In the past my team has used a lot of improvised chain tensioners (pvc, bolts) and now for an off-season drivetrain project we are looking to use something a little better, thoughts?
Check out this recent thread. There are some good ideas in there:
threadid=117430http://www.chiefdelphi.com/forums/showthread.php?threadid=117430
That thread is good.
You can use special bearing blocks with tapped holes on the sides to use a screw tensioner. Look at team 221’s site for more info on screw tensioners.
Vex cams are great tensioners, but will be less rigid than screws if you don’t design it right. However, they are lighter than screw tensioners.
I personally love mcmaster’s extended life roller chain tensioners.
Fenner Drives makes a low weight plastic #35 chain idler sprocket with integral bearing. The part number is CS3502. We used to buy them from MSC but they no longer carry it. Motion Industries shows it on their website.