My brother and my sister-in-law were busy as bees and between the three of us, we managed to do all the necessary work re-painting the kitchen in just two days. On Wednesday I had to do some little cleanups and shopping and on Thursday I could continue to work on my drum sander. So I did.

After the first successful test run of the drum sander, I glued up a 50×1500 mm leather belt to drive it. For better precision, I bought an already-cut leather strip (a prefabricate for leatherworkers to make belts), cut both ends at an angle of 45°, and glued it up with special extra-strong elastic cement for shoes. I was thinking of reinforcing the seam with sewing, but so far it does not appear necessary – the glued joint can withstand all the force my hands can exert, which is significantly more than the spanning spring on the belt sander can do. I run into a minor setback here – I made the driving wheel on the drum sander with a groove as I would for running it with a rubber belt. That was a mistake, the leather jumped the low fence quite easily and when I tried to make the fence higher, it jumped the spanning wheel and the motor wheel. The best solution (which, luckily, did not take long to find out and implement) was to remove the fence on one side and to make the cylinder wider. The leather belt is not precise and needs some space to oscillate from side to side.

After this, It was running quite well. The crowned spanning wheel does keep the belt on track and on the motor wheel, and on the driving wheel of the drum sander, it moves a bit side-to-side when running. With that problem solved, I could move on to dust collection. Pushing the wood with one hand and vacuuming the dust with the other is neither an easy nor elegant solution.

The dust collection does not need to be especially sturdy. Its main two functions are to stop sanded-off particles flying all around the shop and to prevent me from accidentally grinding off my fingers on the drum. Thus I opted for the easiest and cheapest material to use I have available – cardboard. And it is held in place by four M6 fly screws that go into threads cut directly into beach wood.

I cut a piece of pine board to put across the drum and I glued on it fences from cardboard that slot into the grooves I pre-cut in the two pillars holding the drum. To prevent the edges from fraying, I glued strips of sturdy paper over them. To attach the vacuum cleaner I used a reduction I saved from my old hand-held circular saw when it broke.

As far as inner geometry goes, I tried to glue in two strips of paper to reduce the space between the drum and the walls. I tested it with these and without them and I think that they did help with the dust collection, but they were not very stable and had issues (dust collected behind them). I am currently in the process of finding a better and more permanent solution to getting the inside of the housing to conform to the drum better. For now, it works, albeit it can be improved.

Initially, I intended to glue the belts on the drum but rsmith’s link in the comments under the first article gave me the idea of using velcro. If I can change the belts reasonably fast, I can use the drum sander not only for material removal and flattening of surfaces but also for getting a reasonable surface finish on completed cutting boards. And I also could have a separate set of belts to flatten metals, if I need to. So I went and ordered some velcro and a set of belts. The velcro was so far the most expensive part of this whole assembly- about 30,-€! I hope it was worth it. I glued it in a spiral around the drum and I wound up a strip of abrasive around it in the same direction. On the trailing edge (left side of the drum) the velcro suffices to hold the paper in place. On the leading edge, I had to make a groove, bend the paper into it and secure it with a screw.

The next day I made a few optimizations. I improved how the whole assembly is held near the belt sander by inserting two M10 hammer-in nuts into the table. I made one of the two supporting legs adjustable in length so I could adjust it to the uneven ground of my workshop. I made two long M8 fly screws and I used them together with two hammer-in M8 nuts to attach the legs in a secure yet easy to disassemble way. And finally, I made a specialized push tool to shove the pieces through the sander without endangering my fingers and without exerting myself needlessly.

It is made from an old furniture leg and two offcuts from an old spruce board. The table height is just below my navel so I can easily brace this thing against my belly and gently but firmly push with my body weight.

And with all that done, it was Friday evening and I went to bed late. Yesterday, I ran it for about 6 hours to test it thoroughly. In those 6 hours, I managed to flatten twelve jatoba boards approximately 15×30 cm. I think I could do the job faster if I used a coarser abrasive, but unfortunately, 40 grit was not in stock and the 60 grit I ordered had not arrived yet. Thus I had to do with 80 grit. I ordered the 40 grit finally yesterday and the 60 grit should arrive on Monday. I still have some unflattened glued-up boards and I will probably wait for those to see how much faster I can do the same work.

I do consider the test to be a success. The machine ran the 6 hours (three 2-hour segments) without a single problem. The boards are not tutti flatti perfetti, but they are flaterooni accepti. As in within a few tenths of a mm over the 30 cm. That is enough for a good and practically invisible glued joint.

I learned a few things while doing this. The food-safe PVA glue does not gum up the abrasive but it does create small resin-like chunks that can attach to the wood and/or the table and make the board run unevenly. So I have to brush those off, especially at the beginning when it grinds off the glue runoffs. I also learned how to incrementally lift the table for best results and I got a few more ideas for improvements and optimizations.

That was significantly easier and quicker than I thought it would be. It is not completely finished yet and I will write about the finishing touches. However, as of now, I have a fully functional drum sander. I made it in about three weeks and so far it cost me less than 200,-€, most of which was the velcro and the abrasive belts.

And while I am waiting for the coarser abrasives to arrive, I will paint it.