I ended up using 2 bearings in each hole. The bearings allowed more angular variation than I would have liked. Putting 2 bearings on and supporting it at 2 places seemed to do the trick. The bearings I used were McMaster-Carr part number 57155K365, app. $5 each. Some of the double pendulum building guides use skateboard bearings because of their low cost – on ebay for under $1 each. They are metric, usually with a 22mm OD and 8mm ID. That causes me two problems. First, my 3/8” rod is…
Bones Super Reds Skateboard Bearings Set of 8
Penny Abec 7 Skateboard Bearings - One Size by Penny. Penny Abec 7 Skateboard Bearings - One Size. One Size.