Compressor has bad belt slap
I built a Devilbiss 445 with parts i had laying around. The tank is a 200 gal. Devilbiss with a right and left compressor pad, prob. set up for center mounted electric motor.
The first rendering was with a 13 hp gas engine and 4" motor sheave, which spun the pump just fast enough to be in spec. This was a proof of concept thing, i knew the engine wouldn't last, and it didn't.
Now I have a 28 hp Diahatsu diesel, i'm using a 8.25" sheave and a 3 groove BX105 banded belt. The issue is with both motors, i have the most insane belt slap ever. Both the work and coast side of the belt.
I made a spring loaded idler pulley for the coast side, then added 3 more fixed. It helps but its just covering up the problem.
Is there some strange magic I don't know of going on here?
My main form of work is large scale HVAC so i know about belt alignment and all that stuff. If i didn't know any better id think the pulses from the pump are at war with the motor.