Making a Tailstock Digital Readout DRO for my Lathe

I machined a Tailstock Digital Read Out for my Colchester lathe to allow precise depth holes to be drilled. The scale filled with oil and swarf and died, so I am replacing the original scale and cleaning and refitting the collar, magnetic parts and mounting wedge.
The mysterious connections between Off-By-One errors, strange Lincoln Darts boards kept in tubs of murky water in pub yards, oil ingress and my desperate failures with arithmetic subtraction in my head.
A low cost Vernier Caliper gets chopped up and shoe-horned into acting as an interim replacement for the recently-deceased linear scale. Spoiler alert - It All Ends Happily.
No actual machining this time, just a lot of Dial Indicator action, plus of course, Aimee sticks her oar in to make sure I know when I'm doing things incorrectly.
I don't have the original CAD files for the wedge, but it will be pretty much a bespoke item for every model of lathe, as will the collar.
I found the original video that inspired this build. It was from ChrisB257 • Simple Tail Stock DRO so thanks very much for the idea Chris!
Attributions:
Richard Croft / The Treaty of Commerce / CC BY-SA 2.0
Darts: Klaus D. Peter, Wiehl, Germany Creative Commons Attribution 3.0 Germany creativecommons.org/licenses/...
www.reddragondarts.com/winmau...
Loozrboy from Toronto, Canada Creative Commons Attribution-Share Alike 2.0
Everything else is either by me or is in the public domain as far as I can tell.
Chapters:
00:00 Subtraction is my Nemesis
01:07 The Quest for a Tailstock DRO
05:15 One of our Scales is Missing
07:21 Scale Precision

[@MachiningandMicrowaves]

I found the original KZbin video where I got the idea for this accessory. It was by ChrsB257 kzbin.info/www/bejne/Y3XPgpl4ic6bfLM

[@Kombivar]

I admire how much effort and freshness is put into these videos you make, great sense of humor, stunning narration and even tangent to the Pink Floyd's 10th studio album!!! You made my day - again!

[@jduncan459]

Oh man, the KZbins recommended your video today, out of the blue. I must say you've hit the ground running! Even my wife watched. High production value right out of the gate. As a hobby machinist, I love to watch other's processes. You do not disappoint.

[@MachiningandMicrowaves]

Algorithms are marvellous things sometimes. So long as everyone bears in mind that "I Have No Idea What I Am Doing But I Am Not Afraid Of Failure" is my hidden mantra, there should be loads of fun to be had. if I ever work out how to use this editing software and keep oil off the camera lenses, things might get better. Apart form my terrible TIG welding, that's never going to improve, I'm just rubbish at it.

[@apexmcboob5161]

I had the spindle collar figured out but attaching the end of vernier to the hardened tailstock of my lathe had been eluding me. Thanks for the idea of using magnets! I'm glad I discovered your channel; combining microwaves and machining with your wit suits me perfectly. And I'm embarrassed to admit I'm developing a crush on Aime....

[@MachiningandMicrowaves]

I'm sure I must have got that idea from someone, but it was a long time ago and I've slept since then. I've been trying to teach Aimee to speak Yorkshire, and she can do a passable Sheffield, but Barnsley defeats her.

[@jackjackson5137]

I love your style and the narration (including the wonderful stories of mysterious critters in the shop)

[@MachiningandMicrowaves]

I've spent my entire life having to be fairly serious. Not any more. I can be as silly as I like now. "When I am old, I shall wear Purple" is applicable.

[@FullSendPrecision]

The magnet attach is a neat feature. I haven't made a tailstock DRO yet because I haven't felt like I've needed one, but when I do I'll incorporate that for sure.

[@MichaelKJohnson]

I designed a tailstock DRO holder for calipers and then discovered that it interfered with the toolpost in use, so started looking for alternative designs. I really wanted one that doesn't permanently occupy the top of the tailstock (that's where the oilcan goes during tapping and parting...) and the idea of a tab and magnets is great. Starting over now on my design! ☺

[@MachiningandMicrowaves]

This can be a little tight when using a rotating centre in the tailstock with small diameter workpieces, but it's nice to be able to pull the scale off when needed. Two pinch bolts hold the collar to the tailstock quill so that's an easy thing to remove. Hugely useful accessory

[@evzone84]

😆 I'm so glad I started watching you. Not only are you clever and full of great ideas, but you keep me laughing the whole time. Keep it up and I'll keep trying to mimic your projects.

[@MachiningandMicrowaves]

Next video is about making the mount for a mag chuck for making thin ferrous parts and precision grinding on the lathe, with appropriate abrasive dust protection. The big vacuum chuck for turning thin plastic and dielectric parts should be the next, but I have an operational microwave vid that I must get published before the Radio Society of Great Britain magazine hits the streets, and several small antenna parts to get made and shipped first.

[@kentuckytrapper780]

I put the same one on my sebastian lathe, I never drill another hole without one,great video, keep'um coming..

[@jimsvideos7201]

The tab and the magnet to allow the tailstock to rotate is genius.

[@MachiningandMicrowaves]

I can't remember where that idea came from, but it's a great safety measure and I can disconnect and/or remove the scale if I need better access.

[@RustyInventions-wz6ir]

Nice work. Planning to install a DRO on my lathe as well soon.

[@kevingarrett1433]

I've got 3 vernier calipers. A moore and wright. A fractional moore and wright and a mitutoyo. Not only don't they read the same, the difference is not linear. At different diameters the caliper reading the highest could change with no logical pattern to it.

[@MachiningandMicrowaves]

When dimensions are really critical, I use gauge blocks and relative measurements!

[@TheDistur]

Precision in machining. What a concept!

[@MachiningandMicrowaves]

It's firmly in the "it'll do" class of metrology, but it's repeatable even if it lacks absolute precision. My subtraction issue is so bad that it would lead to scrapped parts. My mother has the same brain-wiring issue, and she used to work in finance back in the days when "computers" were humans. She did have mechanical calculating machines though. She expressed some concern about my under-age drinking exploits when I played her the intro last night!

[@TheDistur]

@@MachiningandMicrowaves it looks good to me. Whatever gets the job done!

[@HexenzirkelZuluhed]

Well, there's already a pair of calipers sitting on my tailstock. Not attached. But waiting for the same treatment. Well done.

[@MachiningandMicrowaves]

3D printed blocks or plastic probably work fine. I'm just a metalhead. Mmm, Rosewood though. Teak perhaps? Bit of brass inlay? Nice.

[@hobbified]

Funny, at 2:00 I was thinking "wow, that looks like exactly the same digital unit they use on those cheap calipers."

[@MachiningandMicrowaves]

It's pretty much identical to the cheap calipers, although weirdly, it isn't identical in the way it mounts. They fill with oil every year or two and need to be scrapped, but at £25 or $30, that's not too bad

[@pyrobeav2005]

For those more apathetic, extend the quill a bit and stick your mag-base indicator stand to it. Then put your dial indicator against the face of the tail stock or another magnetic block on top if you don't have the space. But it's prone to getting bumped and gets in the way, so one should really get around to making one of these someday.😉

[@MachiningandMicrowaves]

I do like a nice dial indicator. One option I'm considering is hacking the remote display protocol of these cheap scales and adding a webserver and wifi interface using a Raspberry Pi or something. Then I can have a large analogue-style indicator display on the wall display in the shop. That might be a neat facility, especially if I mix in a microscope camera feed looking at the tiny parts I'm making.

[@edgeeffect]

Excellent.... both project and video!

[@MachiningandMicrowaves]

It's been really useful, I use it just about every day

[@luvmechanix]

Dude you're a riot! Like an English AvE

[@MachiningandMicrowaves]

Slightly less sweary perhaps, my mother watches the channel!

[@chrislee7817]

I'm going to have a go at this, thanks. My Hardinge tailstock is rather curvy though and needs to be fully retracted to eject stuff. So my plan is to cast a carbon fibre cover and bond the scale to that. Then use the handwheel end to mount the other end of the scale. We will see....

[@MachiningandMicrowaves]

Sounds like a plan! I use it just about every day, didn't realise how useful it would be

[@paulsotheron710]

Excellent idea. 👍

[@MachiningandMicrowaves]

Definitely not my idea, but it's really proved its worth over the last few years

[@trollforge]

I don't know about the wisdom of making you delirious, before the job is done... ;)

[@MachiningandMicrowaves]

Delirium is definitely deprecated while operating rotating machinery.

[@graemebrumfitt6668]

Cool Dude, both you and the project! TFS, GB :)

[@MachiningandMicrowaves]

Thanks!

[@theradiorover]

Great humour! I love your work (and patience). I still haven't fathomed out how you use the lantern chuck, despite having watched the video on its construction. 🙄

[@MachiningandMicrowaves]

It will feature in an upcoming vid where I need to modify my lathe headstock spider to add a fourth M8 screw with a brass tip. The lantern chuck is used to hold the M8 capscrew firmly in place and prevent rotation as well as keeping it coaxial with the lathe so I can turn it to length, then drill the end, fit the brass insert and finish it. Without the chuck, I'd have to try grabbing the head of the screw in a chuck, or perhaps put the lathe in reverse and use a rear toolpost and fix the M8 screw in a tapped hole in some scrap or something. They are using mainly by clock and watch makers to make really tiny screws.

[@theradiorover]

@@MachiningandMicrowaves thanks. I'll look forward to that one.

[@pascalrhins3770]

A fan of This Old Tony too ?.. anyway, good job man !

[@MachiningandMicrowaves]

Tony is just next-level, isn't he! The effort he puts into lighting and editing is immense. I'm full of ideas but lacking skills and time, but I take influences from Derek at Vice Grip Garage, Quinn Dunki and lots of others. I'm not aiming to be educational and passing on decades of machining skill, because I'm a beginner at this stuff, so I watch Robin Renzetti, Joe Pie, Tom Lipton, Brian Block, Kurtis, Chris Maj, Clickspring and others to try to learn stuff. My focus is around using machining as an enabling technology for microwave/mmwave weak-signal experimentation, with a bit of tool and fixture making and some practical experiments

[@bambukouk]

thank you - great vid 👍

[@MachiningandMicrowaves]

I had a lot of fun making it and remembering my old friend Darryl, who was on the darts team with me

[@bambukouk]

@@MachiningandMicrowaves :-) and we had a lot of fun watching it and being entertained! BTW any particular magnets you recommend (I guess ebay?)

[@MachiningandMicrowaves]

@@bambukouk These were cheap ones from ebay, I don't have the details now sorry, but I use a lot of them for mounting things. They were 10mm diameter, 2.5 mm thick

[@sophieparker3795]

I can't unsee the incorrect allen key size you used to tighten the M4 bolts. What was that, 5/32" ?

[@MachiningandMicrowaves]

I saw that when I was editing and went back to check. Definitely marked as the right size. I don't have any imperial tee-bar keys. I am going to measure it when I get back into the shop today, I am wondering if the tolerance on the batch of screws is poor. I'll check the fit with my "good" sets of keys. Those keys are the ones I keep near the lathe and are 5 years old but don't get much use. I'll have a look under the microscope. Well spotted!

[@harrax1017]

Nice little project presented in an entertaining way. I have though one thing that puzzled my dusty grey cells, it appears that your scale has units in mm, inches and F. What is F, Frequency, Farads, Force or some other obscure archaic unit.

[@MachiningandMicrowaves]

Fractional inches. Some of them do 1/128ths, this one does 1/64ths, but doesn't have any sense about showing 16/64ths as a quarter inch. It's not something I ever use as I think in decimal inches and convert the fractions in my head. I *can* do mental arithmetic division, but I have an Alexa thing in the shop, so I can simply yell "ALEXA, CONVERT FIFTEEN SIXTY-FOURTHS OF AN INCH TO MILLIMETRES" and she says "0.2344 inches is 5.953 mm"

[@MachiningandMicrowaves]

Or could it be "Fingernails". A British Standard Thumbnail as used for gapping spark plugs is, of course, 25 thou, and fingernails are thinner, so perhaps....

[@harrax1017]

@@MachiningandMicrowaves cheers, I can see that being useful, as I do struggle with converting decimals to fractions. Might just have to run out out and order a few.

[@MuntyScruntFundle]

So, you’re around Lincoln? I’m out near Sleaford!

[@MachiningandMicrowaves]

My father was born at Thorpe Tilney and lived in South Kyme. My mother's family are from Ropsley. I lived in Heighington, where my mother, sister, aunts and uncle still live. My cousin lives in Sleaford and I have family in Ewerby, Heckington, Gosberton, Burton Coggles,Ruskington and Great Hale. I'm an ex-pat Yellowbelly living in the Humberhead Levels just over the Ouse in East Yorkshire

[@manudehanoi]

I don't use the cheap chinese DROs anymore, the scale becomes faulty after a while and they drain too much batteries, , such that I would often but looking for a button battery at 22h at night without being able to find one. I bought a cheap chinese DIAL caliper instead, it's kinda hard to read but very reliable

[@MachiningandMicrowaves]

These ones work remarkably well and the batteries last longer than most. They are pretty much a consumable item though. I've replaced the battery twice in three years and the scale died because I kept dripping oil on it. I have two dial calipers and two vernier calipers for when I can't find a battery!

[@paulsotheron710]

Where does one purchase those vernier scales please? I don’t want to butcher my callipers.

[@MachiningandMicrowaves]

Arceurotrade, part number 100-040-10200 www.arceurotrade.co.uk/Catalogue/Measurement/Standard-Digital-Readouts/Standard-Digital-Readout-Bars---Horizontal-100mm-to-400mm-Length I guess there are similar units from other suppliers

[@TechGorilla1987]

I may as well be really early here.

[@danielmclellan7762]

So, what is that chuck you mentioned at 2m 54s, please and thanks??

[@MachiningandMicrowaves]

That's the Lantern Chuck that features in this video: kzbin.info/www/bejne/q2aqYYumnrx8iJY

[@andrewcrist1676]

You can make the attachment parts on a 3d printer, just an idea.

[@MachiningandMicrowaves]

I didn't have a printer back then, now I have a Bambu X1 Carbon Combo, which I am using for a lot of projects

[@JohnMullee]

This one sealed against mysterious oil ingress ?

[@MachiningandMicrowaves]

Nope, that triples the price. At least. Three years for £22 seems reasonable enough. Perhaps if I didn't drop oil on it, it might last longer. A Mitutoyo or SPI IP67 sealed version would probably end up getting wrecked by having something dropped on it. if I was really serious about it, I'd be using an inductive/LVDT scale with steel balls in a preloaded tube like Newall Spherosyns instead of this cheapo capacitative slider.

[@JohnMullee]

As a tobacco-wizened irishman, sure just gob some beeswax allover it, be grand

[@MachiningandMicrowaves]

@@JohnMullee Those old boys were like a second family to me and my mate Darryl. We were outsiders and they were adults we could relate to. We were also a good foot taller than most of them, which helped with the darts performance.

[@vincei4252]

Of by one errors? I worked with a guy who enjoyed? writing his code using datastructures he designed that were either 0 based or 1 based indexes and calculations used to index into these datastructures were freely mixed together. Needless to say it was the worst code in the system and just before I left that team the general wisdom was to not make any changes in there at all. Me being the last person that had made a change to that godawful mess I got to be called the "expert" while the original author (my manager) would make every excuse not to look at or opine on any change. Leaving was just too easy when the time came.

[@MachiningandMicrowaves]

I always insisted on the first element of any data structure being item zero. Any language unable or unwilling to support that paradigm was strongly deprecated!

[@fletcherreder6091]

Arithmetic is the worst math and I refuse to be convinced otherwise.

[@MachiningandMicrowaves]

I love a bit of number theory or vector calculus. Subtraction can do one though!

[@HAL_9001]

If AIMEE ever gets too bothersome be sure to let her know that google translate has numerous different voices when you type English into different "translate from" selections.

[@MachiningandMicrowaves]

I tried the TTS French female voice on English and it sounded like someone deliberately trying to put on a comedy French accent. I have an AWS account so I might try those voices for the.... OOPS, SPOILER ALERT.

[@grimoirworkshop6623]

What is the “epoxy”, some sort of Russian herbal toothpaste?

[@MachiningandMicrowaves]

The tubes were so old the paint had flaked off the tubes. Could have been hair remover or oil paint for all I know. It was mightily sticky though, whatever it was.

[@grimoirworkshop6623]

I mean not the actual epoxy, but photo you pasted for lulz. That seems to be some sort of Russian toothpaste. That’s not great adhesive, but semidecent polishing compound though :)

[@MachiningandMicrowaves]

@@grimoirworkshop6623 Haha, I was half asleep when I answered! It is an "interesting" colour. I'd worry about it etching aluminium. Also I think is might make cast iron burst into flame. Lovely stuff!