Building a belt grinder

My experiences have come with larger belt sanders, 6 x 48 and larger. In all cases, the top roller tilts side to side, to accomplish proper tracking, and moves straight up or down to tension the belt. Any other motion would have an affect on how your belt sees the backing plate, which is likely not a good idea.

Harold

I made a 1 1/2" x 60 inch belt grinder and have since made an additional wheel for it and its now cpable of using 1 1/2 x 60 or 2"

72" belts.......I made the angle of my grinder to suit what and how I use it, and its used mainly for snagging castings, but the basics are the same and you can mount the belt and back support plate in any plane you would need. Its on my project page, listed as belt grinder.... Visit my website: expressed are those of my wife, I had no input whatsoever. Remove "nospam" from email addy.

Here's one pic of my shopmade belt sander, which takes any 1", 2" or 3" belt from 21" to 60" long:

The adjustable frame is of two 1x1" angle irons, bolted together at top and bottom to give a 1" gap between them. The top drum is on a swivel block, mounted on the top of the adustable frame, carrying a 5/8" stud axle going into two bearings captured in the drum. Tracking is adjusted by a screw in the frame, bearing on the swivel block and tension is held by the belt itself (no spring). The drive shaft, in 3/4" pillow blocks, sneaks through the gap of the adjustable frame and has the bottom drum bolted to it. The adjustable frame is bolted to a short piece of 3" angle, which is attached to the bottom of the baseplate that carries the driveshaft and motor. I thunk this up myself a few years ago, should draw up some plans. It's a pretty simple design.

Ken Grunke

IF you look closely at the rollers on the belt grinder, they are slighly convex. The convex surface makes the belt climb to the center of the roller. Also the roller is tipped left to right by the tracking adjustment screw. This moves the peak hight of the roller along the roller and the center of the belt automaticly lines up on it. Almost all the older flat belt driven equipment used a convex roller to maintain belt tracking.

John

Here is the post/thread for the one that I built:

(I hope the < and > keep the URL from wrapping)

Bob

This works for me... This is only the top roller of the sander...

You will be the envy of me forever. What a great piece of work! Thanks!........But, I doubt if I can duplicate it:(

Thanks for the reply.

Another fine job by an obvious mechanical guru. Nice Job!

Just what i was thinking! But, to elaborate, when you say " the roller is tipped left to right"........

Do you mean the whole axis is moved perpendicular to the plane of the belt, OR do you mean that one side of the tracking roller is moved in/out in relation to it's brother?

Thanks for the reply.

Well, Kevin, that about does it for my education.......It seems that you indeed, move the lateral plane in slight angles to the belt to adjust tracking. So.........according to the above guys, the convex wheels keep the belt on, and the angle of attack makes the belt track left and right, correct?

Man, I'm so glad I didn't waste a bunch of steel finding this out

It certainly was not hard to make.......actually it was quite simple once I figured how I was going to make the tracking adjustment......

Only the drive wheel needs to have a crown on it. All the others can be flat. GIve the wheel a crown of 1 1/2 to 2 deg, and its more than sufficient to keep the belt tracking properly. You can make it pewrfectly flat, which I did initially as an experiment, just to see how good my alignment of the wheels etrc was. I figured if it wold run without throwing the belt they wewre probably pretty darn close to being in alignment. It worked just fine and never had a belt run off the edge........and I would have been content to leave it like that with all wheels having a flat surface, except it prevented you from being able to move the piece your grinding back and forth along the belt, no matter how much tension you applied to thr belt......So that proved to me my alignment was dead on, and that a crown also serves to keep the belt in position on the contact wheel when moving the work sideways......... Visit my website:

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There is a many a belt grinder made out of nothing more than a couple of pieces of plywood stacked together and the wheels fasioned fron it, and 2 x 4 or plywood frames. Its amazing just what you can use to make a belt grinder and still have it work..........I have a freind who s using a 2 x 72" belt grinder his father made many many years ago, and its nothing more than an old cast iron caster wheel, with a strip of inner tube glued on it for a contact wheel, running in oil lite bushings, with a laminated plywood drive wheel with crown sanded on it thats attached directly to an electric motor shaft, one speed only, and the entire thing is mounted on a 2 x 12 plank with some 2 x 4's. It works, works fine, is not pretty by any stretch of the imagination no matter how you look at it, but the key point is it works and does whats asked of it very well........ Visit my website:

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Yes, yes!. We're waiting!

-- Gary Brady Austin, TX

Regarding convex wheels on belt machines. On 1 and 2 " machines I have foud a wrap of one or two turns of electrical tape around the center of a flat wheel serves the same purpose. Also, look into skateboard wheels for idlers if you can stand the bearing noise.

My 2"*48" grinder is at:

for the main page Geoff

I should have added, that a visit to your local antique gas engine collector could yield the perfect drive pulley with a crown. There were many small diameter and width pulleys that were mounted to engines to drive small flat belt accessories.

I have a few, but want to build a sander too someday.

Chris L

And, it's fun trying the "thought experiment" to understand how that "climbing" self centering works. I've never been able to do it.

Can someone post an understandable explanation for me please?

Jeff

Thee simple way of thinking of is you have a wagon. Attached tp the wagon is three ropes each going to a mule. These are union mules and only one at a time pull any load. So one rope is tight and all the others are lose. The wagon will always follow the mule that is working at that point in time. The only time the wagon will travel straight ahead is when the mule straight in front of it is the union mule working.

In a crowned wheel the center is always the tight rope and that union mule never gets a break.

Clear? (as mud) Garry

On 24 Oct 2004 18:02:42 -0500, geoff m calmly ranted:

That's quite an unusual array of laundry for a machinist, Geoff.

Is that some other machine's motor mount you modified to hold the brackets for the front grinder wheel?