Oooops. I obviously got the decimal point in the wrong place when doing the conversion. I'm not as familiar with Imperial measurements as with metric. Apologies, and thanks for pointing this out. I'll pin this comment.
2/10000 of an inch accuracy of a mechanical edgefinder is good enough for a normal milling machine where machining tolerances are much larger than the accuracy of a mechanical edgefinder. With the limitation of using it only for conducting metals, I'd rather rely on the mechanical model.
@SubramaniamLakshminarayanan Yes I'd be more than happy with being able to work to 2:10,000." I was just making a comment that Jonsey had mixed up his units, that's all.
I've used both types of edge fighters for years they both have their advantages and their disadvantages. Electronic edge Finder must be precise in that the ball must rotate around the center rotation of the spindle yet there's no reason why that should be if the device is not very precisely made and carefully handled. The electronic edge Finder can be used in the vertical direction whereas the rotating one cannot. They both have their purpose and they're both handy for different things. The mechanical edge Finder can be put in a poorly centered Chuck because it's rotation characteristics it will still find the edge regardless of how not concentric it is to the spindle. Mechanical edge finders post is intentionally a little undersized so that out of necessity you have to over travel to get it to kick off and a smaller dimension there will help compensate for that over travel. Electronic edge Finder are of course completely non functional without conducting work pieces. Tr y spinning your electronic edge Finder to see how concentric it is with you're a spindle you'll probably find that it beeps intermittently as it gets close to your work piece indicating that it's not actually concentric.
As others point out mechanical edge finder compensates for spindle + collet / chuck TIR and the preferred approach is to use it in the collet or drill chuck which will be used in machining. You need a decent edge finder with hardened lapped surfaces that kicks out reliably, get a starrett or vertex.
This is a really important observation. The design of the "traditional" edge finder means that it always kicks off when the actual center of rotation moves past the edge of the part so you know that whatever the status of your spindle, you've found the actual center of rotation. The electronic one, I'd wager, might give you a different reading depending on how it's oriented in the spindle. Not a huge amount, and probably doesn't matter for a hobbyist machinist, but it is a consideration.
I have been using edge finders for about 50 years now and about 10 years ago I purchased and have used extensively the electronic edge finder. The repeatability and accuracy of the electronic is unsurpassed. they do have their faults but I have purchased three different sizes of them and all work extremely well. Well worth the money. Cheers.
As for the mechanical edge finders being "undersized", that would be deliberate. In order for the edge finder to actually kick to the side, it has to have gone "too far". When it's just touching the surface, then it will be exactly in line with the rotating surface and not wobbling at all. Go a smidge further, then the friction of the rotating surface rubbing against the part will cause it to kick to the side.
Hoping for reliable electrical contact at effectively zero force and no wiping action is a big ask. The tiniest bit of contamination and it simply won't work.
Edgefinders are not deliberately ground undersize, they are lapped to a very close tolerance. Use a micrometer to measure them, they can wear but only by a couple of tenths over years.. If you are concerned with the end marking the part, there are mechanical edgefinders with a ball end. Huffam have been around for ages and kick out much less than the wigglers. One thing that can cause errors is the edgefinder, part and vise jaws need to be regularly demagnetizsd. Could you set up a part using a lever indicator to accurately find the edge and then see how the others perform in comparison. Lock the knee, Y axis and keep the spindle locked in the same position.
I've used electronic edge finders, and have noticed that you should also spin up the digital edge finder at around 60rpm, (Not all are like this however a majority I have seen are) you shall notice when touching onto the part, that only one side will touch first, showing the light only on in certain places. -Edit, (Will still be super accurate without spinning but this is just for the extra bit)
Hey Nick! Great video as always - concise and to the point. Here's my two pence worth on this - I bought a couple of these for the bridgeports at work, and they're really good. Got them from Chronos engineering, and if memory serves they were about £45 each. With that said, my experience with them is somewhat soured, as it seems they're not all made equal. My mill at home has an MT2 taper, so I naturally had to go for the smaller variant(which, to absolutely no one's surprise costs about the same, if not more. Go figure), however, I bought it from one of those chinese import websites, and quite frankly - it's crap. First of all, it doesn't have a buzzer, so you're relying on a very dim LED, but more annoyingly than that, it only works when it feels like it, so my advice for anyone with a small mill would be to either stick to a standard edge finder, or at the very least buy from a reputable source. Edit: I just went on chronos website, and it seems like they now do an MT2 version of the same tool. Might have to give it a go, since the price is actually rather reasonable.
I've got one of the EBay cheap copy of the electronic edge finder and surprisingly it is very accurate on dimensions my one has a nominal ball diameter of 10 mm and it is spot on at 10.008 . Much more accurate than my milling I can tell you and its repeatability seems to be good. I say seems to be because my dro is all over the place and sometimes I have to rely on the good old dials especially on the cross slide. I know there is a linear compensation on the dro but my unit will not go into that function no matter how many time I try it. I probably need a new unit, the scales are glass and are clean so it's not them also the discrepancy occurs at different places on the scale and does not happen every time or in the same place twice. So it is what it is. The eBay edge finder was only £9.99 so I think for the amount of times I use the milling head ( I've a Warco WMT300 Lathe/Mill combo) which has quite serious limitations, but it's better than nothing especially as I'm working inside a shed only 7 feet by 5 feet lol so no room for anything else. My two bandsaws and grinding equipment are elsewhere.
Regarding your comment about having to watch the mechanical edgefinder, over the years I find that I have learned to tell when it kicks off by ear much quicker and more precisely than by eye. It might not work so well on a loud mill, but on my belt driven brushless minimill, it is very apparent.
Remember, the entire setting accuracy will depend on machine alignments and head squareness as this will be tested with any variation on the X axis with height differences ?
A mechanical edge finder can be used in a drill chuck since it will per definition always rotate around the spindle axis, regardless of the offset of the chuck. Therefor it will be more accurate on a hobby machine. It's self correcting. That also means that any stationary edge finder will inherit the error of the holder (the chuck, collet,...). I think your accuracy test may be biased. In both cases you should NOT look at the DRO. If you looked at the DRO during the electric test, you will inevitably have introduced a bias. The same goes for caliper and micrometer measurements - never look while measuring! That said, I saw elsewhere that electric edge finders are indeed a bit more accurate.
Well the offset of the chuck does have to be taken into account If you had a chuck that ran out .03 for example if you edge find with a traditional edge finder and move over half the edge finder You are going to be .015 off
The skill in using a wobbler is just the start of machining job, that is why with4/5 year apprenticeships you develop suck skill as taking the burs off a work piece before you start. My Bridgeport never had dro only .200" lead screw also we would set the dial minus a .100" so when you came around the dial was on ZERO to start your count of turns as I point out to a TH-camr who never though of that lol
The fact that an electronic edgefinder does not spin may reveal errors because of possible runout in the spindle/chuck/collet combination. Something that is automatically overcome with a turning edgefinder.
If you turn the mill spindle on and rotate it at low rpm you will find that almost all electronic edge finders are not running with precise concentricity to the spindle centre axis.
Disatvatages of the electronic one: Sometimes I mill non conductive materials, then it does not work. The longer edge finder adds an error when the spindle is not exactly trammed. The 0.01mm under size of the mechanical one is a good compensation for spindle run out. very few spindles and adapters will have less. 12V batteries are difficult to get and quite expensive.
Actually I've never used edge finders in mills. I've always started with an oversized piece of stock. Squared it up and then milled it down to size. Then again, I've never done really complicated shapes.
I’d be interested to hear more on that? I’m always keen to learn from those with more experience than I. Are you referring to the fact the electronic edge finder isn’t rotating?
Good discussion. I bumped my electronic edge finder a little too hard (OK, WAY too hard) and wanted to get a more bullet proof replacement. I bought one of those small electronic probes that are probably more intended for CNC use and I fitted it to my DRO for about the cost of a good electronic edge finder (with some difficulty). In addition to edge finding now in three axes, the DRO has a number of other functions that use the probe for finding the center of a circle with three random points, distance between features inside and out, angles, etc. I think the jury is still out on accuracy and repeatability. It’s in the range of 0.03mm but seems good enough for what I do. I couldn’t honestly say that I was doing any better with the other units. A bonus is that the probe will withstand at least 4mm of deflection so I will have to work harder to destroy it.
@@joneseymakes My DRO (Electronica EL700) requires a normally closed contact probe. The units I found online are normally open. This type of probe is actually NC by design as a contact is broken when the probe touches a stop. They achieve NO operation via electronics in the probe. I removed the electronics and re-wired the probe connector directly to the contacts, then re-centered it. Contacts are gold so should be reliable. Pre-contact behavior seems more or less predictable and you can adjust it by setting the probe diameter in the DRO. As received the probe required 5vdc power for the electronics, mine is now a passive switch. Hope this helps. Apologies for all the words. I feel like you just asked me for the time and I tried to tell you how to build a watch.
Good video to get people talking. Any sort of collet which holds the edge finder has got some eccentricity. While your test showed repeatability of the electronic unit, is it repeatability of an incorrect reading? The test should have been with the collet rotated 90 degrees between readings. I have not got an electronic edge finder I use a Tschorn mechanical probe. It would be interesting to measure the eccentricity of the electronic probe in your setup. Cheers.
Just a bit of side info, there are some that believe with some justification that the mechanical should be used slightly differently to that described. Ignoring the oft quoted that the wobbling bit has to be off set to start with, you advance until to end kicks sideways AND then back off till it runs tfue again. The point being you can over reach going one way but use it as the rough start and backing off gives a truer result. Personally i used to use DTIs for better accuracy.
recently bought a electronic edge finder to, but it was more like a renishaw probe. not going back to those wobbly thing anymore because i had 2 of them fly apart after setting the spindle to 2000 rpm 😅
I use a cheap electronic one in my lathe. It works decently but I wish the ball bearing was hardened. Essentially I chuck it up in the lathe then it allows me to work out my tool offsets. I wonder if its worth me getting this cutwel one, it looks better quality.
Totally agree with you. The electric edge finders are fantastic. I've had my one for a year now, and it works perfectly. Very accurate and repeatable. Wish someone would make a shorter one, as I have a mini mill with not a lot of Z height. I only paid £12 for my one, but notice they are available from £10 now. I wouldn't be without one now. Cheers Nobby
With the mechanical edge-finder, surely it's found the edge once it stops wobbling. Once it kicks over you've obviously gone past the edge which is probably why it isn't as repeatable as the electronic one. This may also account for the 0.02 undersize shaft.... although that is pure speculation on my part. Saying that though, every machinist channel I watch seems to use the mechanical edge-finder the same way so maybe I'm wrong 😜
Hi Jonesey. I recently bought an electronic edge finder via EBay. It cost £9.98 Inc postage. My DRO shows it too is 100% repeatable. The only downside is the size of it. I wish it was not so big! 🥴
It seems there is a challenge here. Who can create the slimmest static edge finder? Does the electronics do anything other than generate the beep or flash the light?
Agreed about the size. I bought the electronic one last year and didn't realise until it arrived that you need a 20mm collet to hold it. Nothing else I have uses such a large collet, so it's rather inconvenient to use.
The spinning mechanical edge finger has greater accessibility than the electronic one as you're restricted with its ball diameter. Good mechanical ones are rated to 5 microns accuracy. The overshooting issue is a problem of manual machines only so if it's a big deal then you need an edge probe with built in either dial or digital gauge to catch the exact contact position.
I love my electronic edge finder, and I got it for like 20$ on amazon. My only complaints are that it uses lr44 batteries and has a 3/4 inch shank, , and I would prefer it used AA‘s and had a half inch shank. I would like to be able to hold it in my drill chuck, for quick checking as needed, which only goes up to a half inch. My drill chuck sticks out quite a ways from the spindle, and whatever the length of the drill it is,. And the furthest I can stick the finder out of an r8 collet is 3 inches. So it means a lot of cranking of the z axis hand wheel to switch between edge finding and drilling. Not the end of the world though!
It shouldn't be a major task to make a homemade electronic ball type edge finder with a much shorter/more compact mounting body....just don't integrate the battery inside the body and there is loads of scope for it to be much shorter. As for gaining concentricity that should not be too big a challenge if all the external turning and boring ops are done without removing the body from the lathe chuck then part it off to length afterwards.
My concern is if you spin the electronic one/rotate it 90 or 180 degrees, does your edge move? This would indicate that something is off with the setup or machine, however how do you know this? Would the electronic edge finder always be centred to the spindle axis?
I think the best option would be to take a reading, then rotate the electronic edge finder 180 degrees and take another reading. The midpoint would then be your edge. This should account for any concentricity issues.
A recommendation to add even more accuracy to your mill/dro. - forget about this type of edge finder (wont even work in plastic/pom qne such) but, get a 3D taster ect s Tschorn SAVEplus. 100% (almost😅) better repeatability and accuracy. Will work in every material and show actual movement and not rely on when you see/hear something and stop the movement. Best regards 🙂
These are way to long for my warco wmt 300/2 , have tried the cheap chinese edge finders as you show here but at slower speeds they done like kicking out. The best edge finder I have found and use are the Huffam edge finders they are a wiggler type but really kickout well at slower speeds and work from 400 up.
It would be interesting to see how turning the spindle manually would influence the returning to zero. Zero on your dro might not actually indicate the center line of the spindle because of runout. Taking the half of two measurements rotated 180 degrees apart would help IMHO
You're missing the point on this completely. I prefer the ball type wobbler. A cylindrical edge finder won't repeat as well as that. I think you're condeming a mechanical arrangement for the wrong reason. Electronic edge finder not turning is a disadvantage, because you're assuming that the tip is being held true to the axis of rotation of the spindle. If you put a dial clock on the ball and turn the spindle, you'll be surprised at how far out that will be, especially since it sticks out so far. Repeatability without it rotating is irrelevent if it's not on the centre line. Finally, you can't use calipers to give an accurate reading of the cylinder diameter, you have to use a micrometer.
I was taught you never use an edge finder or drill bits in endmill holders. You should use your edge finder and drills in collets to ensure keeping them on the centerline of the spindle. Solid endmill holders are off a very small amount.
***Long Comment Alert*** Lots of people don't know how to use edge finders. Even some people at the companies that make them don't know too! The following are some statements I believe. Quality mechanical edge finders have both; repeatability and a trueness of position (within a tolerance of course) regardless of machine condition! Electronic edge finders on the other hand, have better repeatability but an unknown trueness of position that is reliant on the spindle bearing condition, spindle bore condition, chuck arbor runout, chuck / collet runout and edge finder runout from manufacture. Bring your electronic edge finder to the work until it beeps and then rotate the spindle by hand. You may find that it stops beeping at some point. This becomes impossible to compensate for because the ball at the end is now in an orbit with no fixed points to measure from and every time you change your tooling, that runout changes too. If you see the clapped out machines I work on, you'd know the mechanical edge finder is the ONLY way to go because it self-centers to the arbitrary axis of all the worn out garbage hanging out of the spindle. If you made it this far, great video! I enjoyed it. For those that like info here's a bit of minutiae & tips: - Machines with worn ways or thick oil won't give good repeatability. The table may lift on a cushion of oil and then settle as you slow to get close to the edge, messing with the repeat. Tighten those gibs! Use proper oil! - Surface finish on the edge of the part is 10x more important than having worn ways. If the spring in the finder is too soft making the tip too loose, or the rotational speed is too high, the tip will pick up on the roughness and get dragged away, messing with the trueness of position. Remember that in general both edge finders reference the peaks of the roughness, not the average or valleys. 600 rpm is the max speed for mechanical edge finders in my opinion. I like 400 for best results. - Lastly, how you use your edge finder is 10x more important than the aforementioned. As said in the video, the proper way to take a reading with a mechanical edge finder is when the tip shears off to one side since it has overrun the edge. But that's just it. It doesn't tell you when it has found the edge, but rather when it has gone just slightly past the edge, again messing with the trueness of position. Approach the edge as slowly, smoothly and continuously (to avoid sticktion) watching the finder the whole time until it shears, and you can be very certain that you are either perfectly on the edge or (in most cases) just slightly more. Never less. And how much depends on your skill with the machine you're acquainted to. Remember, manual machining is an art that takes time to master. Don't let anyone tell you otherwise.
I use both types of edge finder but I favour the electronic one. When edge finding the inside of a hole there is a tendency for the mechanical types to not kick out on contact due to the curvature of the hole and the need for the contacting part of the finder to try and climb the surface. The smaller the hole the greater the problem. I find the electronic type to be more accurate nd more repeatable. Cheers SteveO
I bought a cheaper electronic one ($25 on eBay) and noticed the ball is not perfectly centered and it’s just under 10mm. So the cheaper ones are definitely not great quality. But for the kind of work I do, it’s been close enough.
The static edge finder model (electric contact) is hopelessly sensitive to spindle imperfection, not the dynamic model. The dynamic method gives us the edge with respect to the dynamic axis thereby avoided the accumulated error down stream of the spindle axis. The only set back to the dynamic method is - do we have patient to wait for the nose to indicate an edge? I have the ball model but I all my tool holder are imperfect on eccentricity. I tried the probe model ($99) with user recalibration screws on four sided. It enables me to calibrate out my tool holder eccentricity. That create a new problem. The last calibration is a paired calibration may be perfect but next time we insert it back to the same holder to run edge finding again the last (spin angle) registration has gone. The eccentric error adds up to doubled. Do we expect to run another calibration? NO. So I revert back to factory calibration means: a V block and calibrate it with a dial indicator. Then I store it into a box with a label on top that says “ box of shame”. The dynamic method will give us same edge-spindle offset time after time and holder after holder wrt the dynamic spindle axis so I can casually pick any imperfect holder, insert it at any rotation angle and to expect perfect and consistent offset value.
The electronic edge finder is designed to be spun. As you approached the workpiece you will see it blinking and hear it beeping intermittently. When the light/beep goes steady, you came too far. You should split the difference between “blinking started” and “light steady” and back off that distance (which is your TIR). If you do not rotate the edge finder, the TIR of the spindle+holder introduces the error. Give it a try :-)
Thanks, great advice, I will bear that in mind. I’ve had quite a few people suggest similar. Having said that the instructions for this edge finder state it’s not to be used under power. I guess if I manually rotate it 180 degrees in the chuck that should account for any run out.
@@joneseymakes But the circuit is based on the ball contact to the shaft? The ball diameter can be any size, with in reason. So the center is about the shaft, not the ball, if am correctly thinking this through?
because it does not rotate you can add any runout to the error( up to double the runout). All battery tools are dead when you REALLY need them. Neither the electronic nor the mechanical can match the accuracy of "picking up an edge" with an indicator, jig bore style.
Having read all the comments there are no positive advantages and lots of negatives too many to list here. It's important to remember that on manual mills the workpiece is sitting on 3 dovetails all with sliding clearance and geometric tolerances. So chasing tenths with an edge finder has its limits.
Now you know the downsides and errors raised in the comments below isn't this the cue to make a homemade electronic edge finder with a much shorter body and less stick out? Also to mention that an electronic edge finder rotated at slow rpm in the collet will give a more precise reading of where the true spindle centre axis is.
Bonjour, je viens personnellement d acheter un détecteur électronique sur aliexpress à moins de 10 euros, les piles n'étant pas fournies (je n'y avais pas prété attention) je les ai commandé sur Amazon pour 4 euros. Bref moins de15 euros l'ensemble qui est bien plus petit que celui que vous nous montez. Il se rapproche en taille des détecteur mécanique. Le seul bémol à son utilisation est qu'il faut absolument respecter la chaîne de continuité électrique... je m'explique: moi je travaille sur une CNC et je coupe majoritairement du MDF, l'appareillage électronique ne fonctionnera pas, pas plus que tenter de détecter le bord d'une planche sur votre fraiseuse... Bref, c'est un très bon produit dans l'idée mais perfectible suivant son utilisation (mon avis) Merci pour votre travail, votre chaîne est fort intéressante, j'adore !
Really? No one is going to mention working plastic parts? Also I've found "dead" spots in my mill that somehow don't make contact. I never could explain it but to scrapped the part. Cheap mechanical ones are not worth your time. Starrett is the way to go.
Starrett edge finders are spot on 0.200” +-0.0002” so your import ones are just poor quality. Sure would be nice to have an electronic one the same size.
I never use them, I just put the tool in I am going to use, then slide a piece of paper between the tool and the job, set zero on the DRO, move to the other side and do the same, then use the half function, if I am doing something from one edge, I just add on the radius of the tool Less tool changing I do have the none battery operated type
You left out the big DISadvantage of the electronic one; it does not rotate! So if your collet or spindle etc has 1 thou of runout then your electronic tool will have 0 to 1thou of error, randomly, because you dont know the rotational position. To compensate that you need to rotate it and test in multiple positions and find the "high spot". Or, use a tool that rotates... 😎
It seems to me that a fella who knows both machining and electronics, a clever fella, could make a better version of this (and have the fuel tanks of his v8 Interceptor booby-trapped).
5 microns is 2 10,000 of an inch, not 2 thou.
Oooops. I obviously got the decimal point in the wrong place when doing the conversion. I'm not as familiar with Imperial measurements as with metric. Apologies, and thanks for pointing this out. I'll pin this comment.
I came looking for this comment@@joneseymakes
I was about to make exactly the same point. 2 ten thousandths!
2/10000 of an inch accuracy of a mechanical edgefinder is good enough for a normal milling machine where machining tolerances are much larger than the accuracy of a mechanical edgefinder. With the limitation of using it only for conducting metals, I'd rather rely on the mechanical model.
@SubramaniamLakshminarayanan Yes I'd be more than happy with being able to work to 2:10,000." I was just making a comment that Jonsey had mixed up his units, that's all.
I've used both types of edge fighters for years they both have their advantages and their disadvantages. Electronic edge Finder must be precise in that the ball must rotate around the center rotation of the spindle yet there's no reason why that should be if the device is not very precisely made and carefully handled. The electronic edge Finder can be used in the vertical direction whereas the rotating one cannot. They both have their purpose and they're both handy for different things. The mechanical edge Finder can be put in a poorly centered Chuck because it's rotation characteristics it will still find the edge regardless of how not concentric it is to the spindle. Mechanical edge finders post is intentionally a little undersized so that out of necessity you have to over travel to get it to kick off and a smaller dimension there will help compensate for that over travel. Electronic edge Finder are of course completely non functional without conducting work pieces. Tr y spinning your electronic edge Finder to see how concentric it is with you're a spindle you'll probably find that it beeps intermittently as it gets close to your work piece indicating that it's not actually concentric.
All great points, thanks for the info.
I spent hours drafting my comment and you beat me to what I wanted to say 😭
That is exactly what happens with my electronic edge finder.
Same thing with mine
Now turn the electronic one through 180 degree and see the repeatability
I doubt it would be any more accurate than the mechanical one
As others point out mechanical edge finder compensates for spindle + collet / chuck TIR and the preferred approach is to use it in the collet or drill chuck which will be used in machining. You need a decent edge finder with hardened lapped surfaces that kicks out reliably, get a starrett or vertex.
This is a really important observation. The design of the "traditional" edge finder means that it always kicks off when the actual center of rotation moves past the edge of the part so you know that whatever the status of your spindle, you've found the actual center of rotation. The electronic one, I'd wager, might give you a different reading depending on how it's oriented in the spindle. Not a huge amount, and probably doesn't matter for a hobbyist machinist, but it is a consideration.
Good point, thanks.
I have been using edge finders for about 50 years now and about 10 years ago I purchased and have used extensively the electronic edge finder. The repeatability and accuracy of the electronic is unsurpassed. they do have their faults but I have purchased three different sizes of them and all work extremely well. Well worth the money. Cheers.
Good to know, thanks
I just bought one of the electronic ones from China, which was considerably cheaper, and still works just fine. Nice video btw.
Thanks! Good to hear the cheaper ones are good.
Nice video and presentation.
Test the led edge finder again only this time with spindle running and make a second video on that.
As for the mechanical edge finders being "undersized", that would be deliberate. In order for the edge finder to actually kick to the side, it has to have gone "too far". When it's just touching the surface, then it will be exactly in line with the rotating surface and not wobbling at all. Go a smidge further, then the friction of the rotating surface rubbing against the part will cause it to kick to the side.
Makes perfect sense. Now I know! Thanks.
Nice straightforward and useful thank you. I've just been given an electronic finder and I love it! Mechanical one out less often these days.
Glad to hear it! In like mine a lot
Hoping for reliable electrical contact at effectively zero force and no wiping action is a big ask. The tiniest bit of contamination and it simply won't work.
Edgefinders are not deliberately ground undersize, they are lapped to a very close tolerance. Use a micrometer to measure them, they can wear but only by a couple of tenths over years..
If you are concerned with the end marking the part, there are mechanical edgefinders with a ball end. Huffam have been around for ages and kick out much less than the wigglers.
One thing that can cause errors is the edgefinder, part and vise jaws need to be regularly demagnetizsd.
Could you set up a part using a lever indicator to accurately find the edge and then see how the others perform in comparison. Lock the knee, Y axis and keep the spindle locked in the same position.
Jones, fantastic video. Thank you!
Glad you enjoyed it!
I've used electronic edge finders, and have noticed that you should also spin up the digital edge finder at around 60rpm, (Not all are like this however a majority I have seen are) you shall notice when touching onto the part, that only one side will touch first, showing the light only on in certain places.
-Edit, (Will still be super accurate without spinning but this is just for the extra bit)
Thanks, I will try this
@@joneseymakes Let me know result! Would love to find out, I know ours is definitely more accurate while spinning
@@pillbag340 Will do!
Hey Nick! Great video as always - concise and to the point.
Here's my two pence worth on this - I bought a couple of these for the bridgeports at work, and they're really good. Got them from Chronos engineering, and if memory serves they were about £45 each. With that said, my experience with them is somewhat soured, as it seems they're not all made equal. My mill at home has an MT2 taper, so I naturally had to go for the smaller variant(which, to absolutely no one's surprise costs about the same, if not more. Go figure), however, I bought it from one of those chinese import websites, and quite frankly - it's crap. First of all, it doesn't have a buzzer, so you're relying on a very dim LED, but more annoyingly than that, it only works when it feels like it, so my advice for anyone with a small mill would be to either stick to a standard edge finder, or at the very least buy from a reputable source.
Edit: I just went on chronos website, and it seems like they now do an MT2 version of the same tool. Might have to give it a go, since the price is actually rather reasonable.
Interesting to hear, thanks.
The rotation of the edge finder also averages out any spindle runout where the digital does not
Yes, good point.
I've got one of the EBay cheap copy of the electronic edge finder and surprisingly it is very accurate on dimensions my one has a nominal ball diameter of 10 mm and it is spot on at 10.008 . Much more accurate than my milling I can tell you and its repeatability seems to be good. I say seems to be because my dro is all over the place and sometimes I have to rely on the good old dials especially on the cross slide. I know there is a linear compensation on the dro but my unit will not go into that function no matter how many time I try it. I probably need a new unit, the scales are glass and are clean so it's not them also the discrepancy occurs at different places on the scale and does not happen every time or in the same place twice. So it is what it is. The eBay edge finder was only £9.99 so I think for the amount of times I use the milling head ( I've a Warco WMT300 Lathe/Mill combo) which has quite serious limitations, but it's better than nothing especially as I'm working inside a shed only 7 feet by 5 feet lol so no room for anything else. My two bandsaws and grinding equipment are elsewhere.
I haven’t seen one led model with 10mm shank.
Regarding your comment about having to watch the mechanical edgefinder, over the years I find that I have learned to tell when it kicks off by ear much quicker and more precisely than by eye. It might not work so well on a loud mill, but on my belt driven brushless minimill, it is very apparent.
Interesting, I can't hear mine unfortunately
Remember, the entire setting accuracy will depend on machine alignments and head squareness as this will be tested with any variation on the X axis with height differences ?
A mechanical edge finder can be used in a drill chuck since it will per definition always rotate around the spindle axis, regardless of the offset of the chuck. Therefor it will be more accurate on a hobby machine. It's self correcting.
That also means that any stationary edge finder will inherit the error of the holder (the chuck, collet,...).
I think your accuracy test may be biased. In both cases you should NOT look at the DRO. If you looked at the DRO during the electric test, you will inevitably have introduced a bias.
The same goes for caliper and micrometer measurements - never look while measuring!
That said, I saw elsewhere that electric edge finders are indeed a bit more accurate.
Thanks Erik, that's a good point.
Well the offset of the chuck does have to be taken into account
If you had a chuck that ran out .03 for example if you edge find with a traditional edge finder and move over half the edge finder
You are going to be .015 off
The skill in using a wobbler is just the start of machining job, that is why with4/5 year apprenticeships you develop suck skill as taking the burs off a work piece before you start.
My Bridgeport never had dro only .200" lead screw
also we would set the dial minus a .100" so when you came around the dial was on ZERO to start your count of turns as I point out to a TH-camr who never though of that lol
Well said. If you haven't completed an apprenticeship you won't know what you don't know. So be careful what you see online.
Very nice video. I have one for a while now, but never used it yet. Glad I brought it now
Thanks!
I’ve got one somewhere, which says it all. Too many flickering contacts. Is it or isn’t it situation.
I've just bought the same edge finder. I haven't used it yet so thanks for the video
No problem 👍
The fact that an electronic edgefinder does not spin may reveal errors because of possible runout in the spindle/chuck/collet combination. Something that is automatically overcome with a turning edgefinder.
Very true, I didn't think of that originally.
If you turn the mill spindle on and rotate it at low rpm you will find that almost all electronic edge finders are not running with precise concentricity to the spindle centre axis.
Disatvatages of the electronic one:
Sometimes I mill non conductive materials, then it does not work.
The longer edge finder adds an error when the spindle is not exactly trammed.
The 0.01mm under size of the mechanical one is a good compensation for spindle run out. very few spindles and adapters will have less.
12V batteries are difficult to get and quite expensive.
Thanks, all good points.
Actually I've never used edge finders in mills. I've always started with an oversized piece of stock. Squared it up and then milled it down to size. Then again, I've never done really complicated shapes.
Nice review. FWIW shorter electronic edge finders are available.
Thanks, good to know!
You need to make a new video about runout and edge finders.
I’d be interested to hear more on that? I’m always keen to learn from those with more experience than I. Are you referring to the fact the electronic edge finder isn’t rotating?
@@joneseymakes Yes, that.
Good discussion. I bumped my electronic edge finder a little too hard (OK, WAY too hard) and wanted to get a more bullet proof replacement. I bought one of those small electronic probes that are probably more intended for CNC use and I fitted it to my DRO for about the cost of a good electronic edge finder (with some difficulty). In addition to edge finding now in three axes, the DRO has a number of other functions that use the probe for finding the center of a circle with three random points, distance between features inside and out, angles, etc. I think the jury is still out on accuracy and repeatability. It’s in the range of 0.03mm but seems good enough for what I do. I couldn’t honestly say that I was doing any better with the other units. A bonus is that the probe will withstand at least 4mm of deflection so I will have to work harder to destroy it.
Sounds interesting, was it hard to connect it up to your DRO?
@@joneseymakes My DRO (Electronica EL700) requires a normally closed contact probe. The units I found online are normally open. This type of probe is actually NC by design as a contact is broken when the probe touches a stop. They achieve NO operation via electronics in the probe. I removed the electronics and re-wired the probe connector directly to the contacts, then re-centered it. Contacts are gold so should be reliable. Pre-contact behavior seems more or less predictable and you can adjust it by setting the probe diameter in the DRO. As received the probe required 5vdc power for the electronics, mine is now a passive switch. Hope this helps. Apologies for all the words. I feel like you just asked me for the time and I tried to tell you how to build a watch.
@@Dogfather66227 Haha, no that's great info. Thanks for taking the time to respond.
I wonder how about the concentrity of the electronic one. Can you use it while spinning at very low rpms?
The manufacturer says it’s not to be used spinning, but I think low RPMs would be fine
Good video to get people talking. Any sort of collet which holds the edge finder has got some eccentricity. While your test showed repeatability of the electronic unit, is it repeatability of an incorrect reading? The test should have been with the collet rotated 90 degrees between readings. I have not got an electronic edge finder I use a Tschorn mechanical probe. It would be interesting to measure the eccentricity of the electronic probe in your setup. Cheers.
Thanks, yes agreed, I will do that.
Did I get right, it needs the work piece to close the circuit? If yes, it would not be usable on non conductive materials.
That was my exact thought. If it only works if a current can be run then non-conductive materials and holding solutions would not work.
This is true, only good with conductive materials.
Just a bit of side info, there are some that believe with some justification that the mechanical should be used slightly differently to that described. Ignoring the oft quoted that the wobbling bit has to be off set to start with, you advance until to end kicks sideways AND then back off till it runs tfue again. The point being you can over reach going one way but use it as the rough start and backing off gives a truer result. Personally i used to use DTIs for better accuracy.
I like that idea, I'll do some testing, thanks.
recently bought a electronic edge finder to, but it was more like a renishaw probe. not going back to those wobbly thing anymore because i had 2 of them fly apart after setting the spindle to 2000 rpm 😅
Ha, yeah, I broke mine running it too fast too. I think they are designed for about 600 rpm.
@@joneseymakes Yeah 600 seems to be the sweetspot
I use a cheap electronic one in my lathe. It works decently but I wish the ball bearing was hardened.
Essentially I chuck it up in the lathe then it allows me to work out my tool offsets.
I wonder if its worth me getting this cutwel one, it looks better quality.
I’m pleased with the quality of the Cutwell one myself
I have a smaller one with a 6mm shank
It's meant for cnc, but if you just feed it 5 volts, you get a green led that turns red when contact is made
Ahh, sounds good, thanks.
Totally agree with you. The electric edge finders are fantastic. I've had my one for a year now, and it works perfectly. Very accurate and repeatable. Wish someone would make a shorter one, as I have a mini mill with not a lot of Z height. I only paid £12 for my one, but notice they are available from £10 now. I wouldn't be without one now. Cheers Nobby
Cheers Nobby!
With the mechanical edge-finder, surely it's found the edge once it stops wobbling. Once it kicks over you've obviously gone past the edge which is probably why it isn't as repeatable as the electronic one.
This may also account for the 0.02 undersize shaft.... although that is pure speculation on my part.
Saying that though, every machinist channel I watch seems to use the mechanical edge-finder the same way so maybe I'm wrong 😜
Hi Jonesey. I recently bought an electronic edge finder via EBay. It cost £9.98 Inc postage. My DRO shows it too is 100% repeatable. The only downside is the size of it. I wish it was not so big! 🥴
Ahh good to know, thanks!
It seems there is a challenge here. Who can create the slimmest static edge finder? Does the electronics do anything other than generate the beep or flash the light?
@@johnsherborne3245 I can’t see the electronics doing anymore than you say. The makers of these use rather large batteries! 🥴
Agreed about the size. I bought the electronic one last year and didn't realise until it arrived that you need a 20mm collet to hold it. Nothing else I have uses such a large collet, so it's rather inconvenient to use.
Have you measured the runout of the ball?
Just one comment. A mechanical edge finder can get closer vertically to the vice jaws (if needs be), or a feature on the part.
Very true.
The spinning mechanical edge finger has greater accessibility than the electronic one as you're restricted with its ball diameter. Good mechanical ones are rated to 5 microns accuracy. The overshooting issue is a problem of manual machines only so if it's a big deal then you need an edge probe with built in either dial or digital gauge to catch the exact contact position.
Thanks, great advice
I love my electronic edge finder, and I got it for like 20$ on amazon. My only complaints are that it uses lr44 batteries and has a 3/4 inch shank, , and I would prefer it used AA‘s and had a half inch shank. I would like to be able to hold it in my drill chuck, for quick checking as needed, which only goes up to a half inch. My drill chuck sticks out quite a ways from the spindle, and whatever the length of the drill it is,. And the furthest I can stick the finder out of an r8 collet is 3 inches. So it means a lot of cranking of the z axis hand wheel to switch between edge finding and drilling. Not the end of the world though!
The stick out is the main thing I don’t like about mine, lots of cranking the head up and down!
It shouldn't be a major task to make a homemade electronic ball type edge finder with a much shorter/more compact mounting body....just don't integrate the battery inside the body and there is loads of scope for it to be much shorter. As for gaining concentricity that should not be too big a challenge if all the external turning and boring ops are done without removing the body from the lathe chuck then part it off to length afterwards.
@@joneseymakes The greater the 'stick out' length the more any eccentricity of the collet will be magnified with a long bodied electronic edge finder
I use the Inatool flex edge finder. Works great has many advantages. My other edge finders just collet dust.
I've never heard of those, how do they work?
@@joneseymakes look it up on Google see if it pops up. There are videos on the website
Do you think the mechanical ones are deliberately made undersize to compensate for the inevitable overshoot in use ?
Apparently that is the case yes.
He didn't measure it accurately with a micrometer, so who knows. I doubt it.
My concern is if you spin the electronic one/rotate it 90 or 180 degrees, does your edge move? This would indicate that something is off with the setup or machine, however how do you know this? Would the electronic edge finder always be centred to the spindle axis?
I think the best option would be to take a reading, then rotate the electronic edge finder 180 degrees and take another reading. The midpoint would then be your edge. This should account for any concentricity issues.
The answer is yes. It's not a good way to find the edge really accurately.
A recommendation to add even more accuracy to your mill/dro. - forget about this type of edge finder (wont even work in plastic/pom qne such) but, get a 3D taster ect s Tschorn SAVEplus. 100% (almost😅) better repeatability and accuracy. Will work in every material and show actual movement and not rely on when you see/hear something and stop the movement.
Best regards 🙂
Thanks, I'll check that out!
These are way to long for my warco wmt 300/2 , have tried the cheap chinese edge finders as you show here but at slower speeds they done like kicking out. The best edge finder I have found and use are the Huffam edge finders they are a wiggler type but really kickout well at slower speeds and work from 400 up.
Sounds interesting, I'll check them out, thanks.
It would be interesting to see how turning the spindle manually would influence the returning to zero. Zero on your dro might not actually indicate the center line of the spindle because of runout. Taking the half of two measurements rotated 180 degrees apart would help IMHO
Yes, this is something I am going to try, thanks.
You're missing the point on this completely. I prefer the ball type wobbler. A cylindrical edge finder won't repeat as well as that. I think you're condeming a mechanical arrangement for the wrong reason.
Electronic edge finder not turning is a disadvantage, because you're assuming that the tip is being held true to the axis of rotation of the spindle. If you put a dial clock on the ball and turn the spindle, you'll be surprised at how far out that will be, especially since it sticks out so far. Repeatability without it rotating is irrelevent if it's not on the centre line.
Finally, you can't use calipers to give an accurate reading of the cylinder diameter, you have to use a micrometer.
I was taught you never use an edge finder or drill bits in endmill holders. You should use your edge finder and drills in collets to ensure keeping them on the centerline of the spindle. Solid endmill holders are off a very small amount.
OK that’s interesting, thanks for the tip
Edgefinders are designed to eliminate any concentricity issues, this allows them to be used in eccentric tooling.
***Long Comment Alert***
Lots of people don't know how to use edge finders. Even some people at the companies that make them don't know too! The following are some statements I believe. Quality mechanical edge finders have both; repeatability and a trueness of position (within a tolerance of course) regardless of machine condition! Electronic edge finders on the other hand, have better repeatability but an unknown trueness of position that is reliant on the spindle bearing condition, spindle bore condition, chuck arbor runout, chuck / collet runout and edge finder runout from manufacture. Bring your electronic edge finder to the work until it beeps and then rotate the spindle by hand. You may find that it stops beeping at some point. This becomes impossible to compensate for because the ball at the end is now in an orbit with no fixed points to measure from and every time you change your tooling, that runout changes too. If you see the clapped out machines I work on, you'd know the mechanical edge finder is the ONLY way to go because it self-centers to the arbitrary axis of all the worn out garbage hanging out of the spindle. If you made it this far, great video! I enjoyed it. For those that like info here's a bit of minutiae & tips:
- Machines with worn ways or thick oil won't give good repeatability. The table may lift on a cushion of oil and then settle as you slow to get close to the edge, messing with the repeat. Tighten those gibs! Use proper oil!
- Surface finish on the edge of the part is 10x more important than having worn ways. If the spring in the finder is too soft making the tip too loose, or the rotational speed is too high, the tip will pick up on the roughness and get dragged away, messing with the trueness of position. Remember that in general both edge finders reference the peaks of the roughness, not the average or valleys. 600 rpm is the max speed for mechanical edge finders in my opinion. I like 400 for best results.
- Lastly, how you use your edge finder is 10x more important than the aforementioned. As said in the video, the proper way to take a reading with a mechanical edge finder is when the tip shears off to one side since it has overrun the edge. But that's just it. It doesn't tell you when it has found the edge, but rather when it has gone just slightly past the edge, again messing with the trueness of position. Approach the edge as slowly, smoothly and continuously (to avoid sticktion) watching the finder the whole time until it shears, and you can be very certain that you are either perfectly on the edge or (in most cases) just slightly more. Never less. And how much depends on your skill with the machine you're acquainted to.
Remember, manual machining is an art that takes time to master. Don't let anyone tell you otherwise.
Some great info in there, thanks for commenting!
So the digital edge finder does not "beep" if I'machining plastic material?
Correct, it needs to be a metal work piece in order to complete the circuit.
I use both types of edge finder but I favour the electronic one. When edge finding the inside of a hole there is a tendency for the mechanical types to not kick out on contact due to the curvature of the hole and the need for the contacting part of the finder to try and climb the surface. The smaller the hole the greater the problem.
I find the electronic type to be more accurate nd more repeatable. Cheers SteveO
Cheers Steveo, that sounds like a good use case for the electronic type.
I bought a cheaper electronic one ($25 on eBay) and noticed the ball is not perfectly centered and it’s just under 10mm. So the cheaper ones are definitely not great quality. But for the kind of work I do, it’s been close enough.
Good to know, thanks.
The static edge finder model (electric contact) is hopelessly sensitive to spindle imperfection, not the dynamic model.
The dynamic method gives us the edge with respect to the dynamic axis thereby avoided the accumulated error down stream of the spindle axis. The only set back to the dynamic method is - do we have patient to wait for the nose to indicate an edge?
I have the ball model but I all my tool holder are imperfect on eccentricity.
I tried the probe model ($99) with user recalibration screws on four sided. It enables me to calibrate out my tool holder eccentricity. That create a new problem. The last calibration is a paired calibration may be perfect but next time we insert it back to the same holder to run edge finding again the last (spin angle) registration has gone. The eccentric error adds up to doubled. Do we expect to run another calibration? NO. So I revert back to factory calibration means: a V block and calibrate it with a dial indicator. Then I store it into a box with a label on top that says “ box of shame”.
The dynamic method will give us same edge-spindle offset time after time and holder after holder wrt the dynamic spindle axis so I can casually pick any imperfect holder, insert it at any rotation angle and to expect perfect and consistent offset value.
Very interesting, thanks!
The price seems to be all over the place for these. I have seen them as low as 30$… from the jungle site!
Ok, thanks, good to know!
The digital calipers are all +/- .001 thou accuracy, this may we'll account for your undersized measurement.
The electronic edge finder is designed to be spun.
As you approached the workpiece you will see it blinking and hear it beeping intermittently. When the light/beep goes steady, you came too far. You should split the difference between “blinking started” and “light steady” and back off that distance (which is your TIR).
If you do not rotate the edge finder, the TIR of the spindle+holder introduces the error.
Give it a try :-)
Thanks, great advice, I will bear that in mind. I’ve had quite a few people suggest similar. Having said that the instructions for this edge finder state it’s not to be used under power. I guess if I manually rotate it 180 degrees in the chuck that should account for any run out.
@@joneseymakesyou can safely spin it at a slow speed.
Why did you measure the Ball and not the shaft?
Because it’s wider than the shaft and’s that’s what you use to contact the part
@@joneseymakes But the circuit is based on the ball contact to the shaft? The ball diameter can be any size, with in reason.
So the center is about the shaft, not the ball, if am correctly thinking this through?
Edge brrr will throw off even an electronic edge finder
because it does not rotate you can add any runout to the error( up to double the runout). All battery tools are dead when you REALLY need them. Neither the electronic nor the mechanical can match the accuracy of "picking up an edge" with an indicator, jig bore style.
Good point, thanks.
Having read all the comments there are no positive advantages and lots of negatives too many to list here. It's important to remember that on manual mills the workpiece is sitting on 3 dovetails all with sliding clearance and geometric tolerances. So chasing tenths with an edge finder has its limits.
Good point. Thanks.
I use both types constantly, however I do rotate the electronic also, seems as accurate as the mechanical ones.
Good to know, thanks.
Man @ 0:40 you're clipping the mic HARD.
Yes, I’ve always struggled with audio. Need to upskill.
try it on non conductive material
It only works with metals
Now you know the downsides and errors raised in the comments below isn't this the cue to make a homemade electronic edge finder with a much shorter body and less stick out? Also to mention that an electronic edge finder rotated at slow rpm in the collet will give a more precise reading of where the true spindle centre axis is.
That’s a great idea, perhaps I should try making one.
Bonjour, je viens personnellement d acheter un détecteur électronique sur aliexpress à moins de 10 euros, les piles n'étant pas fournies (je n'y avais pas prété attention) je les ai commandé sur Amazon pour 4 euros. Bref moins de15 euros l'ensemble qui est bien plus petit que celui que vous nous montez. Il se rapproche en taille des détecteur mécanique.
Le seul bémol à son utilisation est qu'il faut absolument respecter la chaîne de continuité électrique... je m'explique: moi je travaille sur une CNC et je coupe majoritairement du MDF, l'appareillage électronique ne fonctionnera pas, pas plus que tenter de détecter le bord d'une planche sur votre fraiseuse...
Bref, c'est un très bon produit dans l'idée mais perfectible suivant son utilisation (mon avis)
Merci pour votre travail, votre chaîne est fort intéressante, j'adore !
Merci pour le commentaire et merci d'avoir regardé ! Trouvez-vous que les détecteurs de bords électroniques bon marché fonctionnent bien ?
I see you bought the John Holmes model....
😂
Really? No one is going to mention working plastic parts? Also I've found "dead" spots in my mill that somehow don't make contact. I never could explain it but to scrapped the part. Cheap mechanical ones are not worth your time. Starrett is the way to go.
mechanical edge finder is more than good enough for most jobs.
Especially the wobbler type with a ball.
Starrett edge finders are spot on 0.200” +-0.0002” so your import ones are just poor quality.
Sure would be nice to have an electronic one the same size.
Agreed. Always better to buy quality tools rather than imports in my opinion!
I never use them, I just put the tool in I am going to use, then slide a piece of paper between the tool and the job, set zero on the DRO, move to the other side and do the same, then use the half function, if I am doing something from one edge, I just add on the radius of the tool
Less tool changing
I do have the none battery operated type
Whatever gets the job done! I think the paper trick is a good one.
Bro, your not getting the recognition you deserve.
Thanks man!
It's true, but time will tell, the best is yet to come for Jonesy Makes
If that is a 23A battery, they suck, expensive as hell and poor capacity. Cheap ones leak almost always.
I do like the concept though.
Good to know! Thanks
Now rotate the electric probe 180 deg and see the error .
I'll try that, thanks.
Just to point out the obvious, the electronic one is no use on plastic.
Yep, good point, thanks.
You left out the big DISadvantage of the electronic one; it does not rotate!
So if your collet or spindle etc has 1 thou of runout then your electronic tool will have 0 to 1thou of error, randomly, because you dont know the rotational position. To compensate that you need to rotate it and test in multiple positions and find the "high spot".
Or, use a tool that rotates... 😎
Thanks, I realised this after shooting the video!
Rotate the electronic one 180 degrees and see what your previous zero compares.
That would have been the real test.
I'll try it, thanks.
It seems to me that a fella who knows both machining and electronics, a clever fella, could make a better version of this (and have the fuel tanks of his v8 Interceptor booby-trapped).
😂
I do alot of work with plastic and can't use elec. edge finder have had some luck with laser edge finder,
How do you like the laser edge finder?
Rotate the collet 180 degrees and repeat the measurement
You will see your run out ....
I'll try it, thanks.
If you're measuring your results with a mitutoya then you probably need, and can justify the electronic edge finder 😂
😂
Electric =! Plastic
There is resistance :D
😂
just too bulky
Zed not zee - you're not a yank
Haha fair point!