Once the belt sander was in this state I was confident that it would work. I ordered a piece of 3 mm thick sheet metal from the Metal Supermarket to use as a platen. This adds 3 mm of thickness, which is how much the rollers are above the plywood. But I realized, I should ideally raise it slightly higher to make sure the belt pushes against the platen a little.
I also experimented with using a piece of laminate flooring as backing material. I sanded a lot in the same spot to see how it would hold up, but I couldn't see any signs of wear afterwards. The main issue with the laminate flooring was that it's much thicker, so it lifted the belt quite a bit, and that made the sander much louder.
If running the belt at high speed, heat build-up might also be an issue. I have mine running at about 440 meters/minute or 1500 fpm.
I butt joined the pieces together with glue. After the glue dried, I drilled pilot holes and added screws to the corners.
Then screwing the sander part to the base. Ideally, the piece of plywood on the back of the sander would extend down a bit further, but at this point I diverged from my initial design, so this wasn't very pre-planned.
The motor mount ended up interfering with the back panel of the sander
A jigsaw could have worked for cutting that out, but the whole thing just fit on my bandsaw, so I used that instead.
I made a blank by gluing several layers of really hard wood together. This wood, ironically, came from a shipping palette.
I drilled the hole 31/64" in diameter, a bit smaller than the motor's 1/2" shaft. I then drove a nail in where the motor's flat spot is to act as a key to keep the pulley from spinning loose.
With the motor running I used turning chisels to shape the pulley.
I didn't have the motor clamped down firmly enough, and the motor's mount is also a bit "springy", so there were some vibration issues. I ended up shaping much of it with a parting tool, mostly to take smaller cuts to cut down on vibration.
Sanding the inside edges of the V-groove. I wanted this to be nice and smooth to avoid unnecessary wear on the belt.
Then shaping the end of the pulley a bit more.
The motor needs to be bolted down to the base. The logical choice would be to use carriage bolts, but I have a whole bunch of these T-slot jig bolts left over from a 149 part jig and fixture kit I bought from Lee Valley Tools a few years ago, so I'll use those.
These require an elongated hole on the back, which I'm making by drilling overlapping holes with a Forstner bit.
Then screwing the bottom onto the sander.
Motor bolted on.
Using some pieces of wood to lever the motor to the side to add belt tension, then tightening the nuts to lock the motor in place.
And running the belt sander. I could just add the metal platen now and call it done!
The sander could also be tipped on its side, so it can be used as an edge belt sander.
Here, tracing the shape for one of the parts, then cutting the shape on the bandsaw.
Adding a ledge to the pieces to hold the sliding shroud.
Then attaching the far side to the sander.
Checking the shape for the side pieces of the sliding part of the shroud.
I bought a piece of 4" to 3" clothes dryer vent hose adapter to use for the dust collection hose. For light duty applications, dryer hose works quite well for dust collection.
I sanded the burred edges on my belt sander.
Looking through my plywood offcuts stash for a suitable piece of plywood for the back of the shroud.
Then tracing the size of the hole on a piece of plywood and cutting it out on a scrollsaw.
Gluing it together.
I sanded some sticks of wood round to use as small dowel pins to reinforce the corners of the part that I just made.
After gluing the pins in, I cut them flush on the bandsaw.
Then sanding them fully flush on the sander. I also rounded the corners while I was at it.
I used some small finishing nails to temporarily hold the sheet metal platen in place.
Checking the fit.
The piece of wood that holds the other side of this shroud could have been attached with long screws through the whole part, or with screws from the back (but the motor would be in the way of the screwdriver). I figured the most elegant way to attach it was with pocket holes from the inside.
Yes, pocket holes. I couldn't use my pocket hole jig because the ledge I already glued on was in the way, so I clamped another piece of wood to the side of where I needed to drill to help guide the drill in at an angle.
I want air to get sucked in from the top. To avoid having too much air coming from the side, I added a piece of wood between the box and the sanding belt to block that air flow.
I attached that with a screw at an angle from below...
... and another screw from the back.
I thought about screwing the hose flange to the piece of wood, but then decided to use small blocks of wood to hold it in place.
The pieces of wood have a rabbet cut in the side to accommodate the thickness of the plastic flange.
Naturally, I sanded these smooth on my belt sander.
Then clamping them while the glue dries.
I also needed a way to lock the vertical position of the shroud.
I used a 1/4" machine screw, screwed
into a slightly undersized hole from the back, then a wing nut
on the outside, which presses a piece of wood against the ledges
that hold the dust collection shroud. Tightening the wing nut
locks it in place.
A hose clamp holds the dryer hose.
I'm using a clamp to temporarily hold the 3" dryer hose to my 2.5" dust collector hose, which leads to my small dust collector
Trying it out. It's hard to see the moving dust in the photo, but the majority of the dust went into the shroud.
And when sanding curves, the shroud can be lowered to make room.
I started by measuring the distance between the pulleys.
Then drawing semicircles on a piece of plywood of the right length.
I had to drill some holes to accommodate parts of the pulleys on either end.
Then cutting the ends round.
Gluing on the sides of the belt guard.
I used some thin sheet metal (about 0.5 mm thick) for the top end of the belt guard. That way, the guard fits around the pulley without protruding beyond the sanding belt.
The sheet metal screws to the wooden guard with two screws on each end, plus another screw in the middle. I added an extra layer to the plywood for where the screw goes in the end (not shown)
Placing the belt guard against the belt, lining it up so that the pulleys are centered in the holes. Then using a mallet to tap the screws so they leave a divot in the part that it's screwed against.
After drilling pilot holes, I was able to screw the belt guard in place.
At this point I could call it done. But because I also want to be able to lie the sander on its side to use as an edge belt sander, an adjustable table is also necessary for this. I will get into that in my next article.
Next: Redoing how tracking and tension adjustment work