Building a Belt-Disk Sander Homemade Machines & Jigs
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I first had the idea for this diy belt sander two years ago and quickly made the prototype, with the intention that I would build the final version shortly thereafter. Of course, one thing leads to another and the build was put on hold while other, more quickly finished projects were done.
What has been keeping me from finishing is that I wanted to get a comprehensive plan together for this, plus a detailed build article and video. It can take quite an effort and a fairly large amount of time to make all of this happens at once, and with my busy schedule, finding the time has been a challenge.
To begin, I printed the plans and separated the parts drawings from the assembly drawings to work from. I then made each of the parts for the sander, starting with part A – the base of the sander. It’s made from 3/4″ plywood with all of the hole locations carefully marked:
I have a #8 countersink bit in my drillpress to drill all of the holes.
Next is to cut out part B, the back. It has an angled cut that is easy to do on the table saw using double sided tape to adhere it to a guide piece:
The fence is set to the width of the guide piece with the angle on part B lined up with the edge:
The fast, safe way to make the cut:
The holes are marked and drilled. Note that I actually missed two, but later marked them and drilled them out:
To allow the t-nut in C2 to be below the surface, a shallow counterbore is drilled before drilling the through hole:
With part D clamped to part C1, a 7/8″ counterbore is drilled into both parts about 1/2″ deep. This is to clear the t-nut and bolt on part B:
Part D also has to have a 1/4″ hole drilled about 1-1/2″ deep centred on the top end to receive a 1″ hex bolt:
Part E1 and E2 have notches that can be cut on the table saw:
Just run the blade in to the mark, and stop the saw.
This leaves a slight over cut, but this is of no consequence:
E1 and E2 are the same size, but E2 has a 7/8″ hole for a bearing, while E1 has a 1/2″ hole in the same location:
Part G2 has a 7/8″ hole for a bearing, and a notch that was cut by hand:
The notch makes it possible to tighten or loosen the set screw on the stop collar:
Part H is 1/2″ plywood. It primarily supports the left side of the 5″ disk sander tilting table:
The upper wheel bracket assembly consists of parts I1 and I2. I’m using my compact compass to lay out the arc on each part:
The arcs are cut on the band saw and sanded smooth. Both parts are identical.
Part J2 has to have a shallow rabbet for the butt hinge, and the easiest way to do that is to nibble it away on the table saw with the blade set to the depth needed:
J1 has to have a 5/16″ hole through, centred from top to bottom. This will be for the tension adjustment rod:
It’s worth noting that the dimensions on the plans are based on the plywood being a true 1/2″ and a true 3/4″. I made the mistake of using a cheap grade of 3/4″ that was only 11/16″ thick. As you can see in the picture above, a full 1/4″ was lost over four pieces. This is something to be aware of while building your own, and make allowances as needed. Some parts will have to be slightly smaller and hole locations may have to be moved:
My K1 and K2 are 1/4″ less wide than what is detailed on the plan to make up for the thinner plywood:
Next, part M needs a notch cut to fit around the belt. After marking the location, I made a series of stop cuts to remove all of the material:
Part L gets a slot and the easiest way to do that is drill a series of holes:
Then clean it up with a file:
These parts make up the 1″ belt tilting table.
Part N is cut from 1/8″ aluminum. I’ve laid out the shape and make the cut with the hacksaw, then smooth the edges with a file:
The holes need to be countersunk and I used a 3/8″ drill bit to do this, then drilled the 3/16″ hole:
Next, parts O1 and O2 are cut to size. I’m using the same double sided tape trick to cut the angle on these parts:
And made the slot in the same way as part L:
The 5″ disk tilting table length depends upon the overall dimension with part B and part H screwed to part A. If the plywood used is less than 1/2″, part P will need to be shorter:
Part P – 1/2″ plywood for the tilting table surface. The edge closest to the sanding disk has to be cut at 45 degrees:
Next, the parts for the upper wheel are marked using my compact compass, cut to size and sander smooth:
Part Q1 needs to house the bearing, and the hole for it has to be drilled deep enough so that the bearing is flush with the face of Q1:
These parts can also be made from MDF, but I recommend good quality plywood instead.
The lower wheel parts, R1 to R3 are marked, cut and sanded as close to the line as possible, then drilled at the centre for the 3/8″ shaft. For these, I’m using 1/2″ MDF:
The 5″ disk, part S is made from 1/2″ MDF as well:
After drilling the 3/8″ hole in the centre, a shallow slot is cut with a sharp knife for the locking pin.
The handles are next. These are made from lengths of 1/4″ threaded rod glued into wooden knobs. I already had two from the prototype, so I just have to make three more and cut pieces of spruce 1″ square and 3″ long for the knobs:
Drilled a 1/4″ hole in the centre, then shaped the knob by tapering the front half.
To lock the threaded rod in the knob, a flat spot is filed:
The rods are then glued in, using polyurethane construction adhesive. Epoxy can also be used:
The arcs are cut on the band saw and sanded smooth. Both parts are identical.
The handles are set aside to cure overnight:
A flat spot is filed on the end of the shaft to make starting the drill easier:
I had a problem with the shaft, in that it was exactly .375, and the bearings would not slip on easily. To fix this, I chucked it in my drill press and used a file to grind it down enough for the bearings to fit. It didn’t take long:
The locking pin in the hole at the end of the drive axle is just a piece cut off of a 2″ nail:
At this point, all of the parts were cut and ready for assembly. I thought it would be neat to lay them all out on a sheet of MDF for this photo:
I will not be going into a lot of detail on the assembly in this article, just covering some of the finer details. Instead, I made a video that goes through putting the sander together from beginning to end:
The first step is to attach part B to part A, but you need to get the t-nut into part B first. Note the counterbore on part D lines up with the t-nut:
Next, parts E1 and E2 are glued together and screwed to part B and part A. It is recommended that glue is not used at this point for these points, to make adjustment easier:
When the entire project is finished and tuned, it can be disassembled, painted and reassembled with glue:
Setting the t-nut into part H with a clamp. Epoxy is used to hold all of the t-nuts in place:
Parts C1 and C2 are glued together and a t-nut is inserted into C2 as shown:
When the lower drive wheel / sanding disk are assembled, it can be installed in the unit. The face of the sanding disk (part S) should be in line with this side of the sander. Use 3/8″ washers between part R1 and the shaft collar to adjust:
The other bearing and shaft collar can then be slid onto the drive axle to lock the shaft in place. It should turn freely:
When installing the t-nuts, it’s a good idea to use one of the handles to hold it in tight while the epoxy sets:
The butt hinge is screwed and glued with epoxy to part J2.
When taking apart the prototype, I discovered that gluing the hinge to the wood is very effective, so decided it was a good idea do it with this one as well:
In the prototype I used polyurethane construction adhesive, but epoxy should work as well.
In order for the upper wheel bracket to slide easily on the C1, C2 post, I had to shim the parts with a couple of layers of paper:
As shown in the video, the slight wobble is removed from the sanding disk with a chisel while running. After it is completely flat, I sprayed on a few coats of urethane to seal the surface. The self adhesive sanding disks should stick well to this, but also be easy to remove:
The sander completely assembled:
The unit can be driven with a small (1/4HP or less) motor, or with a hand drill:
I’ve found that nothing is needed to hold the drill in place, other than tightening the chuck on the drive axle.
Definitely a project worth doing and a very useful sander to have on hand. It’s been pointed out that you can buy sanders like this fairly cheaply, but nothing equals the sense of accomplishment when you do it yourself.
I’ve been using the sander a lot lately and thought I would make it more convenient to use by adding a small motor to run it, instead of the drill. The motor is 1/3 hp from a sump pump:
The right size and the right speed. I bought the sump pump last year for the float switch that was on it to use in the aeration tank in my house, and figured the motor would come in handy for something.
I had to take the end cap off to get at the wires:
Pretty basic, just the two supply wires to the motor winding and the ground wire bolted to the motor case. I twisted these together and screwed on two small wire nuts. I checked to make sure that the wires and the wire nuts were well clear of any moving parts.
I used a regular wire clamp to secure the cord where it exits the case:
To mount the motor, I cut a piece of 1/2″ plywood that screws onto the base of the sander and extends out the side. I used four 1-1/4″ wood screws to fasten it:
Another piece of 1/2″ plywood the same size as the motor was cut to make a bracket to hold it in place. I could then set the motor on that to line it up:
The two shafts have to line up fairly well and this is still a bit too low, so I cut shims about 1/8″ thick and put those under the motor to lift it up::
The shafts line up much better now.
Two more pieces of 1/2″ plywood were cut for the sides of the bracket:
These have a 5/16″ hole at the top for a threaded rod that will pull them tight around the motor.
Some glue and 1-1/2″ wood screws hold the bracket together:
It’s simple but it very securely holds the motor. I used wing nuts, but regular nuts (or lock nuts) would be better:
To connect the shafts, I’m using a short piece of 3/8″ inside diameter vinyl tubing. To get it onto the 1/2″ shaft of the motor, I warmed it with a heat gun to make it pliable enough to fit:
Dipping the tubing in hot water will also work. Small hose clamps hold the ends of the tubing in place on the shafts. This flexible coupling compensates for any slight misalignment between the shafts and reduces vibration. It also has the very attractive benefit of being cheap and easy to do:
With the bracket finished, it can be screwed to the base extension with four 1″ wood screws:
To turn it on and off, I mounted an electrical box to the side of the bracket for a switch:
The switch is just a regular household light switch and will be perfectly suitable for this. The wire I’m using is a three conductor extension cord cut to length. For safety, this has a ground wire that must connect through to the motor and switch box.
To protect my hands from the spinning clamps on the shaft, I cut a piece of 2-1/2″ ABS pipe in half to use as a guard:
Just a single short screw holds the guard in place on the motor:
I have it temporarily set up on my large storage boxes until I can do some more shop organization. Even though it’s only been set up for a few days, I’ve already used it several times. As it does not sand as aggressively as my 12″ sander, it is really well suited to shaping and smoothing small parts. Even metal parts can be ground and smoothed on the belt.
Dust collection is not really a problem, since it doesn’t kick up much into the air like bigger sanders.
I made a short video going through the project with a short demonstration on how it works: