Best edge finder for oldie

I am 85, sight not marvelous and am about to aquire a new mill.

What is the best edge finder for me?

Electronic/laser would seems to be the best for me but would be very grateful for any advice.

Many thanks

Richard 2.

Being a ‘“self taught” machinist I find the sprung loaded edge finder works for me. I have two types the wobble types and the spung type with the centre finder one end and the edge finder the other. The other addition to this is a good light for illustration. The IKEA Jansjo is small and doesn’t get in the way of the work to restrict viewing.

John

P.S. take a look on YouTube for video clips on edge finders - there’s a lot of useful stuff on there. 

Edited By Johnboy25 on 09/03/2018 12:04:41

Richard

I like the Huffam "wiggler" edge finders as the walking sideways action of the stem gives a very clear indication of when you have just passed the centre. Huffam claim 0.001" resolution. I figure on around half that, maybe better with extra care, in practice. A decent DRO makes it all very easy. Especially if you work off both sides and use the centre finding function on the DRO so the tiny over-travel needed to make beast work cancels out. I claim to have managed tenths thou resolution that way.

At around £50 , e.g. Zoro Tools **LINK** , the Huffam is about twice the price of the common plastic walleted set with various tips that snap into a collet style holder. But its far more consistent and needs rather less movement past centre to trigger. The collet in walleyed sets is more draggy than the sprung loaded nylon bearing used by Huffam which can't help. Collet adjustability also means its difficult to get it set same every time. My cheap set has the pin point for line picking out permanently mounted which works great.

Comes in imperial and metric too. Worth looking on E-Bay. Usually £20-25.

Clive.

Edited By Clive Foster on 09/03/2018 12:09:27

Edited By Clive Foster on 09/03/2018 12:09:52

I uses one of these. Less than $10 on ebay

Paul.

Me too. Ashamed to say I had one for ages before realising how to use it like this. So quick and easy - and accurate.

Type C is less than £4 from Arc.

Murray

I use the ball ended type that lights up an LED on contact. It requires a certain 'feel' but I find it very easy to use, and certainly accurate enough for me in combination with a DRO.

Andy

I use one very similar to the finder shown in Paul's picture above. The only thing is you have to remember add or subtract 1/2 the diameter of the contact surface of the finder. The movement of the sensor is very obvious and being spring loaded you don't have to worry about winding past the edge as you do with contact sensors that have a fixed probe which can relatively easily be damaged.

Martin W

LOL!

Only a few days ago I was discussing these devices with a 'supplier of model engineering accessories' who will remain nameless. We both admitted that we don't know how they work but people seem to like buying them.

Well now I do know. Much better than the probe on stick type as you can work it in and out to get the right position, but it looks more liable to mark the work.

Neil

Partly to this and partly to the laser safety thread, here are a couple of photos of edge and height finders I made form my CNC mill. The edge finder is equally suitable for manual mill where contact is sensed by my multimeter on the lowest resistance range which has a continuity buzzer function too. One lead goes into the 4mm hole in the brass block, the other to the machine table. Slowly advance the finder to the edge and it buzzes when it touches. Spindle axis is then 4.99 mm away from the edge. Took about 30 minutes to make, then 2 days for araldite to cure, and another 30 minutes to finish off.

Edited By John Haine on 09/03/2018 13:52:28 sorry the photos are on their side

Edited By John Haine on 09/03/2018 14:03:34

I treasted myself to a Starrett double ended edge finder. Very useful, 10mm dia body and 6mm dia tip.

Got it from Amazon at a reasonable price. Doesn't mark the work very much if at all. Very easy to use, just allow for the 3mm radius to find the edge.

John

Richard,

You may be OK to see the led on the electronic type such as in the video posted by Muzzer at https://www.youtube.com/watch?v=f0od-cp_9dg     
but you maybe better to have an audible indication when the tool touches the work. as John Haine pictured.

I believe the electronic edgefinder shown is the same as one I have made in the USA by PEC who recommend it is used in a dead spindle, not running.
I use mine as the video but you have to take great care as there is no means of absorbing over-travel which could result in damaging the tool.

I also use a mechanical edge finder with a centre point which locates centres precisely, with the spindle off it is easy to feel any out of truth with a finger/thumb nail.

Emgee

Edited By Emgee on 09/03/2018 14:15:36

Richard, the best edge finder I have found is the "Machinist's Mate" one from Borite Manufacturing Inc. in the US.

It has a light that turns on when the .100" dia tip touches the work. This edge finder uses the work, the vise and the machine itself to complete a circuit between the tip and the shank of the tool. You do not rotate the spindle to use this tool. I have found mine extremely repeatable and accurate to less than a thou.

These go for about $30 here in Canada. One place to get one here is at the link below.

https://www.kbctools.ca/products/MEASURING%20@@26%20INSPECTION/EDGE%20@@26%20CENTER%20FINDERS/EDGE%20FINDERS/ELECTRONIC%20EDGE%20FINDERS/6113.aspx

The manufacturer may be able to direct you to a UK distributor. Link below.

http://www.boritemanufacturing.com/machinist_mates

Good Luck. JD

Many thanks indeed everyone.

I have decided to go for an LED edge finder as that will be easier to see than having to use a magnifier.

Truly you are all very kind.

Very like the half dozen people who stopped their cars and vans and lifted me and my mobility scooter a few days ago when I was stuck on a patch of ice.

I haven't got over their kindness, yet.

Richard 2.

I use an electronic touch probe with LED but I can link it to my DRO and use it to find the size of holes by 3 point method and also of course the centre of the hole.

Of course on occasions a sticky pin can also be quick and easy.

Edited By KWIL on 09/03/2018 14:30:06

Funny, I thought that the use was obvious - but I own one like Journeyman with the pointed centre and I have never managed to work out how to use the pointed part for centre finding......

Is this equally obvious to all bar me?

Edited By Simon0362 on 09/03/2018 16:03:25

I've only ever used the straight end on mine so any pointers to using the sharp end would be good!

John

I use mine in a collet but only tighten by hand to allow the edge finder to move up when the point is lowered into a centre drilled hole, any off centre can be easily seen or felt and the table axis moved to correct alignment.

The same method can be used in a chuck but these normally have less length to allow the tool to slide upwards.

Emgee

Mine is single ended with the "square" end, so I've not used the pointy type. However, I assume it's for centre finding smaller holes than the square end will fit in (4mm in my case).

I tend to use mine with the DRO or CNC, so it's easy to subtract the 2mm radius of my square end or use the "1/2" function on the DRO. Obviously with a pointed end you can't subtract the radius but that's not an issue when finding the midpoint ie hole centre.

There may have been a handful of situations where a pointy end may have been useful. When I eventually shear the end off in a senior moment, I may replace it with a double ended version that has a pointy end.

If you look carefully, there is sometimes a very light witness mark where it touched if you use it on loominum but it's really not a concern on my work.

Murray

The center point picks up center marks or I sometimes use it to pick up a chamfer on a hole.

This thread has made me take notice.

Milling in my lathe, up to now I've always used a bit of precision ground silver steel in the chuck to touch on the edge of a workpiece for a datum. I do remember using a wiggler in the 1970s, but didn't at that time find it materially better. Now my eyesight isn't quite as good as it was, the idea's coming back.

I was wondering about the mechanical edge finders that seem to be available, but at least one of them says it isn't suitable for a horizontal machine, which would presumably also apply in lathe use with a vertical slide.

Makes me wonder about wigglers too.

Are mechanical - and for that matter electronic - edge finders attitude-sensitive? Do they need to be vertical?

Thanks in advance for any answers.