serious changes next year…
^ That got really far away from the topic of hanging, but I totally agree! If we are able to completely overhaul our current hang system, I think we will try to go for the EveryBot climber since we are a bit low on $ currently. Our hang was totally scuffed and it was evident that we wouldn’t be able to get it to work at the MVR with the time/materials that we had. I wish that we would have prioritized our needs and been more productive, but hindsight is 20/20 and we were competing in Week 1, so…
Thanks for the help; I appreciate everyone who took the time to comment!
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We used an elevator kit but instead of using a traditional rectangle frame between the masts we used a single piece of 1x2 tubing. It is chain driven using a 100:1 gear ratio with a Vex ratcheting gear box that can be engaged using a servo. A bag motor is used to power the gear boxes.
