Interapid Slow Return to Zero

[Mr. PishPosh]

I recently bought a used Interapid .0005" test indicator. It looks brand new with the exception of a couple of numbers have been free hand engraved on the side, but no scratches on the bezel as I would expect.

Any way, the first time I used it I found when I took the load off of the needle it slowly returned to zero, instead of the immediate return that you would expect. It only does this in one direction, the other way works fine (the direction I rarely use, of course).

So I assume it's just got crap built up somewhere from just sitting around and needs to be cleaned? Anyone ever experienced this and fixed it successfully? I'd hate to pop the thing open, lose a part, or have some other unforeseen thing happen and be stuck buying another $200 indicator.

Or do I just live with it...

Any help would be appreciated.

Thanks, Josh.

 

[paul39]

I just did a search for my sticky indicator.

See: http://www.practicalmachinist.com/vb/metrology/starrett-dial-indicator-repair-advice-208874/

http://www.practicalmachinist.com/v...n-about-brown-sharpe-no-738-indicator-228837/

027 : Long Island Indicator Service : Sales, Repairs and Spare Parts Lots of info on the web site, and highly recommended by folks on PM.

I can't find the thread that described how to clean an indicator.

The advice given was to apply alcohol or solvent (WD-40 is mostly Stoddard Solvent or Varsol, or mineral spirits), to the rack with a camels hair brush and lubricate the rack with watch oil or instrument oil.

I was given two old, good, .0001 indicators, Federal & Boice, not well cared for, one so sticky the needle would not move. I squirted WD-40 around the plunger and into the hole on the top and worked them back and forth.

The less sticky one works fine, the completely locked up one works mostly with a slower travel in some areas.

I may carefully open the still sticky one and have a look. It has a cover plate on the back held on with two screws.

Paul

 

[jonathan2jones]

anytime an indicator acts irregularly, I question the accuracy. Does it repeat its return to the same exact spot every time? If so, it probably does need a good cleaning and/or an adjustment. Attached please find a drawing with callouts and the part numbers/descriptions referenced in that drawing. I have a few interapids and use them daily along with a BesTest tenth indicator. Brown and sharpe/ interapids are the only way for indicators. My favorite is a five tenth interapid with one inch face mounted in the noga HD indicator holder. Easy to use and can be placed anywhere I need. Good luck Josh and us know what happens.

 

[RJT]

Try to unscrew the set screw like bearing at the pivot of the needle just a tiny bit (loosen locknut first). Don't unscrew it more than 1/4 turn and see if that make a difference. It may be too tight or the ears may have been crushed slightly. It's items 10 and 11 in the above diagram.

 

[wesg]

Can't help on a fix, other than suggesting to send it to Long Island Indicator.

I have one that does the same thing, as a result of dropping the box and having it pop open when it hit the concrete and tossing the indicator across the floor. I bought a new one to use while I get around to having it looked at.

 

[gr8life]

Just had an Interapid repaired by Long Island Ind. about $100 and it works and looks like new.
thanks
ed

 

[Kevco]

Try to unscrew the set screw like bearing at the pivot of the needle just a tiny bit (loosen locknut first). Don't unscrew it more than 1/4 turn and see if that make a difference. It may be too tight or the ears may have been crushed slightly. It's items 10 and 11 in the above diagram.

Totally agree with RJT. 90% of the time it's the #10 screw that is too tight or too loose. I have fixed a lot of them for guys at work and yours sound like it is too tight. Get some jewelers type screwdrivers and try it. It doesn't take much. Interapids are the most durable brand I've dealt with.

 

[Mr. PishPosh]

Thanks for all the help guys. I'll play with it tomorrow and see if I can get it to loosen up, the diagram helps a lot. To answer your question Jonathan: yes it does return the same spot every time.

I agree Interapid is the only way to go, through school, my own shop and my job I think I've used about every brand of indicator out there, from cheapo imports to Starretts and Mitutoyos and I've found Interapid to be the one that I liked best. Though I could be a little biased since I was kind of spoiled with .0001" Interapids at school when we did grinding, those were awesome indicators.

Thanks again for the help everyone.

Josh

 

[Philabuster]

Totally agree with RJT. 90% of the time it's the #10 screw that is too tight or too loose. I have fixed a lot of them for guys at work and yours sound like it is too tight. Get some jewelers type screwdrivers and try it. It doesn't take much. Interapids are the most durable brand I've dealt with.

I agree as well.

One caution though, after pivot adjustment, bottom the needle out gently with your fingers and then try to wiggle the tip side-to-side. This will let you feel if the pivot is too loose.

Also, check the indicator tip and screws under the bezel as they will work loose over time.

 

[Schaub]

+1 for LIIS

I think its like $94 for a complete inspection and repair.

-Nate

 

[Kevco]

I agree as well.

One caution though, after pivot adjustment, bottom the needle out gently with your fingers and then try to wiggle the tip side-to-side. This will let you feel if the pivot is too loose.

Also, check the indicator tip and screws under the bezel as they will work loose over time.

Good points. About 1/2 the time when someone brings one to me for "not repeating", it's a loose tip. I guess i should say I need to look at it a while and charge them $5.00!

In 20 years in the shop, I've never seen one fail unless is was smashed. VERY rugged pieces.

 

[Mr. PishPosh]

Thought I should let you guys know that I got the indicator fixed. Turns out we had a couple bottles of Starrett "measuring instrument oil" on the shelf at work. Put a couple drops of that on the moving parts, let it sit for a day and it's good as new. Good thing too, because it saw heavy use yesterday. The picture is just one of the many things I had to set up...

Thanks again for the help, Josh.