Same here. I use the 6"x 48" or 12" disk for larger stock, and the 1"x 42" for the smaller stuff. The 1"x 42 works great for sharpening mower blades. Much easier to maneuver the longer ones into the proper position. I also like the fact that it only takes a few seconds to change belts on the smaller machine. Sometimes locating and tensioning the 6"x 48" belt can be a real PITA.I have a 6 x 48 belt grinder with a 12" disc which I use a lot, and I use to have a 1 x 42 belt grinder, and neither one have variable speed and I never had a desire to have variable speed.
Ted
To make things even more fun there’s also this doohickey called a linishing machine.Same here. I use the 6"x 48" or 12" disk for larger stock, and the 1"x 42" for the smaller stuff. The 1"x 42 works great for sharpening mower blades. Much easier to maneuver the longer ones into the proper position. I also like the fact that it only takes a few seconds to change belts on the smaller machine. Sometimes locating and tensioning the 6"x 48" belt can be a real PITA.
One thing I noticed a while ago when looking for belts for the 1"x 42" is that machines listed as "belt sanders" usually have speeds around 8,000 SFPM and use relatively low hp high rpm (3450) motors. Those listed as "belt grinders" usually run at 4,000 SFPM or less and use more powerful lower rpm (1725) motors.
Having said that there are certainly marketers willing to list their machines in whatever category they think they will sell the greatest numbers.
3.14 x 6.69" x 1400rpm = 29,409 inches per minute. Divided by 12 for FPM belt speed = 2450sfpm= (pi × drive wheel diameter) × motor rpm.
They give very different answers,so now I am not sure.