# New Digital Edge Finder



## Susquatch (Apr 1, 2022)

I am finishing up the install of a DRO on my Hartford Mill. Now it needs to be commissioned and calibrated.

I already have two mechanical edge finders. But they only work on the X and Y Axis. To be truthful, I'm not sure how the Z-Axis works, but more on that further down.

So I decided to splurge on an electronic X/Y/Z finder. I decided on this one:

Accusize Industrial Tools Electronic Short Shank Edge Finders with Sound Alert, C028-9273 https://www.amazon.ca/dp/B01F44BQDQ/ref=cm_sw_r_apan_i_CWM2FQ1AP1SERQY2SJ5X?_encoding=UTF8&psc=1

It has a 0.4" precision ball on it. The ball is spring loaded so you can't damage it by going a bit too far. It also has both sound and a bright red LED.

Let me just say that for old guys with bad eyes and ears, it was worth the money!

To check accuracy, I used it from both sides of a precision block. This also demonstrates the versatility of the DRO.

Coming from Right to Left, I zeroed my DRO on contact, then rechecked it several times. Totally repeatable within a tenth. Then I plugged in the ball offset (1/2 of the diameter of 0.4 = 0.2) by hitting X, then 0.2, then enter.

Then I repeated the same exercise Left to Right on the block. Exactly 2.2000 inches plus minus a tenth.

Now for the Z. Drum roll please........

Hmmmmm....... Nice ball that allows for precision sensing. But it seems the OP on this thread is an idiot. The edge finder does a great job of finding the top edge, but now what? There is no way to use that edge! Every tool and every collet has adjustable length. There is no collet/spindle to maintain a zero like the X & Y........

The traditional methods is to take a scuff cut using whatever bit you plan to use. But that loses the benefit of the precision ball, the LED, and the Beeper.

In conclusion, it's a nice edge finder and well worth the money, but unless another member has a better idea, it's pretty much useless as an edge finder in Z.

The only idea I can come up with is some kind of insulated fixture and a separate led/beeper. Or maybe put the sensor into a 3/4 inch collet in a 2" collet block and then bring the end mill down to contact the edge finder. But I doubt those collet blocks are all that accurate......

Ideas?


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## Darren (Apr 1, 2022)

use tool holders, number them, record the z height offset in the DRO's tool library. 

Also when edge finding, you can find the edge, move over - 0.100 in your case, and just zero the axis in question....no need to enter numbers. May save a few keystrokes...


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## Susquatch (Apr 1, 2022)

Darren said:


> use tool holders, number them, record the z height offset in the DRO's tool library.
> 
> Also when edge finding, you can find the edge, move over - 0.100 in your case, and just zero the axis in question....no need to enter numbers. May save a few keystrokes...



I'll address your suggestions in reverse. 

Re zeroing the DRO. That's actually what I did with my old edge finders before the DRO or the electronic edge finder. I just found the edge, and then moved the dial to account for the offset. So naturally, that's what I did with the DRO and EEFinder too. 

But I actually found entering the new coordinate to be much easier than moving the spindle and re-zeroing. Ya, moving it isn't hard, and tapping on the handle allows you to get tenths pretty easy. But I found that entering the new coordinate is even easier. Just find the edge, hit X, then 0.2, then enter is a lot easier than backing away on x, moving y out of the way, then moving x back to zero, then carefully tapping in to 0.2000, then hitting X0.  Maybe is just my Noob DRO Experience. That may change in time. But you should try it my way a few times too. Who knows it might be your habit that needs a revision too! 

There is soooooo much to learn about using a DRO that I am downright giddy about it! So many habits to break, and so many new processes to learn. 

RE the tool library idea. I ABSOLUTELY LOVE THAT! The library is a function I have not explored yet. But I know it's there and I'm sure I can figure it out. I can even use that to take the cutter size into account. But I'm not sure what you mean about the holders. How do you index a tool bit in the holder collet so it always goes in to the same place?


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## Darren (Apr 1, 2022)

dedicated r8 endmill holders for example, or tormach tts system, will always , in theory, have the same Z height, ie, you can remove the holder and reinstall and Z will remain constant. When you swap tools, you tell the DRO what number holder is installed and it adjusts Z offset.


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## Brent H (Apr 1, 2022)

@Susquatch : check this video out - good explanation of edge finders and some issues with the digital ones to look out for:


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## Susquatch (Apr 1, 2022)

Darren said:


> dedicated r8 endmill holders for example, or tormach tts system, will always , in theory, have the same Z height, ie, you can remove the holder and reinstall and Z will remain constant. When you swap tools, you tell the DRO what number holder is installed and it adjusts Z offset.



I have dedicated R8 Endmill Holders. Some junk ones I bought as a set, some well worn ones that came with the mill, and a few really good Hardinge ones that also came with the mill. None of them have a register stop for an endmill. At least not where it belongs - the endmills would have to clamped in thd cutting edge to reach the stop. I'm not familiar with the tormach tts system, but it sounds really $$$. Makes some sense for cnc, but do you use them? 

Regarding the collet holders - doesn't the retaining torque change the zero? 

But ya, the DRO can do it so it seems worthwhile to figure out how to index the endmills themselves.


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## Darren (Apr 1, 2022)

You'd leave the endmill in the holder and number the holders. When you remove the endmill from the holder itself, you'd have to reset the Z offset in the DRO. So to swap from your 1/4" to 1/2" endmill, yo would be swapping out the holder by undoing the drawbar.


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## Susquatch (Apr 1, 2022)

Darren said:


> You'd leave the endmill in the holder and number the holders. When you remove the endmill from the holder itself, you'd have to reset the Z offset in the DRO. So to swap from your 1/4" to 1/2" endmill, yo would be swapping out the holder by undoing the drawbar.



I think I am missing something REALLY important here Darren. 

Doesn't the endmill move around in the holder once the tension is off? In some cases, it falls right out on mine! Certainly, even the tight ones move when you tap the draw bar to release it. 

None of mine have a stop (at least not in the right place).


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## Susquatch (Apr 1, 2022)

Darren said:


> You'd leave the endmill in the holder and number the holders. When you remove the endmill from the holder itself, you'd have to reset the Z offset in the DRO. So to swap from your 1/4" to 1/2" endmill, yo would be swapping out the holder by undoing the drawbar.



Even if I never figure out how to handle the Z-Axis, I love this tool indexing idea for the X&Y Axis. I could make a chart for all my tools and then plug them into the tool library on the dro and never need to add/subtract the tool radius ever again! Just select the 3/8 tool and it automatically accommodates the 4 digit 3/16ths offset (0.1875) and done!


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## Darren (Apr 1, 2022)

i think that you are thinking collet. this is an endmill holder:


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## YYCHM (Apr 1, 2022)

Susquatch said:


> Even if I never figure out how to handle the Z-Axis, I love this tool indexing idea for the X&Y Axis. I could make a chart for all my tools and then plug them into the tool library on the dro and never need to add/subtract the tool radius ever again!



You probably have a tool radius function where you simply enter tool diameter.


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## Susquatch (Apr 1, 2022)

YYCHM said:


> You probably have a tool radius function where you simply enter tool diameter.



To my knowledge, there is no tool radius function. But I think the library is prolly a better way to do it anyway.


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## Susquatch (Apr 1, 2022)

Darren said:


> i think that you are thinking collet. this is an endmill holder:



By George, you are right! I have some of those in MT3, but none in R8. Never even thought about using them. The collet style is sooooo much more useful. Might be worth buying a few in the standard diameters. (3/4, 5/8, 1/2, 3/8, & 1/4 - maybe 12 and 6mm too. More $$$$ on tooling. (Insert forlorn  hopeless look here.) 

How do you take drawbar torque into account? Or does it really matter?


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## Darren (Apr 1, 2022)

I'm not sure how much effect the drawbar torque would influence Z height. You'd have to experiment. I have always set Z manually. I dont have a DRO on the Z. 

Starting over, i think i'd be looking more closely at the TTS or other type of quick change setup. I really like putting everything in the ER40 collet chuck for speed, but with the power drawbar i can swap fairly quickly now.


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## David_R8 (Apr 1, 2022)

The TTS system is fantastic.


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## whydontu (Apr 1, 2022)

Little plate. 2”x2”x1/8” chunk of plastic, something you can use with epoxy. Glue it to a similar-size chunk of aluminum to make a sandwich. Aluminum needs a small tab to attach a wire. Clamp sandwich to mill, face to a known thickness. You now have an insulated gauge block, connect an LED and a battery so the LED lights when your tool bit touches the block. Zero the DRO, remove the block. You now have a known distance bit to table.

This is how I zero the cutter on my little CNC engraver.


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## Darren (Apr 1, 2022)

whydontu said:


> You know have a known distance bit to table.


 or the top of the vise, top of the part, feature etc..great idea.


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## Brent H (Apr 1, 2022)

@David_R8 - I had to Google the TTS system as  my mill is a 30 taper not R8.

Bridgeport came out with the Erickson QC 30 collet system in the 80’s I think?  My mill has that but with the quill bored for using a draw bar if required. Works well and 30 tapers fit great and are easy to index (common for CNC use) 

I don’t have the nut required for using the quick change process:






It runs about $350 to $600 CDN so it will not be a purchase I plan on making.   Hopefully I will find one some day and be able to test its abilities.


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## David_R8 (Apr 1, 2022)

@Brent H I use the TTS holder in an MT3 collet as that's what my mill has.


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## YYCHM (Apr 1, 2022)

Susquatch said:


> To my knowledge, there is no tool radius function. But I think the library is prolly a better way to do it anyway.



Nope, I don't see it either.......



			https://www.machinetoolproducts.com/content/Ditron/D80%20User%20Manual%202017.6.28.pdf


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## Tom Kitta (Apr 1, 2022)

I may try this - found exactly same one for $14 CAD - 








						13.87C$ 16% OFF|Precision Electronic Edge Finder With Beep Led Milling Cnc Lathe Led Beep Lathe Digital Edge Finder Milling Machining Optical - Gauges - AliExpress
					

Smarter Shopping, Better Living!  Aliexpress.com




					www.aliexpress.com
				




There are others available - all well under $20 with fast shipping to Canada. Main difference is 10mm metric ball - which is 0.393701 in. So for extra 80 CAD you get imperial ball. This is so far the most extreme example of price gauging by Accusize. Usually they are less 50% more. Heck sometimes as close as 10% - I almost considered buying set of square 5C collets from them but decided to go with aliexpress and saved $20. 

Thanks for the tool tip - I get mine in three weeks.


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## PeterT (Apr 1, 2022)

Tom beat me to it. I'm pretty sure I've seen that same edge finder that Accusize re-markets for a lot less cost, but that's another issue.

A disadvantage to most of those IMO is an overly large diameter shank & ball. Yes you can put the EF in a 3/4" collet, but rather limited in any other kinds of smaller tool holders. I use this Borite model. USA made, half the price, smaller diameter shank & edge surface, same quoted repeatability. I can insert in a much wider range of tooling, even a drill chuck. That speeds up setups. Also the measuring end is a smaller 0.200" diameter cylinder. That allows it to get inside smaller diameter holes or smaller vertical spaces for (center finding) half measurements. For conventional edge finding, works the same way - make contact enter nice round +/- 0.100" on DRO and you are done. All subsequent measurements are relative to that edge.





__





						BORITE,BORITE ELECTRONIC EDGE FINDER,1-275-98315,KBC Tools & Machinery
					

BORITE,BORITE ELECTRONIC EDGE FINDER,1-275-98315,KBC Tools & Machinery




					www.kbctools.ca


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## Tom Kitta (Apr 1, 2022)

Yeah, the Chinese version is a bit "massive" 20mm for metric and 3/4 for imperial. Both use LR1 batteries (well technically they are the same thing, just one imperial the other metric). 

The Borite stuff looks great and a good price as well, made in USA also a bonus as its well made and imperial. 

20mm is the max ER32 can handle - not exactly an issue as ERs are mostly metric so 20mm works far better then 3/4 as far as accuracy goes.


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## PeterT (Apr 1, 2022)

whydontu said:


> Little plate. 2”x2”x1/8” chunk of plastic, something you can use with epoxy. Glue it to a similar-size chunk of aluminum to make a sandwich. Aluminum needs a small tab to attach a wire. Clamp sandwich to mill, face to a known thickness. You now have an insulated gauge block, connect an LED and a battery so the LED lights when your tool bit touches the block. Zero the DRO, remove the block. You now have a known distance bit to table.


I've seen those & thought about making something like it, but I wasn't sure how good an electrical conductor typical carbide inserts are. Any experience on that front?

For my own (non-CNC manual milling) work, I've never seen much value in using an EF for vertical pre-calibration. Too many variables +/- a couple thou swapping tooling in & out, not to mention time. On a Bridgeport knee type mill with DRO its actually quite easy. Insert the cutting weapon of choice, make light contact with work surface, lock the quill in position, zero the vertical DRO, remember to back off the knee, done. If the work or cutter edge is sensitive, lay a shim of plastic or brass & enter the thickness, same thing. I also have a quill DRO so I often zero it too. It will show any quill drift during machining. All that said I have yet to work with a DRO where you could count on exact part measurement especially through an extended machining range. It always pays to re-measure & re-calibrate DRO as you approach final dimension, at least for +/- thou type accuracy. At least this has been my experience.


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## whydontu (Apr 1, 2022)

I had to run down to my shop to find out, it never occurred to me since I rarely use carbide. So, trusty analog multimeter in hand, I checked. (Using my 1975 analog meter as a nod to Susquatch)

Yellow TiN coated, conductive
Shiny in-coated, conductive
Black PTFE-coated, as expected, non-conductive.
Grainy in-coated parting tool bits, non-conductive


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## Susquatch (Apr 1, 2022)

@Tom Kitta , @Tom O & @PeterT .

Time may prove me wrong on this one and I might have wasted some money. But it was a calculated risk I took with my eyes wide open. (well, maybe some rose coloured sunglasses on). 

I saw the Ali express finders and a few on Amazon too. Accusize also sells two models. The one I got is the better one with 0.0002mm precision. I also bought a Fowler with 0.00001" precision which converts to 0.0003mm at $35. 1/3 the price of the Accusize. So I bought one of those too. (I did say I splurged on this - remember?) 

BUT the accusize has a ball that can also be used for vertical edge detection. The fowler is only rated for side detection. 

The fowler has a 0.2" cylindrical tip. The accusize has a 0.4" ball. I wanted one of each to play with. 

I started out wanting to experiment and I was willing to pay a little for the lessons I might learn. One of those lessons might be "Don't spend money on meaningless precision". 

That said, I have no regrets about the money I may have wasted on my Mitutoyo, Starrett, and Interapid precision tools. Not that accusize is in their league, but I'm absolutely certain that most of the other metrology instruments I have acquired from various sources is mostly pure junk. 

I've been having good experiences lately with Accusize so I figured a hundred bucks for this kind of equipment was a reasonable risk to take given that they actually provide a number. Most of the stuff on Amazon and Ali would not even provide a number. I don't like that, but we will see how that all shakes out with time. 

The specs for the $20 unit that Tom Kitta referenced say that it has 0.003mm precision. That's an order of magnitude poorer than the fowler. 

Maybe that doesn't matter in the end, but for whatever reason I thought it was worth the extra coin to get the Accusize. Time may prove that wrong and perhaps even foolish. 

My DRO is capable of sensing at the 1 micron level (0.00004"). So I used it to evaluate the two units. Sure enough, both were consistently accurate to +/- 1 micron over 10 samples minus a few I Fugd up. I had speculated that the difference in the two ratings might be purely a function of the point contact of a ball VS the line contact of a cylinder. That doesn't appear to be the case - at least not within the 1 micron resolution of my DRO. 

Right about now you might be asking yourself why anyone would care. In fact, that's what I'd be asking if this was your thread. My answer is simple - I don't know what I don't know but in general I believe better is better. I can always use better where it isn't needed but I can't use less where more is needed. My curiosity also needs to be regularly fed. 

Anyway, I remain very impressed with both units, but I favour the accusize unit because it will also do Z (if I can figure out how to do that) and because it also has a beeper and I REALLY like that!


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## Susquatch (Apr 1, 2022)

whydontu said:


> Little plate. 2”x2”x1/8” chunk of plastic, something you can use with epoxy. Glue it to a similar-size chunk of aluminum to make a sandwich. Aluminum needs a small tab to attach a wire. Clamp sandwich to mill, face to a known thickness. You now have an insulated gauge block, connect an LED and a battery so the LED lights when your tool bit touches the block. Zero the DRO, remove the block. You now have a known distance bit to table.
> 
> This is how I zero the cutter on my little CNC engraver.



I had similar thoughts. I even thought perhaps I could use the actual end mill that way. 

Right now I'm leaning toward using the edge finder itself in a VBlock. What I'm not sure about is the conductivity of various types of end mills. 

But I also have a bigger problem that needs to be solved first. How to get repeatable Z height. No point measuring anything I can't repeat. I'm not buying that TTS system. WAY TOO MUCH MONEY. But @Darren had a good idea about using R8 end mill holders. I can afford a few of those. 

Anyway, your thoughts are good ones. I feel like there is a light at the end of the tunnel on this issue.


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## Susquatch (Apr 1, 2022)

Darren said:


> I'm not sure how much effect the drawbar torque would influence Z height. You'd have to experiment. I have always set Z manually. I dont have a DRO on the Z.
> 
> Starting over, i think i'd be looking more closely at the TTS or other type of quick change setup. I really like putting everything in the ER40 collet chuck for speed, but with the power drawbar i can swap fairly quickly now.



I'll do it as soon as I get a 3/4" end mill holder. (I don't have anything else that big - my chuck is only 5/8. Pretty sure an R8 collet will move so no sense trying that. With a holder, I think I can just zero Z, tighten the drawbar and then check how much Z moved - if any.


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## Susquatch (Apr 1, 2022)

Darren said:


> You'd leave the endmill in the holder and number the holders. When you remove the endmill from the holder itself, you'd have to reset the Z offset in the DRO. So to swap from your 1/4" to 1/2" endmill, yo would be swapping out the holder by undoing the drawbar.



So, it turns out that the tool library function only applies to the Lathe configuration. It doesn't exist for the mill configuretion. Too bad, but C'est La Vie. 

However, it does have 200 sets of auxiliary zeros. I may be able to use a few of those. It just won't be as easy because they only work in absolute mode. 

More fun playing in the new sandbox.


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## Darren (Apr 1, 2022)

Susquatch said:


> So, it turns out that the tool library function only applies to the Lathe configuration. It doesn't exist for the mill configuretion. Too bad, but C'est La Vie.
> 
> However, it does have 200 sets of auxiliary zeros. I may be able to use a few of those. It just won't be as easy because they only work in absolute mode.
> 
> More fun playing in the new sandbox.




double check again. I can't see them not having that in mill mode. If its true, that cancels my plan for getting a 4 axis for my mill to replace the 2 axis Mitutoyo. Damn


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## Susquatch (Apr 1, 2022)

Darren said:


> I'm not sure how much effect the drawbar torque would influence Z height. You'd have to experiment. I have always set Z manually. I dont have a DRO on the Z.
> 
> Starting over, i think i'd be looking more closely at the TTS or other type of quick change setup. I really like putting everything in the ER40 collet chuck for speed, but with the power drawbar i can swap fairly quickly now.



I do have a 3/4 Weldon Arbour. That should be every bit as good as an end mill holder so I tried it. On the basis of just one test, the difference between snug and tight is 2.8 thou and the difference between snug and torqued down really tight is 3.1 thou (just another 3 tenths) which makes sense to me. I did ten samples to see how consistent the R8 taper and I both are. Tight (my normal torque application) varied between 2.7 and 2.9 thou. So +/- a tenth. Not bad for most things. 

Now I just need to figure out how to do the Z Axis in a way that translates to tooling, get some R8 end mill holders, and then figure out how to use the alternate zero function on my DRO.


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## Darren (Apr 1, 2022)

If you able to get under 1 thou accuracy on a Bridgeport type mill, you're doing pretty darn good already.


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## Susquatch (Apr 1, 2022)

Darren said:


> double check again. I can't see them not having that in mill mode. If its true, that cancels my plan for getting a 4 axis for my mill to replace the 2 axis Mitutoyo. Damn


Will do. I'll find it in the lathe function and then switch to the mill mode. Stay tuned.


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## Susquatch (Apr 1, 2022)

Darren said:


> double check again. I can't see them not having that in mill mode. If its true, that cancels my plan for getting a 4 axis for my mill to replace the 2 axis Mitutoyo. Damn



Sorry Darren, it's only there in the Lathe mode. Not only that, but it's only for x & y. 

But I am thinking I can use 10 or 20 of the alternate zero settings to do the same thing. It's a bit more complicated but there are 200 of them and they apply to all 4 axis. 

I'm heading off to the house right now. CEO's orders. But I'll read up on it there and test it tomorrow for you.


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## PeterT (Apr 1, 2022)

Surface finish can have large affect on EF accuracy & repeatability. For fun, grip your best 123 block in the vise, get an EF null reading, zero the DRO. Wind out the lead screws, go to a new spot on block, rinse & repeat. No peaking at the DRO, only rely on the EF light/beep. How many of the DRO 0.00000" digits to you get to keep? Now consider if the typical part you are machining will have the same Ra & squareness as your 123 block. 

Even if the EF is 0.000000000 to the edge, that just conveys the center of the cutting tool. But the EM center is not the EM edge, its cutting OD also has +/- tolerance too. Usually we are milling a surface relative to a datum so no getting around breaking out the mic to verify & adjusting accordingly. Drill chucks & drills & collective gripping of the two are typically crude resolution by comparison. I know you know all this stuff, just reinforcing the concept. My own rule of thumb for manual mill/latheis one-thou is pretty good, actually hard to achieve on more complex parts. If finer tolerance is required, at least repeatably, its  probably grinding & lapping territory.


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## Susquatch (Apr 1, 2022)

PeterT said:


> Surface finish can have large affect on EF accuracy & repeatability. For fun, grip your best 123 block in the vise, get an EF null reading, zero the DRO. Wind out the lead screws, go to a new spot on block, rinse & repeat. No peaking at the DRO, only rely on the EF light/beep. How many of the DRO 0.00000" digits to you get to keep? Now consider if the typical part you are machining will have the same Ra & squareness as your 123 block.
> 
> Even if the EF is 0.000000000 to the edge, that just conveys the center of the cutting tool. But the EM center is not the EM edge, its cutting OD also has +/- tolerance too. Usually we are milling a surface relative to a datum so no getting around breaking out the mic to verify & adjusting accordingly. Drill chucks & drills & collective gripping of the two are typically crude resolution by comparison. I know you know all this stuff, just reinforcing the concept. My own rule of thumb for manual mill/latheis one-thou is pretty good, actually hard to achieve on more complex parts. If finer tolerance is required, at least repeatably, its  probably grinding & lapping territory.



Ya, I have no delusions about my ability to actually make things anywhere near that accurate. 

But I am a believer that my measuring equipment should be at least an order of magnitude better than my machining equipment and my skills. 

FWIW, I already did almost what you suggested. Even to the point of not peeking at the DRO. I was actually amazed to discover that all digits were exactly the same - even the very last one. Made me wonder what wasn't working or what did I do wrong. 

My own musing about it goes like this. My DRO is way better than I ever expected it to be. Both my electronic edge finders are as good as their manufacturer said they were. And both my DRO and the edge finders are way better than me or my mill. 

Which is exactly the way I would like things to be. 

But I confess that I am a little out of sorts over the DRO. Maybe unsettled would be a better way to express it. I like to understand things. I don't understand the DRO. How does it achieve that level of precision? How can it be so repeatable? How come my Gibbs, the weight of my table, the ambient temperature change, and a dozen other factors don't mess with it? I kinda feel like I'm dreaming and I'm gunna wake up tomorrow and realize that there is a little man inside there who is just making up numbers to mess with me.


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## Susquatch (Apr 2, 2022)

Ok Darren, no tool library in Mill Mode. BUT..... 

It does look like you can designate any number of the 200 available SDM storage locations to serve the same function (actually a bit better).  There are three benefits of using the SDM locations.  

First, they are relative to the ABS position. If you change the ABS location, the SDM locations change accordingly. Ie set abs 2 inches right, and all the sdms change 2 inches right. 

Second, setting an SDM location saves all 4 axis, not just the x & y. The tool store only saves x and y. 

Third, they can be saved by moving the axis, or they can be entered directly on the keyboard. 

Using them is pretty easy. Just hit SDM, then the number you want (anything between zero and 200). The selected SDM number displays right in the SDM Screen box. Pressing either ABS or INC exits SDM mode. 

I believe they are intended to keep track of features on the part relative to your part zero. But it seems that the part features are not really parts or tools - just a 3D location in space relative to ABS. So the DRO doesn't know or care if it's a part or a tool. 

Go ahead and ask questions. Answering them will help me understand them too.


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## Tom Kitta (Apr 2, 2022)

Susquatch said:


> @Tom Kitta , @Tom O & @PeterT .
> 
> Time may prove me wrong on this one and I might have wasted some money. But it was a calculated risk I took with my eyes wide open. (well, maybe some rose coloured sunglasses on).
> 
> ...



There is the stated accuracy and then there is "real life" like I do not care what Accusize states - their stuff is exactly the same as stuff from China I got just in imperial. So if Chinese state 0.003 then it is probably closer to +- 0.005 in both cases. I could be wrong, and it could be +-0.002 but 0.005 is quite good already. Remember that is +- two thou. Accusize just re-badges stuff. I am sure if I looked a lot I could find imperial one or I could ask seller for imperial one - I bet $5 more. 

The DRO scale step is a micron. That does not mean the measurement will be that precise. I have all 5 micron scales and they are better then a BP needs. Again, this does not mean anything more then a "step is 5 micron". Its like your calipers have 0.01mm step - does not mean you can measure reliably with your calipers down to 0.01mm.

I am unsure of the Fowler unit - but a lot of their stuff is "better China" re-badged - at least for a while now. 

Also I am unsure of the Z stuff - I guess when I get my Chinese indicator I play with the Z as well. For actual precise Z I have a little cylinder with 0.001mm step scale that measures the tool height. To be honest I never yet needed this - I may use it for the CNC stuff. 

For tool library stuff to work with height precisely (or good enough) you would need 40 taper tooling (or 30) not R8 and I don't think MT3. Also multiple holders with multiple pre-set tools. This could be OK in some applications but seems a bit out of the way of most hobby stuff - there was some discussion about this on this board a while ago by Dabbler.


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## Susquatch (Apr 2, 2022)

Tom Kitta said:


> There is the stated accuracy and then there is "real life" like I do not care what Accusize states - their stuff is exactly the same as stuff from China I got just in imperial. So if Chinese state 0.003 then it is probably closer to +- 0.005 in both cases. I could be wrong, and it could be +-0.002 but 0.005 is quite good already. Remember that is +- two thou. Accusize just re-badges stuff. I am sure if I looked a lot I could find imperial one or I could ask seller for imperial one - I bet $5 more.



Perhaps you missed the fact that I actually measured it. It was at least as good as they claimed, perhaps better. 

It meets my personal criteria which is to ensure that my measurement equipment is always an order of magnitude better than my equipment and me. 

I think accusize has changed. It seems like they have started sourcing some stuff locally. Even if not, they have a clear leg up on you and me. They speak Chinese, they buy in volume, and they definitely care about customer satisfaction. They have gone way over board for me several times now. Even when it wasn't their fault. The improvement in their quality suggests they have swung deals that I could not swing to buy better stuff than I can buy on my own. I have no proof of that, but I can say that everything I bought from them in the last 2 years has been first rate. I can't even say the same for KBC! 

I am happy to give them credit for what they have accomplished, and they are earning my respect for it. 

Bottom line is that I'm happy with it, it met my precision requirements, it delighted me from the first moment I used it, it arrived in just a few days, and the beeper function is awesome! To me it was worth every penny I paid for it! I have no regrets!


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## Degen (Apr 2, 2022)

Again I see accuracy thrown around when reading specs and referring to them in performance our equipment.

Regardless of the perceived accuracy of your scales and your DRO's display, what your machine is actual capable of is the determining factor and I'll bet that if you can get down to 1/10 of thou. you are doing really good.  Anything beyond that is truly wishful thinking despite what your DRO says.

That said, a simple probe that is capable of a 0.0001 is more than accurate enough for 99.99% of us.    For the few that have machines capable to go beyond that that gets into a different discussion.


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## Susquatch (Apr 2, 2022)

Degen said:


> Again I see accuracy thrown around when reading specs and referring to them in performance our equipment.
> 
> Regardless of the perceived accuracy of your scales and your DRO's display, what your machine is actual capable of is the determining factor and I'll bet that if you can get down to 1/10 of thou. you are doing really good.  Anything beyond that is truly wishful thinking despite what your DRO says.
> 
> That said, a simple probe that is capable of a 0.0001 is more than accurate enough for 99.99% of us.    For the few that have machines capable to go beyond that that gets into a different discussion.



Relax @Degen, we are on the same page. If you read my previous posts on this, you will see we agree completely. This isn't an exercise in improving my machining accuracy. I have no delusions about that. I can't reliably get to a tenth any more easily than anyone else - at least not directly. That kind of precision usually requires lapping or grinding.

Anyway, my very first post explains my objectives here and my reason for posting. This wasn't about machining in the real world. It was about calibrating my new DRO and some experiments to understand what is really going on with it. Is it as good as they claim?

In that context this isn't about how good I am or whether or not 0.0001 is reasonable or whether or not we are throwing unreasonable numbers around. It's about curiosity, learning, experimenting, and having fun.

We can certainly argue about the merits of good metrology equipment for normal machining, but at the end of the day, I firmly believe that my metrology equipment needs to be better than I am. I tend to prefer an order of magnitude better. If our measuring equipment is only as good as we are then we could be out double or triple what we think we are. But again, that's another matter and a whole nuther discussion.


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## Degen (Apr 2, 2022)

@Susquatch wan't directed at you just as a reminder for those lurking. I know you understand .  Sometimes they miss the intent.


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## Tom O (Apr 3, 2022)

Some people run them at a slow rpm and just get the led to flicker at the edge


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## Susquatch (Apr 3, 2022)

Tom O said:


> Some people run them at a slow rpm and just get the led to flicker at the edge



That may work on some devices. I'm not sure how well it would work on either of mine. I've been impressed at the sensitivity of both. They are either on or off with no in-between at all. It is almost as though they have an internal Schmidt Trigger of sorts. They also seem to work well with or without oil. 

When you think about the fact that any current flowing has to make the full circuit from/to the ball, through the part, vise, bed, saddle, knee, mill body, ram, head, bearings, spindle, holder, to/from the edgefinder body, with all the oil and grease in between, it's easy to see why they might have done that. 

At three times the price of the Ali units, I'm not about to take either of mine apart to see what's in there, but maybe someone who bought an inexpensive off-shore unit would be willing to dissect theirs (or send it to me for dissection). I did look as closely as I could and got nowhere. 

At any rate, they both seem to have extremely good sensitivity and excellent repeatability with no apparent signal leakage of any kind and rock solid edge detection at a much better level of precision than I ever expected. Certainly way better than I can ever expect to realize with my beginner level hobby milling skills. 

Yes, I'm impressed.


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## Susquatch (Apr 3, 2022)

Degen said:


> @Susquatch wan't directed at you just as a reminder for those lurking. I know you understand .  Sometimes they miss the intent.



I see. Sorry for the long explanation then. And of course you are right to make sure that others don't get the wrong ideas or the wrong expectations about all this. It would be easy to do.


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## Susquatch (Apr 3, 2022)

Darren said:


> double check again. I can't see them not having that in mill mode. If its true, that cancels my plan for getting a 4 axis for my mill to replace the 2 axis Mitutoyo. Damn



I spent more time looking at the tool store function and the SDM Function today. As I said earlier @Darren , even the tool store function for the lathe setup doesn't seem to be very good. I like the SDM capability WAY BETTER. The Lathe Tool store function only works in INC mode and then only for x and y. In the other hand, the SDM system is like 200 extra references all relative to ABS. I had no trouble coming up with offset schemes to accommodate tooling for all 4 axis. 

If I do this for tools as you originally suggested, I will probably only do it for 10 or 20 tools. Not 200.

I really think you will be ok and I really don't think you would lose anything by going with the Ditron.


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