Very good post, Henry. I wish I had seen it before starting. The idea of substituting the three inch Viel pulley for the six inch is intriguing. Switching from a six inch to a three inch pulley would reduce the speed of the grinding belt by half, without altering the speed of the motor. I am guessing, however, I think this would produce a substantial increase in torque. This could be quite an advantage for a job involving a lot of stock removal. Using the laser/digital tachometer, I set my speed range from 600 to 2600rpm. The speed control can set the range of the motor to include speeds higher thar 1725 rpm. With a smaller pulley, I would just go with the factory settings. [A safety note: use a plastic screwdriver or piece of wood to adjust the pots to avoid any electrical discharge. I used a whittled down bamboo skewer. Again, with the smaller pulley, I would just go with the factory settings.]
You have presented the first really substantial argument for reducing the shaft diameter. (although, the three inch pulley could also be bored out to 15mm). I must learn more about this. I like the three inch pulley enough to consider redoing mine.
I notice you have the motor positioned lower and closer to the front. Being closer to the front would keep the motor aligned with the bolts holding the platen. Being mounted lower would compensate for the diameter change with the spring arrangement to keep the top pulley sligned. Clever; I'm impressed!
Lowering the motor position could also lower the need for height with a wooden or metal housing to hold the motor speed control. The photo shows how I placed the motor speed control to provide protective covering for the switches. It also shows the positioning of the reversing switch. I wanted reversing to be convenient, but isolated enough so as not to be accidental. I had also thought of a reversing rocker switch to be substituted for the on-off switch. I suspect the motor shop technician chose the course of least resistance. That turned out to be what I wanted. I can see where some might prefer the three position rocker switch.
Reducing the height of the wooden enclosure would reduce the weight and lower the center of gravity somewhat. In theory, both of these would be desirable. In actual operation, I don't see where the difference would matter. If the height was kept the same, there would be room to stow an extension cord on board, a potential plus for a mobile sharpener.
To redo or not to redo? At the very least, I will print out your template. An enterprising machinist could set up and make several templates with instructions and offer them for sale.........
I assume the Viel three inch pulley is the same part used for the smaller 1x30 model which attaches to a grinder? Also, that it comes predrilled and tapped for the holding Allen screw?
I noted that you have incorporated Rupert's idea of substituting plastic knobs for the small tracking screws (with two washers on each side to compensate for the half inch thread length). I have not needed to fiddle with tracking, however, the knobs seem a good idea and I purchased them from the hardware store. They use a 10-24 thread size.
This post is already too long. I look forward to reading more of your updates, Henry.
Ken
You have presented the first really substantial argument for reducing the shaft diameter. (although, the three inch pulley could also be bored out to 15mm). I must learn more about this. I like the three inch pulley enough to consider redoing mine.
I notice you have the motor positioned lower and closer to the front. Being closer to the front would keep the motor aligned with the bolts holding the platen. Being mounted lower would compensate for the diameter change with the spring arrangement to keep the top pulley sligned. Clever; I'm impressed!
Lowering the motor position could also lower the need for height with a wooden or metal housing to hold the motor speed control. The photo shows how I placed the motor speed control to provide protective covering for the switches. It also shows the positioning of the reversing switch. I wanted reversing to be convenient, but isolated enough so as not to be accidental. I had also thought of a reversing rocker switch to be substituted for the on-off switch. I suspect the motor shop technician chose the course of least resistance. That turned out to be what I wanted. I can see where some might prefer the three position rocker switch.
Reducing the height of the wooden enclosure would reduce the weight and lower the center of gravity somewhat. In theory, both of these would be desirable. In actual operation, I don't see where the difference would matter. If the height was kept the same, there would be room to stow an extension cord on board, a potential plus for a mobile sharpener.
To redo or not to redo? At the very least, I will print out your template. An enterprising machinist could set up and make several templates with instructions and offer them for sale.........
I assume the Viel three inch pulley is the same part used for the smaller 1x30 model which attaches to a grinder? Also, that it comes predrilled and tapped for the holding Allen screw?
I noted that you have incorporated Rupert's idea of substituting plastic knobs for the small tracking screws (with two washers on each side to compensate for the half inch thread length). I have not needed to fiddle with tracking, however, the knobs seem a good idea and I purchased them from the hardware store. They use a 10-24 thread size.
This post is already too long. I look forward to reading more of your updates, Henry.
Ken