Can't hurt to run two belts. Probably two belts, or even three, increases power delivery to the shaft, and might -maybe- even out vibration and/oscillation so as to have a smother more consistent cut. Iam just speculating on this, but just ran into vibration problems installing an out of round ancient South Bend 9" drive pulley on my 1919 Dalton lathe power chain. So am wondering if multiple belts spread the load a bit on the VN drive chain.
As FYI, I worked on restoring my '47 VN 12 this past week. I noticed the motor is an original Westinghouse Boat Corporation motor - 1 1/2 hp, 3phase, with a rated speed of 1145 rpm. It has a two belt pully that looks original, although now only running one belt. Images of Victory at Sea and the Silent Service come to mind...
Note : just went out to the shop, and it is NOT a three belt pully as I originally posted - that was the pully for a Burke #4, and it is stepped for speed reduction - Must have been a senior moment. Anyway- edited my post to 2belt , so as not to mislead...
My guess is aboard ship in WW II these things were set up to be bullet proof, mega redundant, and take max cuts every time they were used. hence the big motors, multiple pulleys and heavy duty belts. My belt is a leather link belt affair with steel locking studs through each link. The leather links are very supple, but thick and impervious to breaking - so I concluded after 30 minutes of twisting and fiddling wilst trying to break it open. Finally just left it on the shaft when I pulled the motor. Would like to add a second belt, but don't know if modern belts will be compatible with the existing workhorse.
