drive belt tension
- Thread starter dmackey
- Start date
EdCaffreyMS
"The Montana Bladesmith"
I know of a lot who have mounted their grinder motors in that fashion. Personally, I have the motor for my KMG mounted under the bench, in the same fashion that most table saw motors are mounted...... on a hinge plate. Because the motor I use is so large/heavy (3 hp, 180VDC) I had to attach a spring with a turnbuckle to take a bit of the weight off the belt.
In my opinion, the biggest advantage to is is that you can build/buy a mounting plate that has the four motor mounting holes (not the slots where you slide the motor, then tighten bolts for tension...which usually causes alignment issues) With a hinge plate setup, as long as you have the hinge aligned correctly, the motor/pulley can't help but line up correctly. On some installations I've done, and others I've seen, the weight of the motor isn't enough tension....and a bolt/"tie down" was used to increase belt tension.
In my case, because I mounted the motor underneath the bench, and cut a hole in the bench for the belt to pass through..... it saved lots of room....it also keep the motor out of all the grinding swarf.
In my opinion, the biggest advantage to is is that you can build/buy a mounting plate that has the four motor mounting holes (not the slots where you slide the motor, then tighten bolts for tension...which usually causes alignment issues) With a hinge plate setup, as long as you have the hinge aligned correctly, the motor/pulley can't help but line up correctly. On some installations I've done, and others I've seen, the weight of the motor isn't enough tension....and a bolt/"tie down" was used to increase belt tension.
In my case, because I mounted the motor underneath the bench, and cut a hole in the bench for the belt to pass through..... it saved lots of room....it also keep the motor out of all the grinding swarf.
C Craft
Well-Known Member
My set up has the weight of the motor for belt tension! However the full weight of the motor is not on the belt.
Here are a few pics showing how it is set up.
The placement of the pivot on the motor mount doesn't place all the weight of the motor on the belt, probably 75%.
When I was building this I was checking to see how it was going to work when changing belt. I realized the weight of the motor was going to be hard to lift, thus the handle is too assist in the lifting of the weight of the motor when changing the belt for speed control! The motor also got away from me and crashed down into the frame. I added the chain is to catch the weight of the motor when I release it to change speed on the pulley system.
If you look at that pic you will see a spring it was added to limit the upward travel of the motor at startup. The startup capacitor gives the motor such a kick it literally jumps up. The spring does not add any downward pull but is set to catch the jump and not let it throw the belt.
I have been using this setup for several years and it has worked well for me!
Here are a few pics showing how it is set up.
The placement of the pivot on the motor mount doesn't place all the weight of the motor on the belt, probably 75%.
When I was building this I was checking to see how it was going to work when changing belt. I realized the weight of the motor was going to be hard to lift, thus the handle is too assist in the lifting of the weight of the motor when changing the belt for speed control! The motor also got away from me and crashed down into the frame. I added the chain is to catch the weight of the motor when I release it to change speed on the pulley system.
If you look at that pic you will see a spring it was added to limit the upward travel of the motor at startup. The startup capacitor gives the motor such a kick it literally jumps up. The spring does not add any downward pull but is set to catch the jump and not let it throw the belt.
I have been using this setup for several years and it has worked well for me!
scott.livesey
Dealer - Purveyor
the pros would be you don't need springs or a small hydraulic cylinder to maintain belt tension. cons would be motor is floating, so it could move causing misalignment. i have a wilmont lb1000, which bolts your motor to the grinder frame, belt tension supplied by a small hydraulic cylinder and position of your platen tool arm. I don't use a drive belt, a VFD is not that costly an item
BrandantR
Well-Known Member
That's exactly how I built my grinder, with the motor mounted on a hinged plate. I personally love the setup. It makes changing speeds by moving the drive belt a breeze, no bolts to turn or tools required. The motor's weight gives plenty of tension on the belt to keep it from slipping. The motor jumps a little on startup, but I just keep a hand on the motor as I switch it on. Not really a problem. Here's a pic of my setup. The hinge is behind the motor, so you can't see it in the pic.
