Help me choose a belt grinder and sander

[Need Advice]

I have plans on building a 2x72 grinder with a variable speed motor so i can both sand and grind. The problem is cost. I have two options, either use step pulleys with an AC motor or use a variable speed motor. The latter is expensive. I already have a variable speed treadmill motor but cant seem to figure out which parts i need and how to wire them to make this motor work.

However, it occurred to me that i don't really need one machine to both grind and sand, i can have two different machines for these tasks. Its much easier to build a sander with the materials i have, and much cheaper to buy a belt sander too. I need to know what my needs are. Can i get by with a single speed belt grinder? What about a sander, do i need more than one speed? Please feel free to share your own sanding and grinding machines and how you use them. I have heard that using different grit sanding and grinding belts need different speeds. Is this true? What about disc sanders and grinders, how well do they work? They seem pretty easy and affordable to build or buy. I would like to sharpen tools, sand and grind parts and clean up forgings with these machines. Thanks for your input.

[Lis2323]

Others will have their own opinions but from what you describe you could get by fine with a single speed belt grinder for your needs.

One machine. One speed. And a good selection of belt grits.


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[Need Advice]

Others will have their own opinions but from what you describe you could get by fine with a single speed belt grinder for your needs.

One machine. One speed. And a good selection of belt grits.


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Thank you.

[M J D]

I have a few different belt Sanders or grinders. A 1"x42" sander, a 2" x48" belt grinder and a 2-1/2" x 60" with a 12" disc grinder on the opposite side of the spindle. The 2x48 is homebuilt modeled after a Kalamazoo with a 1 hp 3450 rpm motor. The 2-1/2" x60 is an old Ryman that I modified the base and motor. That currently has a 1 hp 3450 rpm motor that I plan to change to a larger one which may or may not be a 3 phase motor. All are single speed and work fine as I don't use them for fine finishing work.

[Need Advice]

I have a few different belt Sanders or grinders. A 1"x42" sander, a 2" x48" belt grinder and a 2-1/2" x 60" with a 12" disc grinder on the opposite side of the spindle. The 2x48 is homebuilt modeled after a Kalamazoo with a 1 hp 3450 rpm motor. The 2-1/2" x60 is an old Ryman that I modified the base and motor. That currently has a 1 hp 3450 rpm motor that I plan to change to a larger one which may or may not be a 3 phase motor. All are single speed and work fine as I don't use them for fine finishing work.

Thanks. How fine of work do you do? What is the finest grit sanding belt you use?

[52 Ford]

Thanks. How fine of work do you do? What is the finest grit sanding belt you use?

I know this question wasn't directed at me, by on my 1X42, I use 220 up to 1000 grit. It has a 1/5HP motor which is horribly underpowered. I like the 1X42 a little slow, since I use it for finish grinding, but it aught to have at least 1/2HP.

For a main grinder, I'd pick at least a 1-1/2HP motor, preferably a 2HP or maybe a bit more. I HAVE stalled the 1-1/2HP motor on my 4" belt grinder, belted to about 2,500SFM.

Edit: I keep a 36, 80, or 120 grit on the 4" grinder.
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[Need Advice]

I know this question wasn't directed at me, by on my 1X42, I use 220 up to 1000 grit. It has a 1/5HP motor which is horribly underpowered. I like the 1X42 a little slow, since I use it for finish grinding, but it aught to have at least 1/2HP.

For a main grinder, I'd pick at least a 1-1/2HP motor, preferably a 2HP or maybe a bit more. I HAVE stalled the 1-1/2HP motor on my 4" belt grinder, belted to about 2,500SFM.

Edit: I keep a 36, 80, or 120 grit on the 4" grinder.
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That's ok, you can answer that question too, im looking for input. I have a 2hp motor. I also have two radial arm saw motors that i though might make good sanders, i think they are 2 or 2.5 HP but I'm not sure.. I could use those saw motors to power a belt sander, or put a disk on the saw blade side and a drum sander in the chuck on the other side for contour sanding small stuff. What do you use 1000 grit for? Do you make knives?

[52 Ford]

That's ok, you can answer that question too, im looking for input. I have a 2hp motor. I also have two radial arm saw motors that i though might make good sanders, i think they are 2 or 2.5 HP but I'm not sure.. I could use those saw motors to power a belt sander, or put a disk on the saw blade side and a drum sander in the chuck on the other side for contour sanding small stuff. What do you use 1000 grit for? Do you make knives?

I do make knives, but not full time. For me, anything over 220 grit is usually for sharpening or otherwise grinding knives.

I'll give this more thought tomorrow when it isn't so late. (Midnight!)

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[52 Ford]

I'm not gonna tell you what size belt to get, since it's all about how much space you have. The longer the belt, the longer it lasts. Wide belts are good for flat stuff, narrow belts are good for contours.

My belt grinders are all fixed speed and sometimes that can be an issue. It'd be nice to be able to slow them down to sand wood.



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[Need Advice]

I'm not gonna tell you what size belt to get, since it's all about how much space you have. The longer the belt, the longer it lasts. Wide belts are good for flat stuff, narrow belts are good for contours.

My belt grinders are all fixed speed and sometimes that can be an issue. It'd be nice to be able to slow them down to sand wood.

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Thanks. I was thinking about buying or building a separate machine for sanding. Usually sanders are good for wood i suppose although i may or may not need to sand wood. I don't plan on polishing any metal to a mirror finish so I'm thinking maybe 220 or 320 grit would be fine enough for my work? I'm not sure.

[52 Ford]

Also, for metal, FORGET Aluminum oxide. Buy ceramic and Silicon Carbide. The coarse ceramic belts are AWESOME. All my fine belts are SiC, never tried the ceramic belts in fine grits.

I recommend buying a grinder based on availability and cost of belts. I swapped from a 1X30 fo a 1X42 recently, because the belts last longer and cost about the same.

Another edit: I've been using the same set of ceramic belts on my 4" machine for over a year. On the 'ol 1X30, I'd burn up multiple aluminum oxide belts in a grinding session. SiC and Ceramic last WAY longer.
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[Need Advice]

Also, for metal, FORGET Aluminum oxide. Buy ceramic and Silicon Carbide. The coarse ceramic belts are AWESOME. All my fine belts are SiC, never tried the ceramic belts in fine grits.

I recommend buying a grinder based on availability and cost of belts. I swapped from a 1X30 fo a 1X42 recently, because the belts last longer and cost about the same.

Another edit: I've been using the same set of ceramic belts on my 4" machine for over a year. On the 'ol 1X30, I'd burn up multiple aluminum oxide belts in a grinding session. SiC and Ceramic last WAY longer.
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Thanks for the ceramic belt info.

[M J D]

Thanks. How fine of work do you do? What is the finest grit sanding belt you use?

I have 24 grit up to 100 grit. I normally keep 60 grit on the 2x48 and 36 grit on the 2-1/2"x60" belt side and 24 grit on its 12" disc. 80 grit on the 1x42. I use zirconia abrasives for everything. Anything finer is done with a orbital sander or scotch Brite discs on a bench grinder or right angle die grinder.

[Lis2323]

Scotchbrite belts are available also-- in three different grits.

I like Klingspoor and 3M belts but there are several good manufacturers out there.


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[Need Advice]

Those saw motors i have run at 3500 RPM. Is that too fast for sanding? Is it better for grinding?

[52 Ford]

Those saw motors i have run at 3500 RPM. Is that too fast for sanding? Is it better for grinding?

Google something like "SFM for belt sander". SFM being short for "Surface Feet per Minute". The RPM really doesnt matter. All has to do with the diameter of the roller that drives the belt. Think truck tires. If you have 54" tires, your first gear will go a lot faster than if you have 32" tires.

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[Need Advice]

Google something like "SFM for belt sander". SFM being short for "Surface Feet per Minute". The RPM really doesnt matter. All has to do with the diameter of the roller that drives the belt. Think truck tires. If you have 54" tires, your first gear will go a lot faster than if you have 32" tires.

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Thanks for SFPM Info. That sounds logical. Im guessing that RPM would matter with a disc sander or grinder.

[M J D]

5,000 sfpm is about ideal for grinding steel

[52 Ford]

5,000 sfpm is about ideal for grinding steel

Just curious, how much HP and what type of work are you doing? I'm not not disagreeing with you - I'd love to run my grinders faster. My grinders are all fixed speed and I set them pretty slow so I don't mess up on finish work. I REALLY need some variable drives.

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[Lis2323]

Don't necessarily get hung up on HP

My older single speed Burr King 482 is only 3/4 HP and I have never bogged it down.

I think the newer versions are 1 HP now and available with variable speed as an option.



Keep a good selection of quality belts handy




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[Need Advice]

Don't necessarily get hung up on HP

My older single speed Burr King 482 is only 3/4 HP and I have never bogged it down.

I think the newer versions are 1 HP now and available with variable speed as an option.



Keep a good selection of quality belts handy




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My neighbor has an old industrial bench grinder he wants to sell for $80. He said once it gets up to speed there is no bogging it down. I thought about buying it and putting a belt grinder attachment on the side.

[Lis2323]

My neighbor has an old industrial bench grinder he wants to sell for $80. He said once it gets up to speed there is no bogging it down. I thought about buying it and putting a belt grinder attachment on the side.

Better check out the make, size and HP. The price is irrelevant without specs. 1/3HP is usually 6”. 1/2HP 7” and 3/4HP -8”.

If it’s an import machine count on the stated horse power as being exaggerated.

If it’s 3450 RPM it might be an okay machine if you intend to do any polishing. Just bolt on a polishing wheel

Here’s the 2HP Baldor polisher I sold recently..





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[Need Advice]

Better check out the make, size and HP. The price is irrelevant without specs. 1/3HP is usually 6”. 1/2HP 7” and 3/4HP -8”.

If it’s an import machine count on the stated horse power as being exaggerated.

If it’s 3450 RPM it might be an okay machine if you intend to do any polishing. Just bolt on a polishing wheel

Here’s the 2HP Baldor polisher I sold recently..





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It looks like really old grinder. I assume is American made but thanks for the warning, I will check it out if i choose to buy it.

[Need Advice]

Better check out the make, size and HP. The price is irrelevant without specs. 1/3HP is usually 6”. 1/2HP 7” and 3/4HP -8”.

If it’s an import machine count on the stated horse power as being exaggerated.

If it’s 3450 RPM it might be an okay machine if you intend to do any polishing. Just bolt on a polishing wheel

Here’s the 2HP Baldor polisher I sold recently..


Sent from my iPad using Tapatalk

3500 Rpm is good for polishing? I though buffers ran at slower speeds. If 3500 RPM is good maybe I can use those radial arm saw motors I have for that purpose.

[Need Advice]

Then again, maybe the saw motor will be ruined by abrasive grinding wheels or buffing compounds. Maybe a saw motor is only good for cutting wood. Maybe it would make an ok wood sander, i don't know. Or maybe i could use those motors for belt driven machines if i protect the motor with a casing of some kind.