My strategy with this topic is to incorporate all I have learned from helpful bessex members and my own experience doing several conversions. I welcome replies and constructive criticism. My plan is to incorporate ideas into this initial post, thus saving readers from having to wade through multiple posts for the instructions. I would encourage readers to read through the replies to gain the collective experience and wisdom of the group.I apologize for the disorganization of my photos. I had a lot of difficulty inserting them and will clean up the mess when I am able to.
Begin here:
Any Viel belt grinder can be converted to variable speed. However, the easiest and most cost efficient way is by using a Viel from sharpeningmadeeasy.com. There are three reasons for this:
1) The bore on the Viel drive pulleys is one half inch. This is designed to match the shaft diameter on NEMA 44 motors. Unfortunately, the shaft on the Penn State Industries (PSI) variable speed motors has a diameter of fifteen millimeters. In the past, we had two choices, both normally requiring a machine shop.
1) The motor shaft could be turned down to half inch. Or
2) The drive pulley could be bored out to fifteen millimeter. The modified Viel units from Sharpeningmadeeasy come with the drive pulley already bored out to fifteen millimeters. This transforms fitting the shaft and the drive pulley from an expensive machine shop job to an easy fit home workshop project.
2) The standard six inch drive pulley has been replaced with a 3 3/4 inch drive pulley. This switch in pulley size alone reduces the Surface feet per minute (SFM) by one third. The smaller diameter of the PSI motor allows using the smaller drive pulley.
3) The Sharpeningmadeeasy unit comes with a specially designed mounting plate. This plate, a collaborative design effort of the Bess Exchange, removes the tedious layout work. It also makes assembly an easy home project with a regular electric drill instead of requiring a drill press.
A few tools are required or recommended for this project:
Required:
an electric drill with a 1/4” bit
a 1/2” counter sink
one or two small (2”) C clamps (a couple layers of masking tape soften the clamp jaws)
1/8” and 5mm Allen wrenches (The Viel pulley screw is Imperial; the PSI motor is metric.)
2 7/16” wrenches to tighten the 1/4” mounting bolts
Phillips #2 screwdriver for the 1/4” flat head mounting bolt
a 3/16” round file
a mill file, six inch mill bastard cut works well
a fine diamond file if the pulley needs a small reduction to slide onto the shaft. ( Two of my conversions needed this, the third did not.)
Highly recommended: a Dewalt or similar 1/4” drill bit, long length (twelve inches) These cost around $7.00 US and make drilling the lower right mounting hole easy. This can also be done by drilling the other two mounting holes and bolting the plate on the outside of the viel frame. The third hole can then be drilled with a regular bit from the outside. A long bit is a real convenience and will prove useful around the shop.
Secure the plate to the Viel as shown in the photograph using the small C clamps with protective tape. Looking from inside the frame, be sure the motor shaft hole is on the right side. The lower right side mounting hole is the hole closest to the bottom (long edge). This hole is the reason for the long drill bit .
Position the plate so that the bottom and right side edges are 1/8”from the Viel frame and the plate is level. Being level is really for aesthetics; it is not critical to the operation of the machine. Drill the three mounting holes one at a time. Use a piece of scrap board for backing to keep the exit holes neat.As each hole is drilled, install and tighten a bolt in it for better alignment. When all three mounting holes are drilled and secured, drill the third motor mounting hole. Then, from the outside, drill the counter sink for the top mounting flat head bolt. Drill the depth until the flat head bolt is flush to clear the grinding belt.
Bolt the mounting plate to the frame.
THE MOTOR
The PSI motor comes with a multistep pulley on the shaft. This pulley can be easy or difficult to remove. Two of my three were difficult, one was very easy. The correct tool for removal is a gear puller. You will want a gear puller with a hexagonal shape on the back to hold a wrench for leverage. Mine was an inexpensive model with a short sliding T handle. It did not work. After much strain, I was finally able to remove the pulley on my first conversion motor. The second motor would not surrender its pulley. A friendly motor repair technician removed it quickly with a proper gear puller as a customer courtesy. An auto mechanic also has the tool to do this. The procedure takes about a minute. I have been told that Auto Zone loans tools.
I ground two flats on my gear puller to fit into the jaws of a Crescent wrench for my third motor conversion. Since I was well prepared, the third pulley came off easily. The lever bracket makes a secure way to hold the motor when the other flat end is held flat on a bench.
Once the multi pulley is removed, check the fit of the Viel drive pulley (3 3/4” diameter). It should be a sliding fit. If it doesn't slide easily, do not force it.
Bolt the motor onto the attached mounting plate using the 7mm Allen wrench. If the drive pulley fit is too tight, turn on the motor and lightly touch the diamond file to the shaft until the sliding fit is achieved.
With the drive pulley still unattached, place a C clamp around the motor shaft (with protective tape) to prevent the shaft from rotating. The flat should be on top. Use the mill file to add a large enough flat surface to secure the Viel drive pulley.
Secure the drive pulley using a 1/8” Allen wrench.
The smaller diameter drive pulley means the height of the idler pulley needs to be adjusted. Placing half inch flat washers on top of spring solves this problem. Start with a dozen washers. Eleven washers is common. Adjust the number until the belt tension seems right.
Enjoy your new variable speed Viel. A useful tool is now more useful.
Begin here:
Any Viel belt grinder can be converted to variable speed. However, the easiest and most cost efficient way is by using a Viel from sharpeningmadeeasy.com. There are three reasons for this:
1) The bore on the Viel drive pulleys is one half inch. This is designed to match the shaft diameter on NEMA 44 motors. Unfortunately, the shaft on the Penn State Industries (PSI) variable speed motors has a diameter of fifteen millimeters. In the past, we had two choices, both normally requiring a machine shop.
1) The motor shaft could be turned down to half inch. Or
2) The drive pulley could be bored out to fifteen millimeter. The modified Viel units from Sharpeningmadeeasy come with the drive pulley already bored out to fifteen millimeters. This transforms fitting the shaft and the drive pulley from an expensive machine shop job to an easy fit home workshop project.
2) The standard six inch drive pulley has been replaced with a 3 3/4 inch drive pulley. This switch in pulley size alone reduces the Surface feet per minute (SFM) by one third. The smaller diameter of the PSI motor allows using the smaller drive pulley.
3) The Sharpeningmadeeasy unit comes with a specially designed mounting plate. This plate, a collaborative design effort of the Bess Exchange, removes the tedious layout work. It also makes assembly an easy home project with a regular electric drill instead of requiring a drill press.
A few tools are required or recommended for this project:
Required:
an electric drill with a 1/4” bit
a 1/2” counter sink
one or two small (2”) C clamps (a couple layers of masking tape soften the clamp jaws)
1/8” and 5mm Allen wrenches (The Viel pulley screw is Imperial; the PSI motor is metric.)
2 7/16” wrenches to tighten the 1/4” mounting bolts
Phillips #2 screwdriver for the 1/4” flat head mounting bolt
a 3/16” round file
a mill file, six inch mill bastard cut works well
a fine diamond file if the pulley needs a small reduction to slide onto the shaft. ( Two of my conversions needed this, the third did not.)
Highly recommended: a Dewalt or similar 1/4” drill bit, long length (twelve inches) These cost around $7.00 US and make drilling the lower right mounting hole easy. This can also be done by drilling the other two mounting holes and bolting the plate on the outside of the viel frame. The third hole can then be drilled with a regular bit from the outside. A long bit is a real convenience and will prove useful around the shop.
Secure the plate to the Viel as shown in the photograph using the small C clamps with protective tape. Looking from inside the frame, be sure the motor shaft hole is on the right side. The lower right side mounting hole is the hole closest to the bottom (long edge). This hole is the reason for the long drill bit .
Position the plate so that the bottom and right side edges are 1/8”from the Viel frame and the plate is level. Being level is really for aesthetics; it is not critical to the operation of the machine. Drill the three mounting holes one at a time. Use a piece of scrap board for backing to keep the exit holes neat.As each hole is drilled, install and tighten a bolt in it for better alignment. When all three mounting holes are drilled and secured, drill the third motor mounting hole. Then, from the outside, drill the counter sink for the top mounting flat head bolt. Drill the depth until the flat head bolt is flush to clear the grinding belt.
Bolt the mounting plate to the frame.
THE MOTOR
The PSI motor comes with a multistep pulley on the shaft. This pulley can be easy or difficult to remove. Two of my three were difficult, one was very easy. The correct tool for removal is a gear puller. You will want a gear puller with a hexagonal shape on the back to hold a wrench for leverage. Mine was an inexpensive model with a short sliding T handle. It did not work. After much strain, I was finally able to remove the pulley on my first conversion motor. The second motor would not surrender its pulley. A friendly motor repair technician removed it quickly with a proper gear puller as a customer courtesy. An auto mechanic also has the tool to do this. The procedure takes about a minute. I have been told that Auto Zone loans tools.
I ground two flats on my gear puller to fit into the jaws of a Crescent wrench for my third motor conversion. Since I was well prepared, the third pulley came off easily. The lever bracket makes a secure way to hold the motor when the other flat end is held flat on a bench.
Once the multi pulley is removed, check the fit of the Viel drive pulley (3 3/4” diameter). It should be a sliding fit. If it doesn't slide easily, do not force it.
Bolt the motor onto the attached mounting plate using the 7mm Allen wrench. If the drive pulley fit is too tight, turn on the motor and lightly touch the diamond file to the shaft until the sliding fit is achieved.
With the drive pulley still unattached, place a C clamp around the motor shaft (with protective tape) to prevent the shaft from rotating. The flat should be on top. Use the mill file to add a large enough flat surface to secure the Viel drive pulley.
Secure the drive pulley using a 1/8” Allen wrench.
The smaller diameter drive pulley means the height of the idler pulley needs to be adjusted. Placing half inch flat washers on top of spring solves this problem. Start with a dozen washers. Eleven washers is common. Adjust the number until the belt tension seems right.
Enjoy your new variable speed Viel. A useful tool is now more useful.
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