I can perfectly understand your frustration. But you have to be proud of yourself for what you've done. The project, the design, the making of that tool. In my opinion you are a all-round engineer. Well done mate!
Nothing ventured, nothing gained. You proved your tool worked as designed. Just needed to be toughened up a bit to withstand the forces at work. Great job...as always.
I don't usually watch Mini Lathe videos. but machining is all about being able to solve problems of work holding and cutting. You had both in this video. Thanks.
I work for a tooling company which is specialized in parting off, grooving, precision grooving and threading tools, mainly for turning machines. We also do lots of custom tools to machine challenging parts and/or materials. Face grooving tools are one of the most challenging cutting tools we produce. The blade of the tool must be very precise to avoid it flexing out of alignment with the spindle. If there is a small alignment error, the blade can permanently bend like your homemade tool did. Even a little warpage after heat threatment affects this. Alignment must be precisely controlled. Warping because of internal stress in the raw material is also problematic. Depending on the face groove diameter, the insert must be tilted to get sufficient relief angles on both sides of the cutting edge. This is especially the case with small diameter grooves. There is a way you can build a simple and stable face grooving tool for shallow cuts. Your tool holder needs to hold the insert at an 90° angle. This way you can not cut very deep in the parts face but you can realise very sturdy clamping between the tool holder and cutting insert. Also the tool gets more simple to machine in general. Depending on the diameter of the face cut, your insert needs to be angled around the axial direction of your workpiece to get sufficient relief angles on both sides. You can easily visualize this effect on paper or in cad. Otherweise try to manufacture a tool holder with a shallow grooving depth first, as it is more stable and more forgiving in small machines, including chattering
Thank you so much for your detailed comment! It's really great to have an expert talking here, super interesting and helpful! I didn't know that these tools are so critical for alignment. I probably should have set it up more carefully. Was just to excited to test it and went in a hurry. The tools you describe with the insert a 90 degree came into my sight during the researches for this build. They looked a bit awkward to me but what you say makes totally sense. If I'm crazy enough I might made a second try on a trepanning tool using this design. Getting the relief angles an the insert seat about right is really extremely difficult, especially when having no real calculations and exact measurements and doing it more by feeling. Again I really do appreciate you sharing your knowledge with me. Thank you very much! PS: als ich deinen Namen gelesen hab, musste ich erstmal laut lachen :D nice :D
I love hearing your thoughts via narration as you move through your work! Your design is elegant and practical so do what we all do - heave big sigh, figure out what worked and didn’t and then ‘you can do that better’!! I always enjoy watching your videos and love picking up on techniques and methods. Looking forward to the next one!
Thanks WCDTB for another great video. That was a fantastic and challenging build. You had a great set of methods for workholding/toolholding and a good idea of the geometry to achieve. It's a real shame the tool grabbed, I think that bending it back into alignment is a good idea, and heat treatment also a good idea. Good luck, please let us know what happens. PS: Also great to hear another narrated video. Thanks, Craig
One thing that can make it difficult is that lower right outer corner. The geometry to get the tool cutting is tricky. The insert has to be ground so that the corner is inside the radius. Not easy for me to explain but I hope I make any sence...
Thank you very much for sharing your skills with us. As a fellow countryman of mine once said, "If at first you don't succeed, try, try again." Also, I love your sense of humour!
The shop I worked in ordered a trepanning tool for a particular job once. When we received it the instructions included were it was not for manual machine use CNC only. We had a Harrison CNC in the shop that it was used in exclusively without any problems.
It is too bad that the tool was damaged after putting so much effort into it. I appreciate you more for being candid enough to post the failures as well. You may have already answered this in another video, but I am really curious about your engineering background. Your work is quite impressive. My lathe is made in China and has many casting and design flaws; I do not have the bravery to attempt a fraction of what you have done to your machine to make it more capable.
cool machine worsk and I think you are right on with the hardening, I believe the lower arm bending was purely down to the steel being too malleable. Altogether nice job and a very cool learning experience.... Thanks for sharing
As the toolsteel I used is a bit tricky to harden at home, I thought about using it unhardened before ruining it while hardening. But now I will try to harden it anyway :)
Can rigidity be improved by using brazing instead of screw? This way is nicer but I think that braze on top and bottom will be much steardier than that flexible clamping.
That's a really nicely made tool, definitely worth bending it back and getting it treated. I normally just eyeball a bit of HSS for trepanning work, I was doing 25mm deep x 2mm wide in 7075 this afternoon. Until I reground the tool for a smaller radius and snapped it off at 15mm deep. Bah.
Thank you! Going 25mm deep with a 2mm blade sounds extreme o: For quick work grinding a hss bit would be the best I guess. But I was curious if I could make a proper trepanning tool as I found these quite interesting :)
It may have already been said or too late, but 'heat treatment' doesn't make steel stronger, it makes it harder while sacrificing ductility. The only thing heat treatment will do is cause that fin to snap off instead of bending. With such a thin cut, you need to be tenacious about swarf removal in that kerf. High pressure wash on a mini-lathe isn't viable, but air/lube and a lot of retraction will go a long way. You should also be more aggressive with relieving the fin, you are not going to take deep cuts with that thing anyway and a lot of that fin seemed superfluous. Good luck!
Questi utensili, li ho visti solo con piastrina saldata, indubbiamente meno soggetto a piegatura. L'asportazione di truciolo è importante, dovresti usare olio da taglio per alluminio.
Impressive engineering and execution on the lathe. I wonder if the bending was caused by the buildup of swarf and if compressed air or coolant might prevent grabbing and bending. Good luck with your project and thanks for the very well-done video.
Thanks for your kind comment and feedback! I really do appreciate that! I have no idea what caused the tool to bend. When I look at the part, there is a line going outwards. So the tool got pushes out, causing it to bend to the outside.
Thank you very much for your feedback! I really do appreciate that. It's not that easy to talk for me, but I will try to speak a little bit more often in future videos.
Nice video and presentation. Quality channel on mini lathe. I share the frustration. Thinking about the bending. It looks to me the loading vector coupled wasn’t tangential with respect to the top of the lower jaw. Such that a vertical force at the cutting edge (aligned to spindle axis) will be taken by the lower jaw at compound angle with a side load, towards the operator. Hence bending away from the axis, in this case. An attempt to avoid side load, can we set cutting edge below spindle axis slightly? and watch carefully with minute offset and shallow feed a bit at a time? Principle? Each segment / point along the cylindrical lower jaw calls for a local side load free tangential force which is impossible by any design. Unless the top and lower jaws circumstance meet in the far side of insert, resembling a carpenters hole saw. This limits the tool to a single radius cut. An alternative idea is to integrate the insert on a boring bar with the insert well section reshaped in favor to a deeper grove. Play what if with this in you CAD program. Luck is on your side.
You made a beautiful tool with very limited resources. I take my hat off for you. The problem is not your holder, but the insert itself. In an small lathe you need a razor sharp insert, instear the mgmn, try the mggn series.
Does that insert have enough side clearance to avoid rubbing? Heat treating the tool would help, i think, but i think it's still quite likely to break. It's too long and narrow. You could either use an annular cutter in the tailstock or grind a short tool from a tool bit. Having done exactly that, it's tedious but does work.
Good question, I think it does. But it's all very tight indeed. I think for the workpiece I have to make, I will use an annular cutter now and perhaps do a second attempt on the trepanning tool later.
Very nice work. Often times you learn more from your failures then you do your victories. So they say. In this case I think the tool needs to be hard so it is rigid which is even more critical with a mini lathe that isn't all that rigid in the first place. You did an excellent job with the machining though. I think heat treat will make it work and perhaps giving it more relief on the down or bottom side of the tool. Remember also that heat will make the tool expand inside the cut so additional relief may compensate for that expansion as well as lots of lube while cutting. Good Luck
Thanks for your comment! The steel I used is not that easy to harden at home. I thought about it, but decided to first try it without hardening. I destroyed it anyway :) Perhaps I bend it back and try hardening now.
Hi and thanks! The saw arbor was made by myself. I made a video about it, you find it on my channel. The saw blade is a proxxon 50mm 1,1mm wide carbide plated blade.
I’m sorry that happened. Super impressive on the work making the tool!!! Might I recommend hardening the tool steel before using it. Keep up the incredible work 👍🏻
I have purchased these before. Even the inserts are special with relief built into them for a given radius. Even then, I would use plenty of cutting oil. Running in reverse is bad as there is opportunity to lift the saddle of the lathe. It is likely that that small lathe is not rigid enough for this type of operation. Good work though.
I'm enjoying your narrations on your most recent videos. The extra explanation of what and how you're doing things is most welcome. Sorry that the tool bent. Thank you for sharing your process and posting the video, despite your setback. Lastly, is the 3D printed multifix dial indicator holder file available anywhere? I'd love to print one for myself. Keep on going! Loving all your content!
I appreciate your sharing success and failure - It certainly is hard to beat the uniform cutting action of a typical trepanning saw blade ie a 'bi-metallic' hole saw blade. They've been used in medicine since the time of the Egyptians. That being said, yours is an elegant way to approach the problem. Have you determined where the tool caught? Maybe put some bluing on the straightened out tool and see where it grabs/rubs?
Very cool project! Maybe you could use an insert with a sharper edge to reduce tool pressure. Like something for aluminium. It will dull quicker but the tool looks like it's meant to make a very specific part and not something for everyday use. Thanks for sharing!
No, toolsteel and HSS are different things. Toolsteel is a steel which you can harden but you purchase it soft. So the bandsaw has no problem cutting it. HSS is already hardened and able to cut metal when you buy it. The bandsaw can't cut it.
Greetings dear friend. First of all i've impressed about your accuracy while doing this tool. In my workshop i've made couple of trepanning tools, but other way. I've used HSS steel blanks and a grinder. Your way is more percise and way too nice looking. But trepanning tools are limited fo their diameter capacity. Are you shure it's worth it? Whith all my respect to you. From KZ.
Such is life with homemade tools, it was designed to be used the right way up so its not suprising it failed when used in reverse as it was a lot weaker that way. A more rigid solution might be to modify a tool with a braized carbide tip, or braize on your own if that's possible. I noticed that you often part off with the tool upside down and in reverse, as I have a lot of problems parting I tried this and got my first ever good parting cut, the only issue was getting the tip on center which meant cutting away half the height of the tool and reshaping it. I would like to see a video on this subject as no-one else seems to do it and you don't seem to mention it either, I only spotted it in one of your previous videos. I have a Chinese 7 x 14 lathe that will never be as rigid as I would like but I have improved it a lot, including your compound rotation solution, that was soo good. keep up the videos, they are very instructive.
I was really surprised how well the tool worked when turned upside down. In normal position it chattered like crazy. Flipped over, it runs very smooth until it bend :) This seems to be the only way to use a parting tool on small mini lathes.
I normally work with brass which will part with a HSS tool, mine is around 1mm width and it tends to drift leaving a hollow in one face and a dome on the other. I also part 2mm steel rod which is small enough to be no problem. A friend asked me to make some hand tools which start from 20mm aluminium and 12mm steel, neither of which I can part as it chatters and grabs. With the tool upside down both part cleanly, square and with almost no chatter. The problem is probably the height of the tool above the bed in relation to the width of the saddle, the measurements are around the same which causes the tool to drop slightly under load and lean towards the work causing a jam up. This is not an issue on a bigger lathe as although the tool is higher, the width of the saddle is a lot wider and therefor more stable. With the tool upside down and running in reverse, under load the lean is away from the work whick reduces the tool pressure and prevents jam ups. I am very happy to have found your channel and will have to try you gib fix on my cross and top slides as both have play that can't be adjusted out without making them unusable.
That was great setup work on the lathe. I haven’t watched anyone use a reference surface (20mm bar) to create offsets for tooling. I’m sorry that the tool holder bent.
I think you need to remove a small amount of material on the bottom to give you a negative rake thereby giving you a bit of clearance with the lower section of your tool. Just my 2 cents.
Yeah, that was always going to happen. The problem is that the radius of the tool has to match the groove fairly precisely, and any deflection or translation causes a mismatch. When it gets deflected, it changes the radius and will cause it to grip on one side of the groove at one point and on the other side at another - jamming it up - this something a crocodile style parting tool doesn't suffer from - it might rub, but only on one side. Other than being fixed to a radius, this is probably why other kinds of tools are used: if you want a shallow groove, just remove some material from a parting tool for clearance, if you want a deep groove, use a hole saw which is much more able to keep its shape.
Versuch und Irrtum. Also ich muss sagen dass du das super gemacht hast. Du hast echt viele gute Ideen. Ich dachte eigentlich das der Drehmeißel etwas länger lebt. Ich weiß leider nicht was da passiert ist, weil ich kein Englisch kann. Aber so was passiert sogar mit Fabrik Meißeln. Bei meinem Abstechmeisel wurde die untere Stufe (so wie bei dir) nach unten gebogen. Ich habe dem einfach umgedreht, auf den Ambuss gelegt und mit dem Hammer paar Mal drauf gehauen. Praktisch die Stufe wieder zurück gebogen. Und weißt du was, der funktioniert immer noch.😂😂😂 Vielleicht war die Schneide bei dir einfach zu lang. Die haben ja alle eine bestimmte Länge zum eintauchen in das Material. Wie gesagt, schade dass ich kein Englisch kann. Dann wüsste ich jetzt was schief gelaufen ist. Du bist aber auf dem richtigen Weg und ich weiß du kriegst das noch hin. Du wirst uns noch nicht letzte Mal Überrascht haben mit deinen Ideen. Super Arbeit, freue mich schon auf das nächste Video. Alles gute und bleib gesund.
Vielen Dank für deinen netten und ausführlichen Kommentar! :) Was genau schief gelaufen ist, weiß ich leider auch nicht. Ich hab einfach noch ein wenig weiter testen wollen und zack hat sich das Teil eingehakt und war sofort verbogen. Die Schneide ist schon extrem lang und dünn. Trotzdem hätte ich bei einem "besseren" Werkzeugstahl mehr Stabilität erwartet. Ich denke, dass ichs mit zurückbiegen und härten mal probieren werde. Vielen Dank für die aufmunternden Worte! :)
The steel I used is not really meant for cutting. I could have made the tool from HSS, but I have no way of properly grinding HSS and I wanted to proof if I could make the inserted style tool.
Дуже сподобалося,ваша думка по створенню такого канавачного отрезного різця, можна було у вас попросити ,створити ще один ,для мене дуже-дуже треба для праці,можливо це?
Man I love your work. I've been subscribed since I bought a small import lathe a year or so ago. I think you might have slightly over thought this one. Don't get me wrong your machining and understanding of the geometry of the tool was more than impressive to say the least. But grinding a trepanning tool from hss isn't bad if you have the understanding that you obviously do. If I can do it I know you "can do it better".lol
You didn't heat treat the tool right? Heat treating it would definitely make it lots more rigid and it won't be able to bend and deform like that. I don't know what tool steel it is but if it's a simple tool steel you can easily give it a pretty decent heat treat yourself with a torch, just need to be careful and patient to get it to the right temp before quenching. Even better if you have a simple two piece or three piece firebrick forge. The tool holder turned out beautifully though. You did a great job. I really think you should bend it back and heat treat it with more heat being applied to the tip that holds the insert. If you do it well enough you can give the shank of the tool some moderate hardness which which prevent it from getting marred by clamping screws and have a full hardness towards the insert holding tip to provide lots more rigidity and alot less flex in the steel under cutting forces. And after just temper it back slightly. Even if you don't get the heat treating "perfect", it will still benefit even from a moderate increase in hardness.
A very nice job on making the tool holder, and a shame about the outcome, but I think it was innevitable :( It is a lot quicker to grind a trepanning tool out of HSS for this sort of thing. If you persist, I think that the tool holder needs some side relief, and will need to be hardened. Is there even enough side relief on the insert for it to fit into the curved groove? Thanks for posting the video, anyway :)
Thanks for your comment! Yes HSS would be an option too. But I don't have a proper way to grind HSS and I was curious about this complex looking trepanning tools and wanted to build one by myself :) The relief angles should be sufficient but it's all very tight.
I broke 2 parting tools with these cheap chinese yellow inserts, they are crap. Then I switched to DESKAR brand (also from china) and I never had a problem since. Also you just need rigid lathe for face grooving, your tool was visibly moving while cutting even in aluminium.
Эти желтые пластины с надписью NC3020 очень низкого качества, они не выдерживают длительной работы даже по пластику, не говоря о металлах. Я стараюсь их не покупать.
did you adjust the groove tool height to zero or a bit under zero? In my experience: for such a thin groove tool, even a tiny movement of the compound slide dips the tool and let it grab into the metal which causes the failure. Therefore a much more sturdier tool post should help immensely. Great work to achieve your goal non regarding a failure.
Thanks! The hight isn't that critical as the surface I'm cutting into isn't curved but flat instead. But I might not got the right position for enough clearance for the tool.
I know how ya feel at the end...I made a version of this tool for parting some time ago ....but...for some reason it just didn't work quite right...grr.. At least yours looks way better then mine
If you heat treat it, you'll just snap it off instead of bending it. I'd say re-make it, and leave a little more of a fillet where the flanges attach to the main body of the holder. Or, make your flanges thicker and count on making wider grooves.
I can perfectly understand your frustration. But you have to be proud of yourself for what you've done. The project, the design, the making of that tool. In my opinion you are a all-round engineer. Well done mate!
Thank you so much for your kind words! I really do appreciate that! Thanks a lot.
@@WeCanDoThatBetter 👍🙋♂️
Nothing ventured, nothing gained. You proved your tool worked as designed. Just needed to be toughened up a bit to withstand the forces at work. Great job...as always.
I don't usually watch Mini Lathe videos. but machining is all about being able to solve problems of work holding and cutting. You had both in this video. Thanks.
Thank you very much. Happy to hear, you like it :)
As always, you have uploaded a video of a mad genius at work.
Thank you so much!
We learn something every time we try - we only fail if we give up before we succeed.
Good video!
Thanks :)
I'm sure that a Heat treated part Will work perfectly! Believe me, The hardest work you've made with perfection! Congrats!
Thank you very much for your kind comment! I will try to heat treaten the part but before, I have to modify my little furnace.
I work for a tooling company which is specialized in parting off, grooving, precision grooving and threading tools, mainly for turning machines. We also do lots of custom tools to machine challenging parts and/or materials. Face grooving tools are one of the most challenging cutting tools we produce. The blade of the tool must be very precise to avoid it flexing out of alignment with the spindle. If there is a small alignment error, the blade can permanently bend like your homemade tool did. Even a little warpage after heat threatment affects this. Alignment must be precisely controlled. Warping because of internal stress in the raw material is also problematic. Depending on the face groove diameter, the insert must be tilted to get sufficient relief angles on both sides of the cutting edge. This is especially the case with small diameter grooves.
There is a way you can build a simple and stable face grooving tool for shallow cuts. Your tool holder needs to hold the insert at an 90° angle. This way you can not cut very deep in the parts face but you can realise very sturdy clamping between the tool holder and cutting insert. Also the tool gets more simple to machine in general. Depending on the diameter of the face cut, your insert needs to be angled around the axial direction of your workpiece to get sufficient relief angles on both sides. You can easily visualize this effect on paper or in cad. Otherweise try to manufacture a tool holder with a shallow grooving depth first, as it is more stable and more forgiving in small machines, including chattering
Thank you so much for your detailed comment! It's really great to have an expert talking here, super interesting and helpful! I didn't know that these tools are so critical for alignment. I probably should have set it up more carefully. Was just to excited to test it and went in a hurry. The tools you describe with the insert a 90 degree came into my sight during the researches for this build. They looked a bit awkward to me but what you say makes totally sense. If I'm crazy enough I might made a second try on a trepanning tool using this design. Getting the relief angles an the insert seat about right is really extremely difficult, especially when having no real calculations and exact measurements and doing it more by feeling.
Again I really do appreciate you sharing your knowledge with me. Thank you very much!
PS: als ich deinen Namen gelesen hab, musste ich erstmal laut lachen :D nice :D
I love hearing your thoughts via narration as you move through your work! Your design is elegant and practical so do what we all do - heave big sigh, figure out what worked and didn’t and then ‘you can do that better’!! I always enjoy watching your videos and love picking up on techniques and methods. Looking forward to the next one!
Thank you very much for your kind comment and feedback! I really do appreciate that. Thanks for your support! :)
Sad that it failed because it was very well done!
I always appreciate your builds as I learned something new every time I watch.
Thank you very much for your kind comment!
Thanks WCDTB for another great video. That was a fantastic and challenging build. You had a great set of methods for workholding/toolholding and a good idea of the geometry to achieve. It's a real shame the tool grabbed, I think that bending it back into alignment is a good idea, and heat treatment also a good idea. Good luck, please let us know what happens. PS: Also great to hear another narrated video. Thanks, Craig
Very nice work. Parting-type tools are an ongoing source of frustration.
Thanks. Oh yes, that's right right.
Dont feel too bad. Ive broken a few trepanning tools before, mostly HSS tools. They can be a real bugger to get working right on a small lathe.
Thank you very much! A HSS tool would be an option too, yes :) Next time perhaps.
One thing that can make it difficult is that lower right outer corner. The geometry to get the tool cutting is tricky. The insert has to be ground so that the corner is inside the radius. Not easy for me to explain but I hope I make any sence...
Thank you very much for sharing your skills with us. As a fellow countryman of mine once said, "If at first you don't succeed, try, try again." Also, I love your sense of humour!
some insane setups in there
called a trepanning tool btw
great production value for a small channel, definetly worth a sub
Thanks for your comment and feedback! I really do appreciate that :)
The shop I worked in ordered a trepanning tool for a particular job once. When we received it the instructions included were it was not for manual machine use CNC only. We had a Harrison CNC in the shop that it was used in exclusively without any problems.
Very nice. Some very clever setups you had there. Thank you.
Thanks! :)
Nice project! I can imagine your felling when it gets destroyed after much of work.
Oh yes, thank you :)!
Есть же Г образный резец для торцевых канавок. Зачем изобретать велосипед?
It is too bad that the tool was damaged after putting so much effort into it. I appreciate you more for being candid enough to post the failures as well.
You may have already answered this in another video, but I am really curious about your engineering background. Your work is quite impressive. My lathe is made in China and has many casting and design flaws; I do not have the bravery to attempt a fraction of what you have done to your machine to make it more capable.
Сколько нужно сводного времени,чтоб резцы полировать.
Tool steel must be the answer. Your work is great. Make a new one and heat treat like you said!
cool machine worsk and I think you are right on with the hardening, I believe the lower arm bending was purely down to the steel being too malleable.
Altogether nice job and a very cool learning experience....
Thanks for sharing
Thankyou for saving me a lot of time ! I thought your approach was very plausible- but....
I think I made the blade a little bit too long. I will heat treat the tool and try again.
Very interesting tool. Good description and editing. Subscribed.
Термообработку ни кто не отменял😂
Heat treatment and tempering would do it some good, but you did an awesome job making the tool, its a real beauty!
I was very surprised you didn't harden and temper tool holder before use.
As the toolsteel I used is a bit tricky to harden at home, I thought about using it unhardened before ruining it while hardening. But now I will try to harden it anyway :)
Neat work! good luck getting it fixed!
Thanks! :)
Can rigidity be improved by using brazing instead of screw? This way is nicer but I think that braze on top and bottom will be much steardier than that flexible clamping.
Brazing would also shorten the insert holding fingers and stiffen the tool. Heat treating the holder will also make it stiffer.
That's a really nicely made tool, definitely worth bending it back and getting it treated. I normally just eyeball a bit of HSS for trepanning work, I was doing 25mm deep x 2mm wide in 7075 this afternoon. Until I reground the tool for a smaller radius and snapped it off at 15mm deep. Bah.
Thank you! Going 25mm deep with a 2mm blade sounds extreme o: For quick work grinding a hss bit would be the best I guess. But I was curious if I could make a proper trepanning tool as I found these quite interesting :)
It may have already been said or too late, but 'heat treatment' doesn't make steel stronger, it makes it harder while sacrificing ductility. The only thing heat treatment will do is cause that fin to snap off instead of bending. With such a thin cut, you need to be tenacious about swarf removal in that kerf. High pressure wash on a mini-lathe isn't viable, but air/lube and a lot of retraction will go a long way. You should also be more aggressive with relieving the fin, you are not going to take deep cuts with that thing anyway and a lot of that fin seemed superfluous. Good luck!
Questi utensili, li ho visti solo con piastrina saldata, indubbiamente meno soggetto a piegatura. L'asportazione di truciolo è importante, dovresti usare olio da taglio per alluminio.
That looks like an air compressor valve assembly. I made one of the but used a modified hole saw to make the groove 😂. Awsome work on your tool!
Impressive engineering and execution on the lathe. I wonder if the bending was caused by the buildup of swarf and if compressed air or coolant might prevent grabbing and bending. Good luck with your project and thanks for the very well-done video.
Thanks for your kind comment and feedback! I really do appreciate that! I have no idea what caused the tool to bend. When I look at the part, there is a line going outwards. So the tool got pushes out, causing it to bend to the outside.
Straighten the blade and heat treat it. That will fix the problem. That is a very nice tool that you have created. 👍👍👍👍👍👍👍
Thank you very much, that's kind! I will try this.
Você fez um excelente trabalho, realmente as vezes não conseguimos os melhores resultados mas a construção da peça foi surpreendente.
Parabéns.
Great machining , great skills . Ive never seen machine work done on such small machines. Im subscribing ,thanks
Thank you so much for your kind feedback! I really do appreciate that!
That tool looks amazing 👍 Nice job🙂
Could the groove be cut by a rotary tool, such as dremel or rotozip, mounted on the toolpost?
That sound like a great idea! (Though not for production probably, because it should increase worktime.)
Good job! I've got to say, I started watching some of your older videos and I definitely prefer the style of this one where we can hear your voice.
Thank you very much for your feedback! I really do appreciate that. It's not that easy to talk for me, but I will try to speak a little bit more often in future videos.
Nice video and presentation. Quality channel on mini lathe. I share the frustration.
Thinking about the bending. It looks to me the loading vector coupled wasn’t tangential with respect to the top of the lower jaw. Such that a vertical force at the cutting edge (aligned to spindle axis) will be taken by the lower jaw at compound angle with a side load, towards the operator. Hence bending away from the axis, in this case.
An attempt to avoid side load, can we set cutting edge below spindle axis slightly? and watch carefully with minute offset and shallow feed a bit at a time?
Principle? Each segment / point along the cylindrical lower jaw calls for a local side load free tangential force which is impossible by any design.
Unless the top and lower jaws circumstance meet in the far side of insert, resembling a carpenters hole saw. This limits the tool to a single radius cut.
An alternative idea is to integrate the insert on a boring bar with the insert well section reshaped in favor to a deeper grove. Play what if with this in you CAD program.
Luck is on your side.
You made a beautiful tool with very limited resources. I take my hat off for you. The problem is not your holder, but the insert itself. In an small lathe you need a razor sharp insert, instear the mgmn, try the mggn series.
Thanks for your kind comment! I will try to find different inserts.
Sometimes life just goes like that... Live and learn. Next time it will be better and stronger!
Thanks! In that moment hard to believe, but you are right.
Excellent work.Any reason why you use such a thin insert ? Engravers chisel point self supported works fine for trepaning wood and -metal?Thank you.
I already had these inserts so I thought about using them on this tool as well.
Does that insert have enough side clearance to avoid rubbing?
Heat treating the tool would help, i think, but i think it's still quite likely to break. It's too long and narrow. You could either use an annular cutter in the tailstock or grind a short tool from a tool bit. Having done exactly that, it's tedious but does work.
Good question, I think it does. But it's all very tight indeed. I think for the workpiece I have to make, I will use an annular cutter now and perhaps do a second attempt on the trepanning tool later.
very nice project, we always learn something new with every project and prototype we make 👍
Thank you! :)
Very nice work. Often times you learn more from your failures then you do your victories. So they say. In this case I think the tool needs to be hard so it is rigid which is even more critical with a mini lathe that isn't all that rigid in the first place. You did an excellent job with the machining though. I think heat treat will make it work and perhaps giving it more relief on the down or bottom side of the tool. Remember also that heat will make the tool expand inside the cut so additional relief may compensate for that expansion as well as lots of lube while cutting. Good Luck
Thanks for your comment and feedback! I really do appreciate that. I think I will try hardening the tool.
Nice design. Sad that it bent. Can't you heat-treat it yourself?
Thanks for your comment! The steel I used is not that easy to harden at home. I thought about it, but decided to first try it without hardening. I destroyed it anyway :) Perhaps I bend it back and try hardening now.
Great video! Every time we learn something we're going forward.
Could you recommend the shop where you bought your slitting saw and arbor?
Hi and thanks! The saw arbor was made by myself. I made a video about it, you find it on my channel. The saw blade is a proxxon 50mm 1,1mm wide carbide plated blade.
Amazing work!
Insane what you are making with the Proxxon Mill and the tiny lathe ! could it be that you also posted this in the Zerspanungsbude ?
Thank you so much! Yes, I did ;)
I’m sorry that happened. Super impressive on the work making the tool!!! Might I recommend hardening the tool steel before using it.
Keep up the incredible work 👍🏻
Exactly what I was thinking. Had he heat treated and maybe used better material like 4140, it wouldve worked better. Still a good project and video.
I have purchased these before. Even the inserts are special with relief built into them for a given radius. Even then, I would use plenty of cutting oil. Running in reverse is bad as there is opportunity to lift the saddle of the lathe. It is likely that that small lathe is not rigid enough for this type of operation. Good work though.
Beautiful work.
Thanks!
Great video .Congratulations !
I'm enjoying your narrations on your most recent videos. The extra explanation of what and how you're doing things is most welcome.
Sorry that the tool bent. Thank you for sharing your process and posting the video, despite your setback.
Lastly, is the 3D printed multifix dial indicator holder file available anywhere? I'd love to print one for myself.
Keep on going! Loving all your content!
I appreciate your sharing success and failure - It certainly is hard to beat the uniform cutting action of a typical trepanning saw blade ie a 'bi-metallic' hole saw blade. They've been used in medicine since the time of the Egyptians. That being said, yours is an elegant way to approach the problem. Have you determined where the tool caught? Maybe put some bluing on the straightened out tool and see where it grabs/rubs?
Very cool project! Maybe you could use an insert with a sharper edge to reduce tool pressure. Like something for aluminium. It will dull quicker but the tool looks like it's meant to make a very specific part and not something for everyday use. Thanks for sharing!
Thanks! I have to search for different inserts, yes.
First harden than a little bit of anneling to relieve the stress but keeping it's composition high in the strength.
I will try.
I didn't know that a bandsaw could cut tool steel. Are you defining tool steel as being the same as high speed steel?
No, toolsteel and HSS are different things. Toolsteel is a steel which you can harden but you purchase it soft. So the bandsaw has no problem cutting it. HSS is already hardened and able to cut metal when you buy it. The bandsaw can't cut it.
Greetings dear friend. First of all i've impressed about your accuracy while doing this tool. In my workshop i've made couple of trepanning tools, but other way. I've used HSS steel blanks and a grinder. Your way is more percise and way too nice looking. But trepanning tools are limited fo their diameter capacity. Are you shure it's worth it?
Whith all my respect to you. From KZ.
Such is life with homemade tools, it was designed to be used the right way up so its not suprising it failed when used in reverse as it was a lot weaker that way. A more rigid solution might be to modify a tool with a braized carbide tip, or braize on your own if that's possible.
I noticed that you often part off with the tool upside down and in reverse, as I have a lot of problems parting I tried this and got my first ever good parting cut, the only issue was getting the tip on center which meant cutting away half the height of the tool and reshaping it. I would like to see a video on this subject as no-one else seems to do it and you don't seem to mention it either, I only spotted it in one of your previous videos. I have a Chinese 7 x 14 lathe that will never be as rigid as I would like but I have improved it a lot, including your compound rotation solution, that was soo good.
keep up the videos, they are very instructive.
I was really surprised how well the tool worked when turned upside down. In normal position it chattered like crazy. Flipped over, it runs very smooth until it bend :) This seems to be the only way to use a parting tool on small mini lathes.
I normally work with brass which will part with a HSS tool, mine is around 1mm width and it tends to drift leaving a hollow in one face and a dome on the other. I also part 2mm steel rod which is small enough to be no problem. A friend asked me to make some hand tools which start from 20mm aluminium and 12mm steel, neither of which I can part as it chatters and grabs. With the tool upside down both part cleanly, square and with almost no chatter. The problem is probably the height of the tool above the bed in relation to the width of the saddle, the measurements are around the same which causes the tool to drop slightly under load and lean towards the work causing a jam up. This is not an issue on a bigger lathe as although the tool is higher, the width of the saddle is a lot wider and therefor more stable. With the tool upside down and running in reverse, under load the lean is away from the work whick reduces the tool pressure and prevents jam ups. I am very happy to have found your channel and will have to try you gib fix on my cross and top slides as both have play that can't be adjusted out without making them unusable.
That was great setup work on the lathe. I haven’t watched anyone use a reference surface (20mm bar) to create offsets for tooling. I’m sorry that the tool holder bent.
Thanks my friend! This was the only idea which came to my mind to set the tools to the right diameters :) For this purpose, it worked just fine :)
Ferramenta ficou linda ,acho que faltou tratamento térmico e material adequado.
I think you need to remove a small amount of material on the bottom to give you a negative rake thereby giving you a bit of clearance with the lower section of your tool. Just my 2 cents.
have a question, if the circle is big the rounded area dont change their angle? ty for share
Hi, you can only cut circles in a specific range with this tool. If the circle is too big, the tool will rub and if it is too small it will rub too.
Yeah, that was always going to happen. The problem is that the radius of the tool has to match the groove fairly precisely, and any deflection or translation causes a mismatch. When it gets deflected, it changes the radius and will cause it to grip on one side of the groove at one point and on the other side at another - jamming it up - this something a crocodile style parting tool doesn't suffer from - it might rub, but only on one side. Other than being fixed to a radius, this is probably why other kinds of tools are used: if you want a shallow groove, just remove some material from a parting tool for clearance, if you want a deep groove, use a hole saw which is much more able to keep its shape.
don't worry sir you can made best tool never give up making and making
Versuch und Irrtum.
Also ich muss sagen dass du das super gemacht hast. Du hast echt viele gute Ideen. Ich dachte eigentlich das der Drehmeißel etwas länger lebt. Ich weiß leider nicht was da passiert ist, weil ich kein Englisch kann. Aber so was passiert sogar mit Fabrik Meißeln. Bei meinem Abstechmeisel wurde die untere Stufe (so wie bei dir) nach unten gebogen. Ich habe dem einfach umgedreht, auf den Ambuss gelegt und mit dem Hammer paar Mal drauf gehauen. Praktisch die Stufe wieder zurück gebogen. Und weißt du was, der funktioniert immer noch.😂😂😂
Vielleicht war die Schneide bei dir einfach zu lang. Die haben ja alle eine bestimmte Länge zum eintauchen in das Material.
Wie gesagt, schade dass ich kein Englisch kann. Dann wüsste ich jetzt was schief gelaufen ist.
Du bist aber auf dem richtigen Weg und ich weiß du kriegst das noch hin. Du wirst uns noch nicht letzte Mal Überrascht haben mit deinen Ideen.
Super Arbeit, freue mich schon auf das nächste Video.
Alles gute und bleib gesund.
Vielen Dank für deinen netten und ausführlichen Kommentar! :) Was genau schief gelaufen ist, weiß ich leider auch nicht. Ich hab einfach noch ein wenig weiter testen wollen und zack hat sich das Teil eingehakt und war sofort verbogen.
Die Schneide ist schon extrem lang und dünn. Trotzdem hätte ich bei einem "besseren" Werkzeugstahl mehr Stabilität erwartet. Ich denke, dass ichs mit zurückbiegen und härten mal probieren werde. Vielen Dank für die aufmunternden Worte! :)
Greetings. Maybe you need steel with a return memory. Like a car spring
a negative result is also an important result - he brings a view on the matter
Is there a company where you can order a costum made face groove, i have tried to search the net but no luck, allways enjoying your videos ✅️✅️
i would sharpen the insert to reduce tool pressure. i did the same with my trepanning tool btw, but it broke instead of bending :D
Very well made, i would have thought you send the tool for heat treatment then make a second video of your tool cutting different materials.
👍
We'll see. I guess, I try to fix it.
I would have started with Cobalt hss round stock. hss allows a larger cutting angle, so less force and less chatter.
Heat treating is definitely the way to go! 👍👍
I will try that, yes.
The overhang is so much, creates vibration easily
Yes, that's probably not ideal.
They are expensive but an annular cutter can do this. On soft metals a hole saw if the measurement isn't critical.
How many hours took to complete this ?
Couldn't you just have sharpened the tool steel and left our the insert? I. E. if it is for just a one of a kind job?
The steel I used is not really meant for cutting. I could have made the tool from HSS, but I have no way of properly grinding HSS and I wanted to proof if I could make the inserted style tool.
Very impressed with the build, Im sorry about the ending..
Thanks!
Excelente trabajo, pero usted necesita hacer esto mismo con acero y realizar un tratamiento térmico para endurecer.
Дуже сподобалося,ваша думка по створенню такого канавачного отрезного різця, можна було у вас попросити ,створити ще один ,для мене дуже-дуже треба для праці,можливо це?
I can only wonder whether grinding a tool from a HSS blank would have been less effort, and more robust.
It probably would be, yes. But I was curious if I can do it.
@@WeCanDoThatBetter there is no doubt you can do it! That’s why I watch your channel!
this might be the first time I hear you speak... good
It's the second ;) Made a video on metal etching where I spoke the first time, but that was not very successfull :)
Bist du Mechaniker von Beruf oder von wo hast du dein Wissen gelernt?
Man I love your work. I've been subscribed since I bought a small import lathe a year or so ago. I think you might have slightly over thought this one. Don't get me wrong your machining and understanding of the geometry of the tool was more than impressive to say the least. But grinding a trepanning tool from hss isn't bad if you have the understanding that you obviously do. If I can do it I know you "can do it better".lol
Great Work, but man thats a bittersweet moment in the End. Keep going! Maybe you trying to grind some HSS roundbar ?
Thanks for your kind comment!
You didn't heat treat the tool right? Heat treating it would definitely make it lots more rigid and it won't be able to bend and deform like that.
I don't know what tool steel it is but if it's a simple tool steel you can easily give it a pretty decent heat treat yourself with a torch, just need to be careful and patient to get it to the right temp before quenching.
Even better if you have a simple two piece or three piece firebrick forge.
The tool holder turned out beautifully though. You did a great job.
I really think you should bend it back and heat treat it with more heat being applied to the tip that holds the insert. If you do it well enough you can give the shank of the tool some moderate hardness which which prevent it from getting marred by clamping screws and have a full hardness towards the insert holding tip to provide lots more rigidity and alot less flex in the steel under cutting forces. And after just temper it back slightly.
Even if you don't get the heat treating "perfect", it will still benefit even from a moderate increase in hardness.
A very nice job on making the tool holder, and a shame about the outcome, but I think it was innevitable :(
It is a lot quicker to grind a trepanning tool out of HSS for this sort of thing. If you persist, I think that the tool holder needs some side relief, and will need to be hardened. Is there even enough side relief on the insert for it to fit into the curved groove? Thanks for posting the video, anyway :)
Thanks for your comment! Yes HSS would be an option too. But I don't have a proper way to grind HSS and I was curious about this complex looking trepanning tools and wanted to build one by myself :) The relief angles should be sufficient but it's all very tight.
I broke 2 parting tools with these cheap chinese yellow inserts, they are crap. Then I switched to DESKAR brand (also from china) and I never had a problem since. Also you just need rigid lathe for face grooving, your tool was visibly moving while cutting even in aluminium.
Эти желтые пластины с надписью NC3020 очень низкого качества, они не выдерживают длительной работы даже по пластику, не говоря о металлах. Я стараюсь их не покупать.
did you adjust the groove tool height to zero or a bit under zero? In my experience: for such a thin groove tool, even a tiny movement of the compound slide dips the tool and let it grab into the metal which causes the failure. Therefore a much more sturdier tool post should help immensely. Great work to achieve your goal non regarding a failure.
Thanks! The hight isn't that critical as the surface I'm cutting into isn't curved but flat instead. But I might not got the right position for enough clearance for the tool.
great job it sucks when it goes wrong but hay most of the time it works
keep up the great work thanks
Ah bummer, but I'm pretty sure you'll find a good workaround!
Прекрасная работа ! Жаль, что существует много способов это не делать🤣👍
I know how ya feel at the end...I made a version of this tool for parting some time ago ....but...for some reason it just didn't work quite right...grr..
At least yours looks way better then mine
Thanks for your kind comment!
Use a rotary table and milling tool for grooving in the face
If you heat treat it, you'll just snap it off instead of bending it. I'd say re-make it, and leave a little more of a fillet where the flanges attach to the main body of the holder. Or, make your flanges thicker and count on making wider grooves.
Just use tool steel and harden it after machining. And you will succeed. + other inserts are needed for such operations