Chris, thanks for your input.Willem, I dont know the pulley diameters of your machine, thats why I asked about the calcs. It may be "ok", according to the calculation. I dont understand your last comment about belt tension versus joint fit though.... ?
I won’t put the time in to go into the belt drive design calculations and the belt manufacturer’s empirical data to prove a point. I did this 17 years ago when I purchased my G1026. In 17 years mine has done a lot of mileage and I replaced the belt three times. Each time was due to operator error.
As per your last question, on any shaper if you over tension the belt, with high quality cope and stick cutters, the joint will become too loose and you will have to shim. A 3hp is really entry level and it becomes more prevalent. Therefore not a good idea to change pulleys and belts on a G1026, as the spindle housing and bearings are light and will deflect more.