Edge Finder Heads Up

[Ken I]

Since there is always some new and completely stupid thing you can discover every day I thought I would post this.

My mechanical edge finder has always been spot on repeatable but suddenly went out - serviced and cleaned it - no joy.

Then tested it against a piece of brass and it was fine. Against steel still useless...

AH-HA ! Eureka moment.

Tip had become slightly magnetized after coming into proximity of a very powerful Neodium magnet.

Whilst I figure out how to demagnetise it - I thought I would post this caveat:

Beware of magnetized steel parts and / or accidentally magnetising your edge finder - either will cause wildly faulty results.

Ken

 

[b.lindsey]

Good observation Ken! If you know anyone locally that does precision surface grinding, there's a fair change they would have an industrial strength demagnetizing unit which might solve your problem.

 

[purpleknif]

Try tapping it with a small hammer. (lightly)

 

[jim216]

If you have a loop type soldering gun ( Weller) ,try passing it through the loop.


.

 

[Ken I]

Good observation Ken! If you know anyone locally that does precision surface grinding, there's a fair change they would have an industrial strength demagnetizing unit which might solve your problem.

Come to think of it I do know someone with a demagnetizer - thanks for jogging the old grey matter.

Jim thanks for that tip as well - I think you've posted that before but it had slipped my mind (more and more does these days).

Ken

 

[mklotz]

When you visit your local electronics boneyard, keep your eye peeled for a bulk tape eraser. They work well for this and can handle parts that won't fit the soldering gun.

 

[Tin Falcon]

http://www.sears.com/shc/s/p_10153_12605_SPM2203284501P?sid=IDx20070a921x00003a&ci_src=14110944&ci_sku=SPM2203284501
Cheap and readily available
Tin

 

[tornitore45]

Tim Falcon, your link is interesting, I need one of them but is the opposite of what is needed to DEmagnetize the edge finder.

 

[Tin Falcon]

Product Description

Screwdriver Magnetizer/Demagnetizer, Magnetizes and Demagnetizes Screwdrivers, Taps, Nutrunners, Etc. Clamshell Packaging.
Tin

 

[Mainer]

Hmmm...I wonder if that explains why my Starrett edge finder isn't kicking as well as it used to.

 

[Tin Falcon]

could just need a drop of oil
Tin

 

[bezalel2000]

Does any one have a good design for turning up a brass edge finder?

Bez

 

[Mainer]

@Tiin:
I wish it was that simple. I've cleaned and oiled the mating surfaces with instrument-grade Nyoil. The action feels the same to my fingers as that of a new Starrett edge finder I bought. Yet, the new one kicks out strongly and the old one sort of grudgingly moves off-center. I think there is a certain amount of magic involved in the operation of edge finders.

 

[Ken I]

Mainer,
Edge finders can be fussy about the oil - I cleaned mine once and lubricated it with Automatic Transmission Fluid and it simply stopped working - you could push it way off centre and it would not kick over.

Cleaned it and lubricated with 3in1 and it worked fine again.

Go figure.

Ken

 

[b.lindsey]

Bez, why brass? Non-magnetic yes...but i would think wayyyyy too soft for actual use.

Bill

 

[mcostello]

I called Starrett years ago before start of the Internet and asked why their edge finder worked so smoothly. Asked what did they use for lubrication. STP was the answer, so with some scrounging at local Auto parts merchants, I found a can that some had used and the can still had some in it as it will not drain right away. Lifetime supply for free.

 

[Lew Hartswick]

Bez, why brass? Non-magnetic yes...but i would think wayyyyy too soft for actual use.

Bill

And a "brass" spring ?
...lew...

 

[lemelman]

How about one of the non-magnetic stainless steels?

Gary

 

[Hopefuldave]

Quote from: b.lindsey on May 11, 2012, 08:14:20 AM
Bez, why brass? Non-magnetic yes...but i would think wayyyyy too soft for actual use.

Bill
And a "brass" spring ?
...lew...


Aluminium bronze body, phosphor bronze spring? Non-magnetic and hard enough to take some use before it wears out?

I was wondering what to do with that little leftover stub... Hmmm, the shank to go in the chuck could be steel?
Anyone have a source for phosphor bronze wire in small lengths/gauges in the UK?

Dave H. (the other one)

 

[abby]

Aluminium bronze is magnetic :