Metrology fans are usually at least a little bit in love with Mitutoyo, and rightfully so. The Japanese company has been making precision measuring instruments for the better part of 100 years, and users appreciate their precision almost as much as the silky smooth feel of their tools. If you can afford it, a Mitutoyo caliper is quite an addition to your toolbox.
As good as they are, though, they’re not perfect, which is what led to this clever Mitutoyo digital caliper hack by [turbanedengineer]. The calipers in question, a digital set from the early 1980s, happen to have a unique history with a tangential Hackaday angle — they belonged to [Dhaval], mechanical engineer and avid motorcyclist who happens to be the late elder brother of our own [Anool Mahidharia].
The tool, in need of a little TLC, made its way to [turbanedengineer] who first restored the broken battery contacts. Once powered up again, it became apparent that while the caliper’s native metric measurements were spot on, the internal conversion to inches was considerably off. This led [turbanedengineer] to the data port on the tool, which is intended to send serial data to an external computer for logging measurements. After a little experimentation to nail down the data format, he prototyped a tiny circuit using an ATtiny85 and an OLED display that reads the caliper data, converts metric to inches, and displays both measurements on the screen. The prototype led to a more permanent version, which cleverly sits over the original display and taps into the data port without any free wires. The video below shows the very slick results.
Our hearts go out to [Anool] and his family for their loss, and we tip our hats to [turbanedengineer] for his thoughtful and respectful hack of a storied tool. We know that anthropomorphizing tools makes no rational sense, but we think it’s safe to say that a tool like this has a soul, and it’s probably happy to be back in the game.
I’n not sure if this hack will fix my broken Mitutoyo, as its pcb appears to be corroded, I only get a brief flash on the LCD when power is applied. But I’ll follow the link(s) to see what is there.
Well, there are some differences of my Mitutoyo’s Digimatic port (and PCB?) to the one in the link, but it is something more to go on. (Mitutoyo no longer supports my model)
Depending on how bad it is, cleaning it with descaler and rinsing it off, letting it dry, might help. Might need to refix some solders but there’s a chance you can bring it back to life.
Make it talk!
That is a slick add-on. It’s a hat but with a reach behind.
this seems to indicate something about the difficulty of using that non metric system of measures!
All systems of measures are metrics.
It sounds very surprising that even an old Mitutoyo would have inaccurate unit conversion.
The example case displays 4.44 mm and 0.1750 inch. I could be that internally it measures with higher resolution (not necessarily accuracy!) and has e.g. 4.444 mm. This then correctly rounds into both displayed values.
Though with 0.0005″ resolution spec and 0.0008″ accuracy spec, the 0.0002″ error compared to naive unit conversion seems irrelevant.
The great thing about my Mitutoyo caliper is that it doesn’t need any batteries;)
Through miniaturization you can now convert it to digital with bluetooth which sends the measurements to a phone app.
Or you know, use it as a mechanical caliper :)
Maybe you can add an list of retrived value in an list on the display, will be usefull.
I have liked Mitutoyo for a long time for their accurate and pleasant to work with tools. It is a bit unfortunate that they very quickly become extremely expensive when you deviate from the “base model”.
About 5 of 6 years ago I bought a Mitutoyo digital calipers and for about half a year it’s now complaining that it’s battery is getting empty. I paid EUR100 for it (Those EUR40 from ali are fakes) and I want another decent quality digital calipers, but this time with data output. A Mitutoyo costs around EUR140 with data output (That EUR100 is a bit below the regular sales price). Mitutoyo data cables are also redicilously priced. You almost pay more for the cable then for the calipers. And this makes it unlikely that my next callipers is going to be a Mitutoyo. So now I’m up to the difficult task of finding a decent quality digital calipers for a reasonable price. (All those things below around EUR40 are simply garbage and not worth my money. I do want and need decent quality).
I’ve been happy with my Clockwise Tools calipers for the past three or so years of using them, inexpensive and accurate. They support a rs232 data cable and both can be had for around $60 USD (€55) for the 6″ (15cm) model.
They also have excellent support and stand behind their products.
I’m so happy to see this resurrected and live on, thanks to [turbanedengineer]
These kids don’t know how to read analog.
Holy butts, that’s awesome. I have the same old set of calipers, inherited from my dad.