Knobs and switches can make or break the aesthetic and tactile appeal of a project. Fine hi-fi hardware goes hard on these details, while cheap knock-off guitar pedals often go the other way. If you’re looking for a unique, cheap, and compelling solution for potentiometer knobs, you might like to consider using converted brass hardware for the job.
The idea comes from [Kevin Jordan], who realized that some simple 3D printed parts would enable him to repurpose brass hardware for use with common split-shaft potentiometers. He grabbed a bunch of brass flare caps intended for use with gas piping, and got to work.
The result is the simple 3D printed cap converter. It has a threaded outer portion, which screws neatly inside a brass flare cap. Inside, it features a hole to mate to the potentiometer shaft. While this could be done with a spline, it also works with a simple hole since the plastic is soft enough to simply push the potentiometer shaft into.
The flare caps look great when pressed into service as knobs. [Kevin] uses them on a tennis racket guitar he built, and the brass knobs beautifully set off against the natural wood finishes of the build. If you’re looking for some unique adornments for your own projects, you might like to experiment with this concept yourself! Alternatively, you can try making your own knobs from scratch.
18 thoughts on “Brass Hardware Makes For Pretty Potentiometer Knobs”
They look like someone found some junk and pressed them into service instead of getting nice knobs.
That’s why it’s called a “hack”…
Nah they have some industrial vibe. Not much room on the top for a good arrow line. I’m trying to figure if even or odd numbers on the facets would work as well for a reference setting at a glance. Stamped or engraved, but not going to 11.
The engraving is missing. That was my first thought. Lines, patterns, animal figures.. They’re screaming “culture!” Remember when furniture had lion feet (not my taste) ? 😂
depending on your aesthetic preference, polishing or machining the basic brass fitting can lead to easy, repeatable, nice fittings. My personal most frequent use is as a ferrule on the end of a tool handle – a brass plumbing reducer looks jank, but once you file off the surface features and bring it up to a nice satin or even a gloss, it looks much better.
The original method of using a wooden dowel is fine – it’s not that hard to drill a centered hole in a dowel. This is just a TV-shop butterfingers excuse for a gadget (i.e. the 3D printer) when the faster and cheaper, better solution already exists.
another similar method:
I don’t mind the idea of making brass knobs this way, but that picture with the “Gorgeous, no?” I have to answer with: NO is right, it’s fugly as hell.
But that one on the brass plate I like though.
Years ago I had a guitar amp that had missing knobs on the control panel. The pots had a odd shaft size so after trying a generic set without success I decided to make my own. I used old .45ACP shell casings. They were a bit long but a pipe cutter worked out to make them a little shorter. Covered the shafts of the pots with plastic wrap and filled the shell casings with epoxy and slid them on. After 24 hours I slid them off, cleaned things up and pressed them back on. I then had a buddy make a Marshall badge in brass for the speaker grill. The badge looked like a 1911 with Marshall on the slide.
Wait, aren’t potentiometer knobs made of “toothpaste tube plastic screw caps” good enough anymore? ;)
A famous punk band from Indy could have had their name on every knob made from a child resistant cap. Turned up to 11. Push Down and Turn!
The beauty of art on any level is that it truly is in the eye of the beholder. I really like those brass knobs and would rock them on a guitar or even on any kind of a steampunk-themed creation. Well done!
I like them as well. I am working on a nixie clock just screaming for a knob, and this is probably the solution for the encoder. I don’t have a lot of trust for 3D printed things. I’ve had too many things break at the wrong moment, but think epoxy or a wood center would work fine. I just want to make sure it can be removed.
I can see where some people definitely wouldn’t like the look of these, but if they match the style of the project (like something based on visibly repurposed parts, as in the guitar shown) I think they can look cool. Any hardware can produce an ugly result if it doesn’t match, so I’m not too concerned that it only works with a pretty specific style of project.
That being said, I think I’d be inclined to modify the fittings more in most cases. Turning the facets away to make a plain round knob with a rounded top would probably look good, and you’d be able to easily polish it to match the finish of other brass in the project. Even without a suitable lathe, you could probably grind or file the facets away without too much trouble. If I wanted to have some facets, I might try filing down the corners to make a circumscribed dodecagon rather than a circumscribed hexagon, but the very obtuse corners might end up being a little tricky to get even by hand.
One big advantage of these fittings, I think, is that these are probably going to be pretty convenient to obtain, and wouldn’t need much work to use–especially if you do use wood plugs and drill them out. Making similar knobs out of solid brass would need pretty decent size stock, and you’d either bore most of the mass away or end up with a very heavy solid piece. The nearest metal supplier to me has inconvenient hours for hobbyists, and local hardware stores where I am don’t carry brass round bars above 1/4″ (and even that is often out of stock), but these fittings I could probably nip down and pick up on any given Saturday.
From the picture I thought these were oil burner spray nozzles. Knobs, and other things, could be made out of nozzles in a similar way. Although much more expensive than caps a they are commonly replace every year and old ones trashed.
Some brass alloys contain lead, so it wouldn’t hunt to spray a lacquer layer once the desired patina has set in.
There’s a good number of oilite bushings in all kinds of shapes and sizes too.
I don’t think you touch a potentiometer knob quite that much, nor does your skin exhibit quite that much abrasion to need to protect yourself from any trace amounts of lead.
Plus copper kills viruses and bacteria, so by shielding it with lacquer you become more prone to be infected, so what risk do you choose? Think hard :)
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