Making a Drum Sander – Part 3 – First Run

With the drum sander being essentially functional, I could start fixing it in its working place and truing the drum. Both issues were simple but not easy, so it took me a whole day and some more to do it properly.

The first problem to solve was how to fix the drum sander besides the belt sander so it could be powered by it. Here has shown my first serious mis-measurement. I had to trim a sliver of the belt sander base because I could not position the drum sander close enough for the wheels to align properly. Then I stood in front of the problem of how to fix the drum sander in place so it does not slide around.

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From the start, I wanted to do it with two M10 bolts at the back but my first attempt was a bust. You can see the results of that first attempt, those two yooge holes in the back of the base. The problem was not that it was not stable or somesuch. The problem was that the bolts would be in the way if I wanted to sand something longer than about 40 cm. What followed was about an hour of serious thinking and faffing around in the workshop and when I started to work on another solution, I accidentally found two metal angle irons with pre-drilled holes.

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I undid all the work I did in the last hour, screwed these two onto the back of the belt sander base, and cut the 10 mm holes open. That way I could slide them onto the M10 rods inserted into holes in my workbench and fix them in place with winged nuts. I also had some play to slightly re-position the belt sander to align the wheels properly before tightening the nuts.

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With the back of the belt sander being fixed to the table, I could run it but I also added two legs on the front just in case. They are not strictly necessary – in fact, one of them is a tad short and is not even touching the ground properly and I will have to add a screw extension – but I feel better with them.

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With the belt sander standing, I could run it for real. I used an old trizact belt to power it. That works for now as an impromptu measure, I will make a proper sturdy leather belt to do the job. For now, I stood in front of it for a couple hours running a piece of particle board with 60-grid sandpaper glued to it to true the drum, holding the board in one hand and vacuuming the particles with the other.

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Here you can see the drum being sanded down to being nearly, but not entirely, concentric. There are still visible gouges made by the table saw. I had to run the sandpaper under it quite a few times after each lifting of the table, and I only could lift the table about ¼ of a mm at a time. I only ran it at 20% speed at first because the drum was so unbalanced and the whole assembly vibrated violently. After a while, I could increase the speed to 40% as the cylinder became more and more concentric and thus better balanced. That is also the top speed at which I intend to use the machine since higher speeds would burn the wood and destroy the abrasives (I built the machine so the surface speed of the drum is approximately the same as the surface speed of the belt so I can transfer experience from one to the other).

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Late in the evening truing the drum was finished and it was flush with the table across the whole length to within a tenth of a mm. I left a bit of a gap here so it can be seen.

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With the drum being concentric and true, I could finally fix some abrasive to it. For a test, I used an old torn 40-grit belt. First I wound it around the cylinder, fixed it with rubber bands, and trimmed the edges to flush (these scissors are used for trimming abrasives and nothing else, in case you are wondering). After that, I cut grooves into the sides of the cylinders, tucked a bit of the belt in it, and fixed it in place with a screw.

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It worked reasonably well as a temporary solution and I learned a few things when running it for a few hours with some testing pieces of wood. The leading edge held up fine but the trailing edge eventually tore off. It seems that at the trailing edge, the screw is completely unnecessary and a bit of double-sided adhesive tape would suffice plenty. That is good to know, but I am already looking for a better way to do it in the final version. I am ordering some velcro and abrasives with velcro.

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And that’s it for now. The 40 grit did hog off material quite nicely. I flattened a seriously twisted and bent piece of jatoba that I definitively would not be able to flatten manually, ever. Although manually feeding the stock through the machine is still hard work (for me) – I did get some workouts on my back and my pecs that way. Still an order of magnitude less work than trying to flatten one of the hardest woods on the planet by hand.

There is still a lot of work to be done and I will do it and write about it. Optimize the assembly/disassembly, optimize the attachment of abrasives, optimize the legs, make dust collection attachment, make a proper and safe push tool to feed the wood through, and finally, paint job. Only I do not know when I will do all this it because I have to take about a week’s pause from this work. I have to paint the kitchen now. I hate it, but it needs to be done and it has to be done now because now my brother can come by to help with things that need four hands.


  1. Jazzlet says

    To this inexperienced eye it looks amazing. And it sounds as if using a different set of muscles to paint the kitchen might be a good thing on the ‘a change is as good as a rest’ theme ;-)

  2. says

    You’re so stubborn!
    Are planers prohibitively expensive there? New carbide inserts in a planer will give you a 600# equivalent finish even on oak, in one pass..

  3. says

    @Marcus, the cheapest thicknesser I found and would consider buying costs about 500,-€ and weighs about 40 kg. The cheapest drum sander that I could find costs about 1.000,-€ and is bigger than my table saw when in use. Those costs are prohibitive for me and even if I could afford one or the other, neither would fit in my workshop and both are gross overkill for my needs.

    If I manage to get this to run, it will weigh about 10 kg max and I can disassemble and stove it away when not in use in 15 minutes since I am building it specifically to fit into my workshop and the space I have available.

    So far it looks promising and 500,-€ saved is as good as 500,-€ earned.

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