Last week we reviewed the biggest dial that Capstan runs on. This time it is the two smaller ones, both from Elecrow, and both with something the big one does not have: a ring of coloured light around the knob. We put them side by side, built the same things on each, and came away with a clear favourite.
Our homework, handed to you
Every part that ends up in a TrailCurrent rig gets tried, printed around, programmed and lived with first. That is how we pick hardware. It also leaves us with a pile of notes on what works, what is fiddly, and what the box does not tell you. That knowledge is just as useful on a workbench with no RV anywhere near it, so we publish it.
Elecrow sent us both dials free of charge. They did not see the video before you did, and we would not take it down if they disliked it.
Two sizes, one idea
Both are a small round touchscreen set inside a knob you turn, with a click you can feel at every step. The smaller is 1.28 inches across with a knurled metal grip and five lights in its ring. The larger is 1.46 inches, with a sharper screen and eight lights. Underneath, they share the same brains, the same wireless, and the same way of connecting to a computer, so the software we wrote moves between them with very little change.
Do not let the small screen put you off. There is more room on it than you would expect, and it still looks sharp when it is full. The catch is touch: on a screen that size you have to keep the things you tap generously big.
What a ring of light adds
We already liked these dials for how they feel. The lights take it a step further. Each one can be set to its own colour, which means the dial can talk to you before you read a word on the screen.
- Feedback as you turn. Light that follows your hand around the ring makes every click feel answered.
- Status from across the room. Green for fine, red for not, readable before you get close enough to see the screen.
- A label that never wears off. On Capstan's Climate screen, one side glows blue and the other red, like the printing on a car's heater knob.
Those are our ideas. The video shows a few more we have in mind for the desk tool, and we would honestly like to hear yours in the comments.
Same family, very different to build around
A dial needs something to sit in, so we designed and printed a desk stand for each. First, a genuine thank you to Elecrow: they publish 3D models of both boards. After a week of tracing photos for the Makerfabs dial, that felt like a gift. The base of each stand fit on the first print. Well, the second for the small one, and that one was our fault.
From there the two went in opposite directions. One was simple to wrap a case around and lets its ring of light glow through the print with a single change of filament. The other fought us on shape and on getting its lights to show at all. We finished a case for both, but only one of them is a design we are completely happy with yet. Which is which, and the printing trick that made the glow so easy, are in the video.
The press is not where you think
On both dials, pushing the outer ring does nothing. The screen is the button. We expected that to be a deal breaker, since it means a tap and a press can get in each other's way. It turned out to be easy to get used to. If you are writing your own software for one, plan for it from the start. In Capstan we switched touch off entirely, so a press is always a press.
That is one of three things we would change. The other two are in the wish list near the end of the video.
So which one?
We should not have a favourite. We do. It is the one we would pick for most of our own projects, and the reasons have less to do with the spec sheet than you might guess. The runner-up was close, and for some projects it would be the better pick.
Stay to the end for something else, too. Between them, these two dials gave us an idea for a much bigger project, and we want to know whether you would like to see it built.
Take all of it
Everything from the video is free and MIT licensed, same as the rest of TrailCurrent.
- The desk tool for each size: 1.28 inch and 1.46 inch. Plug it into a laptop and it acts as a keyboard that changes with the program you are using, now with the ring lighting up as you turn.
- The stand files, ready to print or change.
- The Capstan software, which runs on both.
If you want one of your own, here are the 1.28 inch and 1.46 inch dials. Both links carry our affiliate tag. It costs you nothing extra and sends a small cut back to the project. If you would rather it did not, search for them on Elecrow's site directly.
Want to see what Capstan looks like on one? The Capstan page has a dial you can turn in your browser. If you build something with one of these, tell us in the video comments or on Discord. More like this goes up on the open source channel.