DIY Disc Sander




Introduction: DIY Disc Sander

Last year I was in need of a disc sander for a little project. I wouldn't be using it that much so I didn't wanted to buy one as they can be pretty expansive. An old electromotor from a blown compressor became the powerhouse for this project. Did I just say project? Ofcourse I ment to say 'infernal death machine' since I already lost a fingernail trying to sand a small block of wood with this deathtrap. No joking around: this is some dangerous equipment so handle with care!

Step 1: Motor and Setup

I started out with making a little table on witch I bolted the motor. I ordered 30cm (diameter) round 80 grid sandingpaper that I used to eyeball the height of this contraption. The motor is a converted 380v to 220v electromotor from an old blown compressor. Nothing fancy here, old but reliable I geuss.

Step 2: Making the Wheel

I made the wheel out of old plywood I had lying around. I just used a jigsaw so it wasn't perfectly round. I found the center by drawing a few lines and where they met I made a hole. This way I could center and bolt down the old pulley that came with the motor.

I actually ended up clamping the whole thing down next to a vice. In the vice I clamped down a chisel and with a hammer I wacked it closer and closer to the spinning wheel shaving of the excess wood untill it was spinning nicely without shuddering. I left it spinning while I sanded the edges with sandpaper. This method is not really save but it worked for me. Afterwards I made the wooden casing.

Step 3: Balancing

When I fired it up the machine was thumping all over the place. Without clamping it down to my workbench it just took of. I balanced it by boring small holes in the back of the spinning wheel. I took quite a few holes but now the disc sander is pretty stable and there is no need for extra clamping.



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    7 Discussions

    Very useful! Thanks!

    Nice, I made one out of an old sink disposal motor I found on the curb. Someone had tossed it out because it was jammed. I tore the case off and found out the reason it was jammed is because someone (a child I suppose) had tried to grind up some balloons. Once I cleared those from around the shaft it spun perfectly. Bolted a board to the front, got it rounded and balanced, and now it's a very nice sander. Just goes to show that just because something in in the garbage pile, it doesn't necessarily mean it's garbage.

    3 replies

    Awesome find! I'm still looking for another one for my new project (a blower for dustcollection) and I'm told old washmachines got good motors aswell. But you're right, it's amazing what some people throw away!

    I'd highly recommend making a table for the front of it. Then you can draw some lines on it perpendicular to the sanding wheel, or clamp a board to it to use as a fence. That really helps when you are trying to sand things down and keep them square.

    Thats a good idea. I saw this on a few models in the store. In addition to lines on the table, the tables themself could also be moved diagonaly up and down. Definitely seomthing to look into!

    Good for you!

    It's almost identical to the one I made 40 years ago out of plywood offcuts from railway sleeping cars. Have great fun with it.

    Now I'm old, I have bought a more delicate one that I can lift :-)

    1 reply

    Yeah this thing can be a major pain when you'll have to move it constantly. It's heavy and my garage is only so big. But good to hear that even 40 years ago this kind of tool was used. I'v got the impression that old tools are often are better then the new 'plastic' stuff we have today.