# DTI Mods



## cfellows (Jun 4, 2011)

Like most folks, I use a Dial Indicator to center work in my 4-jaw chuck. Unfortunately, the pointy little anvil on the DTI requires it to be set very close to center height on the lathe.







To get around that issue, I made a new anvil for the DTI. Since the original anvil unscrews from the stem, my first thought was to make a screw in anvil. I abandoned that idea when I tried to determine the thread size. About the only thing I could determine was that the thread size was probably metric and somewhere between m2.5x.45 and m3.0x.50. I didn't have a die in either of those sizes, so I decided to fasten the new anvil over the DTI stem with a set screw. Probably easier all the way round because trying to adjust the thread stop so the anvil would wind up perfectly vertical would have been a challenge that's way beyond my reservoir of patience. Here's what I wound up with.






It's made from a half inch length of cold rolled steel, 1" wide x 1/4" thick. The center hole size needs to be .175" which a #16 drill is just about right for.

Chuck


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## 90LX_Notch (Jun 4, 2011)

Chuck,

Great idea. I don't know if you considered it, but you might want to put a piece of brass or lead in the setscrew hole to prevent marring the indicator shaft. It doesn't take much for them to bind in the bushing on the stem.

-Bob


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## mklotz (Jun 4, 2011)

I've made many attachments for my DIs (dial indicators), including sets of extenders*. They all have a 4-48 thread. There may be other threads out there, of course, but so far 4-48 has worked for everything I've encountered.

Also, though not as satisfying as making one's own, the inexpensive tip sets sold by ENCO and others contain a large diameter tip to solve this problem.

---
* A set of extenders made in lengths of 1,2 and 4" will allow you to construct any integer inch length up to 7"


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## cfellows (Jun 4, 2011)

90LX_Notch  said:
			
		

> Chuck,
> 
> Great idea. I don't know if you considered it, but you might want to put a piece of brass or lead in the setscrew hole to prevent marring the indicator shaft. It doesn't take much for them to bind in the bushing on the stem.
> 
> -Bob



Thx, Bob. I usually grind the tip of my setscrews flat when I don't want to mar the shaft.



			
				mklotz  said:
			
		

> I've made many attachments for my DIs (dial indicators), including sets of extenders*. They all have a 4-48 thread. There may be other threads out there, of course, but so far 4-48 has worked for everything I've encountered.
> 
> Also, though not as satisfying as making one's own, the inexpensive tip sets sold by ENCO and others contain a large diameter tip to solve this problem.
> 
> ...



Yeah, I did determine that it was pretty close to 4-48, but don't have one of those dies or taps, either. And, single point cutting seemed like more work than I wanted to fool with.


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## jct842 (Jun 4, 2011)

I bought a set of anvils for the DTI , I believe I got the set at LMS. What happened is I lost the only one that I had and needed some thing right away. I tried a screw and untill I polished off the slot it did not work. I think I will make me a flat one like chuck has there. john


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