WIP: Grinder Build

69_knives

69_knives

Joined
Nov 20, 2008
Messages
1,855
I've gone and done it... started building a grinder, I'll take lots of pics and document as best I can to give ideas to others that want to make a cheap grinder.

Is it wrong that my workbench is a toilet?



A square wheel?

The contact and Idler wheels are made of 3/4" plywood, 3 layers each. This contact wheel was cut to 15" and will probably be 14.75" when trued up.



I use a piece of wire, screw and pen to draw the circles and then rough cut with a jig saw.



A good build deserves a few frosty beverages.



Contact wheel glued up.



Some more components; pillow blocks and steady bearings.



Idler wheel glued up, this one is 6" diameter.



So far, half a sheet of plywood, the 7/8" shaft, pillow blocks and steady bearings cost $75.00 Canadian.

I'm going to take the wheels and shaft to my machinist friend to drill the centre holes in them and to cut a 1/8" shoulder 2" in on the left side of the shaft and so I'll have a 2" section of 5/8" shaft which will be reverse threaded so that I can put polishing/buffing wheels on the left side of the shaft.
 
This should be interesting to watch. I've always read about making your own wheels being potentially very dangerous. I know you're getting a machinist buddy to help you out with centering it, but just be careful. those things spin very fast with alot of inertia.
 
If I was to use wood wheels ide have some one make them on a lathe out of oak. Thats just me, I think munky is right the plywood might fly apart once running and heated up.
 
Munky88; thanks for the concern. If you could refer some links to the material you read about the homemade wheels it would be much appreciated. Aside from making sure everything is bolted down, I fail to see any danger.

hellgap; I trust laminated plywood much more than any solid hunk of wood; not just because the wood could split at the grain and fly apart but as the wood dries it will make the wheel warp and become egg shaped.
 
I can't wait to see this one done, 69. I wish I had the know-how and motivation to try building something myself, but I'm likely going to just buy one soon.
 
great post! I need to make an idler wheel and three pices of plywood, the first bored (big hole) for the first pillow, the second bored (small hole) for the shaft, the third bored (big hole) for the second pillow, would be perfect! thanks for the idea.

keep on going, I love the build-along posts :thumbup:
 
Rubber tired cart wheels available through MSC or Grainger.

They are steel or aluminum, you can bore the center to accept a bearing that you size from a supplier, and presto!

Chuck
 
I agree with you Chuck! my drive wheel is a steel cart wheel (without pillow) but to make a track/idler wheel the plywood sounds good to me as I don't have a lathe!!!! :grumpy:
 
My idler wheels on my flat platen are laminated plywood. Been running them for nearly a year now. No problems. I didn't have a lathe when I made them so I turned them on a drill press. Originally my tracking wheel was laminated oak, it ran fine to, I just finally got around to replacing it with a aluminum wheel.
 
I have been thining of doing the same thing to allow me build a grinder. Build the frame just like a regular KMG Clone.

I have been kicking around such idea in my head also. 3 layers of 3/4" plywood laminated together, would give you a wheel of 2 1/4" width. You can use a router and a trammel point to rough cut them. You drill a small hole to anchor the trammel point and they will come out real close to perfect circles.

This would allow for cheaper alternative to let you get started. Then when you get money ahead replace them with aluminum wheels. As for them flying apart don't think you got a problem there, just alternate the grain on every piece, and glue them good. If you have a lathe or know someone that does then that would be no problen either. When you get them trued, up you can laminate the edge if your are worried about them coming apart. The biggest problem is getting them balanced up. If they seem unbalanced you may have to play around with a weight. Kind of like the wheel weight on a tire.

I believe that if you use quality plywood you could even turn then for bearings. You might want to epoxy the bearing in. If worst came to worst you could heat the bearing and punch it out with a drift.
Sounds like a plan to me. I think I just talked my self into it. Thanks to this thread.
Let me know how you come out with this and pics, plenty of pics!!!!!
 
I played with the idea of turning the idler wheel for bearings but I decided to do it differently. If my way doesn't work, I can always have the bearing recesses turned into the wheel.

I picked up a reversible 2 HP 1725 RPM TEFC motor and the pulleys today and did some mock up positioning. That is all I can do until I get the wheels and shaft back from the machinist tomorrow.

I struggled with the concept of building a tensioner and tracking adjuster in one unit AND making it out of wood but I think I got it nailed.



These are all the parts for the tensioner, idler and tracking adjuster, minus 1 steel brace and the idler wheel.



Today I spent $25.00 on hardware and $250 on motor and pulleys so the tally to date is $350.
 
for the idler wheel a couple of epoxyed pillows could be really effective in my view but without a lathe I think I will not be able to bore a hole big enough and centered enough in the first and third sheet of plywood... but I can try to use the drill press. any suggestion? :confused:
 
The way I am going to try it is to use those steady bearings on the tracking adjuster so basically the wheel and shaft will turn. If it ends up not working satisfactorily, I will take a sharp chisel and turn the bearing recesses while the machine is operating and put the shaft solid on the adjuster block with a couple square steel plates. One of the steady bearings is sitting on the tracking block in the last pic in post #13.
 
I got the wheels and shaft back today and the shaft is great but the wheels, I cannot begin to think of words to explain what may have happened to them.

My machinist friend wasn't available so I took them to a shop down the street from us. I was very clear in specifying that the holes be squared up perpendicular to the flat of the wheel. OK, sure somewhere in the geometrical shape of the hole, whatever that shape may be, there is a section that could be considered square but it is not on the surface of the wood. I could have worn a blindfold and drilled a straighter, tighter fitting hole with a hand drill. Egads.

I truly thought I would have to make new wheels but mazingly enough the contact wheel runs true when I put the pulley on one side and a collar on the other side but I'm going to have to try and fill the 1/4" gap on one side of the wheel where the hole is egg shaped. I think what I will to is put a light coat of grease on a section of shaft and use small wedges of oak and epoxy them into the hole while the shaft is in.

The point of no return... The base is 2 layers of 3/4" plywood and is completely glued up and drilled for the allthread pillow block studs. I did weld the studs to the plates but welding is not necessary to make this work. Using a nut with a permanent loctite would work, you would just have to raise the base with some strips of plywood, something I will have to do as well otherwise the plates and welds will be a high point on the base.



 
How much was just the motor and where did you buy it im shopping. Is it 110 1hp or 220 ??????? Let me know ill check the post tommorrow . My grinder will be here hopfully tommorrow.
 
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