Could someone explain the rigging on 1323’s elevator this year? I understand the internal standard 3 stage continuous rigging, but the concepts relating to the tensioning on the top and bottom of the carriage trip me up. How many rollers/spools are there? How many runs of cable? Which axels are ratcheted and how does this maintain tension?
I would also like more clarity on how this all works.
FUN Behind the Bumpers Video for context.
I count 10 roller/pulleys, and 2 cable runs and it tensions on the carriage where the ratchets are. It also sounds like they rigged their elevator upside down so that the elevator gearbox is integrated with their carriage passthrough intake.
So not to scale and as pretty as their cad, but it’s the general idea. (Just one side and not accurate now that i realize they did it differently)
That’s 3310 2018 though
It’s pretty similar tho
Does anyone know the cable that they are using? We used steel cable on our 2018 bot and it had a really large bend radius but the cable on the 1323 looks to be very flexible around the rollers.
It looks to be grey Dyneema rope in 1/8" or 7/64" diameter. A lot of teams use that kind of rope as it’s extremely strong and light and also relatively cheap.
What material is it?
Ultra high molecular weight polyethylene or UHMWPE for short.
That sounds fancy do you happen to know where they get the rope also is it 1/8"
You can get some from West Marines.
Check @YaBoiScarce link. The rope we’ve used from West Marines in the past was 1/8" but I can’t say for sure what other teams use. The thinner rope would probably be way more than strong enough for just about anything an FRC robot would be doing though.
We purchased ours from EmmaKites on Amazon. I believe we used the 1/8" for our climber last year and didnt have an issues.
We bought ours from Online Ropes and have had tons of success with it this season. AmSteel Blue is made out of Dyneema fibers and is crazy strong. We had no problems with 1/8".
Thats looks like a cad, you have a file or just the picture?
I can get some better pictures later this week but some information:
- There are 4 string runs, 2 to pull up and 2 to return.
- We used 4 ratchet wretches so we could tension each string run. Initially we only tensioned the pull string but over time it would result in super loose return string runs. Ratchets are on each end of the string run and are simply attached to pieces of 1/2" hex.
- This years elevator is 3 stages because we wanted enough overlap & travel when scoring on level 3.
- The rope used is bought here
- There are two spools at the bottom of the elevator that have both the pull/return string on there. To make life easier we geared them together so they would spin in the opposite direction.
Overall we were very very happy with the internally rigged string elevator. Its a drastic improvement over the cascade style elevators we have done in the past.
Wait. The ball gets intaked over the rollers?