Quote:
Originally Posted by Chak
Chain doesn't stretch all that much for FRC robots, especially #35 chain. So, if you have decent manufacturing tolerances you can just set it and forget it.
If you do want tensioners just in case, vex sells bearing blocks + cams that you can buy/imitate. |
This is definitely not universally true, and shouldn't be posted as a general statement. It is a function of the size of your chain (25 vs 35), size of your sprocket, size of your wheel, loading, run time, etc. With the small sprockets used in WCDs, "chain stretch" (really, chain link pin wear) is absolutely possible and should be accounted for.
Quote:
Originally Posted by Type
My team is looking at developing a West Coast Drive platform during the off season so we have more knowledge about one before this year's game is released. We pretty much have our CAD finished up but the issue we are running into is figuring out how to keep the chain tight. We thought of making sliding bearing blocks to tighten as the chain loosen but then we realized if each side isn't stretching the same, and we adjust one side, then it may pull to one side. What do you guys do to keep the chain tight? Do you just do the math before hand to get it close enough and just remove links when it stretches too much?
|
You can do the math for exact centers beforehand, and you will initially find success doing that. Depending on the circumstances the chain may indeed "stretch" though, and you should be prepared to handle it. It's not invalid to replace entire chain runs when they stretch too much to be usable, although it is a bit wasteful. But chain will stretch too much to be usable long before it stretches an integer number of links, so the "remove a link" method won't solve your problem - if you want to use chain as it stretches you need a tensioner.
I don't understand what you mean by "pull to one side" here. You generally chain the axles so that each axle is connected to a stationary axle (i.e. the gearbox output shaft) - that way, adjusting the axle won't mess up the chain tension for any other axles and you don't have to juggle anything.