Belt Grinder - Economy Model

[Cal_W]

Greetings all. I'm a new member here but have been viewing the forums for a while. Good reading. Love the photos and the humor too.

Old Man, I know you already have a belt grinder thread going and you’re still considering design features. Our concepts are different but hopefully there’s something here that will be of benefit to you.

This build is probably most suitable for those that want to try out a belt grinder but just can’t bring themselves to lay out the price of premium components or a manufactured product. It has been put together with odds and ends around the shop, scrap box treasures and a few purchased components.

Results so far ... it seems to be a solid piece of hardware, it’s versatile and configuration changes are relatively easy. Disappointments – the pillow block bearings are a little noisier than I had hoped. It’s not terrible, just not the smooth, low hum I had hoped for. More grease didn’t help either.

Here’s some details:

Belt sizes – 2” width, lengths from 48” to 72”.

Belt speeds with 1:1 pulleys – 10” wheel = 4,514 sfm - 8” wheel = 3,611 sfm

Contact wheels - 8” and 10” o.d. x 2” wide - laminated plywood, formica sides, aluminum sleeve center adhered with J.B. Weld. Facing is 1/8” x 2” rubber strip applied with Weldwood contact cement. Face is flat.

Contact wheel – 3” o.d. x 2” wide - laminated plywood, aluminum sleeve center. Face is wood and flat.

Contact wheel – 1-1/4” o.d. x 2-1/4” wide – aluminum sleeve center with press fit rubber hose jacket. Face is very slight crown.

Idler wheel – 8” o.d. x 2” wide – laminated plywood, aluminum sleeve center with 1/2” bore sealed ball bearings. Facing is 1/8” x 2” rubber strip. Face is flat but will probably be converted to a crown before it’s over. Mounting an 8” wheel in the idler position looks awkward but works OK. With the small diameter contact wheels doing the driving, it turns fairly slow. I wouldn’t want to drive it with anything much larger though since any amount of unbalance will show up in a hurry. The light spring tension is all that keeps the whole idler assembly steady.

Buffer wheel – 8” shown. Will accept any wheel with a 5/8” bore and a diameter of 12” or less. Works well with sanding discs also.

Main shaft – 3/4” x 18” drill rod. Drilled and tapped 5/16-18 on contact wheel end; turned down to 5/8” on buffer wheel end and threaded 5/8-1l left hand.

Steel base – 8” wide x 9-1/2” long channel ... rusty.

Pipe assembly – 1-1/4” std. wt. pipe, nipples and tee. Right hand inlet of the tee is tapped deep enough to accept all the threads on the nipple. The additional thread depth probably isn’t necessary but I wanted to maximize the grip of the mounts.

Pipe, idler assembly and platen assembly mounts - 7/8” thick steel bored to fit the pipe o.d., then split. Mount caps retained with 1/4” and 5/16” bolts. It doesn’t take a lot of torque on the bolts to get a secure grip. In retrospect, single sided mounts with a “V” or “U” shaped seat and U-bolts would probably be strong enough.

Motor – 1/2 hp, 1725 rpm. Grossly underpowered by most standards. If I’m still happy with the design after more use, I’ll consider upgrading to 1-1/2 hp.

Potential enhancements:

- slot the cart top for drive belt pass-through and move the motor underneath. Will also allow the upright to rotate down into a full
horizontal position.

- add a backstand idler to left rear of the cart top for use with small diameter contact wheels or sleeves. Will probably use 36” or 42”
belts.

- change drive pulleys to multi-step versions for added speed control.

- paint ... uhhhh, probably not!


Photos to follow.

[Cal_W]

More photos.

[Cal_W]

More photos.

[Cal_W]

Last ones.

I didn't label them but if you can decipher my file titles they kinda describe what's being viewed.

[cutter]

Welcome aboard, Cal.
That's quite an impressive opening-act slide show.

Bear in mind that on football afternoons you sometimes have to wait a bit for the crowd & comments to filter in.

[midmosandblasting]

Boy oh boy two belt sander builds at the sam time but I do think you beat OM done though. Looks good.I spent many a hour on one in the 70's at McGraw Electric portable tools.Yes castings were Al and the plastic insulated ones were just coming in.

[LW Hiway]

Great write up Cal and very crisp pictures as well.

A nice working rig you got together there.

BTW, I wasn't watching no darn Fooooootyball, I was at HF and giving gas away.

I think it could use paint, but then, I'm a paint whore.

[Scotts]

Cal,

Welcome in and well done.

Now you have documented this so well......... Is that a home built power feed I see in the corner of the last picture?

Scott

[1911man]

If it is, show/tell us more. Oh- welcome aboard!

[greywynd]

There's a way to think outside the box! Using the pipe as a frame is a great idea! How much time do you figure you have in the build?