Bearing Blocks vs. Idlers

[BJC]

Originally Posted by MattC9

Recently I have been looking to chain tensioning systems for drives and I have been designing in a movable idler sprocket into my drive, but recently I have herd that idlers decrease efficiency and take power away from your drive. I would like to run bearing blocks but I think they require a lot of machining. Do bearing blocks require a lot machining, and are they worth the extra effort when it comes to the over all efficiency? Also do idlers really take a lot of power away from the system, where you would want use a lot of machining resources for the bearing blocks?

If you have any other input tips or tricks that you have found while designing something like this I would love to hear it!

I'm guessing that you heard this from the Wildstang drivetrain video.

In 2011, 33 used a bearing block setup which pulled the chains tight. This drivetrain was around 85% efficient which is pretty good.

In 2012, 33 ran "loose" chains. We had delrin skids which we shimed up to tention the chains but not to the point where the chain was tight around the sprockets. This drivetrain was around 92% efficient which is extremely good.

Basically, either is exceptable for FRC applications if done correctly. A bearing block setup is inherently more efficent but as proved by our 2012 robot idlers can be made more then good enough. There isn't much in the way of tentioning thats simpler then bolting 1/4" delrin slabs between wheels.

Edit: Curses! Beaten by Andrew.