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.

We learn something every time we try - we only fail if we give up before we succeed. Good video!

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.

As always, you have uploaded a video of a mad genius at work.

I always appreciate your builds as I learned something new every time I watch.

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

I'm sure that a Heat treated part Will work perfectly! Believe me, The hardest work you've made with perfection! Congrats!

Very interesting tool. Good description and editing. Subscribed.

That tool looks amazing 👍 Nice job🙂

Amazing work!

Nice project! I can imagine your felling when it gets destroyed after much of work.

Great video .Congratulations !

Very nice. Some very clever setups you had there. Thank you.

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!

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!

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.

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

Sad that it failed because it was very well done!

Neat work! good luck getting it fixed!

Thankyou for saving me a lot of time ! I thought your approach was very plausible- but....

Você fez um excelente trabalho, realmente as vezes não conseguimos os melhores resultados mas a construção da peça foi surpreendente. Parabéns.

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

Beautiful work.

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!

Heat treatment and tempering would do it some good, but you did an awesome job making the tool, its a real beauty!

some insane setups in there called a trepanning tool btw great production value for a small channel, definetly worth a sub

Great machining , great skills . Ive never seen machine work done on such small machines. Im subscribing ,thanks

very nice project, we always learn something new with every project and prototype we make 👍

Very nice work. Parting-type tools are an ongoing source of frustration.

Super good

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.

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.

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.

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

Thanks to information 🙏

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!

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.

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 👍🏻

Sometimes life just goes like that... Live and learn. Next time it will be better and stronger!

a negative result is also an important result - he brings a view on the matter

Good vid 👍

thank you.....Paul in USA

have a question, if the circle is big the rounded area dont change their angle? ty for share

Heat treating is definitely the way to go! 👍👍

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!

They are expensive but an annular cutter can do this. On soft metals a hole saw if the measurement isn't critical.

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.

Great !

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

Very good 👍

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?

great job it sucks when it goes wrong but hay most of the time it works keep up the great work thanks

Great video! Every time we learn something we're going forward. Could you recommend the shop where you bought your slitting saw and arbor?

Could the groove be cut by a rotary tool, such as dremel or rotozip, mounted on the toolpost?

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.

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

Straighten the blade and heat treat it. That will fix the problem. That is a very nice tool that you have created. 👍👍👍👍👍👍👍

super very nice👍👍👍

Great Work, but man thats a bittersweet moment in the End. Keep going! Maybe you trying to grind some HSS roundbar ?

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.

this might be the first time I hear you speak... good

Dobra robota ! :) 🦾🦾🦾🦾🦾

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 was very surprised you didn't harden and temper tool holder before use.

Espectacular !! Faltaria Templarlo.

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 ✅️✅️

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.

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.

Ah bummer, but I'm pretty sure you'll find a good workaround!

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.

Nice work bro Its a part of work But appreciate your thoughts

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.

Insane what you are making with the Proxxon Mill and the tiny lathe ! could it be that you also posted this in the Zerspanungsbude ?

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.

Very impressed with the build, Im sorry about the ending..

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.

How many hours took to complete this ?

Nothing gets learned when nothing fails

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. 👍

Высочайшее качество изготовления!

Прекрасная работа ! Жаль, что существует много способов это не делать🤣👍

Greetings. Maybe you need steel with a return memory. Like a car spring

Ah sometimes that's the way it goes. But without trying you'd never know. Great work though. Regards. Steve.

Термообработку ни кто не отменял😂

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 didn't know that a bandsaw could cut tool steel. Are you defining tool steel as being the same as high speed steel?

First harden than a little bit of anneling to relieve the stress but keeping it's composition high in the strength.

Ferramenta ficou linda ,acho que faltou tratamento térmico e material adequado.

If you need to cut a smaller cylinder out of a large cylinder, install a milling spindle or a hand-held milling trimmer in the tool holder of the lathe. Install the mill parallel to the cylinder in the right place, turn on the rotation of the lathe chuck at minimum revolutions, approximately 10 revolutions per minute, and, at a low feed speed of the longitudinal movement of the caliper, drive the rotating mill into the cylinder. kzfaq.info/get/bejne/l6pzobiqvNjXZoU.html

Very impressive work, it's a shame that it bent.

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.

I made it from a round holder, left a round side cheek and soldered a car tenon, firmly.

Friend, the problem is not the tool that causes vibrations, it is that you do not have a wider surface in the car to be able to hold the tool holder on the car, you need to make a wider surface to be able to hold the holder to the car.

I would have started with Cobalt hss round stock. hss allows a larger cutting angle, so less force and less chatter.

Nice design. Sad that it bent. Can't you heat-treat it yourself?

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.

:( Hope the heat treatment helps that issue