I took Sunday off and on Monday I had other things to do but yesterday and today I could work on the drum sander some more and I progressed significantly. First I finished and attached the propulsion wheel. I started that right at the beginning but it progressed slowly because I glued it from several layers of old plywood and I had to wait for the glue to dry a few times. Just before the two-day break, I soaked the surface with epoxy resin to make it harder and on Tuesday I turned and sanded it until it was passably round. I will probably give it another layer of epoxy once everything is finished, I will use the epoxy on other parts too to improve their surface hardness and strength.

The wheel is attached to the axis with an M4 screw going through a thread drilled and cut into the axis. I hope it is strong enough and won’t get sheared off in work because I do not have any better idea how to do it. I need to be able to eventually remove this wheel in case a ball bearing gets busted and needs replacing. I am also leaving myself a bit of the axe poking out so I can power the thing with my drill in case powering it with the belt grinder does not work.

On the right side, I added a fence with a shelf to lift the base 55 mm; on the left side, I simply added a 55 prism. Then I screwed two spruce boards on it to reinforce the structure. Though I screwed them on with the wrong grain direction of the core but it seems to hold strongly enough. Should a problem occur, I will reinforce it later or replace it with properly oriented boards.

The base under the propelling wheel is unsupported. This has a reason – I need to be able to slide this side over the base of the belt grinder because I need to align this wheel with the motor and the spanning wheels of the belt grinder. It should not be under too much stress but I did reinforce it with steel under the wheel where there will be most of it. Again, I might add some more support later, for now, I think this suffices.

That was Tuesday done. I attached it improvised to the belt grinder and it worked, albeit it was loud as hell. I think that can’t be helped, the ball bearings are not perfectly aligned and the drum is not concentric yet and I can only solve the second of these two issues.

Today I made the tilting table to adjust the sanded thickness. And here I must thank to rsmith for pointing me to a page with useful information about how to make a very simple one.

I started by cutting-out a piece from the lifted base. This was the plan all along, to use this space for some sort of mechanism to lift the table. On the front, I added a 55 x 20 mm beech board across. Beech is reasonably strong hardwood, it should be able to support the table. In the middle of the board is inserted a 24 mm long M8 nut with a sufficiently long rod through it. To operate the screw I tightened on it a hex nut and a winged nut against each other.

I decided to make the table from a 15 mm particle board because the piece I had had a very smooth surface and it is straight. However, particle boards are not exactly known for their strength, so I had to reinforce it. I reinforced the rear end with stripes of beech wood for the hinges to have better and stronger anchor points. I put it under weight and went for lunch while it was setting

After lunch, I continued reinforcing it. On the front end, I added an offcut of angle iron. That also provides a hard surface for the screw to lift the table.

For longitudinal support, I screwed on two beech strips. I forgot the exact measurements, somewhere around 25×15 mm or somesuch. I tested it and it seemed to be sturdy enough against bending, but not against twisting due to the table being supported by a single point on the front. It should not be a huge problem if the sander is loaded in the center as it should be, nevertheless, I decided to reinforce it further with three offcuts from the same particle board intended for firewood.

One continuous piece would be better and I had a suitable one – the one that I cut out of the base in the morning – but I completely forgot about it until these were screwed on and I did not want to go through the hassle of trimming it and drilling all the holes again. I think it is strong enough and if not, I can add more support later. I say that a lot.

And this is where I finished today. I think the work is progressing nicely. I have a tilting table with a range of about 35 mm, which is plenty for my purposes. It takes about 80 half turns to lift from zero to full. That is enough sensitivity to sand off only tiny layers of material when needed. The whole assembly so far is sufficiently light and compact that I can easily lift it and put it under the table next to the table saw when not in use. I am reluctant to be optimistic but I do feel ever so slightly positive about this project.

How the time flies – it is two years since I wrote a series of blog posts „Showing off my wood“ where I have shown various woods at my disposal for crafting. I have so much material in fact that it is not improbable but downright impossible for me to use it all up making knife handles and knife blocks, I just cannot make that many different knives alone. So I would like to make some high-quality end-grain cutting boards to convert at least some of that massive amount of material into something useful.

I started last year but I hit a snag. I need to mate wooden surfaces together perfectly, but there is no convenient way for me to flatten wooden surfaces in reasonable time and in scale. My manual method is precise, but also tiring and time-consuming. I need a drum sander to make even a few end-grain cutting boards. And I cannot buy one for two reasons. Firstly I don’t have the money. Second, I don’t have the space needed for one.

But since I have managed to build myself a belt sander, I decided this year to spend some time trying to build a drum sander too. I had more than a year to think about it and with the money these things cost, even if I spend a whole month building one, it would still be worth it.

I started by gluing three large pieces of black locust wood together to form a large prism through whose center I put a 10 mm threaded rod. I cut the edges off on a circular saw and then I stood in front of a bit of a problem – how to turn a large-ish wooden cylinder without a lathe. I rigged up a temporary wooden structure that allowed me to span the prism in such a way that it could run against the edge of the circular saw whilst being continuously rotated with hand-held akku drill. I hope the picture makes it clear what I mean.

It made an absolutely unholy mess and I was terrified the whole time but I succeeded in making a rough cylinder round enough to progress to other works. I will make the cylinder perfectly round and concentric with its rotational axis later.

I swapped the threaded shaft for a smooth 10 mm one and to secure it to the cylinder I drilled 3 mm holes throughout it and the shaft on both ends and I drove 3 mm hard steel through the hole. I hope it’s strong enough for the forces needed, if not and it shears off during work, I will have to think up something better. I also cut grooves in the shafts to secure one ball bearing on each side with circlips. I later decided to use two ball bearings, with the second one being put near the first one and not being secured with circlips. As you can clearly see, I am making things up as I go along and I do not always know what I am doing.

A 15 mm particle board from an old PC table serves as a base to build upon. To hold the ball bearings I cut short boards from hardwood (beech) and I made cutouts for the ball bearings between two pieces and screwed them together with long wood screws. It appeared to be reasonably strong and it held the ball bearings firmly, but it was a bit wobbly. So I glued 15 mm particle boards to the beech boards to widen the bases a bit.

While the glue was setting on that, I trimmed the edges of the cylinder. I used the boards that held it in the circular saw jig and a hand-held drill as the source of rotation again. That left me with only one hand free to trim the edges but a hacksaw blade proved to be quite efficient at that. Setting the initial groove was a bit fiddly but once started, it went easily, albeit slowly. The edges are not perfectly square and flat but they do not need to be.

Once the boards for holding the ball bearings were glued together, I glued them to the base with five-minute epoxy. Epoxy is expensive, but I needed a strong bond to make subsequent works easier.

Once the epoxy cured, I added 4 80 mm wood screws through the beech cores and then also multiple 6 mm bamboo dowels glued in with PVA glue. I do hope that is strong enough in itself but it was additionally reinforced with the last step.

 There are strong anchor points on the base for the ball bearings and I changed the way they are held between the boards from the temporary wood screws to the final solution – I put two M8 rods through the whole thing with pronged nuts hammered into the particle board base and wing nuts on top. It holds the ball bearings firmly in place and the cylinder can rotate freely.

And this is where I am right now. Next, I can start working on the propulsion part.

During all this work I am also spending a lot of time just thinking not only about each step but also about what might be the main challenge of this project – the adjustable sanding thickness. I have several ideas but they all are fiddly and complicated and I would like to keep things as simple as possible. The simpler the mechanism, the fewer potential points of failure. I won’t even attempt to make some sort of automatic feeding – the wood will be fed through the machine manually (if I manage to make it work).