pic: Concept 8wd Drivetrain

[AdamHeard]

Originally Posted by B.Johnston

One way to avoid tensioners is design.

Not that you can see the chain in the pic I attached.

We:

1. used sprockets with an even number of teeth.
2. spaced them apart a multiple of the chain pitch (#25 = 1/4")
   our axle CL to CL = 10"
3. changed the chain loop when it stretched to sag more than 3/8"

And to answer Cory:


Here's why I like redundancy and fault tolerance.

2006

2nd match of the Greater Toronto Regional (Finals)

We're(1680) up on 1114 by 1 match

30 seconds in our driven transfer sprocket shatters kinking the chain.

We spin in circles for the rest of the match.

now even 1 -1 against our sister triplets (this was an amazing tank system)

Change the broken sprocket with a replacement (from 1114 BTW)

Third match in autonomous we throw the chain...

The rest is history.

With redundancy and fault tolerance you shouldn't be susceptible to these sort of events.

Those who fail to learn from history will repeat it.

Yes, redundancy and fault tolerance are good, no one is disputing that.

What people are disputing is putting too much emphasis on it rather than what the problem truly is.

If you are throwing chains or breaking sprockets in a drivetrain, the issue isn't that you don't have enough redundancy built in; the issue is something is causing you to throw chains and/or break sprockets. Sure, adding a lot of fault tolerance is a way to reduce the negative effects of the problem, but I would rather have a system that didn't break as much period.

Also, when it comes to choosing numbers of wheels in a drive, fault tolerance should not be a factor. Fault tolerance is something that results from good design.