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View Full Version : Looking at building a 12 Disk sander



outlawspeeder
08-22-2016, 09:32 PM
I have a motor and I am thinking I can build the rest. The mount, the tilt table, and the 12 " disk. Has anyone built one? How thick should the plate be? Thought on turning this? Weld on a motor mount or screw it on, then true it...?

My plans are pretty much the grizzly. Unless someone knows of a better design?


http://www.grizzly.com/products/12-Disc-Sander/G7297?utm_campaign=zPage

I look here for good advice.

darryl
08-22-2016, 10:42 PM
I built a disc sander using a saw blade for the disc. Worked fine, but I've come to not like the disc- the drum is much nicer to use. Also I switched to a zirconia belt, a 4x36 to fit my drum, and can see no reason to use alox again. These are about 3 times as expensive to buy, but last more than 3 times as long so they are actually cheaper in the long run. I have not worn out the first belt yet.

One difference between the disc and the drum is that the disc is flat while the drum will make a concave. In practice this doesn't happen because I'm always moving the workpiece around on it and can control where I take material off. My drum has a soft surface under the belt- some foam rubber. I wrap some string around it to compress it, slip the belt over it, then pull the string out. The belt has some give to it, so this also tends to help decrease any gouging you might do by accident.

This is probably my favorite shop machine, used almost everyday. I still have the disc sander but never use it now.

1-800miner
08-22-2016, 10:47 PM
I built a twelve inch. then hardly used it.
But I used a 3600 rpm motor and it wanted to burn instead of sand.
I always went to the combo belt and disc to do everything. Seemed more versatile.

H380
08-22-2016, 11:04 PM
I built a twelve inch. then hardly used it.
But I used a 3600 rpm motor and it wanted to burn instead of sand.
I always went to the combo belt and disc to do everything. Seemed more versatile.

Exactly. Look up spare parts for disk sanders. The large ones use a specially wound motor to have a non standard RPM. So buying a broken disk sander is worthless unless you have the specific motor for direct drive or use some type of home made reduction for a common motor.

BCRider
08-23-2016, 12:01 AM
Consider too that it's really tough to change grits easily on a disc sander unless you get one of those new fangled magnetic mounts that allows you to swap plates. Then you can have multiple thin plates with different grits.

You may also want to consider how expensive a disc is on a cost per square inch of usable surface vs something like a 2x72 inch belt.

The upside to a disc sander if you can justify buying or making one of the magnetic plate mounts is that it will be much more compact. A belt sander tends to take up a lot of space.

Tundra Twin Track
08-23-2016, 01:08 AM
I have a 12" and DD 24" if your going to all the work of building from Scratch I would build a 15 to 20".My 12"Kalamozoo has a 1740 rpm 1hp works well but table is poor design,the DD24" Max has 1140rpm 3hp 3ph that works fantastic and built like a Tank.You could run a jack shaft and pulleys to get desired rpm.Both have zirconia abrasive and will not be using oxide again,there is green abrasive that suppose to be step above zirconia might try that next time I order.http://i1371.photobucket.com/albums/ag292/tundratwintrack/image.jpg4_zpspxnxbo3o.jpg (http://s1371.photobucket.com/user/tundratwintrack/media/image.jpg4_zpspxnxbo3o.jpg.html)

flylo
08-23-2016, 07:00 AM
I have 12 new 1140rpm 3HP 3 phase motors, they weigh 115# each Williams drill presses uses them so I bought some spares. I had a 15" disc & the plates were 3/8" or at least 5/16". I ended up with a 2HP 12" disc/6" belt 240 sng phase, much happier.

Glug
08-23-2016, 09:23 AM
I was hoping this would be a sander with 12 different discs, all a different grit.

A local knife sharpener has a rig somewhat like that, but with belts.

randyjaco
08-23-2016, 07:00 PM
Don't waste your time on the disk sander. I built a 12" disk sander about 10 years ago. It worked as planed. I used a 1.5 HP motor and a Shop Smith sanding platen. Then about a year ago I built a 2 x 72" belt sander. It is a much more versatile machine. Changing grits on a disk sander is a PIA. On a belt sander it's a quick 15 second swap. I use the belt sander nearly every day and regularly find new uses for it. There are also numerous attachments you can make for it.
With a free treadmill from the trash, it cost me about $200 to build it.
Randy

outlawspeeder
08-23-2016, 10:49 PM
2X72 is the way I'll go then. Does anyone have a thought on what to do with a 1750 1hp with a 1 inch shaft? I would to use it on the 2X72 but the 1" shaft is stopping me.
Yes , I can put the shaft, weld on to it and then turn it down... Thoughts on that or is that a really dumb thought?

Tundra Twin Track
08-24-2016, 12:51 AM
Don't waste your time on the disk sander. I built a 12" disk sander about 10 years ago. It worked as planed. I used a 1.5 HP motor and a Shop Smith sanding platen. Then about a year ago I built a 2 x 72" belt sander. It is a much more versatile machine. Changing grits on a disk sander is a PIA. On a belt sander it's a quick 15 second swap. I use the belt sander nearly every day and regularly find new uses for it. There are also numerous attachments you can make for it.
With a free treadmill from the trash, it cost me about $200 to build it.
Randy
I agree the abrasive on disk machines are a pain to change compared to belt grinder which is on my to do list,have components to build a 6" belt grinder.The one thing that is very handy with the disk machine is the large table and large grinding surface.They are very accurate when set correct,I guess that is why the pattern makers and Aircraft manufacturers used them extensively in the past.

BCRider
08-24-2016, 01:35 AM
Nothing at all wrong with a 1" shaft on the motor. The larger output bearing will more easily take the side loads of the belt tension. You just need to find or make up the proper output pulley to get the right SFM for the belt.

Paul Alciatore
08-24-2016, 01:42 PM
Yea, I was wondering why the heck anyone would need 12 disks on a sander. I mean, coarse, medium, fine, extra fine; that about does it.




I was hoping this would be a sander with 12 different discs, all a different grit.

A local knife sharpener has a rig somewhat like that, but with belts.

strokersix
08-24-2016, 03:42 PM
In my experience the disc sander is slower but much more accurate than a belt sander because the disc stays flat and the abrasive firmly stuck to the disc. Belt sander the abrasive squirms around and is backed up by a worn platen so it does not make as accurate work. If that matters to you.

Doozer
08-24-2016, 04:41 PM
If I were to build a disc sander
I would size the disc to match the
sandpaper discs they sell for the floor sanders
like they rent at Lowes and Home Depot.
You know you can always buy the sanding
paper discs there. I think they are 18" or 22"
or something like that.

--D

boslab
08-24-2016, 06:20 PM
I have a body of a horizontal disk, German thing, it's a 300mm disk, the disk or platten is missing, it was off the machine and got nicked as it weighed about 15lbs, what was interesting about the platten was the fact it was full of holes, there was a chamber underneath with cast in "blades" for want of a better description, when it spun vacuum pulled the disk down, the only fixing of the disk was a twist beyonet boss in the centre, I hammer edit and never got the disk to slip.
The badge is a circle of ball bearings but I've forgot the name kugelmuller,
I wonder if it would be possible to recreate a vacuum hold down on a sander, after all it's been done, but I for the life of me couldent figure out how to do it, no glue required, I could change the sanding disk from grade to grade in seconds which was handy.
Mark

randyjaco
08-24-2016, 06:57 PM
2X72 is the way I'll go then. Does anyone have a thought on what to do with a 1750 1hp with a 1 inch shaft? I would to use it on the 2X72 but the 1" shaft is stopping me.
Yes , I can put the shaft, weld on to it and then turn it down... Thoughts on that or is that a really dumb thought?

I would try to go with a 1.5- 2 HP motor on a belt grinder. You will be happier with the extra HP.

Randy

Ohio Mike
08-24-2016, 07:39 PM
I built a twelve inch. then hardly used it.
But I used a 3600 rpm motor and it wanted to burn instead of sand.
I always went to the combo belt and disc to do everything. Seemed more versatile.

Yep, 2x too fast. Needs to be a 1750RPM motor. Disc sanders are good when you need that large flat surface and you can live with a single abrasive grit. I have the little Powermatic. If I was going to make one it would be 20" or so.

lakeside53
08-25-2016, 02:00 AM
I have a 3600 rm 12 inch disk sander. Stunning... It can eat literally eat a 2x4 (wood). Sfm is proportional to diameter. Choose the right grit and diameter point for your work. All are close to useless in the center.

Puckdropper
08-25-2016, 08:26 AM
I was hoping this would be a sander with 12 different discs, all a different grit.

A local knife sharpener has a rig somewhat like that, but with belts.

I want one! Sure would make taking a piece of raw chisel-shaped material and making a useful cutting tool a lot quicker. I've been contemplating building something with two belts partially for the experience and partially so I can switch to a more aggressive belt quickly when I need it. Belt changing is the most boring part of edge making.

Illinoyance
08-25-2016, 09:42 AM
Build your sander with a sliding motor mount. That way you can change discs without having to dismantle the table.

strokersix
08-25-2016, 12:06 PM
Had to smile Illinoyance :) You must not know the trick of only removing half of the adhesive protective paper until you get aligned and stuck, then remove the other half?

Dan Dubeau
08-25-2016, 05:32 PM
Always worked in shop that had a 24" disk sander. Pretty handy thing to have. Would love to have one at home as well, but am looking at building a 2"X72" belt grinder instead. I think i'd get more use out of a belt, than a big disc. But I wouldn't pass up a good deal on a big disc. Not sure I'd sacrifice the floor space for only a 12" though (it's tight in there).