Best edge finder?

[TomG]

(07-19-2012, 04:04 PM)ScrapMetal Wrote: Dang, I looked up some info on those Moore edge finders, they seem simple enough, so why the high dollar amount on them?

-Ron

Ron,

Moore make jig boring stuff and everything they make is the best of the best and priced accordingly. That edge finder with reliably locate an edge within .0001".

If you don't need that kind of precision, and I'm guessing you don't, SPI makes one for about $60.

Tom

[Bill Gruby]

#1 and foremost is accuracy. I understand that Moore would like to discontinue them. Moore will not just pull something off the market. Theory for them is raise the price so they don't sell. Then over time sales will drop off now it's time to gradually phase the product out. I can't remember where but this was a big discussion on one of the Forums when someone spotted one on ebay for a mere 4,000 (no typo) He then supposedly went to the Moore catalog and found it at 4,110. On the bay now the fetch between 350 and 700. Yes they are extremely pricey.

"Billy G"

[Rickabilly]

I've been using the LED style spring loaded ball on a stick type for ten years now, I get five years battery life without drama, absolutely rock solid reliability, except when one of the employees bent one by crashing it hard in a CNC MC , they use a 10mm ball on the end spring loaded into a ground socket so you can overshoot without damage, to test it for runout simply find an edge and zero then rotate the finder by 180 degrees and retest, they can also be set for depth to set z offsets but they suffer from overshoot unless you are very careful, For Z's I use a 50mm LED Z tool which sits on top of the work and you bring the tool down to it until the light shows, at which point the tool is 50mm above Z surface, too easy, one very important point is that they don't work on non conductive work, but there are ways around this, number one is to use the vise jaws as datums, as you generally know where these are in relation to the work, like touching the work that is.

Rick

[EdK]

(08-27-2012, 03:55 PM)Rickabilly Wrote: I've been using the LED style spring loaded ball on a stick type for ten years now, I get five years battery life without drama, absolutely rock solid reliability, except when one of the employees bent one by crashing it hard in a CNC MC , they use a 10mm ball on the end spring loaded into a ground socket so you can overshoot without damage, to test it for runout simply find an edge and zero then rotate the finder by 180 degrees and retest, they can also be set for depth to set z offsets but they suffer from overshoot unless you are very careful, For Z's I use a 50mm LED Z tool which sits on top of the work and you bring the tool down to it until the light shows, at which point the tool is 50mm above Z surface, too easy, one very important point is that they don't work on non conductive work, but there are ways around this, number one is to use the vise jaws as datums, as you generally know where these are in relation to the work, like touching the work that is.

Rick

Hi Rick,

Any chance you feel like doing a "How To" on using that type of edge finder? Including pictures and/or drawings?

Just a thought.

Ed

[TOM REED]

I have an electronic one like Rickabilly that I bought from csc in china it has the led and is also audible, I have not really used it other than just to play with it but it seems very accurate.It was fairly cheap and I had it shipped with several other items so shipping was reasonable. Too much money + good credit, not enough time to play with my toys I have to work too hard to pay for them. hihi tom

[Rickabilly]

  !B7rlr0QBGk~$(KGrHqZ,!h4EzLtF2yk(BM06Vq7Scg~~0_12.jpg (Size: 6.82 KB / Downloads: 68)

So this is the Ebay picture from CTC so should be the same as Tom's and looks a lot like mine, they are so cheap that we used to keep one in a holder on each machine when I had employees, when I first started using them they were over $100 Au and even at that they were so handy that I felt it was essential on any CNC.

simply mount it in the spindle in a collet of some type and bring the ball up to the side of the work piece and stop when you first hear the buzzer and see the light, even when a truck and three other machines were running I could still hear the buzzer and my ears aren't great. then either set to -5mm or raise the z and wind the dials a further 5mm observe that the centre of the ball is directly over the edge and set to zero and you are done,
When finding centre of horizontal shaft you don't need to be on the vertical centreline, rather just close by eye and maintain your z when checking both sides then split the difference.

When finding centre of a vertical round pin or boss first roughly guess set centre in x and then locate centre in Y, once you have centre in Y touch off and find accurate centre in x.

I would use the LED finder and then finish with a DTI at the beginning but after six months of checking it was always within a thou or two so now I only check if it is absolutely required.

Another handy edge finder is the Laser one I have, it is pretty much a really fine laser pointer that has a shaft for spindle mounting and some centering screws for adjustment, you simply mount it in the spindle, turn it on, run the spindle, and bring it up to the edge, when you first see the light on the side of the work stop and zero the dials then continue travel until the spot is on top of the job and the lightest bit is still running down the side (just a shadow of the beam light, not that you can have a shadow of light, but you would know what I mean when you see it) read the dial, halve it and you have edge. They advertise it by saying just see the light and you're on centre and it's close but not quite, I prefer to split the beam. I have attached a picture below. It is really handy if you are setting up to parts that are complex in Z as you just leave the Z up to 12" away and the light beam does all of the "up and down work" for you, it's also great for centering drills in centre punch marks
   

Regards
Rick

[SnailPowered]

So how important is an edge finder? It seems like it would be darn near essential.

[Mayhem]

Snail's question initially made me think essential but it also made me think about turning on the lathe.

Generally I will take an initial cut, zero the dial, measure the diameter of the work piece and then progress from there. Could this approach not be replicated in the mill?

[Highpower]

That is fine if you are working with rough stock, but what do you do if your work piece is already at it's final exterior size?

Say for example you have a pair of 1x2x3 surface ground blocks that you want to drill a series of holes in. Taking an initial cut to zero your machine would ruin the dimensions of the part.

[TomG]

An edge finder is an essential tool on the mill. I keep one in the coolant trough of my vise so it's always within easy reach. As Willie pointed out, it's the best way to find the edge on a finished part if you need to add more features. Edge finding is done on the lathe as well, but it's normally done by just touching the edge of a shoulder or a diameter with the tool.

Tom