I was asked how my idler wheel setup worked. First I needed a place to mount it and there was this crank shell at the back of my frame so,,,
1. I made a wood plug and to make sure it was a tight fit I wrapped it in hockey tape.
2. Next I put one bearing cup into the crank shell.
3. Then tapped in the plug
4. Next added the second bearing cup to trap the plug.
5. I then needed to space the idler wheel out so I used some 1/2 sced 40 pvc to space it
6. Added the idler wheel.
7. Gathered the chain up into the UHMW plastic piece I machined previously and bolted it all together.

Works quite slick I must say. Greg asked me if the top chain or the drive chain was being pulled down or redirected by this idler setup as it would make a low efficiency system, so, worried, I went to the shop and checked, strangely enough it does not hinder the chain in anyway all the way through the gears... Got lucky on this one eh!