Indicator lug to noga adapter

[Masterjuggler]

I have a noga indicator holder and I've been using the holes in the end to slip my indicator's stem into, but I find it can make some configurations awkward. Do most of you have some kind of adapter to hold onto the lug on the back of the indicator?

I've thought of just tapping threads into the lug hole to accept a bolt, and turning down the end of the bolt to fit into the noga end. Maybe I'm overthinking this, but it looks like the fine adjust screw would then be 90 degrees off and wouldn't do much.

 

[darkzero]

Most of my dial indicators are Mitutoyo & they have dovetails on them. So for years I've been attaching them that way. Been using flat backs on my DIs also.




Earlier this year I was bored being stuck at home due to the pandemic & made an adapter for the lug back. An adapter is what most people use. I didn't make mine from scratch although it would be simple. I've had this Starrett attachment that I have no idea where I got it or what it's for. But the stem was like 1/4" & my Nogas have 3/8" holes. I just made a sleeve for it & Loctite'd it on.

At first I didn't like it & took it off the next day but that's just cause I was so used to holding by the dovetails. I've since put it back on & still using it now. These pics should give you an idea on how to make one.

 

[Masterjuggler]

The two piece construction is interesting, I'll probably end up going with something similar (though not as nice looking haha).

Some more questions:

1) It looks like you have the stand with the fine adjust at the base. For those of you who have it at the end, do you find that having it turned 90 degrees from lug mounting makes fine adjust harder? Normally when holding an indicator by the stem, the fine adjust moves the indicator in line with the stem, but with the lug mount it sweeps the indicator sideways.

2) I have some test indicators with dovetails, but to get them into the noga holder I feel like I'd have to pry the holder open with a screwdriver, which really worries me. Are there different standard sizes, or am I being a baby about it?

 

[darkzero]

Yeah, it doesn't need to look pretty, won't see it much anyway. The knurled piece is basically just a nut. If I were to make one I would make it similar. Can be as simple as a nut or a screw. You could thread the lug back as you mentioned but I believe they are aluminum, at least mine are. You'd then have to screw your adapter in pretty tight to make sure it doesn't come loose. And if you wanted to swap the indicator you'd have to thread the lug back on the other indicator(s).

Yes mine are fine adjust on the base. I did used to have the ones with fine adjust on top but I sold them all, I prefer the the fine adjust on the base. But when I did use them, they still worked fine. Probably got some paralax error or whatever due to it but really we're usually more concerned about how much the needle moves back & forth (for runout) rather than what the actual measurement is.

Hmm, I'm not sure if all indicators have the same size dovetails, I never really thought about it now that you mention it. All my DTIs & DIs fit my Nogas fine. I don't recall ever having them fit too tight.

 

[Masterjuggler]

I guess you're right about the error not really mattering that much, the same is true of test indicators. I was thinking more about range of motion before you get to a crazy angle. I get about 0.100" of travel out of my noga's fine adjust with the indicator stem mounted.

The test indicators I have are a federal testmaster and a scherr tumico. Both have the same size dovetail, and both are about 20 thou too wide for the noga dovetail holder when it's fully loosened. I wonder if the noga took a set somehow, but it kind of scares me to take it out and pry it open wider for fear of snapping it.

On a semi related note, I'm definitely going to have to make an adapter for this indicator at some point. I found it on ebay in a set for cheap, looks like it's meant to be hard mounted to something. not sure what machine would have needed a tenths indicator hard mounted to it though.

 

[francist]

I made a post back for one of my small indicators, it works well. Not sure it this way solves or exacerbates the 90-degree thing as I’m having a little trouble understanding that. Doesn’t matter, this is just another way, backs are easy to make.





-frank

 

[homebrewed]

I don't know if it will help w/regard to the 90 degree angle issue that's mentioned, but the back on many (most?) DI's can be rotated -- the back mounting screws are symmetrical. I learned that on this forum.

Of course, due to their design this doesn't apply to DTI's.

 

[Masterjuggler]

I'm probably just thinking about the 90 degrees thing too hard lol. I haven't actually made the stud yet and it seems to work for everyone else, so I'm not worried about it.

I am curious to know if anyone else has issues with test indicator dovetails being a tight fit in the holder, and if it's safe to pry open the holder a bit to remove some of its set. There's space for it to expand on the base, it's just permanently set a bit too tight I think, even when the screw is all the way backed off.

 

[Tozguy]

I see what you mean about the Noga dovetail holder. Although I have not had to use it on either of my Noga holders, it looks like it would spring open some to accept the dti dovetail you have. I would remove the clip completely from the holder to fit it to the dti dovetail and then mount the clip and dial back in the Noga arm.

 

[machPete99]

I have the Noga base and the Mitutoyo test indicator dovetail fits it perfectly, with a somewhat tight sliding fit. I don't think I have any other dovetails to compare it with. Maybe its a metric fit?