Belt Grinder Mods

[cfellows]

This is a picture of my updated belt grinder. Before this weekend, it had a 3450 RPM, 1 HP pool pump motor. When I'd flip it on the, lights would dim and the belt speed, at almost 5,000 SFPM was downright scary. It also had a substantial amount of vibration.

Yesterday and today, I swapped out the motor for a 2500 RPM, DC permanent magnet motor. Now, top speed is around 3200 SFPM and, since it's plugged into a variac, any speed from 0 up to the maximum. It's also reversible, but I haven't figured out any practical need for that. I trued up the 4.5" drive pulley on my lathe and that helped the vibration a lot. Probably should true up the top pulley as well. At any rate, it's now much tamer but still removes metal at a respectable rate.

Don't know how many of you know about this, but several of the knife making supply houses sell ceramic glass platen liners for the platen or backer plate of your belt sander. Here's a link:

http://www.usaknifemaker.com/ceramic-glass-liner-for-flat-platen-2x9x-0192-p-1181.html

I also just ordered the 2" x 9" x .192" piece which I'll JB weld onto the platen. That should greatly reduce the wear on the platen and provide a slicker, cooler running backing for the belt.

Chuck

 

[steamer]

Nice looking sander Chuck...didn't know about the ceramic backers ...saw a show recently on a company that makes duck decoys and they use their sanders without a back and with a pusher stick that they would push on the back of the belt to shape the belt into a given form...hold the decoy with one hand and push on the back of the belt with the other.....

Anyway nice sander

Dave

 

[cfellows]

Nice looking sander Chuck...didn't know about the ceramic backers ...saw a show recently on a company that makes duck decoys and they use their sanders without a back and with a pusher stick that they would push on the back of the belt to shape the belt into a given form...hold the decoy with one hand and push on the back of the belt with the other.....

Anyway nice sander

Dave

Thanks, Dave. One of the things I use my belt sander for is sharpening wood chisels, plane blades, lathe tool bits, etc. To get the best edge requires the sanding belt to run against a dead flat backer. Up to this point, I've just had a mild steel backer and over a period of time, just months with heavy use, the backer plate becomes concave, so you have to periodicaly flatten it with a surface grinder or milling machine. The glass platen liner supposedly stays flat a lot longer, like years instead of just months.

Chuck

 

[smfr]

These might be of interest:
http://www.machinistblog.com/grinding-lathe-tools-on-a-belt-sander/
http://www.machinistblog.com/modifying-a-craftsman-2-x-42-inch-belt-sander-for-tool-grinding/

In the second one he describes how to modify the belt sander to grind tools.

Simon

 

[cfellows]

These might be of interest:
http://www.machinistblog.com/grinding-lathe-tools-on-a-belt-sander/
http://www.machinistblog.com/modifying-a-craftsman-2-x-42-inch-belt-sander-for-tool-grinding/

In the second one he describes how to modify the belt sander to grind tools.

Simon

Thanks, Simon. I had seen the first one, but not the second. Gonna figure out a way to incorporate that rest setup on my belt grinder. I really like that!

Chuck

 

[cfellows]

I got my ceramic glass platen liner in the mail yesterday and last night I attached it to the platen using a generous helping of JB Weld.

I was a little disappointed in the edge finishes. They clearly scored the lines with a carbide glass cutter then just snapped them. While pretty straight, they have varying amounts of bevel to them. Also, the smoothing of the corners with a grinder was a little sloppy, like they were really in a hurry. However, I have to admit that the edges won't really present any problems since it's the face I'm interested in and that is dead flat.

One of my priorities for the rest is to make it height adjustable. Not sure why, but it just seems like a good idea. Toward that end, I found this little dovetailed rail I had made for another project several years ago. I ultimately used something else so this piece was a spare. Turns out to be the exact size I needed to fasten on to the side of the column (Love it when that happens!).

I'll make a carrier block that clamps to any position on the dovetail slide and use that as the foundation for the rest to be mounted on. Still looking to use a variation of the one on Simon's link.

Chuck

 

[cfellows]

Made some changes to the tool rest today. First I added a couple of strips of cold rolled steel to create a groove for a sliding table to slide in. The two pieces are rosette welded from the bottom through 3/8" holes drilled in the supporting piece.

Next, I made a sliding table with a miter gauge to hold tool bits at various angles. The hole on the outboard end of the miter gauge is a mistake. The bar pivots on a flathead screw coming up through the table from the bottom on the end nearest the belt.

Here is a picture of the fixture I use to sharpen my tangential (diamond) tool bits. It holds the tool bit diagonally on a 30 degree angle to the belt. This is handy because it doesn't require readjusting the belt grinder tool rest. It's made from aluminum and helps keep the tool bit cool during grinding.

And this is the fixture for holding woodworking chisels and plane blades for sharpening. The heavy aluminum fixture helps channel heat away from the cutting edge of the chisel so it doesn't overheat during grinding.

Nothing very fancy about this set up and the fixtures, but it does greatly speed up the process of sharpening tools while increasing the accuracy and resulting sharpness.

Chuck