I have a MicroLux Drum Sander which is a nice little tool for sanding things that are too small to go through the planer. The only problem I’ve had with it so far is that the height adjuster, for the table that wood goes through the sander on, is hard to adjust by hand.
So I had a thought the other day, and decided to make a knob for it. I started with a chunk of hard maple, and cut a 4 inch square by ⅜ inch thick piece. I found the center by drawing the two diagonals, then drew a circle on it. Where the circle crossed the diagonal, I used an inch and a half Forstner bit to take off the corners.
That done, I drilled a ½ inch hole through the center and chucked it up on the lathe. Used a parting tool to make it round, and then sanded a bit to clean up the rough edges. Then I popped a ⅜-16 bolt through that center hole, got it as centered as I could by hand, and drew lines to make a hexagon around the hole.
The nice thing about a 9/16 inch hexagon is that a ⅜ inch chisel is almost the exact length of a side of the hexagon. And the ⅜-16 bolt (and nut) have a 9/16 inch head. When I put my (inch) calipers on the bolt-head in the sander, it told me 35/64 inch, which is close enough that a 9/16 will work.
After a short bit of chopping with the chisel, the bolt fit through the hex hole I had cut.
Next I made the hole a hair larger on one side with a ⅝ inch spoon bit, going about an eighth deep, and cut a short bit (also about an eighth) off the end of a ⅝ inch brass bar I had on hand (which has a hole drilled in the end from when I was making nuts a while back) and put them together.
With that done, I gave it a test. Here it is on the adjuster bolt. You can see that the brass is slightly proud of the wood surface, so it will serve as a bearing. I meant to do that!
And with the table set down, it’s now super-easy to adjust the height of the table. I think the bolt is a M6-1 which means every rotation gives me 1 mm up or down. On hard maple, one eighth of a rotation was plenty to lift the table for every pass through the sander, but I’m not sure how much of a change that is where the sanding drum contacts the wood.
Tomorrow, I’ll pull my new knob out of the sander and epoxy the brass into the maple with as little epoxy as possible. I’ll probably give it a coat of oil too. But in about an hour, I had fashioned a new knob, and I’m much happier with my little drum sander now. Yay!
Thanks, guys. Yeah, it’s a lot easier to really dial things in now, which is a big win. Took longer to take the pictures and write it up than to do the actual work, I think.
Nice mod/repair. I've made a similar knob before by drilling but instead of turning it on the lathe, I just used a hole saw to cut out it out after drilling the 4 indentions. Also, I rarely chisel out the the hex hole. It seems like a I always wind up with a wonky fit when I do. I simply drill a countersunk hole that is just slightly smaller than the hex shape (the hole diameter is about the same as the wrench size) and simply press it in so that the corners bite into the wood. A few drops of CA glue or epoxy ensures it doesn't come out.
--Nathan, TX. Hire the lazy man. He may not do as much work but that's because he will find a better way.
Plenty of those annoying "features" on even the best of equipment. Those little details where the designer or management decided to save a few cents.. This makes your life just a bit easier to enjoy the process. Nice shop fix Dave👍
Nathan, I’ve done it that way before, but with hard maple, trying to bash the metal into the wood hasn’t gone great for me in the past, so I decided the chisel was the best answer. There’s now a little bit of epoxy holding the brass in place, but the bolt-head just sits in the hole in the wood so I can easily remove it if I should have some need.
Splint, I’m debating whether I want to send the folks at MicroMark a note. I’ve been impressed with other stuff from them, so I was disappointed by this.
Thanks, Jim! Of course once I finished it, I haven’t needed the drum sander for a couple weeks, but that’s how life works sometimes. At least the epoxy has had a good chance to cure before being stressed.
