Rotary Broaching a Hex Key Recess on a Mini Lathe

[@tenlittleindians]

We experimented with using a cnc lathe to do the broaching. We used a commercial purchased broach that looks very much like yours and we mounted it rigid in one of the collet holders in an AmeriSeki lathe. We drilled the hole in the part to max diameter and plenty deep to allow for a place for the curled chips to go. We programmed a spindle lock and fed the broach into the hole on center. We thought the machine might alarm out under the pressure but it had no problems. We did put a stop in the program so we could brush on cutting oil before each hole. We made thousands of parts like that back in the 90's.

[@Deltarig]

Awesome! Rotary broaching is definitely a massive achievement in the world of machining. It takes a gifted person to come up with an idea like this, the first time I saw it work it changed my way of thinking. The principals and the concept are invaluable. Great video.

[@deucedeuce1572]

Yeah, it is a brilliant idea. It's not even easy to imagine how the parts work and move. If you didn't know, most people wouldn't be able to figure it out. I'm not normally confused when it comes to mechanical things... but this one took me a minute to figure it out (when I heard about them a couple years ago).

[@WeCanDoThatBetter]

Great job! Never seen a rotary broach built this way without real bearings. Interesting approach.

[@tomsmith3045]

Fantastic video, thank you! I love that you are building functional tools with home sized equipment, and even more that you demonstrated approaches that didn't quite work out. The former demonstrates what's possible, and the latter is going to save many people quite a bit of time, as well as imparting us with more knowledge.

[@cognitivedissonancer]

Excellent video, well shot, edited, and narrated. It's great that you include your entire process, and not only successful highlights. The included references are also a nice touch! Keep up the good work, it has been a pleasure.

[@mikedrop4421]

It appears that This Old Tony has been a strong inspiration for this channel down to the camera angles, on screen graphics and subject matter. I'm super excited about this channel. Finally the YT algorithm recommended something I want to watch! Edit: he's even wearing a black sweatshirt like TOT always does. This can't all be coincidence. Well done good sir I'm loving the videos.

[@jklmnop8607]

I've never had to create a hex recess before, but for my work as a machinist/engjneer/problem solver, this looks like an excellent addition to my bag of tricks for incorporating into possible future projects. Thanks. You just never know where the next idea will come from.

[@DursunX]

i havent touched a lathe for 30 yrs.. this video awoke my curiosity. excellent tutor

[@c0rificus]

You have a very calming and reassuring voice which makes the things you are saying easier to digest. Good video!

[@philipbarker7672]

At last I found another machinist channel to gorge on. Good work.

[@CM-xr9oq]

At last? How about Abom79, oxtoolco, AvE, Keith Fenner, This Old Tony, Robrenz, NYC CNC, Edge Precision,

[@philipbarker7672]

C M I did say another. I also watch the others.

[@davewilliams6172]

@@philipbarker7672 I'm glad I am not the only one with a growing list of channels...just wish I could spend as much time in the workshop as I do on KZbin.

[@chipmunkshavenuts]

I've recently made a rotary broach not very long ago to do a 10mm hex in steel. Made the broach out of tool steel, didn't make the hex much longer than the depth I wanted to keep from thinning it out with the relief angle. I also center drilled the other end. I hardened in oil as specified for that tool steel, used a torch to draw to straw color. For use, I just adjusted the tail stock slightly to the side, and used a live center in the center drilled spot on the back end, and used the tail stock to push it against the hole in the steel, with the broach just floating between those two points. Worked great!

[@dennisjewitt3809]

Great video full of practical use and without time wasting

[@oskarGoesTubbe]

We need more of The Recreational Machinist's content. :)

[@DudleyToolwright]

Wonderful narration and well shot. The video was really well paced and shot. I think you are going to give Clickspring, the channel, a run for it's money.

[@mikedrop4421]

You are right about most of that but it's not Clickspring who's got the competition incoming.. It's This Old Tony. These videos could be played without sound for the majority of TOT fans and we'd all buy it as something Tony made a year or so ago.

[@DudleyToolwright]

@@mikedrop4421 You make an excellent point.

[@AMRAMRS]

@@mikedrop4421 You are extremely wrong man. This man couldn't time travel on the lathe

[@mikedrop4421]

@@AMRAMRS that's exactly what a timelord would want you to think. Besides, I think he uses the mill for quantom jobs

[@edgeeffect]

The title sequence is ace... I love that fly cutter and micrometer turning into an "R". The video itself is well shot too and the narration is neither to hurried or too meandering... good to see you leaving your "stupid" mistakes in too... 'cus we all make them. All in all great stuff, hope to see more... keep up The Great Work. (AND this is the clearest and simplest explanation of rotary broaching I've seen)

[@mikebarton3218]

Just stumbled across this channel. Wow what have I been missing! I subscribed and now I'm going to catch up on your content. Great to have a British channel to watch. Thanks. Mike

[@joycemiller4716]

Why not English

[@judd_s5643]

I believe Chris of Clickspring has set the Bar in editing/narration of “machinist” type videos and I believe this video is equal in quality. Excellent work, very informative and enjoyable to watch!

[@n0f8r]

fascinating stuff - and thanks for the rotary broach explanation in the description - I would never have guessed what was going on.

[@TheRecreationalMachinist]

Glad you enjoyed it

[@par5endos562]

Fantastic presentation. Video, narration, content, it's all a pleasure to watch. Well done!

[@donsmith9797]

That's an awesome little side track, loved it.

[@howardhughes6311]

You need a fillet at the corner of the broach, that's why it broke. You had a sharp corner and it became a stress riser. Nice job on the video.

[@ЕвгенийСалин-в9о]

история тгрушнк

[@lsubslimed]

I agree that the corner or shoulder shield have a decent radius to it to distribute the stresses, but it actually looks like it broke near the base of the shaft rather than right at the base where it would have broke if it was caused by a stress fracture at that cross-sectional transition... unless I'm seeing it wrong?

[@jklmnop8607]

A lot of factors come into play here. I think he got it right on the choice of heat treating method. In the first go round, his part spent too long in the furnace and experienced grain growth. You're right about the corner radius, but also, be careful not to make the tool longer than necessary. It's a cantilever beam, where longer equals reduced rigidity.

[@tobinator999]

As a mechanical engineering student, taking a machine design class, I found this particular comment thread super interesting!

[@index7787]

What a clever way to broach. Who the hell thought of that first.

[@binness]

I have no idea, however it as been used for over one hundred years, Hemingway Kits in the UK will sell you the plans

[@RenoLaringo]

Wow, it takes some serious imagination and logical sense to only think of such a method. I didn't know of this technique. Thanks for this very comprehensive video. I also really like the narration. Very well done sir.

[@binness]

Look up rotary Broach, a UK company called Hemingway Kits will sell you the plans, and by the way I have nothing to do with them

[@RenoLaringo]

@@binness Thanks mate, I definitely will !

[@samcoote9653]

Found this channel through Facebook, enjoying so far! love the content! :)

[@michedmck]

Beautiful production, yielding excellent results! I have been wanting to make a broaching tool for some years now, but have always been mystified by the mechanism required to cause the broach to "wobble". Your method precludes the use of the wobble method. I will copy your design unashamedly! Thank you indeed!

[@joksutube]

I love the smell of hot metal and coffee in the morning. Very well done and thank you.

[@rbpercussion89]

Woah. Everytime I think I've seen the limits of the mini lathe I see something like this

[@DubsnSubsSessions]

Subbed. Great technique I would never have thought of! And nice to watch a UK video that doesn't sound like an old man trying to speak between nasal sprays...

[@ronstar8857]

Very nicely done. I learned quite a few tips watching. Thank you for sharing!

[@stylr882]

Great channel. You have nailed it with the format. Informative and entertaining. Like a British This Old Tony :)

[@3maticod]

agreed. Finally another machinist to add to the sub list!

[@JohnJones-cp4wh]

When making the broach, use a corner radius cutter to avoid a sharp corner, that will extend the life of the broach.

[@theonlybuzz1969]

Excellent job I will be remembering this information for some of the custom jobs that I produce, thanks for showing us this, very impressed indeed and I just feel like nipping into work and produce one just to experiment with, this would be great for those not off the shelf fasteners, thanks again...Phil

[@calumbmx1]

Only just found your channel, love the ingenuity required working in a mini machine shop! Waiting for the next episode

[@Dancing_Alone_wRentals]

I'm not sure I understand what my eyes just saw. Great video tHanks for posting

[@ensen89]

You can take a small drill bit and drill a 6 hole pattern inside your 4,62mm circle. The small holes should be tangential to the hex. That removes a lot of material and makes it easier for the broach.

[@TheAwesonymous]

You sound like a narrator on a TV documentary. Nice.

[@robertfensome9293]

Awesonymous RC

[@baraw87]

Keep up the good work, your videos are nicely shot, very well narrated, and to the point! Please keep the content coming!

[@mrayco]

Last week I have made hex abroach I used drill bit tail I machined it as well and hardened it ,, I had success without broken it… ..thanks for sharing.

[@core4365]

This is my favorite video on the internet

[@oldschoolengineer58]

This video is impressive, the narration is spot on one of the best on you tube, nice clear british accent (instead of the usual Yankee or Aussie). so i have subscribed thanks for sharing

[@newmantoolsinc]

Great video. I used this to show various tools being used to my son.

[@JarppaGuru]

3:83 Wow thanks genious mike. this method is knows 100 years LOL

[@biggles258]

Excellent video. Extra points for the pie in the oven at 7:25 :)

[@colleenmolley244]

Fascinating,I could watch this all day

[@Workshopfriend]

Very well produced. Thank you.

[@Cactusworkshopchannel]

very interesting! I knew the technique but I didn't think it would be this "simple" cheers!

[@PropKnucklesFPV]

If you keep it up, your channel will get big!

[@markhobster8113]

great work and this will help a lot, I was thinking of buying a rotary broach kit but ill be sure to try my hand at this one, cheers fella and the pie in the oven to make extra use of the heat is exactly what I would do ;)

[@bobuk5722]

Wow! Such a simple, elegant design. BobUK.

[@dwightcarlson7136]

Looks like something to try to just prove it can be done. Excellent video!

[@argentknight7557]

Thank you Sir, this video have made Me very motivated to make one rotary broach.

[@Preso58]

Hey, great result! That looks completely doable in my shop. Thanks.

[@daos3300]

now we know what sean bean does in his spare time ;)

[@ifell3]

Wow nice result!! You know about the dangers of that wool stuff and inhaling fella.

[@lawrencedavidson5550]

This was in my recommended and glad it was.. I will use this method on some of my projects. Thank you... Subbed.

[@fmdc7442]

I love all the demo and job, thank you!

[@hugostiglitz6914]

I only managed to do this a couple of times and although was easy on brass.just couldn't manage steel unless I used an induction coil. Also, I never cut the hex all the way down the entire length of the tool. Just the tip and the rest just slightly smaller diameter than the diameter of the original hole. It also still needs a corner radius where the tool diameter increases. Having said that yours seems every bit as good with a little modification.

[@_P0tat07_]

It’s not often I subscribe to a channel after watching one video. This is one of the cases where I do.

[@EDesigns_FL]

This video came up on my recommend list and I'm glad it did. Considering how great your narration and production are, you're likely to get a lot more subscribers very soon. Your like Clickspring, but with more relevant content;)

[@musicmaneman38]

That was awesome! Angular broaching a blind hole.

[@KevsShed]

Great video, you sound exactly the same as the guy that narrates How It's Made on TV :)

[@linginfelterh]

What gems one can find by looking around the KZbin. Loved your switchbox. Quite the design. Great job on the vids, you have a new sub. Looking forward to more great content.

[@TechGorilla1987]

What a wonderful video! I happened upon this randomly. Thank you!

[@clist9406]

That was a lot of work , nicely done

[@VanoverMachineAndRepair]

Nice video very well shot

[@ARIFINLATHE]

Your idea is very good sir I was inspired to make it sir.. greetings to Indonesia🤝🤝

[@Zakamooza]

i have the same lathe! very useful , please make more videos on it ! subscribed

[@ErtOzk]

Metric lathe guy on youtube. Long way to become ThisOldTony. Love it 😂

[@Tehinke]

Lovely video. But there is a much easier way. Although anything but as fancy like the way you did it. For such small holes as 4-5mm you can just take an allen key and cut it off. Upset it a little with a hammer and grind the edges sharp. Put it in a chuck in the tailstock and mount your workpiece in the main chuck. Prepare the hole just like in the video and then, with the spindle not rotating slam the allen key into the hole and you're done. Takes just a few minutes. I've used this method for mass production in brass.

[@deckdriver]

This Old Tony would be mad after spending a lot of moneys on buying a rotary brother! Great work!

[@deepinuranus3433]

TOT does and has made his own. Did a square one recently.

[@deckdriver]

@@deepinuranus3433 just the bit it self. He said the holder cost as much as his power filer.

[@deepinuranus3433]

@@deckdriver that's right, he did. I remember that now. I've never priced one or need one yet. I asume it's a holder with a slight ofset bearing in em. Never had a fiddle with one.

[@StevesProjects]

Enjoyed that. Hardening and tempering at different degrees within the same work piece is always tricky, I've had plenty of similar failures.

[@the4thj]

Second time I watched this, and the This Old Tony one too. I wish I could just buy these made lol!

[@djamelhamdia134]

Am I the only one who is astonished by the way he is talking and narrating.

[@core4365]

This is my favorite video on youtube

[@npaisnel]

Brilliant Your dedication to do something totally unnecessary, just ‘ because ‘ is brilliant. You’d fit in well here down in our workshop. One thing I can’t get is why the workpiece and the tool both needed to spin. I can understand where you have a cutting tool with a hollow centre and a drill bit internally, but your cutting tool is solid... can’t see why you spin it all as both parts are stationary to each other. Excellent video

[@npaisnel]

Ah ok Get it now kzbin.info/www/bejne/al6WmIONoZuqnLc

[@BurtonsAttic]

Nice work!

[@monstieb2122]

I just wonder why only 2k subscribers, brill video mate, SUBBED

[@tatemantis9293]

Monstie b 2k, he’s at 6.3k now, this channel must’ve exploded in the last 3 days judging by your comment age.

[@tatemantis9293]

James Lintell-Smith Now 7.5

[@abimanyu9887]

amazing video

[@grottonisred6541]

Excellent video...

[@russtuff]

Nicely done

[@thlee3]

I had absolutely no idea what you were making until the end

[@Jonhenrysneip]

Great video. Tools we all wish we had 😀

[@Just1GuyMetalworks]

Nicely done!

[@davidgodwin8590]

Using an end mill with a radius edge instead of a square one will help to eliminate the stresses causes during the heat treat. The other thing that will help is to quench in oil instead of water. It is a more “gradual” quench and helps to minimize stresses in the steel. Overall a great video though. I’m definitely gonna subscribe.

[@chair2930]

Dude, throw in a few dad jokes and you'll be the British This Old Tony!

[@buddydog1956]

TOT, without a doubt,............is freakn' hilarious!!!

[@goldeee666]

amazing work well done thank you for posting

[@kinnikuzero]

Just found this channel, subbed.

[@jodyolivent8481]

Nice job and keep up the awesome videos!

[@wezzzvanderlinden2019]

Nice poliangolar!! nice job!!

[@deucedeuce1572]

I've always heard that quenching parts in water like that made them brittle and weak. Just recently heard about "silver steel" that said it could be quenched in water... but the person that said that said that other steels can't be quenched in water though.

[@bryansullo9798]

What an insane amount of work! I would not have the patience for this.

[@ArfurFaulkesHake]

I just remembered the words every Milling/Laithe-Instructor says to each trainee at least once.

[@smallcnclathes]

Might I suggest the broach could have been cut shorter and a radius runout would improve the strength. Use drill a little larger than 4mm and make sure to drill deeper to give the swarf (chips) some where to go. If the drill drills right on 4 mm that is making the broach do a lot of work. My rotary broaching tool is from Slater Tools in the US, brilliant piece of kit. Nicely done video thank you

[@pigpig19d]

nice! have never heard of rotary broaching. thanks for the video

[@matthasaname]

Utterly brilliant.

[@rotating-alfadiq]

Thanks for sharing, Veri completed

[@YourOldDog]

Great video and explanation. I expect the failure cutting the steel piece was due to all the stress risers at the base of the cutting tool. A small round file and polishing the base of the cutter head would drastically reduce your stress risers. Someone else may have mentioned this but I haven't read all the comments. Thanks for taking the time.

[@patrickbuildsalot5348]

Watches all of them. Really got videos.

[@jaspermcconnell6417]

I really like this version of the broaching setup. I built one that uses a MT in the tail stock and the 1 degree offset puts a lot of stress on the tail stock as it tries to turn off center

[@nexoxenigma3805]

Nice video! My hex collet block also doesn't have even corners, but I prefer to grip it on the flats with the vise, so I use a couple 10mm round HSS tool blanks as parallels so the block rests on the flats, not the corner.

[@CreaseysWorkshop]

Excellent video