2"x72" Belt Grinder

C

Cabinetmaker

Well-Known Member
This is the beginning "frame" of a scratch built 2"x72" belt grinder. The 1/2" plate steel, as well as the 1" shaft material came from the scrap yard for .40 a pound. All the material was rusty, Evaporust worked well to clean it up. Have had the bearings for over 20 years, they are from a woodworking flap sander that has been taking up space in the attic. It came to me new, never used, and I never used it either. The motor in the background is a 2hp 3ph motor I plan to get a VFD for. More pictures to come.
Thanks for looking. Larry

Grinder .JPG
 
If you are going to use the 3 hp motor and a VFD then why not make the grinder direct drive without the shaft and bearings? You will find that the grinder will have more power, run quieter and smoother. You will also probably have problems sourcing the 1" drive wheel. www.usaknifemaker.com has 5/8 and 3/4" drive wheels.

I can help you with the VFD and wiring kit with wiring and set up instructions.

Let me know if I can help you.
 
Wayne, I had considered direct drive for the reasons you stated, but I have several choices for motors and wanted the flexibility. I have a 4000 rpm, DC variable speed tread mill motor as well.
I will make the drive wheels. The only wheel I will buy will be the contact wheel, only because of the rubber. But, I am not convinced I can't make that too.
Thanks for the offer of help with the vfd, I may take you up on that when the time comes.
 
The only wheel I will buy will be the contact wheel, only because of the rubber. But, I am not convinced I can't make that too.
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My hero! That's the kind of talk I like to hear, and is so often my mantra - "I can make it myself"! There is so much satisfaction to making it your self - anybody can spend money and get it, but it takes real effort to do all the work yourself.

BTW, You're on the right track for direct drive. My first grinder I built was a pulley setup, but this last is so much nicer with direct drive! While a VFD with NEMA 4 rating is so nice, you can use a NEMA 1 (full open) by putting good filters around all the air input opening. Not sure how long it will last - I'll see. I used an open frame 1 ph motor for a yr or so just by blowing motor out from time to time. I'm only a hobby maker so am not using the grinder 5 days a week. Where I a full time maker using grinder for hours each day, I'd go for a real NEMA 4 VFD also. My current motor is a 2hp, 3 ph, TEFC motor that costs $127 shipped.

BTW, for the Platen wheels you might look at the 3" longboard wheels - they work good and are cheap. They run better than all aluminum wheels.

When (IF) you get the contact wheel with rubber covering figured out, be sure to let us know. I used a Grizzly 10" contact wheel I picked up for $70 shipped.

Later
 
Never tried direct drive but I can attest to the fact that KenH has a quiet grinder! His has more of an air flow hum at high speed and at low speed you might accidentally stick your finger in it while it is running because it is kind like one of those electric cars. You just can barely even hear it!!
 
KenH said:
My hero! That's the kind of talk I like to hear, and is so often my mantra - "I can make it myself"! There is so much satisfaction to making it your self - anybody can spend money and get it, but it takes real effort to do all the work yourself

It is about making things. That's what I do. Knifemaking is a hobby I would like to get into, but only one of many. A current hobby is machining. I inherited 2 boxes of machinist tools a few years back, and wanted to learn about machining.
Well, I jumped right in and bought a bridgeport mill, south bend lathe, and a shop full of tools to go along with them. Now I have found that there isn't much I can't make! Truth is I could buy a nice grinder, write it off on my business taxes, and probably get it for about free at the end of the year.
It is not about the destination, it is about the journey.
Click to expand...
 
Cliff - thank you for the nice words on my grinder. I've been VERY pleased with how quiet and smooth it runs. I should have demo'd balancing a quarter on edge while it's running at max RPM. I'd heard of that, but never expected to achieve it.

@Cabinetmaker; your words are much like my own feeling, anybody can buy it, the real fun is in making it!

Ken H>
 
Got a bit more done this weekend. Picked up the bearings locally at Grainger. Bearings are 25mm ID and 50mm OD.
Made a housing from a 3" x 3" round of steel, bearings were pressed in on each side. Made a spindle to press into the bearings. Everything is press fit together with .0004" interference fit. Purchased a 10" contact wheel from Grizzly, the bore was .003 over 3/4", so I made the spindle .002 over for a nice slip fit. Thanks for looking, Larry

Turning the spindle.JPGTapping the spindle.JPGSpindle, Bearings and housing.JPGParts pressed together.JPG
 

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Made some knobs for the grinder this past weekend. These parts took a lot of time to make 2 matching pieces on the lathe.
Custom Knobs.JPGKnobs.JPG
The 3rd picture shows the set up on the mill to cut the finger grips. With the 3 jaw chuck, centered on the rotary table, I made a plunge cut with a 5/8" end mill every 60 degrees, offset by 15/16" from center. Probably need to make at least 2 more of these.
Finger grips.JPG
 
More parts made and some assembly of the different components. It is starting to look like a grinder.
Mounted the Grizzly contact wheel on the shaft that I made, and made a collar for the end. This shaft runs on large high speed (8000 rpm), 52mm bearings. The advantage of this arrangement is that I can make and mount any size wheel from 7/8" and up by just taking out 1 bolt on the end and removing the Grizzly wheel.

Right.JPG

The bearings are mounted in the 3" diameter housing, that is mounted on a piece of 1/2" steel that is adjustable in and out by loosening and tightening the large knobs on the left side.

Left side.JPG

The 3rd picture shows the 4" aluminum drive wheel I made today. The rear 1" shaft is still long, but I am thinking about making a sanding disk for the end of it. Might as well, right?

Back.JPG
 
On the Grizzly wheel did you machine bearing pockets in the wheel or is it unmodified, running on a shaft? I put pockets in mine and set bearings in it. I'm curious how yours is, because mine has a tiny wobble. I thought my machining was good, so wonder if it's slop in the bearings. I'm anxious to hear how true yours runs.
 
Anthony, no the wheel is unmodified. The bearings are in the housing, I was very careful to machine both sides accurately, but we will see. And I will let you know.
I couldn't see a good way to machine pockets in the Grizzly wheel without machining both faces to make it true. The wheel is cast, not machined.
 
I looked at my Grizzly for a while and noticed the inner lip on one side was machined. I figured they cast it and grabbed it somehow to machine that lip, then bored center out concentric to that. So, I chucked it on the inner lip. I had my bearing pockets a little on the tight side and had to tap them in. Maybe one didn't seat exactly square, it's not bad, but at high rpm I notice it if I try to grind right on the edge of the wheel. The way you did it is probably better overall.
 
A few more parts made. The tracking wheel is 3" dia cold rolled steel, because I had some. Crowned at 1° for 3/4" on each side and then filed while on the lathe to blend everything in. I am pleased with it so far, we will see how it tracks. Bearings are 42 mm dia with 20 mm bore. Next is the roughed out parts for the "tracking assembly".

Tracking Wheel .JPGTracking parts.JPG
Machined a nice accurate pivot joint in the upright and the tension arm, .001" clearance.

Pivot.JPGUpright.JPG
New 2 hp 3ph Leeson motor in the background. $143 delivered, found on ebay.
 
Finished up more parts for the tracking wheel, here are the separate pieces, and the assembly (mostly) put together.

Seperate Parts.jpgTracking wheel assembly.jpg
Next is the assembly mounted on the tension arm.

Mounted on arm.jpg

Found this "T" handle in the drawer, it even had the spring on it. Not sure where I even got it, but with a few modifications it will work nicely for the tracking wheel adjusting screw.
T handle.jpg
 
Ken, thanks for saying so!
The Evapo-Rust works well, it gets a bit expensive so I try to use it on several pieces at once. I try to use the smallest container that I can, so the parts are still covered completely.
Last time I lined a baking pan with a heavy duty plastic garbage bag and filled the area around the parts with blocks of wood so it would take less Evapo-Rust to cover the parts. I buy it locally at Harbor Freight, $26.00 a gallon.
Thanks for looking, Larry
 
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