Belt grinder plans?

[Ohio Mike]

That is an excellent design of a belt sander. If I was to make another, that is almost exactly what I would do.----Brian

Its one of those things on my to-do list. It will move up the list when I find the donor motor.

[MattiJ]

Great video. Nice simple design. As he mentioned, it has worn well in a couple decades of shop use.

At what HP and force do any of those build choices become overloaded and deflect or wear? For example, when you're bogging down a 5HP motor. Will the belt walk from pulley or structure deflection?

The aluminum table bracket, with the nearly continuous slot, looks like it might be a potential source of table deflection? Easy enough to make it steel.

He mentioned flush mounting the motor studs to the plate was a challenge but apparently couldn't quite recall how he made the fasteners to do it. And one of them failed - either lost the head or it sheared off.

5hp motor doesn't bog down with slow belt speed like in Brians or Tom Lipton's grinder. "Do you want to grind steel or fall asleep to the purr of a belt gently caressing and warming a piece of Fe"
But it all depends on use, slow speed is better for finer belts.

[lakeside53]

Yes, that's why have a vfd and 3hp on a 2x72. with 18 grit I let it rip full speed (6000sfm). With 2000 grit... lol.. slow way way down.

[brian Rupnow]

My belt sander does not bog down. It takes a fair amount of grunt to go from zero to full rpm, but that is only due to the mass of the solid steel pulleys. Once it's running, there is no "bog down" to it.

[MattiJ]

My belt sander does not bog down. It takes a fair amount of grunt to go from zero to full rpm, but that is only due to the mass of the solid steel pulleys. Once it's running, there is no "bog down" to it.

What is the belt speed on yours?
Gentle caressing or material removal oriented?

[brian Rupnow]

Motor rpm is 1750, and the pulley dia. is 4.5", so---2061 foot per minute surface speed. ---and there isn't much "gentle caressing" about it. When I was heavy into building hotrods, all of my flame cut brackets were smoothed out on that monster. You could press a 4" wide flame cut plate into that sucker, crossways on the belt and not bog it down with a #36 grit belt on it.

[MattiJ]

Motor rpm is 1750, and the pulley dia. is 4.5", so---2061 foot per minute surface speed. ---and there isn't much "gentle caressing" about it. When I was heavy into building hotrods, all of my flame cut brackets were smoothed out on that monster. You could press a 4" wide flame cut plate into that sucker, crossways on the belt and not bog it down with a #36 grit belt on it.

Sorry, couldn't resist after I got good chuckle from Cijuanni's description.

2000 foot per minute IS gentle caressing by todays standards. Try 36 grit Cubitron II belts on a 4kW grinder at 7500fpm and you'll see what I mean.
Probably 15-fold increase in material removal speed compared to standard 36 grit AlO-belt run at 2000fpm.

[brian Rupnow]

I suppose it all depends on what your needs are and what your budget is. My belt sander works great for what I do. My budget was about $75 for the used motor, the pulleys and the bearings. Only a fool builds machinery way beyond what they ever need or can afford.

[MillNut]

Sorry for the delay in replying![emoji848] For some reason the thread is not showing up in my feed on Tapatalk.[emoji33]

The vertical column is 3/4" 6061-T6. Approximately 22" tall by 4" wide. I squared up both sides and one face. Not sure if I will square up other face as that side will see all the abrasive.

The adjuster is only for tension. I made the upper pulley and put 2 deg of crown on it. There is a flat in the center of the pulley which may have to go away. There is no crown on the lower pulley. I made the groove 1 belt thickness deep. Hopefully it is enough to keep the belt in place. I may make a new upper pulley with the same groove design as the lower, the new one would be steel of course.

The platen is 1/2" thick mild steel. I still need to machine an arc in the mast so the platen can rotate down 45 deg because you just never know right? [emoji851] The belt backer is 1/2" mild steel as well( not pictured).

Once I have it wired up and running I will make some sort of guard for it. The design intent is to radius the top and bottom of the mast- should make for a fun sheet metal project.[emoji12] Once the bugs are worked out I will have the steel parts Black Ox'd and maybe the aluminum anodized. Gotta look good while getting dirty!.[emoji1]

I will post more as I progress with it. It is way over kill for a belt grinder, but my experience with tooling and fixtures has proven many times A) Make it adjustable and B) Make it robust unless you want to make it again. We have BurrKings here at work as well as these really robust 1" belt grinders. I have always wanted one like our 1" but didn't like the price. The Kalamazoo's are decent but not as well built as this one at work. So when you are cheap and have free time....


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[MillNut]

Belt grinder plans?

Here are a couple of pics of the "Gemco" grinders which were the inspiration for what I designed. I prefer them to the Burr Kings. The BKs take more metal faster but the Gemcos have better feel. Just my weird preference.[emoji1] The motor is down low so the grinder has to go on a stand. I am cramped for space so I decided to move the motor up.




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[Black Forest]

This is a simple belt grinder I built. I have built several belt grinders in the 2" x 72" category. Previous builds used a swing arm type belt tension as in the KMG type. I didn't really like it. So on this one I used a telescoping tension arm. It only takes a few seconds to change a belt. I built all the wheels. The big drive wheel is made from steel and I knurled the surface to give a little more traction to the belt. The plan has always been to mount a VFD to vary the belt speed but haven't done that yet. This arrangement is good for course belts. If memory serves me right it has just over 4500 SFM. I am more of a fabricator than a machinist so it serves me well. I don't think this design would scale well to a 6" belt. The axles would need to be supported on both ends.

[Danl]

Here you can buy some parts for your DIY belt grinder build: http://www.texasknife.com/vcom/index.php?cPath=659_775

Dan L

[MillNut]

Finally finished mine belt grinder enough to make use of it. I still need to make a belt guard for the top pulley and a proper base for it but it is up and running.[emoji1]










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[QSIMDO]

I may have to flatter you by swiping your tensioner design.
That's slick.
I came up with the same solution to tightening the drive wheel grub screws too!

[MillNut]

Thanks for the compliment! Glad I could help!.[emoji41]

Here is a drawing of the tension sled and the adjust bolt and nut. The "nut" on the bottom of the tension screw bottoms out in the thumb wheel. The shoulder is about 0.005" longer than the mounting block. To adjust the belt I only have to loosen the belt shaft bolt enough for the sled to move up and down.






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