Reply by toolie

Is it necessary to get a matched set?

IMHO, no. the video i posted with the nickel test is with 3 dayton belts, about $5 each from grainger, not a matched set.

How much deflection should the belts have when they’re properly tensioned?

the weight of the motor provides the tensioning force. your OM should have a write up on tensioning.

-- there's a solution to every problem.......you just have to be willing to find it.