Homemade 1"x42" belt sander build (strip sander) part 2Back to part 1
Tracking adjustmentI initially had a different method of tracking adjustment (you can see it in the build video), but it was awkward to adjust and interfered with having a dust port on the right side.
The improved mechanism uses a long threaded rod, with a knob on the front.
Belt tensionerThe upper wheel mount arm needs a hole in the back. This hole is about 1/32" or 0.5 mm smaller than the threaded rod I'm using.
I'm using a block of wood with a V-notch cut in the end of it as a guide to make sure I get this hole square. That was easier than taking it apart again. Hopefully, you will have drilled this hole before assembling your sander.
I then used two slip joint pliers to loosen the nuts from each other and take them off the threaded rod.
A wing nut and washer on the threaded rod push the back of the upper wheel mount down. I later swapped the wing nut for a threaded knob. The wheel mount pivots in the middle, so this raises the wheel on the front. I'm using a small screwdriver instead of a shaft for the time being.
The motor I'm using is a 1/3 horsepower furnace fan motor, which I either picked out of the garbage or paid a few dollars for at a yard sale (I don't remember). For the time being, I'm just attaching it with some 1" C clamps.
You could also use the motor from a clothes dryer, a top loading washer, forced air furnace, sump pump, or diswasher. However, each of these motors may have its own challenges to mount and attach a pulley.
Do not use universal motors (motors with brushes). Those run too fast, though you could use a drill (these are sufficiently geared down)
If you are building a strip sander and have to buy the motor new, you may end up paying more for the motor than you would for a strip sander. So if you are inclined to ask "How much does it cost to buy all the parts to build the strip sander?", that suggests you don't have much of the stuff on hand. In which case, I recommend to just go and buy a new strip sander instead. Or if you really want to build one, buy a strip sandre and take the motor out!
PlatenI need some sort of "platen" to support the back of the sanding belt. It's easiest to just cut this from a piece of steel that already has a right angle bend to it. This piece is about 2.3 mm (3/32") thick. Slightly thicker would be better.
I'm using a saw that can cut metal, but a hacksaw, reciprocating saw (Sawszall), or angle grinder could also be used.
The mount for the platen is made of 18 mm Baltic birch plywood. Two slots allow it to be adjusted or removed. The rationale being that the platen mount moves and comes out with the platen, so that I don't wear out the holes for the small screws holding the platen when swapping it out.
I later experimented with making a rounded wooden platen, and that worked out just fine, so a wooden platen (so long as it's made from a hard wood) can also be used.
Table mountThe table mount consists of two pieces of Baltic birch plywood with a slot in them at an angle. The two pieces are glued together, then screwed to the bottom of the table using screws from above.
First testAt this point, the sander is functional enough to try it out!
There was quite a bit of noise coming from the wheels when I tried out the sander. On closer examination, I realized the bearings were not very tight in the wheels, so they rattled around as the wheel was turned. I could wiggle the bearings with my fingers
I made a paper shim to go around the bearings. This made for a nice tight fit.
Dust enclosureNext I made a cover for the sander. I printed out the template from my plans and cut a piece of 1/4" (6 mm) plywood to the shape, then added 1 cm wide, 35 mm thick edges.
I just marked these off my piece of wood and then cut them on the bandsaw. I also have templates for all these pieces in the plans, but I'd recommend just marking them off like this as you go along.
Now I just need a convenient way of attaching it.
If you follow the plans, you will already have drilled these holes earlier. The holes are 1/32" smaller than the 1/4" threaded rod. In metric, drill 5.5 mm holes and use M6 threaded rods.
Then screwing in the pieces of threaded rod. Again, I jammed two nuts against each other, and I'm using a nut driver in a drill to screw them in (faster than a wrench).
If you can't find threaded rods, you could also drill 1/4" (6 mm) holes and insert carriage bolts from the back.
I drilled 5/16" (8 mm) holes where the studs hit the cover.
While I had it apart, I also cut a slot in the frame so I could put the dust collector hook-up on the other side. I could have attached the dust collector to the side with the cover on it, but I could make a more robust dust hook-up if it wasn't attached to the cover.
You can buy surface mount switches, but I have had problems with some of these in the past. To buy an electrical box, cover, and switch is actually less expensive, and if the switch fails, it's cheaper and easier to replace.
Belt guardMaking a belt guard, I wasn't sure if I needed one. But I figure I should at least set a good example and add one.
The shape of your belt housing will vary with belt length, pulley size and motor size, so it's best to mark it off the machine than use the shape in the plans.
I used a short pencil to trace the shape of the belt on a piece of plywood.
Dust portI made a dust port out of a few pieces of wood. This one is for my 2.5" dust collector hose.
The hose flange has a gap at the top with a screw so I can adjust how tight the fit is to the piece of plastic at the end of the hose.
The coolest feature of this sander is that the platen (the backer behind the belt) is easy to remove and swap out. Here I'm swapping in a convex platen, for sanding inside curves. This allows this sander to do work that is typically done with spindle sanders.
It can't do everytying a spindle sander can do - like sanding inside shapes, but it can do things that spindle sanders can't do, like getting into tight corners. It also works faster, and the dust gets pulled into the machine instead of thrown to the side.
But then I had another idea- to just make a sheet metal clip that snaps onto the straight platen to make it into a convex one. The advantage of this one is that it's easy to swap in and out. Though if I have to sand a lot of curves, the curved wooden platen is more suitable.
With the curved platen to do the inside curves, and the edges of the straight platen to work the bevel edges in the corner, I was able to do all the shaping of the edges and top of this heart using this sander.
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