Back to the Grind
October 23rd, 2008New Internet Daydream
I have no intention of building a belt grinder. Let’s get that straight, right away.
But what if I were?
I have this idea. There is some empty space under my workbench. And one of the annoying things about belt grinders is the way the motors sit beside them taking up room. And another annoying thing about them is the need for some kind of post to hold the whole mess. So why couldn’t I suspend the motor under the bench, put some kind of removable access panel in the top of the bench, and fix the bench so the grinder could be attached to it quickly when I needed it? Think about it. You grab the grinder (which is not that big, in and of itself), and you pop it onto the table, and you yank the access panel, throw a drive belt on the motor and grinder pulleys, crank the belt tight, flip the power switch you mounted on the front of the bench, and GRIND, GRIND, GRIND.
Does that sound insane? Who cares.
There are free no-weld grinder plans available out there, but some of the resulting grinders are monstrosities. If you weld instead of using bolts and so on, you can use a lot less metal. And here I am, with a spiffy welder of my very own.
I assume you want a fast one-horse motor for a thing like this. Time to check Ebay.
October 23rd, 2008 at 5:55 PM
Fast motor, small wheel, or slow motor, big wheel, makes no nevermind.
This is what you want:
http://www.kalamazooindustries.com/images/bigpics/2fs21.jpg
Mount it to one edge of your workbench, underneath.
Mount motor underneath.
Swing up to use, down to store.
Buy here:
http://www.kalamazooindustries.com/belt_sanders.asp
Also, buy a foot switch to turn motor on:
http://web5.automationdirect.com/adc/Overview/Catalog/Pushbuttons_-z-_Switches_-z-_Indicators/Foot_Switches
October 23rd, 2008 at 10:59 PM
To clarify og’s comment, if it needs it: what you are looking for is surface feet per minute. Without coolant, in a home shop, what you want is between 900 fpm (for coarse grinding) and 1200 (for extremely fine). The objective is to strike a balance between material removal (high speed) and cooling (low speed).
Belt grinders are nice in that respect because the relatively long belt gives cooling time when it’s away from the workpiece, allowing higher speed. The tradeoff is that the belt doesn’t last as long as a solid wheel. You don’t have to true the belt, either — you throw it away and buy a new one.
I used a Craftsman benchtop combination belt/disk sander as a belt/disk grinder for a long time, with reasonable success. Of course we also had a solid-wheel stand grinder with a wire wheel on one spindle as backup.
Regards,
Ric
October 23rd, 2008 at 11:12 PM
Steve, look for one of those 900lb steel secretary desks from the 60’s that have the typewriter cabinet. They have a steel shelf mounted to an armature that articulates out and up 90 deg from a closed cabinet strong enough to support a 60lb IBM electric typewriter. Should be plenty to hold a belt grinder and an electric motor if they are not too tall. You could mount the shelf and armature under the bench. Flip it up to use it, fold it back underneath to put it away. The spring that they used to hold the shelf in position is strong enough to harpoon a whale so the table surface is not going to move under belt grinder loads.
October 24th, 2008 at 12:07 AM
I have a belt grinder similar to what Og suggests. I bought it about thirty years ago when I thought I’d try my hand at knife making. It has served me well. If I were going to buy one today I would probably buy the next bigger one that uses 2″ x 72″ belts. I think there is a better selection available. The 2″ X 48″ belts used to be hard to find. With the internet, not so hard any more. I bet your idea of mounting the motor underneath will work. I’d try mounting the motor on a hinged plate and allowing the weight of the motor to apply tension to the belt. I have a planer/molder that uses the weight of the motor to tension the belt. It works well. If you mount the grinder to a bench, mount it near the edge so the contact wheel overhangs the edge.
October 24th, 2008 at 3:45 AM
Just makes me want a nice slack belt setup all the more.
October 24th, 2008 at 6:50 AM
Criminy – how long is that thing? Looks like it would cost $30 a belt.
October 24th, 2008 at 10:52 AM
If you had a belt grinder, wouldn’t it be better to have it permanently set up so you could just turn it on and use it? Going through the whole assembly-disassembly process would rapidly become tedious, I would think.
October 24th, 2008 at 1:47 PM
“I have no intention of building a belt grinder. Let’s get that straight, right away.”
I think we’ve been down this road before.