Home Made Disc Sander

Home Made Disc Sander

A motor was given to me, after looking up the specs on the motor it was perfect for a 12″ disc sander. This whole project was made for scrap plywood lying around the shop. Only having to buy a few things for this build it was well worth the time invested.

Part 1

Part 2

List of some Supplies

Sand PaperMotorMotor HubConnector For Motor3/8-Inch Snap LockExtention Cord, T-Nuts, Dust collector port

Start with the back of the disc suroud. This started out a 14″ by 14″ by 3/4″. I found center by connecting the corners. Then on one edge drew a arc. Cut this out leaving the line. Next took it to the belt sander to sand to the line. Next I drilled a 3/4″ hole right in the center. Later I needed to make this 2″ 
Added this dado to hold the motor shelf. This I feel was important. The weight of the motor plus the vibrations. The dado will just help with a good joint. The shelf was place just right were the motor shaft will go right in the center of the 3/4″ hole the was drilled.
The motor was place on the shelf and roughly placed. Squared the motor mount up to the back of the shelf. This gave a me a good base line to work with.
Made two brackets to brace to shelf to the back board. Trying to keep it at 45 degree. Placed the motor back in place to see if the shaft was square to the back board.

Once the motor was located in the right position. Mark the holes. Drilled the hole at 3/8″ and add T-nuts to the bottom the the motor shelf. After the hole for the motor was drilled I placed the motor on the shelf and figured out were the power cord was coming in from. I drilled a 7/8″ hole. Later add a snap lock to hold the wire in place.
A list of the the supplies are listed at the top.
At this point, I took everything apart and painted what was done. Reassembled the next day.
The shroud arc was traced. Then 5/8″ wide I set the compass trace that first line on the inside. Cut both lines on the band saw. Then trace that whole piece to make another one. Glued them on top of each other. Sanded smooth to fit the arc on the back board. At this point the shroud arc is long later it gets cut off to line up with the middle of the disc.
The sides were added next. (Facing the front) The right side has a 7/8″ hole for the power cord to come in. It also has a snap lock to hold the wire in place. The left side has a cut out for an electrical switch box. The box I had lying around so I made it work.
The cord used was an old extension cord. I cut off the female end. Feed the wire in from the right side panel in the the blue box. Then out the box on the other side. Next up through the bottom of the shelf. Reach into the blue box pull out 3 or 4 inches for the switch. Next mount all the wires so they don’t wiggle loose. Hook up the switch and mount it. I only had a double switch in the shop, but i’m only using one side of it.

 A very basic idea of the wiring. (if your not comfortable doing it your self hire a professional)
A 12 1/4″ disc was cut out roughly on the band saw. Mounted the disc to a motor hub then mounted the hub to the motor. Once the disc was mounted I used a clamp as a tool rest. Then trimmed the disc to the right size. This also helps balance as well. Test fitted the sandpaper till i was happy with the fit.
The shroud was mounted with four screws. You need to be able to remove this from time to time.
The dust collator port was salvaged. The one I used, but this would save time. The port that I need to modify 4″ on one end then an off set 2″ on the other. i cut off the 2″ port. Then scroll sawed out the middle section. Sense the disc rotates clockwise I put the port on the right side panel. Added a a bottom between the two side panels. Then capped off the front.
I placed the work surface on top of the two sides. Checked the clearance between the disc and the work surface. Made the adjustment by moving the motor. I did this till the gap was even.
Added the paper, pill the paper of half the disc. Stick that on then rotate the disc and pill of the rest of the paper to ensure no air bubbles.
Mount the work surface with two screws then check for square. If square use continue mounting.

One last thing add a cover to the switch.
Works perfect and its square. I found it was better to work on the right side of the disc. As the disc is coming down. I might reverse the motor so I can work off the left side. This would be more comfortable for me.