# Tailstock DRO



## deverett (Jan 15, 2014)

I have recently fitted a digital scale to my Harrison M300 lathe tailstock.  The scale is 4" and was obtained from MachineDRO, but these are available from several sources around the globe.




Shows it fitted




These are the parts.

With the tailstock barrel fully retracted, there is only about 90 thou protruding, so the nose ring at 3/16" thick was counterbored to fit the protrusion and extends forwards of the barrel.  

The black bracket which mounts the reader to the tailstock is modified from that which is supplied.  I had to add a washer and spring washer to the screws to attach it to the head, because as supplied, the screws are too long and bind on the scale.

The Tee shaped piece is 1/8" ali and you will notice a pair of ball and socket connectors to join the scale to the nose ring.  The reason for using the ball and sockets is in case there is any slop or rotary motion under load in the barrel, the scale will not be distorted.  There is none, but belt and braces...  It also permits adjustment so that with the barrel completely retracted, there is a few thou gap between the reader and the end bracket.  Once all is set up, they are not altered.

The hardest part was drilling/tapping the holes in the tailstock for the bracket, but the 17" available outreach on the Thiel mill meant I did not have to dismantle the tailstock to get it under the quill.








Another job done and I'm well pleased with it.  The idea was modified from one way these scales have been mounted on a Myford tailstock.

Dave
The Emerald Isle


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## Herbiev (Jan 16, 2014)

Very neat and simple. Great idea.


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## robcas631 (Jan 16, 2014)

It works! Thanks Deverett!


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## robcas631 (Jan 16, 2014)

Dev,

 See how it will work given this photo?


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## BaronJ (Jan 16, 2014)

Hu Guys,

Thought you might like to see how did it on my Myford lathe.

The indicator is a cheap tyre depth gauge. Its held in place by a pair of magnets and uses a pair of tiny magnets to attach the stylus to a steel stud pressed into a perspex arm attached to the tail stock ram.

Sorry for the slight lack of focus.  I keep meaning to get a cheap tripod.


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## deverett (Jan 16, 2014)

I thought these tyre gauges only measured about 1".  What do you do if you want to measure, say, 2-1/2"?

The magnets are a quick and easy mounting solution, I'll grant you, but me being a clumsy oaf, would probably knock the gauge sooner or later, thus requiring the setup again.  Not difficult, but a PITA.

Dave
The Emerald Isle


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## robcas631 (Jan 16, 2014)

Innovative design! I think Dave and Baron out to patent the idea!


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## BaronJ (Jan 17, 2014)

deverett said:


> I thought these tyre gauges only measured about 1".  What do you do if you want to measure, say, 2-1/2"?
> 
> The magnets are a quick and easy mounting solution, I'll grant you, but me being a clumsy oaf, would probably knock the gauge sooner or later, thus requiring the setup again.  Not difficult, but a PITA.
> 
> ...



Hi Dave,
These tyre gauges will do just short of three inches.  I weakened the slide spring a little, just flatten it slightly, because I found that if I was a bit eager winding the tail stock ram out, I could pull the magnet away.

But I cheat a little because I can pull the gauge off the Myford and use it on the Fobco drill as a depth gauge.  Its easier to see than the built in one.

Also I didn't want to drill holes in my tail stock.  The magnets are all just secured with a dot of super glue applied on the end of a tooth pick.

I do like the way you have mounted yours.


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## BaronJ (Jan 17, 2014)

robcas631 said:


> Innovative design! I think Dave and Baron out to patent the idea!



Hi Rob,  No, not at all.  I saw the Idea on a web sites some time ago.  I believe that its also appeared in a magazine somewhere.  I also vaguely recall seeing a photo of a lathe like yours where it was fastened to the lathe bed and recorded the saddle movement.

As a general point the body containing the readout is electrically and mechanically identical for both these gauges.  In fact I've seen somewhere spare bars that can be cut to whatever length is needed.  Now I don't know if these spare bars are the same cross section to fit the readout or not.

Having said that I have a 24" version fitted to my milling machine and when I get round to it a short 6" one for the other axis.

Rob if you want some magnets ex HDD let me know.


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## deverett (Jan 23, 2014)

BaronJ said:


> Hi Dave,
> These tyre gauges will do just short of three inches.  I weakened the slide spring a little, just flatten it slightly, because I found that if I was a bit eager winding the tail stock ram out, I could pull the magnet away.
> 
> But I cheat a little because I can pull the gauge off the Myford and use it on the Fobco drill as a depth gauge.  Its easier to see than the built in one.
> ...



Baron

Do you have a link to the 3" tyre gauges.  All the ones I have seen are only 1" capacity.

I like your mounting system, too!

Dave
The Emerald Isle


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## BaronJ (Jan 24, 2014)

deverett said:


> Baron. Do you have a link to the 3" tyre gauges.  All the ones I have seen are only 1" capacity.
> 
> I like your mounting system, too!
> 
> ...



Hi Dave,
Oddly enough I was looking at the invoice a couple of days ago, not that I could find it now.  However I got mine through Ebay.  They were if I remember £3.99 inc post from HK.  The pictures are a little deceptive because if you use them as intended the stem only seems to come out about 1" !  In practice the slide bar will continue to give measurements all the way to the end which is just about 3".

I can take some more photos of mine and post them here for you.  It will be Sunday before I can do that.  The magnets came out of 3.5" scrapped HDD.  You will need two of them if you are going to copy what I did.  If you get stuck I might be able to acquire some more scrap drives.


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## deverett (Jan 24, 2014)

Thanks for that info, Baron.  If you can remember the seller, I'd be grateful but in the meantime I'll search eBay.

Most of the tyre gauges seem to be used for cross slide travel.  All the articles that I have read seem to suggest 1" travel, which was why I was intrigued by yours.

3" travel would be good on the milling machine quill and a lot cheaper than the usual scales.

Dave
The Emerald Isle


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## BaronJ (Jan 25, 2014)

Hi Dave,

I'm sure that you will find them on Ebay.  If I can find the details of my purchase I will PM you.  When I found the original order I wasn't looking for it.  It just happened that I was searching through my backups for something else when I came across it.

I made a height gauge using an Aldi 6" digital caliper.  I think that was only £8 or £9.
You could adapt one of those easily.


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## robcas631 (Jan 26, 2014)

Must have been a typo, gosh what a few digits can do?


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## deverett (Jan 26, 2014)

It seems that all the digital tyre depth gauges are 1" by design.  If you pull the business end out far enough so that the beam is inside the head, they will get to the 3" measurement.

Is that right, Baron?

Dave
The Emerald Isle


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## necchiom (Jan 26, 2014)

Hi Baron. With compliment: a very smart idea!
Moshe


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## BaronJ (Jan 26, 2014)

BaronJ said:


> Hi Dave,
> 
> I'm sure that you will find them on Ebay.  If I can find the details of my purchase I will PM you.  When I found the original order I wasn't looking for it.  It just happened that I was searching through my backups for something else when I came across it.
> 
> ...




Hi Dave, n all,

<http://www.ebay.co.uk/itm/car-tyre-Digital-Tread-Brake-pad-Shoe-Gauge-depth-tester-van-tire-guage-NEW-/121182976466?pt=LH_DefaultDomain_0&hash=item1c371179d2>

This is what you are looking for.  I haven't found my original seller but this is the item you want.  A different color but should be OK.

I did notice that all the prices have gone up considerably since articles using these devices has been published.


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## BaronJ (Jan 26, 2014)

necchiom said:


> Hi Baron. With compliment: a very smart idea!
> Moshe



Hi Moshe,

If you want I can take a photo and post it here.


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## BaronJ (Jan 26, 2014)

deverett said:


> It seems that all the digital tyre depth gauges are 1" by design.  If you pull the business end out far enough so that the beam is inside the head, they will get to the 3" measurement.
> 
> Is that right, Baron?
> 
> ...



That is correct Dave.
Note: If you use my trick with the magnets you will have to carefully remove the four tiny screws from the back (might have to remove label) split the device and slightly flatten the spring to reduce its strength.

A friend has copied mine but has put a thread on the little bit on the end and used a nut soldered into a short length of brass tube to connect it to the gauge and the saddle.  At the saddle end he used a 4BA solder tag and fastened to an available screw.


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## BaronJ (Jan 26, 2014)

robcas631 said:


> Must have been a typo, gosh what a few digits can do?



Hi Rob,

You have got me !  Please explain...


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## BaronJ (Jan 28, 2014)

BaronJ said:


> Hi Moshe,
> 
> If you want I can take a photo and post it here.



Hi Moshe,

The Digital Hight Gauge photos.  One showing general layout and the other the mounting arrangement, also how I modified the calliper by removing one jaw and using it so that I could get down to zero hight.  I also removed the probe that is used as for the depth measurements.

I have a mod in mind to make this device more versatile.


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