# Linear digital scales



## jpaul (Nov 10, 2008)

While in the UK I saw several vendors offering linear digital scales. These scales varied in length from 8" to 24" and were available with horizontal or vertical display panels. The price of the scales were approximately $50 US and I got the impression that they were quite popular in the UK. Since returning to California, I have been looking for such an item as well as some conversation on applying these tools to shop set ups. 

I am thinking of adapting such a scale to the carriage of my lathe. I would be interested in a "How To" description if available.

So I put this question to the readers. Has anyone adapted one of these linear digital scales to a lathe (or mill) and what was your experience? Are the scales particularly sensitive to cutting oils and swarf?


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## Mike N (Nov 10, 2008)

Hi,

I have done exactly what you said. I have installed a 12 Horizontal Linear scale to my lathe bed. It works great. Because my lathe has more than 12" of travel I use a magnetic base to hold the digital readout & I can slide it back & forth on the bed. As far as the oil is concerned it seems to stay dry. The vertical scale I mounted on the crossfeed gets beat up with chips & oil so I covered it up with a clear plastic shield. It makes my lathe very accurate! It has worked for over 3 yrs. now.

Good Luck!


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## BobWarfield (Nov 10, 2008)

They're quite handy, even to the point where I've used them to create temporary special-purpose DRO's. Here is one I made for my lathe compound, for example:







Most of the time I don't need it, but when I do, it is a simple matter to pull it out and clamp it in place. I like Mike's idea of a magnetic mounting.

Cheers,

BW


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## firebird (Nov 10, 2008)

Hi Paul

I have fitted them to both my mills and so far have not had any trouble with them. If you type in the search box     DRO on the mill    you will find my post detailing the fitting to my X1 mill.

Cheers

Rich


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## ianjkirby (Nov 10, 2008)

Bob,
 What is the brand name of the digital vernier in your photo, please? I have not seen any with the nice large figures visible on yours.
Regards, Ian.


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## jpaul (Nov 13, 2008)

Thanks for the replys. These are the scales that I am refering to.






Tin,
Did you mount your scale on the front or rear of your lathe's carriage? If the scale was mounted on the rear, then reading the scale becomes difficult. A possible solution would be to tap into the display and read it remotely.

I found this link that discusses such a connection. Unfortunately I am electronically challenged so much of the comments were over my head 

http://www.shumatech.com/support/chinese_scales.htm

BTW I think that the price was 50 pounds about $100


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## firebird (Nov 13, 2008)

Hi Paul

If you look at my post DRo on the mill you will see that I have remote readouts. They are magnetic so will stick to any steel surface. The y come ready wired and simply plug straight into the scales. Go to Arc eurotrade web site for further info.

Here you can see the remotes fitted to the right of my X3 mill






Heres the first one fitted to my X1 mill.






Cheers

Rich


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## Loose nut (Nov 13, 2008)

Make sure that all your brackets and connecting pieces are ridged and lined up actually or there will be flexing that can throw your readings out considerably.


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## jpaul (Nov 20, 2008)

I found the following link that does a excellent job of describing my intentions and it has pictures.
http://www.gadgetbuilder.com/DRO.html


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## Cedge (Nov 20, 2008)

Paul
I've been using the chinese scales for quite sometime now and have had few problems with them. I also found the investment in a 3 scale display to be one I haven't regretted for a moment. 

Below are photos of the way I mounted mine, the last time around. Note they are spaced out from the machine quite a bit. This move did a couple of nice things. One was that the space reduced the amount of swarf and debris on the scales. Another was ease of access to both the scales and machine adjustments. The mounts are simply a turned piece of aluminum hex which I drilled and tapped for mounting. 












I began my DRO upgrade experience using cheap calipers from Harbor freight. They had to be modified a bit, but the darned things are nearly indestructible. I ground off tangs, drilled holes and even carefully lengthened one using silver solder to secure the new end section. As long as alignment of the scale is straight, your measurements will be too. 

Be warned that the stainless used to make them is incredibly hard and will work harden even more, in an instant. I wound up using my Dremel with a "grinding disc" to do most of the mods.

Once I was convinced that the DRO's were of real benefit, then I invested in an "inexpensive" DRO setup with a display. I mounted the display between my mill and lathe so that it could be swiveled to face either machine. I bought extra cords so that I can swap the plugs. In 5 seconds, or less, I can have the DRO display working on the lathe or the mill. 

The mistake I made in the past was in trying to mount the DRO scales up tight to the machine, thinking "compact" meant good things. It resulted in lots of swarf in the scale heads and a real PITA when I wanted to tweak the adjustment of various machine points. I like the system much better now that everything is again easy to reach.

If you want more detail photos, let me know. 
Steve


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## kf2qd (Nov 20, 2008)

I have been looking at some linear scales from US Digital ( www.usdigital.com)- they have the plastic scales - would glue them to steel or aluminum bars for mounting. Seems like the last price I had was around $90 for the read heads and a single stip of scale material for another $100 - and then use my shop PC for the display - could write some code to do all the fancy DRO stuff. Already got the computer. 500 lines per inch would read down to .0005 so it would be more accurate than my minimill will ever be.

BEI has a Dual encoder to USB module - don't know teh price yet...


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