Ideas Needed for a Grinder Build

[Will Brouwers]

Thanks for clicking on this thread! A while back I got this grinder. It was used for sharpening squeegees for printing. That's all I know. All I was concerned about was that it was a belt grinder. 

The belt has since worn out, and as I wait for funds to get a few belts, I have toyed with the idea of making the grinder more user friendly. I have thought about  somehow turning it 90 degrees and making it into something like this picture below:

 

 

But, the problem is, I have no idea where to begin. Should I just leave well enough alone? I only used it a couple times before the belt broke and it seemed to be alright. One member on the forum offered the fact that the current grinder I have wouldn't be good for knife making. I would like this to be as versatile as I can get it, with as little work as possible. 

Also, I do not have a welder, but I live in farming country, where every farmer has a welder in their shop. I also just don't want to get in their way and take up their time. All thoughts and comments are welcome! Thank you in advance!

[George N. M.]

Will, I have always used a belt grinder with the belt running in a vertical orientation.  I have always ground blades at 90 degrees to the length of the blade.  A horizontal belt going from left to right or visa versa seems awkward to me and I don't see any advantages.  The biggest advantages of a belt grinder to me are the speed of the belt and the size of it.  What belt size is yours?  You can calculate the belt speed from the rpm of the motor and the diameter of the driving wheel.

Others with more belt grinder expertise may have a different opinion but I think that it would be more useful in its original orientation and possibly safer.

GNM

[Will Brouwers]

George,

 I think my pictures and wording weren’t the most clear.

 The pictures on the bottom are how it currently is, the first picture is an idea for what it could possibly be. I just have no idea how to get there.

Right now the whole thing is basically mounted on angle iron. I wonder if I could get a heavy plate as a base, weld a pipe vertical on the base and then attach the grinder (rotated 90 degrees from the bottom pictures) to that pipe so it is useable.

 I also forgot to add that the motor is sealed, so it has that going for it, and the RPM is 1725. I wonder if I could bump that up with a bigger contact wheel?

[Latticino]

You are essentially talking about a complete rebuild to get the cobbled together grinder parts reconfigured as a vertical grinder.  If it were me I would essentially toss all elements other than the motor, contact wheel and tracking wheel and then repurpose same with a grinder build kit for a standard vertical 2 x 72 grinder.  Of course you can make knives with a forging setup, a decent 12" file and some sand paper, but if you want to be efficient a 2 x 72 grinder is a life saver.

[Mike BR]

If it were me, I'd drill holes in the feet and bolt them to a wall.  But I think I once heard someone say I was cheap . . .

[Will Brouwers]

Hmm. It’s an idea lol!

[Will Brouwers]

I mocked up an idea that I have for this grinder. Hopefully you can see it against the busy backdrop of my work bench.

One other problem is that this motor is a 1/2 hp. motor. It is sealed, but might be a bit underpowered…

I would do something like this, or rigging up something to get the top wheel mechanism over the motor, like an arch over the motor to hold it up.

[Scott NC]

  Well that looks like it has potential to me.  Beats the squeegee set up.  I would give you some of my ideas but I don't know what tools, skills and the size of your pocket book and scrap pile are.  Also, I like to build projects like that with an idea in mind and on the fly... .  (not always....)  Modification and tinkering around.  It's a wonderful thing when such a project turns out and meets or exceeds your expectaions.

  I'm not sure what you mean by an "arch over the motor" but build it solid for sure.

[Frosty]

You're pretty limited in configuration with only 2 wheels, driver and top. If you mount the motor behind the platen and put a larger wheel on the bottom so they form a triangle you'll have the "arch" and the motor driving a smaller wheel it's HP won't be as important. The belt speed won't be great, think of it like being in a lower gear, more torque less HP. 

Friction is another consideration, a long platen means more friction even without pressure from grinding. I'm running mine on a 1/2 hp motor and I can stall it if I put much pressure against the belt, wiping the back of the sanding belt with a little paraffin wax really helps. A spring tensioner is a BIG plus, it makes up a lot for the lower precision of a home build and the sprung wheel is the perfect place for the alignment adjust screw.  If you don't put an alignment adjustment in the loop you'll need to build everything perfectly aligned in the plane of rotation. 

If you draw a 30 60 90 triangle laying on the long side with the diagonal going downwards to the 60 angle you have a basic 3 wheel sketch. Put a wheel at every angle, I like the large wheel at the 90* (bottom) the vertical line representing a line parallel to the platen. The top roller above, at the 30* position and the driver (motor) at the 60* position. 

The motor being in the 60* angle provides the most contact between belt and wheel and maximizes good friction, (traction) so it doesn't require as much tension to keep the belt from slipping and lessens lateral load on the motor bearings. Make sense so far?

All the wheel's axels MUST be parallel and on the same plane or the belt will just run off when you turn it on. Using a 3 wheel model leaves tensioning the belt as a serious issue. 

A couple designs solve the issue by making the frame from a piece of steel plate. Drill the wheel axle holes on a drill press and your alignment issues are close to zero.  It just leaves the tensioner but 2 bushings and a couple more holes takes care of that.

I built one a few years ago and can live with it's flaws but don't really recommend that design, there are too many moving parts to be easy to build or align.

Frosty The Lucky.

[Jason L]

the grinder I cobbled together is belt drive with the motor mounted on a hinged board so that the weight of the motor provides tension. The motor is really old and I got it for $20 from a flea market with about 3 or 4 other motors. I think I have 3 total that ended up working out of the pile. I have no idea what HP it is or the RPMs and there's no way to mount it other than strap it down but it works and with the 4 step pully that came on it I can adjust the speed to some extent. I have it set up so I can take the belt grinder off and put a bench grinder mounted on a pillar block in it's place. That setup had a broken wheel and the remnants of a wire wheel on the other side on it. I replaced the stone but not the wire wheel yet. I have another sort of attachment that has a cutoff wheel on it and another wire wheel leftover but it has no way to mount it to anything. None of it is permanently mounted, I just use clamps to hold it to the bench and a couple of bolts or screws to mount whatever I need for that day. It works but it has higher RPMs than it began life with so it eats belts like crazy if I use too much pressure. So far I mostly use it for wood but I have used it for metal and it works way better than it did in as bought condition. That said, I'm in the process of designing a 2"x72" belt grinder and as soon as I get the gumption I'm going to start getting materials for it. I just have to settle on a design that I think will do most of what I want. Since you have most of the expensive parts already, I would think it wouldn't be too hard to slap something together. On that note, I notice that Walmart has belt grinder wheels at a pretty reasonable price, I just don't know how good they are. They seem to have good ratings so you might pick up an extra wheel and build one like Frosty is talking about. I know I'm going to put some thought into his suggestions when I get ready to put one together. 

[Frosty]

Walmart has belt grinder wheels!? That's sure not our Walmart!

Frosty The Lucky.

[Jason L]

It's online Frosty. They are Vevor wheels for a 2" x 72" grinder and they are slightly cheaper than Vevor's website. Walmart has almost anything you can think of on their website. They even sell caskets online. Not sure if they get a lot of business on those but they have them. Check them out sometime and see if there's something you can think of that they don't have.

[Frosty]

Okay, I took a look, they have quite a bit of stuff alright. I think Walmart is trying to give Amazon a run for the money. I'll bet they don't get a lot of repeat casket business! 

The Grainger online catalogue is a good place for tools and parts to build things.

Frosty The Lucky.

 

[Jason L]

I was quite surprised when I dove down the rabbit hole. I couldn't believe some of the crazy things Walmart sells. Of course a lot of it is from outside vendors, usually cheaper than manufacturers prices. This is one of those things I miss about my day job. We had hardware and tool vendors that we ordered from all the time so I could get stuff at wholesale prices and sometimes even free if I talked to the rep just right. Now I have to buy my hats as well. Oh well

[Frosty]

Walmart online sales are just a market place, I don't think their store brands are anything but a label. If you have products you want to sell Walmart will market it for you for a %. They're competing with Amazon but don't seem to vet anything for quality. 

When I built my 2" x 72" I cannibalized my 2" x 48" for the 1/2 HP motor and drive wheel because I didn't want to spend the money on a motor. Since then I took the pump motor out of our old dead hot tub and after ONE I suddenly found myself with old hot tubs falling out of my ears. I finally got a little smarter and took the motor out without taking the hot tub off my pickup on the way to the landfill. Old treadmills are a source of motors too but they can be more hassle than they're worth to salvage. 

I've left the 1/2 HP on my belt grinder as I don't really need more but I learned to grind with a light touch sharpening lathe cutters and drill bits when I was maybe 9-10 in Dad's shop. Belt grinders are a lousy choice for sharpening tool bits, a grinding wheel is way better or one of those dedicated sharpening "machines."

If you're going to buy tools and machine parts from Walmart, do yourself a favor and think of them as disposable wear items suitable for experimentation or development. That way you aren't buying good quality, "expensive" components until you have the machine that works.

Frosty The Lucky.

[Jason L]

I look at Walmart branded things as a warning label. I understand that Walmart has contracts for name brand items but corners are cut so quality suffers for a lower price. I don't know how true that is but I heard it somewhere. As far as tools go, Harbor Freight has better quality these days it seems. I don't buy any tools from Walmart, but I am considering those wheels. I got my belt sander from Harbor Freight but the first thing I did when I got it out of the box was take the motor off and throw it away. I've got several old motors with much more power. The one I put on the sander weighs more than the whole sander, box and all. No idea what it's rated at, it has no labels on it. I'm guessing half a horse maybe? I have a hard time bogging it down. I guess they got horsepower from Clydesdales back then and Shetland ponies today. 

[Frosty]

Some Walmart stuff is pretty low order, some not so much. I do have a few tools from them but no power tools. We have some stuff in the RV but not a lot. If I need serious tools or equipment I hit AIH Anchorage International Hardware or the Anch, Grainger outlet, we do have some good real deal hardware and industrial supplies here.

There are no data plates on the motor? There's a way to tell with an electric gage thingy though not being an electrical guy beyond wiring an outlet I can't think of it. It basically reads the current load through the power cord and there are charts for loaded or unloaded draw. 

I think the smallest hot tub motor I have is 2hp the largest 4hp. All of them have a data badge though some less obvious than others. My problem is the output shafts can be really odd sizes.

Two of the hot tubs were free to haul them off and both nicer than ours. We stopped using and drained ours because the deck was starting to fail under it.  <sigh>

Frosty The Lucky.

[Jason L]

The motors I have are probably older than me. I got them in a bulk deal at a flea market off of a guys trailer. I think I have three or four of them. They are probably some of the first generation to have rubberized insulation on the power cords. No plates or markings of any kind left on them. I think a couple of them were seized up so I tossed them. I can't remember what else I got from him but the motors were thrown in on the deal if I remember correctly. 

The only tool that I have from Walmart is a drill and I only bought that because the drill I had died and I needed one to drive screws for something on the honey-do list. Driving screws is about all it can do though and only short ones at that. It bogs down drilling through a 2x4. 

I never thought about hot tub motors, although living near the river, I don't know anyone that has one. My motor came with a step pulley already attached so I don't even know what size the shaft is. I never thought about changing it out so I never pay attention to it. I may upgrade when I build a grinder but I'll wait and see if I need to first. Like I always say, if it ain't broke, fix it till it is, then replace it. 

[Frosty]

I've been buying cordless hand drills since Nicad batteries were THE thing. I only have a couple corded hand drills I use, both old industrial models. I don't recall the brand but if you jam a bit wither WILL throw you across the floor or break bones. Both 1/2",  one 1/2hp the other 3/4hp. The 3/4 is flat out scary!

Lots of old and second hand power tools have 1hp and larger motors wired for 120vac, you just have to keep an eye out. Divorce sales are excellent shopping, Ex-wives often sell the ex-husband's shop for pennies on the dollar. 

Frosty The Lucky.

[Jason L]

We have a flea market near me that sets up Wednesdays and Saturdays and they often have really cool old tools for sale. I always want something when I go there but I can't talk myself into buying it. My wife always asks me why and I don't really have an answer other than I won't use it often enough to justify buying it or I can't use it right now. The other day they had lots of antique axes for some reason. Next time it might be antique sledge hammers or wrenches or something. 

I've found that I've developed a preference for hand tools these days. Unlike most people I can get lost sanding something or whittling down a piece of wood with a pocket knife till I get the shape I want. It's peaceful and I love it. I think that's why if I finish something to my satisfaction, I give it to a friend so I'll have an excuse to make it again. I never sell anything because I don't want a "want to" to become a "have to". 

 

[Will Brouwers]

Frosty and Scott, I realized I never responded to your thoughts! I like the idea of having three wheels, but I am trying to keep it as simple as possible. I have thought about scrapping the idea I mocked up and going to an idea similar to the picture I am posting, but that seems to make more work. I have access to a scrap yard, and some friends who are decent welders, but it is also the technical knowledge that is most important.

 

With the parts I have now, the top wheel is both the tension and has the alignment adjustment.

Another problem, that I now realize I could have avoided, is that these wheels are 4 inches wide, and not many grinders are 4 inches wide. I could have still just ordered 2x72 belts, but I went with 4x90, which is what this was configured as originally. I guess I could have/should have just done 2x72.

 I am not looking to make a lot of knives, just looking to have a halfway versatile grinder that is better than angle grinder.

[Frosty]

Were I to have made that kind of mistake I think I'd sell the 4" wheels  and belts, hopefully for enough to recoup my investment and either buy a kit or a 2" x 72" belt grinder. 

The only guy I know of on IFI who messes with 90" belts cuts and splices them into useful length and only then because he got a mountain of them for next to nothing. 

Frosty The Lucky.

[Will Brouwers]

So far, with the belts and the wheels and the motor, I am $200 in. 

Maybe I am a sucker for pain, but I think I am going to ride this through to completion, if only to learn what not to do.

I ran the machine a few times when it was in the horizontal position with a pretty dead 120 grit belt and it did a pretty good job at some light grinding.

One of the belts I got was a 36 grit ceramic, in the hopes that I’ll be able to hog some stuff. I am now realizing that 1/2hp. motor and hog don’t necessarily go in the same sentence.

 I think my reasoning for going the route of a 4 inch wide belt is that it will allow me to make something that is 4 inches wide very flat, without having to go back and forth. Idk.

Like I said, I just want this to be an all purpose grinder (which 2x72s are) but also just have it be a step up from an angle grinder.

 I have never used a 2x72, so I don’t know any different, so anything is better than what I have.

[Irondragon Forge ClayWorks]

7 hours ago, Frosty said:

The only guy I know of on IFI who messes with 90" belts cuts and splices them into useful length and only then because he got a mountain of them for next to nothing. 

We all know JHCC is an innovator. Or is that a glutton for punishment?

I can't control the wind, all I can do is adjust my sail’s.
Semper Paratus

 

[Frosty]

Heck, once you're set up splicing your own belts is pretty easy and if you can buy it by the roll it's worth tinkering. Dad bought bandsaw blade by the roll, the saw had the shear, grinder, welder in the table and it had a rack for the roll mounted on back. IIRC a 1930s machine and a real workhorse.

Frosty The Lucky.