Here is a drive train made from 80/20. My team is looking at making a test bot this fall. what do you all think of it?
Note: I am aware that there is very little chain wrap on the middle gear. Taking care of it:)
Here is a drive train made from 80/20. My team is looking at making a test bot this fall. what do you all think of it?
Well, first off, the middle wheel will spin in a different direction than the two outer wheels because of the way your chain is right now. I also don’t think that chain-run would work (even if you neglected the fact that the middle wheel is spinning in the opposite direction) without any sort of tensioning system. Even then it would have a higher chance of slippage because there isn’t adequate chain-wrap.
In my team’s past experience, we have always found it difficult to precisely drill holes into 80/20. When trying to offset the holes by 1/8th of an inch (which I am assuming your middle wheel is) the drillbit tended gravitate towards the channels of the 80/20 because it’s unlike drilling into a uniformly smooth surface. However, we centered everything manually and used a drill-press.
that middle wheel is also going to go the wrong direction. otherwise it’s pretty nice.
I should know that I type too slow to get the first post
I like it for a simple drivetrain. A couple things to think of. How are you actually going to tension the chain? I see guides but nothing adjustable. Also it might be easier to drop the transmission down between 2 of the wheels and just have 3 separate chain runs. It would lower the Center of gravity as well as increase redundancy a bit. This design doesnt look like you’re really using the 80-20 adjustability so why not just use plain aluminum tube? You would save weight and potential failure points from loosening fasteners if you weld it
If you weld or drill through 80/20 in this fashion you get pretty much the same weight as 1/8 wall tube and adjustability for whatever you put on top of it. Worked for Shaker this year.
It might be easier to run a Supershifter in the middle.
I plan on running two chains from the gear box, one chain down to the middle wheel then to the from there to the front wheel, and the second to the back wheel. Since the AM shifter is made to have two sprockets inside of it.
For a tensioner I planned on making something that would mount into the slots on the 80/20 bars and/or spacing the plastic slider up with aluminum spacers and washers.
Drilling shouldn’t be a problem. it should be easier to do on a Bridgeport.
My team normally has been able to weld our robots. however we don’t think that we will be able to have welding done this fall.
I know I could use Supershifters and it may be easier. However I wanted to explore other ideas.