Belt grinder options, 2x72

[rattle_snake]

I've been shopping belt grinders for some time now, and keep changing my mind on what to get. Budget is around $800. I don't want to spend the time to build an entire belt grinder, I want use a belt grinder to build other stuff. Use will be for steel tubing, bar, plate up to 1/4". Automotive fab type stuff.

Initially I wanted a Kalamazoo 2x48, then realized there was 2 models with different drive wheels and resulting belt speeds. The BG248 has the larger 8" wheel and and same 1/2 hp motor for almost 2x the price. I would grind on the wheel at times and the smaller wheel doesn't lend itself as well for this.
The 2FS72M 2x72 has same wheel/motor as the BG248, is less money, and uses more standard 2x72 belt. Seemed like a winner. Some more research indicated that 1/2hp is marginal at best and 1 to 1.5 hp would suit me better. The 2FS72 can be had w/o a motor for about $650.

So my current plan (subject to change) is the 2FS72 belt driven by a 1.5 hp. I have a tool stand made out of a semi brake drum with a 12" x 12" 1/2" plate top. I could fairly quickly mount the grinder and motor to this stand and wire it up. 1:1 pulley ratio for 7200 SFPM.

Comments, suggestions, recommendations welcome. Thanks.

 

[zkling]

Pass on the kalamazoo units. The coote is nice for the money.

 

[pstemari]

What's wrong with the Kalamazoo units?

Sent from my Pixel XL using Tapatalk

 

[exmaxima1]

Kalamazoo makes a cute little 1x42 for deburring , but the 2FSM was a toy. The drive wheel is a rubber caster wheel, and nowhere near as nice as a true contact wheel. I upgraded mine to 1hp and it still was not all the great. Quickly sold it.

You might look at the Grizzly 2x72 for your application. I've seen one in use and it runs very quiet and smooth. I don't have much experience with Grizzly machines other than their discontinued big drum/flap sander, and it is exceptionally nice: very smooth and lots of mass.

The Grizzly 2x72 is here: https://www.grizzly.com/products/Grizzly-Knife-Belt-Sander-Buffer/G1015

I can tell you their contact wheels are pretty good. I bought their 10-inch wheels and converted one of my grinders to a belt grinder.

 

[rattle_snake]

Pass on the kalamazoo units. The coote is nice for the money.

Thanks for the info. Looked those up.

Kalamazoo makes a cute little 1x42 for deburring , but the 2FSM was a toy. The drive wheel is a rubber caster wheel, and nowhere near as nice as a true contact wheel. I upgraded mine to 1hp and it still was not all the great. Quickly sold it.

You might look at the Grizzly 2x72 for your application. I've seen one in use and it runs very quiet and smooth. I don't have much experience with Grizzly machines other than their discontinued big drum/flap sander, and it is exceptionally nice: very smooth and lots of mass.

The Grizzly 2x72 is here: https://www.grizzly.com/products/Grizzly-Knife-Belt-Sander-Buffer/G1015

I can tell you their contact wheels are pretty good. I bought their 10-inch wheels and converted one of my grinders to a belt grinder.

Thanks.
Wasn't considering the 2FSM for the wheel as stated above. I checked out the Grizzly, it has a decent price and 1hp. I wouldn't use the buffer, guess I could adapt a stone on it or something.

 

[rattle_snake]

So, what is a good target for belt speed for general purpose grinding? The Coote recommends a 1725 rpm motor for all wheel sizes yielding slower speeds around 2700/3600/4500 sfpm. The Kalamazoo's are up to 7200.

I'm not making blades or handles, use is deburring/chamfering and removing material for fitment. Should I plan on a stepped drive pulley to adjust speed? If so what range? Thanks

 

[Bottlecapdigger]

Any 2x72 I've seen all have a 3450rpm motors. BCD

 

[jeepinerdeep]

Boy I'm bummed you are out the BG248.

 

[LXCam]

Hey RS, I know you’ve got your budget. But if you want to run out to Avondale you’re welcome to beat on my burr king and see what you think. I can say that was some of the best money I ever spent.

 

[zkling]

What's wrong with the Kalamazoo units?

Sent from my Pixel XL using Tapatalk

The platten ***** as it flexes, the tracking is a pain. For the price they just aren't that nice (my opinion). The 2fs72 is about the best (I own one) because of the belt drive that gives more access to the contact wheel than a direct drive unit.

 

[exmaxima1]

Thanks for the info. Looked those up.



Thanks.
Wasn't considering the 2FSM for the wheel as stated above. I checked out the Grizzly, it has a decent price and 1hp. I wouldn't use the buffer, guess I could adapt a stone on it or something.

A flap wheel or 3M Scotchbrite wheel would be very useful, and no issues using without a guard (unlike a stone).

 

[rattle_snake]

Boy I'm bummed you are out the BG248.

Almost bought one... Probably would have liked it, but I have problems with over-analysis and commitment.

Hey RS, I know you’ve got your budget. But if you want to run out to Avondale you’re welcome to beat on my burr king and see what you think. I can say that was some of the best money I ever spent.

Thanks for the offer, I might get spoiled then I have to increase budget and it will be your fault

The platten ***** as it flexes, the tracking is a pain. For the price they just aren't that nice (my opinion). The 2fs72 is about the best (I own one) because of the belt drive that gives more access to the contact wheel than a direct drive unit.

Thanks for the specific feedback. I found similar on some of the knife sites regarding wheel access.

A flap wheel or 3M Scotchbrite wheel would be very useful, and no issues using without a guard (unlike a stone).

Cool thanks. From the reviews the Griz platten is the downside of the tool, but perhaps that is the case with many of the designs.

 

[LXCam]

Thanks for the offer, I might get spoiled then I have to increase budget and it will be your fault.

It’s true what they say J. Once you go BK, ya never go back


Or something like that

 

[rattle_snake]

haha, nicely played.
But, isn't it more of a debur king?

Considering the Coote. It appears to use a rigid vertical bar and tracking/tension is separate as apposed to the Kalamazoo round shaft/spring setup.

A V-8 motor would be cool for variable speed. Flat head, SBC.

 

[rattle_snake]

I contacted Coote, the stated max RPM of the tool is only 2200, yielding belt speed of 4600 SFPM for 8" wheel. I could overdrive it a little with pulley ratio and get around 5000. They have a 10" wheel version as well.

Without experience I'm not sure this should be a concern or not.

Perhaps the right belt type/grit and sufficient torque will remove material quick enough with lower belt speed. The Bur kings are up to 8000. Kalamazoo's 7200. Griz is 3600. Maybe the lighter duty machines that I can afford have other limitations.
I get hung up on math, specs and such when spending a decent amount of $ on something.

 

[exmaxima1]

I contacted Coote, the stated max RPM of the tool is only 2200, yielding belt speed of 4600 SFPM for 8" wheel....

That rating must be based on the balance of the wheels. The bearings look modest in size and could easily do 2-3 times more rpm without issues.

 

[zkling]

It’s true what they say J. Once you go BK, ya never go back


Or something like that

While burr king makes great stuff, they have limitations that a number of the knife maker built 2x72" units fix. Bur for the average industrial shop they are about top.

 

[zkling]

4600 SFPM is plenty.

 

[LXCam]

While burr king makes great stuff, they have limitations that a number of the knife maker built 2x72" units fix. Bur for the average industrial shop they are about top.

No argument there and if I were making knives the 760 wouldn’t be my first choice. But for general fab and slack belt burnishing (which was my primary focus when I bought it), this thing rocks.

 

[exmaxima1]

The platten ***** as it flexes, the tracking is a pain. For the price they just aren't that nice (my opinion). The 2fs72 is about the best (I own one) because of the belt drive that gives more access to the contact wheel than a direct drive unit.

The 2FS72 is very similar to the Coote, except the latter has better tracking and appears more substantially built. In particular I don't like how the platen assembly on the 2FS72 is bolted to the side of a round tube and the table is cantilevered off the oopposite end of that wobbly platen. If the Kalamazoo was cheaper than the Coote it would be an easier decision, but at $645 it is indeed way overpriced. You could fabricate a diy 2FSM72 for less than $200.

 

[rattle_snake]

Thanks again for the info guys.

I started order process for the Coote 2x72x8. The wheel RPM limit is for adhesion of the rubber to the metal. I guess his newer wheels are better and can go faster.

So, 1 or 1.5 hp motor?
Basically same price. Plan to run on 110 V, so 1.5hp is getting up there current wise. I have all 20A outlets and multiple branches for work area so I can support a 1.5 hp, but is there any benefit to 'more power' in this application?? (I'm questioning my manhood to even ask this)

 

[tool_scrounge]

Thanks again for the info guys.

I started order process for the Coote 2x72x8. The wheel RPM limit is for adhesion of the rubber to the metal. I guess his newer wheels are better and can go faster.

So, 1 or 1.5 hp motor?
Basically same price. Plan to run on 110 V, so 1.5hp is getting up there current wise. I have all 20A outlets and multiple branches for work area so I can support a 1.5 hp, but is there any benefit to 'more power' in this application?? (I'm questioning my manhood to even ask this)

If you are really hogging material, 1.5hp could be nice. Some folks like to quote the 1 HP per inch of belt.width requirement. But I do not see many 6x48 belt grinder with 6hp motors out there. Does the 1.5 HP have 120/240 dual voltage? Anything over 1 HP I like to use on 240V due to less power losses in the cable, etc.

 

[rattle_snake]

Yes, that is the plan, Hoggin'.
I went ahead with the 1.5 hp motor. Will run on 110V/20A circuit at this time, all 220v are in use in that area. The motor nameplate claims 17A but should be less at typical loading. The single pole induction motors (3450 rpm) are cheaper, so went that route since I was going to change speed with pulley ratio anyhow.
Initial target shaft RPM will be 2300 yielding a belt speed of 4800 SFPM. Can get there with 2"/3" combo among others.

Actually, the point of this tool is to save time.....

 

[exmaxima1]

Yes, that is the plan, Hoggin'.
I went ahead with the 1.5 hp motor. Will run on 110V/20A circuit at this time, all 220v are in use in that area. The motor nameplate claims 17A but should be less at typical loading. The single pole induction motors (3450 rpm) are cheaper, so went that route since I was going to change speed with pulley ratio anyhow.
Initial target shaft RPM will be 2300 yielding a belt speed of 4800 SFPM. Can get there with 2"/3" combo among others.

It makes sense to buy a 2-pole (3450 rpm) motor since you are using a belt. I would use larger pulleys, however, to get more belt contact area. Old-school machines, especially air compressors, tend to use this approach to increase power transfer and longevity. I would use 3" minimum diameter pulleys AND a notched V-belt with that 1.5hp motor.

Btw, I like your avatar. As a speaker engineer, I am impressed with imaginative enclosure designs like that.

 

[rattle_snake]

It makes sense to buy a 2-pole (3450 rpm) motor since you are using a belt. I would use larger pulleys, however, to get more belt contact area. Old-school machines, especially air compressors, tend to use this approach to increase power transfer and longevity. I would use 3" minimum diameter pulleys AND a notched V-belt with that 1.5hp motor.

Btw, I like your avatar. As a speaker engineer, I am impressed with imaginative enclosure designs like that.

Have had similar issues with pulley contact on my supercharged mustang, so went with larger sizes for reasons you stated above. Little Eaton takes 75+hp to turn with only 2.7" pulley.

I'm an EE and tinker with speakers. Worked as an audio/acoustic engineer for a while. There is info on the enclosures including tuning someplace in my shop thread. The port extensions are functional.

So, is your handle 'X-max' parameter of a driver?

 

[rattle_snake]

Got machine built and running, thanks for everyone's inputs and advice!
https://www.garagejournal.com/forum/showpost.php?p=8187072&postcount=358