Thank you for another excellent video! As with others you've published, this one led me to think of a topic in a different way than what I had assumed (and often have been taught) was the "right" way to look at the subject. You have remarkable insight, and seem able to 'think outside the box' more than most people, and in directions that inspire me to do the same. I've heard you mention Robin Renzetti several times, in a way that recognizes and respects his standard of excellence, and you seem to look at him as a role model. I certainly agree with your perspective about Robin but, in my humble opinion, your own skills and standard of excellence puts you in the same league as Robin - and that is high praise indeed! Regards, Doug PS: On behalf of American novices like myself (who mostly grew up learning only one language) thank you for choosing to humble yourself by presenting your videos in something other than your native German. You give English-only speakers like myself access to some of the best instructional and most thought-provoking material on the web. You're a true credit to machinists toolmakers and, above all, TEACHERS. Thank you.
Stefan, as always you did a nice job presenting your video. I like the fact that you not only show the machining process, but you follow up and show how the part is used and performs. as is this particular video the resharpening of the inserts and then demonstrate how well they perform on various materials. "Walk the Talk", as Keith Fenner likes to say. I was really impressed with the finish on the drill rod when taking such a light cut!
Stefan, I enjoy many of your videos not only for the great content but also the patient and well described process you use. I am also afflicted with the details matter mindset which drives me crazy, lol... Precision does not happen by itself. I am am old dog who continues to learn a thing or two. Thanks for taking the time and effort to share with us.
Thank you Stefan, you answered a lot of my questions in one video. I've been machining a fairly big odd shaped chunk of EN8 which I could not run fast on my 280mm lathe and just could not get a good finish from the carbide insert boring bar. Now I know why, more importantly I now have a good steer on how to fix it.
Good video. I began doing this years ago when I found out a metal recycler had hundreds of carbide inserts for sale by the pound. I use a diamond wheel designed for lapidary work and just touch up as needed. Mostly TPGN and TPUN inserts.
Fantastic video! I learned a lot from this. I'm definitely going to try this technique, as I've been really frustrated by the high cutting pressure and poor finish with regular inserts.
I only use carbide for special things.I still use the old lantern style cutters in my old equipment as I have so many cutters,but it gets the job done for my purposes and tolerances.Even so,I enjoyed this tutorial and did learn from it.I use my dremel to "Kentukey windage a chip breaker on the tool".Thank's again for the clear and concise explanation
Those inserts could also be Korloy inserts with a KM chip-breaker. A very good alternative if you want to buy (not to regrind) inserts in Germany (if you have a company) are ATORN 6310 inserts. These inserts are super sharp (like inserts for aluminium) but with a coating. Tool life of those inserts is decent, even in steel.
I use Tungaloy DCGT070201FL-J10 (label on the box in front of me) for very detailed work. They are available both right and left hand with very small tip radius. Looks much like a smaller version of Your regrinds. Never considered the advantages of regrinding inserts, of course it saves a lot of work compared to grinding complete tools like I often do. I use CCMT in the same size as You, will try it. The grade of the insert is probably important for maintaining a sharp edge. Also found that small DCGT Al inserts with a sharp edge works for fine finish cuts in some steels.
The sharpening you did is the versatile geometry. You can't go wrong. Love watching good skilled guys . I also learn different ways of doing things. Great video thx .
Toolmaker! A wealth of knowledge as usual... love the style and as soon as I find something grinding precise enough I will give it a go. ;) Especially because I found the Chinese started selling dcmt inserts for my micro lathe around 8 bucks a pop (box). So at least I don't have to kill myself if I mess one up. ;)
Since you aren't taking large depths of cut and using that long sharp side why not run across the nose at an angle so as to force the chips to curl back tighter and break shorter. Right now you are at 90deg to work I would like to see you try a 45deg to work to see how it performs.
Good for you. A master machinist. On a shop site, I talk about grinding inserts. They thought I was the anti Christ. So many today dont have the skills to make tools or grind them.
As you are saying, many modern machinists dont have the skills to make tools, grind ect.. Thanks to cnc,...cnc is good in many ways, absolutely, but many skills are lost thanks to cnc....really a shame.
Thanks Stefan for the explanation and for showing your approach. Very good to see your creative, sometimes not so "common" methods. Often, we have misconceptions about the way things need to be (done). For example, at school you might have learned that short circuits need to be avoided only to find out later that some machines use this principle :)
Kennametal doesn't show a current matching geometry for those inserts, but the HP chipbreaker looks very close, it's a ground 15 degree finishing chipbreaker. The insert would then be a CCGT-21.51HP KT325. They don't have one like that, but they have the CCGT-21.51 11 KT325, which is a 7 degree finishing chipbreaker. They have the HP chipbreaker in other grades, just not KT325. That's probably why someone had them custom ground!
Good inspiration... I'm presently working on wood turning tools, where a very sharp edge is required for better performance, the surface grinder is also in my opinion the best tool to use. The plan is to use cheap chinese metal working inserts and redo the top and edges, that's a project that I'm workin on with a TH-cam producer that has a channel on wood working. Naturally minimum modification on the original inserts is one important goal...
Hi Pierre, wood turning tools really need to be SHARP, if you want to do the job properly and slice the wood fibres. Carbide will only really work as a scraper and this is not the ideal way as you invariably get sub surface damage which tales forever to sand out. A sharp tool, with the bevel rubbing the wood, will leave a finish ready for polish. As the great woodtrurner Frank Pain once said, "cut wood the way she wants to be cut."
Going to back up Chris here. Carbide is probably just not the right material here. You need to use really high grade carbide to get a cutting edge sharp enough for wood, and the edge breaks down extremely fast on some woods. Sand and dirt are common inclusions, and some common woods like oak have salt inclusions. Scrapers should be ground on a fine wheel so that a very fine burr is on the top of the tool, the burr is what does the cutting. If you cant raise a proper burr on the grinder (lots of practice) then the burr can be honed off and turned back up using a burnishing tool. Removing the burr and honing the scraper produces a tool more akin to a square end chisel - a useful tool for roughing, but will not produce the quality finish that a proper chisel or scraper will produce. Gouges are usually best ground with variation on the cutting angle as it sweeps to the edge of the tool. Not something you can do on a surface grinder. I personally prefer a convex grind on chisels (similar to an axe grind). I use both chisels ground so the edge is straight or convex. A convex grind allows you to use the chisel free hand since you can rest the tool on the work and roll the edge into the cut. This is extremely useful to fairing around curves and coves where the tool rest will interfere with tool movement. I grind mine on a bench grinder, but some folks use a belt sander with the belt loose.
Good point you're taking in here, I agree with you that a good HSS or good quality steel blade type tool with a very sharp edge is best to really cut wood fibers, this is an experiment and it's possible that it will produce some good roughing toll and there is still gonna be a need to finish the conventional way with steel...
Stefan, interesting video. I have re-sharpend some inserts, using a silicon carbide wheel, but very slow. I will look at getting a diamond wheel and make up some kind of jig to hold them. nice to hear someone who knows all of the terms involved. Thanks for the info
I can now forsee the sale of small surface grinders going through the roof price wise. thanks for the info and demo Stefan.I have boxes of used carbide inserts ,good job I save things for re use. Now all I need to do is to dig through 40+ years accumulation of clutter and junk to find them Yes I know . junk is junk but only until you have a use for it.
Interesting video, thanks Stefan. Finally, somebody who understands what sets the minimum DOC. What was wrong with the inserts before grinding? I often find mine won't "wear" per se, but some will have some sort of catastrophic failure that results in a chip. I presume yours were either new or merely worn before re-grinding?
Good video 👍🏼 Enjoyed it. What brand of surface ginder is that Stefan? Recently had a job turning a tiny shoulder on 3/16" W1 tool steel....horrendous burr....any suggestions on a type of tooling to eliminate burrs on small diameter turning with tool steel?
Brazed carbide may perform just as well as a reground insert, but I do think that a lot of people would get a lot of value from being able to squeeze as much life out of every little piece of tooling they can
I do a fair bit of brazed carbide, but it is so much grinding ;) On an insert, all the hard work is already done by the manufacturer - For example a nice, well defined nose-radius is already built into the insert.
I tried this and realised you need a few things to get this spot on: 1. really rigid setup like Stefan's got there, no free-handing. 2. well balanced, dressed diamond wheel with negligible run-out and fine enough grit (>= 1000 ?) to give it a mirror finish 3. stick out your tongue at the right angle and pray the edges don't chip - which has been my problem so far
Stefan can I ask you about the diamond wheel on your grinder? What type is it and do you dress it yourself? How and what do you use to dress it if you do? I do quite a bit of tool grinding and am always looking for information on how people do things. Thanks I watch all your videos you have very useful content.
Its a normal resin bound diamond wheel, D128. A little bit coarse for real superfine finish, but a good allpurpose grit. I dress them by cylindrical grinding with a silicon carbide wheel - Basicaly I put my die grinder with a SiC wheel on the table of the grinder, let it spin and then plunge down onto the SiC wheel with the spinning diamond wheel. The SiC wheel will wear crazy fast and needs to be redressed with a diamond frequently, but it works. After the diamond wheel has dressed, the resin binding has to be backed of so the wheel cuts free again, there are special handheld stones for that, for example from Tyrolit: www.yumpu.com/en/embed/view/aFfTz8iLj0kt1YJ7/313 (Right lower corner, "Sharpening stick")
Considering that you can make a tool holder, you can fix this kind of insert vertically. Look at Mrpete222 video made about a "shaving" cutter. Thanks for showing your style
I have also been grinding and touching up my inserts for years,never been a problem, the solid carbide all the way through. The only inserts that can't be done are the cubic boron nitride CBN ones, not got a grinding wheel hard enough! There are not many materials the CBN can't deal with? Even hardened bearing shafts and hardened high speed steel bend to its will!
ever considered trying out the ingersoll TT9020 grade with SA chipbreaker? they come as finishing inserts in C, D and V-shape and radius range from 0.4 down to 0.1, precision is top notch as they're -CGT class with grind finish on the release angle and they cut like hell. great multi-purpose insert in my book as we use them a lot in our workshop, only downside is the wear is quite heavy when finishing at high speed as they won't last long, but you could even use them in aluminium. www.imc-companies.com/IngersollCatalog/CatalogFiles/datafile/PICTURE/WD1050_1.jpg
What a good idea! I know some will have a problem with your going off the Reservation and doing your own thing...... like you know better than professional insert makers, right? Hogwash! Those inserts are for your convenience, alone! You don't exist for the pleasure of the insert makers. They exist to serve your needs, not the other way around. Of course it's a great idea to modify inserts to serve your needs......duh. Thanks for sharing how you make inserts meet your needs! :)
Titanium machines absolutely unspectacular, just like "normal" 316 / V4A / 1.4401 stainless steel. Drilling and threading smaller than M3 can be a bit nervewrecking ;)
Excellent video! I've a question about the use of CCMT inserts - I hadn't fully appreciated that they work by creating sufficient cutting pressure, and hence require a suitable depth of cut. That being the case, how is it possible to use them for very shallow finishing passes? Surely they wouldn't work at all? I was a bit confused when you described that Kyocera one as also a finishing insert. I've never had much success with them anyway, because my lathe isn't rigid enough, so I always use the ground CCGT version, even for steel (they sometimes don't last long, but I'm using Chinese-made inserts which are only about $1 each)
It would benefit you to study the various chip breaker info in the insert manufacturers catalogue, one insert can have half a dozen different ones all with different purposes. Some chip breakers have a minimum cut of 2 or 3 mm, while others can go down to a few hundredths of a mm. It is a mistake to think that you want, say, CCMT and think they are all he same, they most definitely are not.
With a normal insert you simply dont do a shallow finishing pass ;) Finishing takes place with a reasonable deep cut - With a stout machine you will have no problem hitting close tolerance/good finish, when taking a 0.5 or 1mm finishing pass. But my toy machine is another game.. ;)
I've just commented on another vid asking the same question. On a mini mill, is there any extra precautions one should take when attempting this with a diamond wheel? How deep and wide did you grind the 5° chip breaker? Just till the rounded cutting edge is gone? Other than the things that have been shown and mentioned in these vids, is there something mill specific to avoid. The vice will be on it side on the mag chuck with the little vice holding the tool shank inline with the X axis, and use the side of the wheel. It's a 5um dro all 3 axis on BF16v mill. You've mentioned carbide and diamond dust is death to man and machine, appropriate precautions will be taken.I noticed you were climb grinding, I was going to conventional grind. Is there a big difference between the two, like when manual milling?Thank you for the advice👍👌🇦🇺
Good to see that pretty face again! I was just thinking of this yesterday as I swapped my CCMT insert, and placed the worn out insert back in the box! I thought of you, and wondered if you possibly even sharpened the cutting edge on new inserts, to make them more free cutting ....appears I need to expedite getting my KO Lee 6062 in and running.
I would like to try your method with my inserts and surface grinder. Looks like a resin bonded diamond wheel. I have never used one of these. Can you tell me how you dress the wheel when new to make it true? I have one on order from China.
Geht jetzt total am Thema vom Video vorbei, aber ich wollte einfach mal danke fuer die tollen Videos sagen. Schaue seit Wochen nach und nach jedes deiner Videos und bin einfach fasziniert von deiner Arbeit und der Praezision mit der du an deine Projekte rangehst. Hoffentlich hab ich selbst irgendwann mal sone tolle "Man Cave" wie du :D! Das erste mal drehen auf unserer kleinen, alten (und ehrlich gesagt zieeemlich schlechten) Drehbank hat heute riesig Spass gemacht. Muss mir unbedingt mal Fraeser fuer die Arboga U2508 die ich vor Monaten gekauft (naja, fast schon gestohlen) hab kaufen damit ich mal mehr "rumspielen" kann.
Dankeschön! Ich höre/lese immer sehr gerne wenn ich Leute inspirieren/motivieren und ihnen vieleicht etwas nützliches Zeigen kann. Glückwunsch zur Arboga, das ist eine schöne solide Maschine :)
They have stout machines - And the inserts have many more cutting edges than positive inserts. (Btw: Negative inserts do not automaticaly have negative rake)
I'm seriously thinking on breaking the bank for some Mitsubishi CCET and CCGT inserts with the SR and SN lead chipbreakers like the ones you ground and they are advertised as a precision finishing-light cutting insert but they cost 2-5 times as the inserts I'm used to buying. If I only had a surface grinder...
The KT325 carbide insert is something that I also got a lot off eBay. I know that I have them. Need to find them and what would you be willing to pay for them Sir ?? Please let me know Stefan and have a Happy New Year too.
very informative stefan, i think i'm going to have to try it. i have a surface grinder but i wonder if you have tried to freehand the grind? have you tried a green wheel and then touch up with a diamond file? could one use a commercial insert holder on the surface grinder ?
Hmm, the chip breaker seems to do nothing. Wouldn't it be better to make it diagonally just behind the cutting point instead of all along the side? Are you even using the more blunt points of these inserts?
Yeah, chipbreaker, chipformer. It is not agressive enough to realy break the chip, but it curls it up and brings it out of the way, so I dont end up with a spinning ratsnest of wire-like chips ;) I didnt want to do a more diagonal one, as I use the long edge of the insert in my chamfer tool. Speaking of the chamfer tool, thats where I use the 100° corner of the insert. (As seen here: th-cam.com/video/ZsPHB1gPink/w-d-xo.html )
It is obvious that your "chipbreaker" is not really effective with the light to very light cuts for which you use this geometry. That is to be expected. How about making that chipbreaker channel more narrow and with a sharper corner at its back. So to speak make the channel smaller and more in proportion to the chip size and more aggressive using a sharper edge radius on your diamond wheel. That way you perhaps get real chipbreaking action for the medium and possibly even light cuts. Of course not for very light cuts. Your close up videos showing the chip flow of the different cuts are very telling and a great help to study the effectiveness of the chipbreaker. For those who dont have an abundant source of chipped index plates you could also buy the simple, plain index plates without any features on it as blank material for customized grinds. They are not that expensive.
I partially agree with chris0tube. Indexable carbide inserts were invented for series production where heavy, sustainable cuts increase productivity. And nowadays series production is largely automated. So the inserts now also need to manage the chips because nobody is standing by to do that. Carbide inserts are around now for how long? 50+ years? And most innovations were protected as intellectual property. So the numerous competition had to find an almost as effective shape without infringing on other's IP rights. That lead to a jungle of different insert geometries. How can innovation still take place ready for the next trade fair after all this time? It is only by more and more narrow niche optimization. Already when only the depth of cut changes a little your insert is not optimum any more and you better use a different one. Here is where the experience of the production pro comes in to know which insert and cutting parameters are best for which application. However, in times of preferred supplier strategies in procurement a production pro may only gather experience with the insert lines of one or two suppliers. When he changes company which uses different insert suppliers his experience is only partially applicable. This all may work in large series production. But smaller shops need more all purpose inserts that may be less optimized for each application. For the home shop productivity is less important. Much more lighter cuts are done and chip control serves more safety, and surface finish. Here the experience of the production pro is only of limited help. So Stefan tries to translate the industrial chip control to the home shop environment with its lighter cuts. For all of the above reasons the indexable insert is much less suited for home shop work. Reground indexable inserts or brazed inserts with sharp edges fit better and the good old HSS cutter fits the needs of many home shop jobs still fine. Many home shop metalworkers use indexable inserts only because they don't know how and/or are not equipped to grind their own tools. If you belong in this group don't worry. Watch some of the many tool grinding videos, pick the method you like and get the necessary equipment which can but does not have to be expensive. And stay away from those plastic, one size fits all sharpening gadgets on the market. If you choose what the old-timers used you will get good results for little money. Start with your lathe cutters, then drill bits, then milling cutters. Get one or two diamond wheels (they are not that expensive) so you can regrind carbide to customize it for home shop duty. Use a fan and/or a dust mask to keep the carbide dust out of your lungs.
On the materials shown, at the diameters he is turning and the limitations of his equipment, he isn't going to see ideal chipping. What he is getting is more than adequate and the chip breaker does its job of pushing the chip out and into the chip pan.
Does the dead sharp cutting edge result in more chipping? I can imagine that the brittle, thin edge is more vulnerable than a factory radius (not nose radius, edge radius).
The English "vise" (and also "vice"!) is pronounced rather like the German Weiß. (Actually the letter "v" in English is always the hard 'Vee' sound and the letter "w" is always the soft 'Wha' sound) I love your attention to detail and thorough treatment of the processes in your videos!
Where would be the character ... the recognition value ... the distinction ... the diversity ... the uniqueness, without the German accent? Oh and are you sure, are you REALLY SURE that this HAS to be spoken exactly THAT WAY that pleases your ear(no offense ... but did I hit a point)? In Wales, in Scotland, in Down Under, in Texas, by the First Nations Yukon Canada? You get it, Gregor. Gruß und schönen Tag from Germany, which is half the size of Texas and according to linguists alone has 20 large dialect groups with different pronunciations. Altogether there are 15 Indo-European/Germanic languages today with around 500 million speakers. This is even more extensive in the case of the English language family, since there are more than 40 English accents and dialects in the United Kingdom alone! As of a 2017 snapshot, around 340 million people worldwide spoke English as their first language, with second speakers estimated at 510 million to 1.75 billion speakers. Now the question is: do we have a right to demand from everyone else to speak High German (or Oxford English)? Or are WE able to learn and broaden our horizons? Or simply tolerate something that looks(and sounds) strange and unknown at first? The former is of course much more convenient ... but destroys any diversity and character! Please forgive me for this lecture. Sometimes the language police (not speaking about you) simply have to be put in their place ... because they are not language police at all, but simply ignorant people who are unable to think outside the box.
I use a Sony cx11 and a Canon Eos700D for filming (The cx11 gets only used as a secondary camera anymore, my main camera is the Eos). For editing I use KDEnlive (Opensource).
@@fayaqureshi8124 Just a simple old pedestal or bench grinder with a "GREEN" wheel, and when I am feeling really determined, I plug in and turn on an additional grinder, that had a diamond wheel already installed on it, just to pretty things up a small bit, but is not completely required, as the green stone wheel, designed for tungsten and carbide removal, seem to do just fine. The down side to the green stones wheels, is that they do not last very long. but they are not expensive either, not much more then the grey stone wheels.. Be safe installing your new grinding wheel stone, study up, (if you do not already know, how to check those for hidden cracks by tapping method) plenty of TH-cam videos about the stone checking methods.. good luck and be safe, Dru
These are the ground CCGT inserts I use: www.ebay.co.uk/itm/10pcs-CCGT060204-AK-H01-Carbide-Tips-Inserts-Blade-Cutter-Turning-Tool-with-Box-/311889678279
Did I imagine this or did you have annother video where you had a homemade diamond wheel grinder that you sharpened carbide on... Or was it some other youtuber. It's turning me slightly mad not finding that video again.
Stefan has proven that if you cannot think of something nice or that moves a conversation forward, you may be a dick. AND more importantly...Why this has not been used for the answer to all who wonder, WHAT DO YOU GIVE WHEN YOU ARE UNSURE?? You give that person a tiny HS Vise, or any size variant depending on how much you like your point to be made. In summation, sometimes it is better to give a vice than to post advice. That is one cool tower of concentrated holding point, the vise, from one cool dude of concentrated knowledge. Thanks Stefan!
Stefan they have cobalt in them you know so use oil or something its very bad for your health to inhale . take care I like your video's and your work and you seem like a good guy .
The ground sharp rhombus insert of which you spoke looks like something used in a Boyer Schultz box mill used in automatic screw machines. I used them frequently by other manufacturers, but I can't recall their names. Also look for that shape in other lines one of which is Kyocera. This style is used for low tool pressure and often in Swiss style machines such as Star and Citizen.th-cam.com/video/tygAIdw-ksk/w-d-xo.html JIM
Thank you for another excellent video!
As with others you've published, this one led me to think of a topic in a different way than what I had assumed (and often have been taught) was the "right" way to look at the subject. You have remarkable insight, and seem able to 'think outside the box' more than most people, and in directions that inspire me to do the same.
I've heard you mention Robin Renzetti several times, in a way that recognizes and respects his standard of excellence, and you seem to look at him as a role model. I certainly agree with your perspective about Robin but, in my humble opinion, your own skills and standard of excellence puts you in the same league as Robin - and that is high praise indeed!
Regards,
Doug
PS: On behalf of American novices like myself (who mostly grew up learning only one language) thank you for choosing to humble yourself by presenting your videos in something other than your native German. You give English-only speakers like myself access to some of the best instructional and most thought-provoking material on the web.
You're a true credit to machinists toolmakers and, above all, TEACHERS.
Thank you.
Stefan, as always you did a nice job presenting your video. I like the fact that you not only show the machining process, but you follow up and show how the part is used and performs. as is this particular video the resharpening of the inserts and then demonstrate how well they perform on various materials. "Walk the Talk", as Keith Fenner likes to say. I was really impressed with the finish on the drill rod when taking such a light cut!
Stefan, I enjoy many of your videos not only for the great content but also the patient and well described process you use. I am also afflicted with the details matter mindset which drives me crazy, lol... Precision does not happen by itself. I am am old dog who continues to learn a thing or two. Thanks for taking the time and effort to share with us.
Thank you Stefan, you answered a lot of my questions in one video. I've been machining a fairly big odd shaped chunk of EN8 which I could not run fast on my 280mm lathe and just could not get a good finish from the carbide insert boring bar. Now I know why, more importantly I now have a good steer on how to fix it.
Good video. I began doing this years ago when I found out a metal recycler had hundreds of carbide inserts for sale by the pound. I use a diamond wheel designed for lapidary work and just touch up as needed. Mostly TPGN and TPUN inserts.
Fantastic video! I learned a lot from this. I'm definitely going to try this technique, as I've been really frustrated by the high cutting pressure and poor finish with regular inserts.
I tried to duplicate this style of grind on my Quorn grinder, and was stunned at the results! Very good indeed!
I only use carbide for special things.I still use the old lantern style cutters in my old equipment as I have so many cutters,but it gets the job done for my purposes and tolerances.Even so,I enjoyed this tutorial and did learn from it.I use my dremel to "Kentukey windage a chip breaker on the tool".Thank's again for the clear and concise explanation
Shouted YES! before I even watched the video. The title said it all. Vielen Dank Stefan!
you just talked me into trying this. Thanks! This could really help the "budget minded person". Please keep making these videos, I learn a lot.
Those inserts could also be Korloy inserts with a KM chip-breaker. A very good alternative if you want to buy (not to regrind) inserts in Germany (if you have a company) are ATORN 6310 inserts. These inserts are super sharp (like inserts for aluminium) but with a coating. Tool life of those inserts is decent, even in steel.
I use Tungaloy DCGT070201FL-J10 (label on the box in front of me) for very detailed work. They are available both right and left hand with very small tip radius. Looks much like a smaller version of Your regrinds.
Never considered the advantages of regrinding inserts, of course it saves a lot of work compared to grinding complete tools like I often do. I use CCMT in the same size as You, will try it. The grade of the insert is probably important for maintaining a sharp edge.
Also found that small DCGT Al inserts with a sharp edge works for fine finish cuts in some steels.
Stefan-
Simple and elegant, obviously well thought through (as always...)
Thank you!
Bill
The sharpening you did is the versatile geometry. You can't go wrong. Love watching good skilled guys . I also learn different ways of doing things. Great video thx .
I need to do this. I use 19mm tips that are £15 each and I've got 1000s of them. Very interesting. 👍
Very interesting video. I think you did a great job in covering this subject. :-)
Toolmaker! A wealth of knowledge as usual... love the style and as soon as I find something grinding precise enough I will give it a go. ;) Especially because I found the Chinese started selling dcmt inserts for my micro lathe around 8 bucks a pop (box). So at least I don't have to kill myself if I mess one up. ;)
Since you aren't taking large depths of cut and using that long sharp side why not run across the nose at an angle so as to force the chips to curl back tighter and break shorter. Right now you are at 90deg to work I would like to see you try a 45deg to work to see how it performs.
Good for you. A master machinist. On a shop site, I talk about grinding inserts. They thought I was the anti Christ. So many today dont have the skills to make tools or grind them.
Grinding and modifying inserts is Heresy for many :D
As you are saying, many modern machinists dont have the skills to make tools, grind ect..
Thanks to cnc,...cnc is good in many ways, absolutely, but many skills are lost thanks to cnc....really a shame.
Thanks Stefan for the explanation and for showing your approach. Very good to see your creative, sometimes not so "common" methods. Often, we have misconceptions about the way things need to be (done). For example, at school you might have learned that short circuits need to be avoided only to find out later that some machines use this principle :)
One insert manufacturer didn't like this video apparently!
That was to be expected. I hope none of them sends their assassins.
Pay the life insurance!
Luckily Sandvik ninjas are dressed in bright yellow so they are easy to spot.
I think there's a market for this stuff. I don't have a surface grinder, but I would love to have inserts with this geometry.
Awesome. Surface finish looks great especially on the softer stuff.
Kennametal doesn't show a current matching geometry for those inserts, but the HP chipbreaker looks very close, it's a ground 15 degree finishing chipbreaker. The insert would then be a CCGT-21.51HP KT325. They don't have one like that, but they have the CCGT-21.51 11 KT325, which is a 7 degree finishing chipbreaker. They have the HP chipbreaker in other grades, just not KT325. That's probably why someone had them custom ground!
And with that RobRenz tool holder, the rigidity is awesome.
Good inspiration...
I'm presently working on wood turning tools, where a very sharp edge is required for better performance, the surface grinder is also in my opinion the best tool to use.
The plan is to use cheap chinese metal working inserts and redo the top and edges, that's a project that I'm workin on with a TH-cam producer that has a channel on wood working.
Naturally minimum modification on the original inserts is one important goal...
Hi Pierre, wood turning tools really need to be SHARP, if you want to do the job properly and slice the wood fibres. Carbide will only really work as a scraper and this is not the ideal way as you invariably get sub surface damage which tales forever to sand out. A sharp tool, with the bevel rubbing the wood, will leave a finish ready for polish. As the great woodtrurner Frank Pain once said, "cut wood the way she wants to be cut."
Going to back up Chris here.
Carbide is probably just not the right material here. You need to use really high grade carbide to get a cutting edge sharp enough for wood, and the edge breaks down extremely fast on some woods. Sand and dirt are common inclusions, and some common woods like oak have salt inclusions.
Scrapers should be ground on a fine wheel so that a very fine burr is on the top of the tool, the burr is what does the cutting. If you cant raise a proper burr on the grinder (lots of practice) then the burr can be honed off and turned back up using a burnishing tool. Removing the burr and honing the scraper produces a tool more akin to a square end chisel - a useful tool for roughing, but will not produce the quality finish that a proper chisel or scraper will produce.
Gouges are usually best ground with variation on the cutting angle as it sweeps to the edge of the tool. Not something you can do on a surface grinder.
I personally prefer a convex grind on chisels (similar to an axe grind). I use both chisels ground so the edge is straight or convex. A convex grind allows you to use the chisel free hand since you can rest the tool on the work and roll the edge into the cut. This is extremely useful to fairing around curves and coves where the tool rest will interfere with tool movement. I grind mine on a bench grinder, but some folks use a belt sander with the belt loose.
Good point you're taking in here, I agree with you that a good HSS or good quality steel blade type tool with a very sharp edge is best to really cut wood fibers, this is an experiment and it's possible that it will produce some good roughing toll and there is still gonna be a need to finish the conventional way with steel...
Stefan, interesting video. I have re-sharpend some inserts, using a silicon carbide wheel, but very slow. I will look at getting a diamond wheel and make up some kind of jig to hold them. nice to hear someone who knows all of the terms involved. Thanks for the info
Great topic.
Thanks for taking the time to make the video and share it.
I can now forsee the sale of small surface grinders going through the roof price wise.
thanks for the info and demo Stefan.I have boxes of used carbide inserts ,good job I save things for re use. Now all I need to do is to dig through 40+ years accumulation of clutter and junk to find them Yes I know . junk is junk but only until you have a use for it.
Sumitomo has a good selection of ground chip breaker, their "FX" chip breaker looks very similar to the one you had.
Good video, good chips and nice surface finish. Thanks for sharing
Interesting video, thanks Stefan. Finally, somebody who understands what sets the minimum DOC.
What was wrong with the inserts before grinding? I often find mine won't "wear" per se, but some will have some sort of catastrophic failure that results in a chip. I presume yours were either new or merely worn before re-grinding?
Good video 👍🏼 Enjoyed it. What brand of surface ginder is that Stefan? Recently had a job turning a tiny shoulder on 3/16" W1 tool steel....horrendous burr....any suggestions on a type of tooling to eliminate burrs on small diameter turning with tool steel?
gtwr.de/shop/pro_lip515/index.html
Thanks Haggis, I appreciate ya
This channel deserves much more than 26k subscribers.
Thanks! Its already 26133 ;)
Brazed carbide may perform just as well as a reground insert, but I do think that a lot of people would get a lot of value from being able to squeeze as much life out of every little piece of tooling they can
I do a fair bit of brazed carbide, but it is so much grinding ;)
On an insert, all the hard work is already done by the manufacturer - For example a nice, well defined nose-radius is already built into the insert.
I tried this and realised you need a few things to get this spot on:
1. really rigid setup like Stefan's got there, no free-handing.
2. well balanced, dressed diamond wheel with negligible run-out and fine enough grit (>= 1000 ?) to give it a mirror finish
3. stick out your tongue at the right angle and pray the edges don't chip - which has been my problem so far
@Stefan Gotteswinter How do you deal with built up edges on Aluminium ? Seems to be a major issue for me with anything over 0.2mm depth of cut.
Where I work they do this all the time, free-handed.
Stefan can I ask you about the diamond wheel on your grinder? What type is it and do you dress it yourself? How and what do you use to dress it if you do? I do quite a bit of tool grinding and am always looking for information on how people do things. Thanks I watch all your videos you have very useful content.
Its a normal resin bound diamond wheel, D128. A little bit coarse for real superfine finish, but a good allpurpose grit.
I dress them by cylindrical grinding with a silicon carbide wheel - Basicaly I put my die grinder with a SiC wheel on the table of the grinder, let it spin and then plunge down onto the SiC wheel with the spinning diamond wheel.
The SiC wheel will wear crazy fast and needs to be redressed with a diamond frequently, but it works.
After the diamond wheel has dressed, the resin binding has to be backed of so the wheel cuts free again, there are special handheld stones for that, for example from Tyrolit:
www.yumpu.com/en/embed/view/aFfTz8iLj0kt1YJ7/313
(Right lower corner, "Sharpening stick")
so where are your diamond flattened stones ala Robrenz style. We know you got em! :D
I ground 20 pairs of them or so ;)
:D
They will have a brief appearance in my next video ;)
Considering that you can make a tool holder, you can fix this kind of insert vertically. Look at Mrpete222 video made about a "shaving" cutter.
Thanks for showing your style
I have also been grinding and touching up my inserts for years,never been a problem, the solid carbide all the way through. The only inserts that can't be done are the cubic boron nitride CBN ones, not got a grinding wheel hard enough! There are not many materials the CBN can't deal with? Even hardened bearing shafts and hardened high speed steel bend to its will!
I recently learned that one can regrind/resharpen cbn inserts with a resin bound diamond wheel without a problem :)
ever considered trying out the ingersoll TT9020 grade with SA chipbreaker? they come as finishing inserts in C, D and V-shape and radius range from 0.4 down to 0.1, precision is top notch as they're -CGT class with grind finish on the release angle and they cut like hell.
great multi-purpose insert in my book as we use them a lot in our workshop, only downside is the wear is quite heavy when finishing at high speed as they won't last long, but you could even use them in aluminium.
www.imc-companies.com/IngersollCatalog/CatalogFiles/datafile/PICTURE/WD1050_1.jpg
What a good idea!
I know some will have a problem with your going off the Reservation and doing your own thing...... like you know better than professional insert makers, right?
Hogwash! Those inserts are for your convenience, alone! You don't exist for the pleasure of the insert makers. They exist to serve your needs, not the other way around.
Of course it's a great idea to modify inserts to serve your needs......duh.
Thanks for sharing how you make inserts meet your needs!
:)
"I don't do much Aluminum, but when I do, I prefer 7075!" ;-)
I dont do much aluminium, but when I do, I prefer toolsteel ;)
Titanium machines absolutely unspectacular, just like "normal" 316 / V4A / 1.4401 stainless steel. Drilling and threading smaller than M3 can be a bit nervewrecking ;)
The brand of the Sharp carbide inserts is mitsubishi
Excellent video! I've a question about the use of CCMT inserts - I hadn't fully appreciated that they work by creating sufficient cutting pressure, and hence require a suitable depth of cut. That being the case, how is it possible to use them for very shallow finishing passes? Surely they wouldn't work at all? I was a bit confused when you described that Kyocera one as also a finishing insert. I've never had much success with them anyway, because my lathe isn't rigid enough, so I always use the ground CCGT version, even for steel (they sometimes don't last long, but I'm using Chinese-made inserts which are only about $1 each)
It would benefit you to study the various chip breaker info in the insert manufacturers catalogue, one insert can have half a dozen different ones all with different purposes. Some chip breakers have a minimum cut of 2 or 3 mm, while others can go down to a few hundredths of a mm. It is a mistake to think that you want, say, CCMT and think they are all he same, they most definitely are not.
With a normal insert you simply dont do a shallow finishing pass ;) Finishing takes place with a reasonable deep cut - With a stout machine you will have no problem hitting close tolerance/good finish, when taking a 0.5 or 1mm finishing pass. But my toy machine is another game.. ;)
Excellent for lighter weight machines where tool pressure is a issue. A fine job on the video.
I've just commented on another vid asking the same question. On a mini mill, is there any extra precautions one should take when attempting this with a diamond wheel? How deep and wide did you grind the 5° chip breaker? Just till the rounded cutting edge is gone? Other than the things that have been shown and mentioned in these vids, is there something mill specific to avoid. The vice will be on it side on the mag chuck with the little vice holding the tool shank inline with the X axis, and use the side of the wheel. It's a 5um dro all 3 axis on BF16v mill. You've mentioned carbide and diamond dust is death to man and machine, appropriate precautions will be taken.I noticed you were climb grinding, I was going to conventional grind. Is there a big difference between the two, like when manual milling?Thank you for the advice👍👌🇦🇺
Good to see that pretty face again! I was just thinking of this yesterday as I swapped my CCMT insert, and placed the worn out insert back in the box! I thought of you, and wondered if you possibly even sharpened the cutting edge on new inserts, to make them more free cutting ....appears I need to expedite getting my KO Lee 6062 in and running.
Can also order from china, there also good insets here, I use mostly Chinese inserts, and some Mitsubishi, Kyocera and others.
Great video Stefan! I'm gonna try this myself.
I would like to try your method with my inserts and surface grinder. Looks like a resin bonded diamond wheel. I have never used one of these. Can you tell me how you dress the wheel when new to make it true? I have one on order from China.
I might have missed it, what was the depth of cut on the grinder, enjoyed the video
Thanks Chuck, I ground a few tenths of a mm deep, untill the freshly ground toprake hit the edge of the insert.
Excellent video as always. You give us hacks something to aspire to.
Geht jetzt total am Thema vom Video vorbei, aber ich wollte einfach mal danke fuer die tollen Videos sagen. Schaue seit Wochen nach und nach jedes deiner Videos und bin einfach fasziniert von deiner Arbeit und der Praezision mit der du an deine Projekte rangehst. Hoffentlich hab ich selbst irgendwann mal sone tolle "Man Cave" wie du :D! Das erste mal drehen auf unserer kleinen, alten (und ehrlich gesagt zieeemlich schlechten) Drehbank hat heute riesig Spass gemacht. Muss mir unbedingt mal Fraeser fuer die Arboga U2508 die ich vor Monaten gekauft (naja, fast schon gestohlen) hab kaufen damit ich mal mehr "rumspielen" kann.
Dankeschön! Ich höre/lese immer sehr gerne wenn ich Leute inspirieren/motivieren und ihnen vieleicht etwas nützliches Zeigen kann.
Glückwunsch zur Arboga, das ist eine schöne solide Maschine :)
Danke! :)
Splendid video as usual! Can you tell me why many You Tube machinists prefer negative rake tooling?
They have stout machines - And the inserts have many more cutting edges than positive inserts.
(Btw: Negative inserts do not automaticaly have negative rake)
great info tks.
whats a “good” surface finish? how to do ?
What lathe are you using in this video? Thanks!
Thats a highly modified 10x20 chinese import machine
I'm seriously thinking on breaking the bank for some Mitsubishi CCET and CCGT inserts with the SR and SN lead chipbreakers like the ones you ground and they are advertised as a precision finishing-light cutting insert but they cost 2-5 times as the inserts I'm used to buying. If I only had a surface grinder...
Great ideas Stefan. Yet another argument for my surface grinder to come.... :-)
I'm sure I've seen those kt325 type inserts at work - I'll ask where they came from.
yes, i found a few larger examples in my home 'stock' (uncoated, coated and left hand) . I'll report back…
Donno if i missed it or what, but how deep are you plunging into the carbide?
Anyways badass info as ussual.
The KT325 carbide insert is something that I also got a lot off eBay. I know that I have them. Need to find them and what would you be willing to pay for them Sir ?? Please let me know Stefan and have a Happy New Year too.
Stefan you are a genius
very informative stefan, i think i'm going to have to try it. i have a surface grinder but i wonder if you have tried to freehand the grind? have you tried a green wheel and then touch up with a diamond file? could one use a commercial insert holder on the surface grinder ?
Nicely done that man !
Nice informative video Stefan and thanks for the extra volume my old laptop appreciates it. Lol
Korloy do some polished inserts for steel that I've found useful of my mini lathe
why not call the radius depth 2 billimeters? I'm an idiot, just a heads up.
Hmm, the chip breaker seems to do nothing. Wouldn't it be better to make it diagonally just behind the cutting point instead of all along the side? Are you even using the more blunt points of these inserts?
Yeah, chipbreaker, chipformer. It is not agressive enough to realy break the chip, but it curls it up and brings it out of the way, so I dont end up with a spinning ratsnest of wire-like chips ;)
I didnt want to do a more diagonal one, as I use the long edge of the insert in my chamfer tool. Speaking of the chamfer tool, thats where I use the 100° corner of the insert. (As seen here: th-cam.com/video/ZsPHB1gPink/w-d-xo.html )
Ok, when you see it like that it makes more sense this way :)
It is obvious that your "chipbreaker" is not really effective with the light to very light cuts for which you use this geometry. That is to be expected. How about making that chipbreaker channel more narrow and with a sharper corner at its back. So to speak make the channel smaller and more in proportion to the chip size and more aggressive using a sharper edge radius on your diamond wheel. That way you perhaps get real chipbreaking action for the medium and possibly even light cuts. Of course not for very light cuts. Your close up videos showing the chip flow of the different cuts are very telling and a great help to study the effectiveness of the chipbreaker. For those who dont have an abundant source of chipped index plates you could also buy the simple, plain index plates without any features on it as blank material for customized grinds. They are not that expensive.
I partially agree with chris0tube. Indexable carbide inserts were invented for series production where heavy, sustainable cuts increase productivity. And nowadays series production is largely automated. So the inserts now also need to manage the chips because nobody is standing by to do that.
Carbide inserts are around now for how long? 50+ years? And most innovations were protected as intellectual property. So the numerous competition had to find an almost as effective shape without infringing on other's IP rights. That lead to a jungle of different insert geometries. How can innovation still take place ready for the next trade fair after all this time? It is only by more and more narrow niche optimization. Already when only the depth of cut changes a little your insert is not optimum any more and you better use a different one. Here is where the experience of the production pro comes in to know which insert and cutting parameters are best for which application. However, in times of preferred supplier strategies in procurement a production pro may only gather experience with the insert lines of one or two suppliers. When he changes company which uses different insert suppliers his experience is only partially applicable. This all may work in large series production. But smaller shops need more all purpose inserts that may be less optimized for each application.
For the home shop productivity is less important. Much more lighter cuts are done and chip control serves more safety, and surface finish. Here the experience of the production pro is only of limited help. So Stefan tries to translate the industrial chip control to the home shop environment with its lighter cuts. For all of the above reasons the indexable insert is much less suited for home shop work. Reground indexable inserts or brazed inserts with sharp edges fit better and the good old HSS cutter fits the needs of many home shop jobs still fine. Many home shop metalworkers use indexable inserts only because they don't know how and/or are not equipped to grind their own tools. If you belong in this group don't worry. Watch some of the many tool grinding videos, pick the method you like and get the necessary equipment which can but does not have to be expensive. And stay away from those plastic, one size fits all sharpening gadgets on the market. If you choose what the old-timers used you will get good results for little money. Start with your lathe cutters, then drill bits, then milling cutters. Get one or two diamond wheels (they are not that expensive) so you can regrind carbide to customize it for home shop duty. Use a fan and/or a dust mask to keep the carbide dust out of your lungs.
On the materials shown, at the diameters he is turning and the limitations of his equipment, he isn't going to see ideal chipping. What he is getting is more than adequate and the chip breaker does its job of pushing the chip out and into the chip pan.
Does the dead sharp cutting edge result in more chipping? I can imagine that the brittle, thin edge is more vulnerable than a factory radius (not nose radius, edge radius).
Yes - It is way less durable, but thats a minor drawback for me. For roughing I use out-of-the-box inserts anyway :)
I think if the edge breaks a little bit you can maybe regrind them again. It will be a little thinner and thus more brittle, though.
The English "vise" (and also "vice"!) is pronounced rather like the German Weiß.
(Actually the letter "v" in English is always the hard 'Vee' sound and the letter "w" is always the soft 'Wha' sound)
I love your attention to detail and thorough treatment of the processes in your videos!
Where would be the character ... the recognition value ... the distinction ... the diversity ... the uniqueness, without the German accent?
Oh and are you sure, are you REALLY SURE that this HAS to be spoken exactly THAT WAY that pleases your ear(no offense ... but did I hit a point)? In Wales, in Scotland, in Down Under, in Texas, by the First Nations Yukon Canada? You get it, Gregor.
Gruß und schönen Tag from Germany, which is half the size of Texas and according to linguists alone has 20 large dialect groups with different pronunciations. Altogether there are 15 Indo-European/Germanic languages today with around 500 million speakers. This is even more extensive in the case of the English language family, since there are more than 40 English accents and dialects in the United Kingdom alone! As of a 2017 snapshot, around 340 million people worldwide spoke English as their first language, with second speakers estimated at 510 million to 1.75 billion speakers.
Now the question is: do we have a right to demand from everyone else to speak High German (or Oxford English)? Or are WE able to learn and broaden our horizons? Or simply tolerate something that looks(and sounds) strange and unknown at first?
The former is of course much more convenient ... but destroys any diversity and character!
Please forgive me for this lecture. Sometimes the language police (not speaking about you) simply have to be put in their place ... because they are not language police at all, but simply ignorant people who are unable to think outside the box.
Stefan DO you think that this would work with used industrial application carbide? I buy it in #lots and get all sorts of geometry cutter bits.
Great video Stefan!
ATB, Robin
Thanks For your Videos Stefan. What Camera and Video Editing Software you using ?
I use a Sony cx11 and a Canon Eos700D for filming (The cx11 gets only used as a secondary camera anymore, my main camera is the Eos). For editing I use KDEnlive (Opensource).
Is it possible for you to do a video on how you, personally, grind HSS? Everyone does, but your take on it would be nice to see.
I want to do a general toolgrinding video, carbide AND hss, because there are many missconceptions about both materials.
Stefan Gotteswinter I would love to hear your views on tangential tool bits. For a beginner they seem an ideal type of tool bit to use.
I am poor, so, regrinding my inserts is just the way of life for me, LOL... I get allot of miles (kilometers) out of my indexables...
What machine you use to regrind your inserts ???
@@fayaqureshi8124 Just a simple old pedestal or bench grinder with a "GREEN" wheel, and when I am feeling really determined, I plug in and turn on an additional grinder, that had a diamond wheel already installed on it, just to pretty things up a small bit, but is not completely required, as the green stone wheel, designed for tungsten and carbide removal, seem to do just fine. The down side to the green stones wheels, is that they do not last very long. but they are not expensive either, not much more then the grey stone wheels.. Be safe installing your new grinding wheel stone, study up, (if you do not already know, how to check those for hidden cracks by tapping method) plenty of TH-cam videos about the stone checking methods.. good luck and be safe, Dru
Can you talk sometime about the toxic dust from grinding carbide please?
There is not much to talk about - It exists, its toxic, use common sense, dust extraction and a dust mask :)
How are they with stainless steel?
I believe it would work better if you didn’t grind the flat so wide as it looks like the steel curls before hitting the chip breaker.
Nice video Stefan.
How can i joint the carbide tips with iron plzzz hellppp me plzz which cemical can joint this both
great stuff< Stefan. thanks for sharing this method. learned a lot again. cheers.
9:00 I could have sworn you had a bottle of tobasco hot sauce chilling out on your grinder.
Actually hss is better for highly positive rake tooling. Carbide sharp edges don't stay sharp for long
These are the ground CCGT inserts I use: www.ebay.co.uk/itm/10pcs-CCGT060204-AK-H01-Carbide-Tips-Inserts-Blade-Cutter-Turning-Tool-with-Box-/311889678279
Just let the mustache ride buddy, it wants too
which name of this re grinding machine??
Do you think its possible to regrind cutoff inserts to make less toolpressure?
Yes! I freehand those on the diamondwheel, just regrinding the top rake surface :)
Check spelling on Kyocera. Good work as usual, Stefan.
Did I imagine this or did you have annother video where you had a homemade diamond wheel grinder that you sharpened carbide on... Or was it some other youtuber. It's turning me slightly mad not finding that video again.
Details about the cbn wheel you used.
Super bedankt. Mathijs.
Stefan has proven that if you cannot think of something nice or that moves a conversation forward, you may be a dick. AND more importantly...Why this has not been used for the answer to all who wonder, WHAT DO YOU GIVE WHEN YOU ARE UNSURE?? You give that person a tiny HS Vise, or any size variant depending on how much you like your point to be made. In summation, sometimes it is better to give a vice than to post advice. That is one cool tower of concentrated holding point, the vise, from one cool dude of concentrated knowledge. Thanks Stefan!
Excellent, just gained a subscriber
Thanks! Appreciate it :)
Stefan they have cobalt in them you know so use oil or something its very bad for your health to inhale . take care I like your video's and your work and you seem like a good guy .
Thank you Stefan
The ground sharp rhombus insert of which you spoke looks like something used in a Boyer Schultz box mill used in automatic screw machines. I used them frequently by other manufacturers, but I can't recall their names.
Also look for that shape in other lines one of which is Kyocera. This style is used for low tool pressure and often in Swiss style machines such as Star and Citizen.th-cam.com/video/tygAIdw-ksk/w-d-xo.html
JIM
I think grizzly.com has a similar inset. part #G745 & G7040 less than $20 for 5pcs.
don warner
Nice video Stefan.
Bob
What where people wining at you for reginding your bits.
Nice work. Thanks for sharing