# Miniature DRO made from a digital tire tread depth guage



## Jwest7788 (Jun 9, 2015)

Check it out! (Turn your speakers down, sorry youtube song to cover up the shop chatting)


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## Mphenley (Jun 9, 2015)

I've seen numerous home-made DRO mods that use readily available digital calipers, but they have several drawbacks. Foremost among them is usually the auto-off feature that can't be disabled. They lose their setting when they turn off, making them only useful for a small time window of inactivity. Bit of a pain, really.

Also, they are somewhat limited in size, so while useful for most desktop size machines (at least on the cross slide and/or quill) they don't have the range needed for a larger machine like a 3-in-1's cross slide or even a desktop lathe's full bed length.

It appears most of the chinese DRO offerings use the same capacitive measurement, and you could take advantage of this and use a particular circuit to increase the length, but at some point your time is better spent making money to buy a full-scale DRO instead.

Ingenuity FTW, however!


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## Jwest7788 (Jun 10, 2015)

For sure. This little guy isn't going to fit all of my needs. But it's perfect for the type of project I've been working on lately!

Do you have a DRO solution in place?


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## Mphenley (Jun 10, 2015)

Nope, but I've done some extensive reading. Because my machine has two large axes instead of just one, it increases the cost quite a bit. I'd been looking at making my own hybrid CNC conversion so I could use CNC operations, still have manual control, and then pull a feed from the electronics to make a DRO display. Might be a bit of a long project though.


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## Jwest7788 (Jun 10, 2015)

That's a slick method, Setup CNC, then extract a DRO. Smarter than the other way around actually.


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## Mphenley (Jun 10, 2015)

Really depends how good you are with custom electronics and programming. And if you take your DRO from a rotary encoder on the screws, you'll introduce some backlash error in the displays, where a straight DRO setup won't have that issue. Might do a hybrid of the two, use a typical linear capacitive encoder to tell the CNC system how much backlash there is, and display the readout after that.


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## kylemp (Jun 14, 2015)

In case you haven't seen this.. http://www.yuriystoys.com/p/android-dro.html
You can get the cheap igauging "scales" from busy bee and adapt them, or just use those as a DRO.. this is just a nicer interface.


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## Jwest7788 (Jun 14, 2015)

Thanks for passing that along. Pretty slick indeed. 

I'll have to add the Igaging to the shopping list. Haha


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## Rick Runciman (Jul 4, 2015)

Tons of great ideas. I saw some dro's that mounted on the machine dials and probably worked from a tachometer. I don't use them,, I apprenticed years ago, and learned old school,, good to go with knobs and dials.


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## Tom O (Jul 5, 2015)

you know the shopping list gets bigger not smaller!


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## Rick Runciman (Jul 6, 2015)

The trick is not to break your bank, learn to work with less.


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## Jwest7788 (Jul 6, 2015)

Rick Runciman said:


> The trick is not to break your bank, learn to work with less.


This is 100% the reason I am using a tire tread depth gauge as a DRO. lol


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## Rick Runciman (Jul 6, 2015)

I'm using a 25 year old tekloc dial indicator that's pretty beat up. I put a magnetic back on it, and just stick it to the ways. Mitutoyo made a digital indicator about 17 years ago, but it didn't do too well, as it's easier to see an analog dial approaching it's zero coordinate. And you have a good grasp on the essence of machining, tooling and accessories cost a small fortune. He who does the most, with less, has the biggest bank account. For my small mill, maybe a cheap Chinese digital vernier would make a good dro.


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