[Kevin45]

It says repeatability is within .001 but you have to rotate it to check to see if it is centered and if not it tells how to adjust it. Just that portion throws a lot of human error into it. For a carpenter it would be fine. For a machinist working in tenths it would not. But that is my $.02 on the subject. Just using a standard edgfinder I always check an edge a minimum of three times and take the setting of the two repeated findings (this is using a readout) Nothing is perfect and if you have to adjust the Laser yourself then it is real far from perfect. If it is as good as they say, then it should be controlled from the factory and locked down permanently. And the case is made from 6061 aluminum. Not my idea of precision.

[kentavv]

It says repeatability is within .001 but you have to rotate it to check to see if it is centered and if not it tells how to adjust it.

The rotating step is to do an initial alignment (which is done at the factory and may be fine when you get the edge finder). I would sure like to know how .001 is achieved though. I come up to an edge, zero, and then come up to the edge again and am normally off a few thou relative to the first zero. It seems even with the optional polarizer, using layout die, and lowering the edge finder within an inch of the stock the dot is simply too big. If someone has insight into how to get better accuracy please do tell.

The 3D testers mentioned earlier in the thread look really nice but $500 is pretty steep. Are there any that are economical?

[rc-monster mike]

I think .005" is about as good as you can get with the laser. I picked one up a while ago hoping to make indicating quicker and easier - it does this, but far less accurate. I still use the laser for adjusting/setting tools in the lathe and simple tasks that don't need to be too accurate, but I don't use the laser when it counts. I think a major factor in the inconsistency is the point of view of the operator - if we could look down through the spindle(same point of view as the laser itself), we could probably get more consistency. The "dot" is also too big(even with the refractor) - hard to get within .001" when you are using a .005" dot.

[ImanCarrot]

just like digital calipers.. I don't trust them

Never a truer word said.. I hate it when folk quote digital measurement without understanding the resolution of what they're using.

[kentavv]

Never a truer word said.. I hate it when folk quote digital measurement without understanding the resolution of what they're using.

What exactly cannot be trusted about them? Do they report more digits than they have resolution, is there an accuracy or reproducibility problem, or something else? I have heard others say they don't trust mechanical calipers because a small sliver can get in there and cause the rack-n-pinion to skip. Let's only consider brand name calipers though... not those $5 calipers from HF which probably are about as good as a wooden ruler.

[jackson]

What exactly cannot be trusted about them? Do they report more digits than they have resolution, is there an accuracy or reproducibility problem, or something else? I have heard others say they don't trust mechanical calipers because a small sliver can get in there and cause the rack-n-pinion to skip. Let's only consider brand name calipers though... not those $5 calipers from HF which probably are about as good as a wooden ruler.

Well i dont trust them cause i have been bit in the a$$ by them"beware of biting calipers"! LOL. Now i have not used the new one that are water proof, but that was one of my deals is you couldnt get them wetthe pair i had " notice i say HAD" at the three inch mark some how they skiped .1 so you decide what you want it just an opinion, now i have used dig. mic's before and they checked perfect every time but i still dont own any nor do i have them in my shop.

[Zumba]

I've got a digital caliper and four digital mics (all Mitutoyo). Going back to dial/vernier would be immensely painful for me. I constantly switch between inch and metric.

I also prefer digital indicators to dial. Dial inducators with tenths readings usually have limited travel. My B&S Bestest test indicator only has .008" of travel. The Mitutoyo dial indicator on my bore gage has somewhere around .080". Better, but not great. My Mitutoyo digital drop indicator with .0001" resolution has 1/2" of travel. It is awesome for tramming my mill head and dialing in stuff on the lathe.

As for the accuracy, I haven't had any problems thus far with any of the digital measuring tools.

[ajl6549]

Renishaw mp10 is all I use since we got it on our FH8800 Mazak

[protopath]

Starret 827B double ended edge finder. $21. Can not be beat for ease of use and normaly toleranced work. Only thing tighter are the indicating rigs or some of the machine mounted rubies.

I would say that after you had some practice you would be faster with it than any visual laser rig.

[jackson]

Starret 827B double ended edge finder. $21. Can not be beat for ease of use and normaly toleranced work. Only thing tighter are the indicating rigs or some of the machine mounted rubies.

I would say that after you had some practice you would be faster with it than any visual laser rig.

Yep thats what i have and what my guys have and i wouldnt have any other way "$18.00" on sale LOL

[Mcgyver]

I've got a digital caliper and four digital mics (all Mitutoyo). Going back to dial/vernier would be immensely painful for me.

mics i agree, but with calipers i'm the other way, dial is preferred (i do dislike very-nears though). why? like an analogue tach the position of the dial means something....like when you are roughing something out i can see from where the dial it'll be another 90 thou (or whatever) before I'm coming up on finish cuts without having to actually read the number or add/subtract. i know its not a big deal in terms of time, but makes for a better work process imo.

back on topic, what good is an edge finder with .004-.005 accuracy? sounds more like a gimick to me.

[Zumba]

Mcgyver, I agree that dial instruments are definitely useful in the way you described. I like them for indicating holes as well.

Back on the topic of edge finders, I just bought a Fowler electronic edge finder a few days ago. Part 54-575-650, 0.750 shank 0.400 ball for about $95. It lights up and beeps when the ball makes contact with anything metalic. I did some testing and it is very accurate. Claimed accuracy is .0002", and my own tests confirmed that. It is more accurate than my DRO that only reads to .0005". The ball is spring loaded to prevent damage.

If anyone's in the market for a very accurate edge finder, this is the one to get. Don't waste time with a laser that can't even come close.

[dertsap]

i agree with zumba ,thats exactly what i've got and it's a great edge finder

[joejared]

I have the edge finder referenced and as expected the beam is not round. I never used it for anything productive. What I am using can be found at

http://www.oretek.com/micromill/user.shtml#edge

I buy the non-ball style from http://www.use-enco.com and the ball style from http://www.wttool.com

There is a video of it in action at http://www.oretek.com/micromill/edge.mp4 and the ball style, although more accurate, is more fragile. For milling of non-conductive materials, I do my edge finding to the jig and then insert the part after the edge finding is complete.

[Mike Stevenson]

What the laser edgefinder is good for is CNC wood routers. Because you can't spin a normal edgefinder at the router's minimum RPM (10,000.) And you can't use the electric edgefinder because the workpiece is wood. A .004/.005 edgefinder tolerance in wood is no problem. I love my laser edgefinder.