Hi Joe, I tried this as an experiment at work today. My workshop foreman was pissed beyond all repair but when I showed him the results he was very satisfied and grateful to learn a new technique. Thank you.
Nice Joe, i'm a french Canadian and i spent 40 years in machine shop and it went by like a flash i am now retired. I used this setup all the time but to center my piece i just put a little pressure on it and centered it using a piece of wood in the tool holder and manually turning the chuck to rub on the piece of wood and it would center very precisely when i needed precision suppose i had only like .010-.050 to take off on the already round part. Thanks a million Joe you give me nostalgia....have a nice day!
In having my students do this over the years I have also discovered if you use a tool bit with a 45 degree lead angle rather than a rather abrupt 90 degree lead, that you reduced cutting pressure on the work piece dramatically. And as Joe points out, anything you can do to help out in this type of operation is to your benefit. This is the same thing that takes place in face milling when you use a face mill (insert style) with a 45 degree lead angle vs. A face mill with a 90 degree or square shoulder. If you are trying this for the first time I would recommend you bandsaw the rough circle out.
Be careful putting angles on the nose of your tool. An 1/8 inch wide 45 degree nose tool has more surface contact than a blunt 90. If I understand you correctly, the part would have a large sharp burr on it once the corners fall away.
Hi joe, nice job. I've been machining since I was a kid, what you did I have done, and seen done plenty of times. As with any job, there are times when you hold your breathe especially while parting off large parts. We have a hydraulic copy lathe for machining the OD of rollers for hot steel mills, we grip them between a stepped mandrel in the chuck and a stepped puck in the tail stock. We use a pressure centre, it has a large spring inside the live centre and a resistance gauge to show how much pressure has been applied by the tailstock. The pressure live centre is a store brought item, worth you looking into if your doing a lot of this stuff, if the tailstock moves a fraction, the spring still holds some pressure, and the gauge shows you straight away. Keep up the information on your channel, don't listen to the haters.
Meant to tell you, Joe, you are an eloquent speaker with excellent diction and meter. My Mom likes listening to you but she hasn't a clue what you are talking about. I 'translate'. I'm can't think that anyone with any machining ability has a difficult time with following your directions. The whiteboard and shop demo are an excellent combination. My brother purchased my old 1754 Standard Modern lathe and is experimenting. He's never cut a thread in his life! I sent him a link to you and told him to learn your method. He's subscribed!
Joe Pieczynski: Last nite I got a message from my brother about lathe threading said, "I did it!, just like Joe!!" I'm trying to teach him outside the traditional box and you're helping. He's 1200 miles away and you're helping me to teach and keep him safe. Thanks.
Great " how to " video, there will always be some nay sayers no matter what, the smart ones will learn from this It's nice to have a friend like you who keeps the memory of a buddy alive. John
I had to make a batch of discs for an order. They were trepanned out of rough cut octagons of sheet metal. Just the squares with the four corner excesses chopped off. The discs were secured to a face plate that was modified to allow vacuum to hold them in place. Also used a similar pressure block like you did but had a layer of rubber sheet 1/8" bonded too it. The vacuum chuck idea came from my woodworking, wood turners use this technique quite often and some bigger wood lathes like those by Jet have a built in vacuum chuck system. Great work mate.
I got a piece that was sheared to more of a rectangle than a square once. Right at the end of this operation, the material broke through and broke off. It came off in a string of 4 curved triangles with razor sharp radiused inner surfaces and needle sharp points connected by a remnant burr you could shave with. It was about 2 feet long and 1/8" thick. It was no doubt the most potentially damaging swarf I've ever seen ejected from a machine ever.
@@joepie221 my first experience with this was a piece of plexiglass that was 12 in in diameter and about a quarter of an inch thick. In addition to being brittle it wasn't uniform in thickness and I did not know this until I started to cut it about 400 RPM. The part ended up melting in front of the tool and the tool quit cutting. The outside diameter the part proceeded to explode in all directions and a moment later the part completely cracked and came out of the machine in three pieces. Do not turn plexiglass this way.
I have a project coming up & on the way home from work tonight i thought how can make a disc that doesn't have a hole in it? Well googled it & you were there with a solution to my dilemma you always seam to have a solution that just seams to work with the minimal of equipment but the maximum of results. Thank you Joe you are such a wealth of knowledge.
Hey Joe, I've done this over the years (40). I've opted for a thinner profile bit, made of carbide, with larger face relief, to form a sharper point. Works very well... I've had my moments. Thanks for spreading the knowledge to all the newbies....they need it!
Nice video, Joe. I used to do that in the same way. We manufactured farewell gifts out of a brass plate combined on a wooden blazon. We high-gloss polished the brass and the electricians used their special tools to etch our coat of arms into the brass plate.... That was a great time back in the days in the German Air Force. P.S. I preferred the second option. To lazy to spent to much time at the band saw ;-)
Awesome vid! My addition, I attached .030 EPDM roofing rubber to the back plate and my puck. Never had any issues. I also mark where my center was on the material when I drew my circle with a protractor. When I initially place the material against the back plate, I reference my center mark with the live center point. I suppose I could draw an additional circle that would be the same size as the puck for easy aligning... Finally, I clip off the corners around the perimeter with the shear. Thank you for spending time to make your informative videos!
As always, yet another informative and well-thought out video, thank you so very much! Guys like yourself, This Old Tony, and Abom 79 are setting the standard for all us fledgling hobbyists out there who might be struggling with the math, order of operations, and other machining issues. I have heard of pressure-turning, but the first time I've seen it, and it looks like a viable option when my fly cutter just simply won't make the larger diameters on flat, thin stock. Thanks again and NEVER stop preaching safety and respect for running equipment! (60 year old and still have all my fingers....)
Wow sir, I completed my apprenticeship in '90, done everything from medical valves to battleship prop shafts in a variety of shops and had never seen nor heard of this. Now a simple hobbyist with a fairly complete home shop, I will certainly use pressure turning when the opportunity arises. Seems like smaller diameter pieces wouldn't even induce much terror and yes what a time saver. Thanks!!
Very sorry to hear about your friends passing joe. I am sure he fought the good fight and is in a better place now. My sincere condolences to his family and friends. Thanks Joe for just being you.
Good demonstration, Joe. I appreciate your emphasis on the safety aspect of this kind of work. I have occasion to do this kind of turning a few times a year, and my method is almost exactly the same as the way you show, even including backing paper. Usually it is a precursor to making rolled end caps from brass sheet, and I use the same turning method when I go to roll the brass circle over a former, using a roller tool to form the flange part of the end cap. Again, your emphasis on safety is well received, Joe!
Most excellent. Used the technique for years. Brilliant idea with the paper if it does slip the piece will not get scratched or welded to the stock. Thanks for posting that . I see so much rubbish on RUclips is good to see something one can respect.
this guy has such great tips and shows so much. I think its really nice that a pro machinist like him is willing to share his way of doing things, and also to "teach" other people thing trough the internet. It probably cotst him some valueable time, but i havent come across a more skilled machinist on youtube yet that is sharing so much information.
First of all, thank you for share your knowledge with the people. What really moved me is the kind of person you are. Your friend Joe was a lucky person to have you as a friend. God bless you!
Thank you for that comment. Joe DeCarlo was like a brother to me. he was the kind of friend you only find once or twice in a lifetime if you are lucky. His illness was unexpected and sad. He is sorely missed by all that knew him.
Joe, you are a valuable resource in my toolbox! I would not call myself a machinist but I have had a few lathes. I have seen more recent tutorials where you demonstrate this technique. I came back to this video. I just built an ammo box stove and made 2 1/2" stove pipe and needed a damper plate. Not satisfied with making one out of ductwork sheet metal, I used pressure turning and trepanning to cut the damper from the centre of an octagon box cover. I owe you man!
I use spray glue on the driver. I've also used spray glue on a back plate when removing the pattern from chequer plate without using the tailstock. It works extremely well as long as the part stays cool.
I never heard of pressure turning or trepanning. But, I have been doing it for many years. I thought I may be the only one, first time I have seen anybody else do this. I devised method 2, trepanning, but my tool also has a profile on it too. It always lets you know it is about to break off with the noise you hear in this video. I devised the set up with a backing plate just a little smaller than the part. Never had any problems. I figured someone else must be doing it, logic says, and finally, here it is. I was doing 20 pcs about 3 times a year, but less frequent now. Definitely a great setup to loose body parts, seriously injure other parts, possibly even get to see if there is life after death.
56 years ago in the university machine shop (taking a class) we had a wood lathe. A wood plate (face plate) and a wood push plug attached to the tailstock. The normal tool bar was off and we had a post. We used an axe handle in wax - thrusting coper plates like the round you had and turning candy dishes. The handle pressed on the copper (or brass) as you moved outward stretching the metal. The bar was used as a lever point. A bit death defying if you know what I mean. Enjoyed the show and thanks for the memory recall.
I am a manual lathe machinist at a Rotary Lip Shaft Seal manufacturing facility. We pressure spin metal blanks over "roll forms" we machine to a specific diameter, and harden. We use a machinists wheel loaded in the tool block to center the blanks while clamped by pressure, much like in this video, then use the same wheel to form a blank into a case using the before mentioned "roll form". It is a very effective way to get the job done fast, so long as you feel comfortable doing this. Our metal blanks are punched out by a press though, or cut out using a circle shear. Nice video by the way!
Forgot to mention, we have customized our tailstocks on our lathes. Instead of the standard point tip seen in this video, we have like a half inch cylindrical knob type tailstock. And have custom "drivers" we make, that vary in diameter depending on what size seal we are making, with a half inch hole in the middle. Makes for a much easier and quicker time when loading blanks, since our driver is already mounted on the tailstock, and can be easily interchanged.
Wow that was intense Joe! I have never seen that done before, thank you for demonstrating, and the hint about the crush was worth it big time! Thanks again, Joe
Thank you for the great video. I have done this before on a wood lathe, but have never seen it done on a metal lathe. And yes, I have no doubt it is very dangerous. But it was still very interesting to watch. I appreciate all of the videos you have done for all of us. I have learned a lot from you. Your years of experience really stands out in these vids. I work in a CNC shop full time and have not seen anyone doing some of the methods you have shown. I'm really sorry to hear your friend passed. I lost both of my parents like that and it's hard to see anyone go like that. My prayers are with you and your friend's family. Thank you Joe. Dan
One thing on centering your parts. You already used a compass or trammel to layout the OD. layout a second circle that matches you outer pressure plate OD. Then use either two sided tape or spray adhesive to apply your gripping material to the pressure plates. And I agree that turning the square material can be unnerving at times. Plus feed with the compound set parallel to the ways. You have a lot more control on the feed with the compound than with the apron hand wheel
When centering the part, use a small hammer tapping on the edge rather then manually pushing. Not only is it easier to make small adjustments, it does not tend to off-center the tailstock end. If work can have hole in center, use center drill to make cone-hole in work, and put tailstock center directly into that. You can turn thicker pieces this way, safely, and centering is automatic. To improve traction, turn a raised rim on the headstock end at its outside edge. If you drill hole small through work, and center drill it on both sides, you can flip work over for access to both sides.
Pressure turning a thicker solid part is OK with a live center and centerdrilled hole, but for thinner material, a centerdrilled hole driver will distort the part and lead to it slipping. I don't endorse that method. Try to have as large of an od on your driver and locators as possible. It helps to deliver more surface contact.
Another great, informative video, with lots of small but significant practical and safety tips as usual. Sorry to hear about the loss of your long-term friend.
Oh goodness, Joe, that was frightening! That's something I'll keep in the back of my mind in case I ever need to do that, but I sincerely hope I never need to do it. Thanks for another great video.
I used a similar technique a while ago to take a disk out of a 3mm thick mild steel sheet. I chopped it down to rough size and shape, used a backing plate like you did and a gripper plate. The big difference is that I cut a series of eccentric grooves in the backing plate and used super glue to stick the metal to before advancing the gripper plate. i cut the disk over size so i cut break off the rough edges when the part was part way through (Cutting toward the chuck into the sheet). I then finished to size with fine cuts and deburred the plate. I have to say I was not comfortable and kept well out of the axis of the plate while it was turning - I have since bought a plasma cutter!
Hi Joe, Sincere sympathy and condolences on the passing of your friend Joe DeCarlo . You can take some comfort in the knowledge that he had a great friend in you. PS Well done on your video of the "o" ring groove in stainless steel. Keep up the good work. Regards Ian
You had me holding my breath on the second part!- Sorry to hear of your loss, I lost my wife of 25 + yrs to brain cancer (in 2011) and I don't know if I could have kept the same up beat attitude and smile every day like she did knowing that you are not going to be around to see your youngest daughter Graduate High School she was the strongest person I have ever know or met.
For the Trepanning, I think I'd probably build a plywood arch over the chuck area (to catch any flying pieces), start in automatic feed, then retreat to the far end of the workshop, until the cut has been completed.
Joe, I really appreciate your videos and techniques. I'm a mechanical engineer who designs and analyzes parts for aerospace and defense, and all too often we have bureaucratic and/or contractural walls put up between us and the manufacturers. So getting manufacturability advice from machinists during the design cycle can be really tough. Your videos have taught me a lot, made my initial designs much better, and probably made life easier for dozens of unknown machinists around the country. :D
I have over 40 years in manufacturing and had the opportunity to teach a "Design for Manufacturability" Course to 3rd year mechanical engineering students at UT Austin. It Really helps when the engineers talk to, and listen to, the machinists that have to make the parts. If you ever have a specific question...ask. Its Ok to listen. They will respect you for it.
Joe Pieczynski couldn't agree more. I've been seeking out machinist advice for nearly all of my 20 years and I haven't been let down or given bad advice yet. This latest job has made it tougher to find out who to talk to, but that's where you've been very instructive. Again, thanks for all the work you put into your videos. Great job!
I don't know how I got to see this video but Thank you So much for being so thorough, I am a CMM technician and have no Idea what's going on in the machining process. So very much happens amazing. Thank you very very much for posting this.
When I do this type of turning, I attached the plate or sheet metal to the driving plate with double-sided tape. Then I apply the pressure with the tailstock. Never had an issue doing it that way and it seems as though you would need less pressure to keep the part from flying off. And you generally wouldn't be doing enough machining to build up enough heat to break it loose from the tape.
I had never seen this technique before. I appreciate the new addition to my arsenal, and in particular the heads up on the dangers of trepanning this way. Excellent video for which I am very thankful. Yet another good one! Sorry about the sad loss of your dear friend.
Thanks for sharing this useful operation with us. A second circle slightly larger than the diameter of the pressure disk would help to locate the larger disc on center.
If you back plate was large enough, a series of short dowel pins could be added as locators and drivers for the various blanks you use regularly. It would help, but ( downside) the burr / cutoffs would come towards the tool and not the chuck.
We pressure turn aluminum tubes between centers. 22” diameter x 40” long x 1.25 wall. There is a center at each end, supporting a 1” thick plate at each end. The plates have a step that fits loosely to the bore (.2 loose or so) just to stop the tube from walking out sideways. Just in case. The OD is four pointed at each end, six inches in, at the soon to be steady band locations. The tailstock is tightened and matching steady bands are cut on the OD. Prep for this is faces get trimmed true at the horizontal. If there is some wobble in the faces, the plates at each end absorbs the effect, and the steady bands come out nice and round for the next operation.
I have one suggestion for you. Try using 3/4" phenolic material. Turn chucking surface on phenolic . mount in lathe and skim face of phenolic to remove slick surface. Thus will give you a great gripping surface and if your part spins, it will not gall your finished part. I used to make fixtures for punching flared holes that required od turning the entire length of part with no place to chuck. Its a good stable set up. I've turned up to 15 lb parts. Definately dangerous like you said but a Chuck shield helps keep your butt from clinching shut!! BTW. Never heard the term pressure turning. I just called it friction drive. Now I know right name.
Came across this now, but did this type job 6+ years ago, on 15 mm thick square plexiglas to be 150 mm round. Also machined flat bottomed groove for 'O' ring x 2 off. Didn't know about the paper 'grabber'. Survived. But knew it could go pear shaped, was careful. Thanks for this teaching.
Very Interesting. I have to do this kind of job several times a year with 1/4" thick material. I cut the blank square and hold it by the outside edges in a four jaw chuck.....so not pressure turning....when I cut through (or almost) I stop and tap the circle out later once removed. Joe's method here will make me think next time about trying it! Thanks Joe.
Wow. That second procedure made me nervous just thinking about those parts flying across the room. I built a attachment for my 4" grinder to attach to my lathe to take off the square corners before I turn a part. It takes a couple of minutes to get those sharp corners off, but I feel better afterwards when I machine the part.
Hi Joe - Very neat information - at some time I am going to make a larger throttle butterfly, after I enlarge the the throat of the inlet manifold of my car. The bit that has thus far stopped me was how to machine the butterfly - you have answered the question. Thank You
Those butterflies should have 2 center holes in them to hold them to the shaft. Put those in first and screw the blank to the face of a soft arbor. Basically work backwards.
glenn whitchurch Just a note Glenn. Most butterflys aren't round. I machine them for carburetors and injector stacks fairly frequently. Most of them are 8 or 9 degrees. Mount your workpiece to an arbor milled to the appropriate angle and tapped for the necessary screw centers. Use a backer piece to mount the butterfly to the arbor. Stack three or four discs to the arbor. The middle ones will be burr free. Check your diameter only at the screw/ shaft centerline. Turn the butterflies 4 to 6 thou smaller than housing bore. It's kind of a wobble plate nightmare when you are machining it but that's the only way to get good closure on the throttle housing. Check the edge of your existing butterfly when you get it out, if it's not square to the plate read the angle and go for it.
Since it technically seals in a radial trajectory about the shaft centerline and is driven by the bore diameter, you may be surprised at what you find if you inspect it closely. Different on each side I bet.
Hi Joe thank you for a very interesting / numerous topic on pressure turning . Yes I've had some near do's performing this operation. I'm a retired mechanical engineer but have always loved the engineering side . At 74 years old I still love it and thoroughly enjoy your engineering videos. All the very best for Christmas and New year. Best regards Brian
Early in my career I knew some manual metal spinners some of them were missing digits from this exact type of work. Indeed wise to use extreme caution when this work is necessary.
Joe, you must be psychic! I was doing this very technique, on a smaller scale, as you posted this video yesterday. 1/8 inch steel on a live centre, with a 2 inch ally hub in the chuck. I did chicken out a little with a superglue back-up.
Looks like a table-saw. This is one of your techniques I won't be using... Ps - thank you for the series of incredible instructional videos. You're my hero!
We used to make orifice plates like this for measuring water flow using stainless plate. We called it friction turning and used emery tape glued to the face plate to drive the stainless plate when turning the OD and facing, and then put it in the 4 jaw to turn the ID :)
*Thanks Joe!* METHOD #2 IMPROVEMENT Takes *pressure* off getting injured. *IDEA #1* For safety's sake - I can't see why you couldn't make a dedicated square *_backplate,_* that has holes, _starting at each corner,_ drilling four straight lines toward the center, at half inch intervals. Make the square *_backplate_* at the maximum size, _that you can get away with,_ for your particular lathe. This will allow you to turn a variety of workpiece sizes. Square the workpiece with the *_backplate,_* then clamp together. Drill a minimum of two holes on each corner of the workpiece, so the holes line up with holes in the *_backplate._* Use the *_backplate_* as a drill guide, or make a dedicated drill guide. Secure the workpiece to the *_backplate_* using eight nuts, bolts; and Loctite® - then remove clamps. This will allow a cut to be made all the way through the workpiece - virtually preventing you from being impaled by an injurious flying Ninja Shuriken. *IDEA #2* EASY CENTER ALIGNMENT Do this when not using a dedicated *_backplate._* Drill a small hole all the way through the center of the *_driver puck._* Prior to pressing the workpiece against the faced off *_backplate,_* mark the center of the workpiece with pencil, or Sharpie® marker. Align the hole of the *_driver puck_* with the center marking which has been drawn onto the workpiece. Hold the *_driver puck_* firmly as you mark its circumference onto the workpiece. Use this circle to center align the workpiece to the *_driver puck,_* thus virtually eliminating having to eyeball the concentricity of the part, then having to fidget with aligning it multiple times. : - edit - fixed typos add beginning comments :
Great video, I can see how useful this would be for turning thin walled parts that a chuck might warp in order to grip it as well. It's actually quite amazing what you can do friction and it continually surprises me how diverse it's applications are becoming. To get a better idea of how strong friction can be, a quick an easy experiment one can do at home is to take two books of about 100 pages each and interleave each page as far into each other as you can all the way through both books. Once that's done, see if you can pull them appart by the spines. JSYK, the correct term for a throwing star is shuriken and hails from Japan ;) Anyhoo, I love all the sound advice, techniques, tips and tricks you empart, I value it all highly as a relatively new and eager home shop machinist. keep up the awesome work my man, I'm loving every minute of it :)
I had to Treepan a 1x1x.125 thick x12od angle outta a 1 x12 square hunk of aluminium, for an airplane shroud....in a situation with nothing but scribe marks, a mill and a lathe with no DRO or vetical saw or rotary table. I managed it. But yes, in the end I had to Pressure hold it all, not unlike what you have described. Thanks for the vid, it helps anyone in a difficult situation, plus you add a little teaching about it.
Wow! This is amazing. I've been searching for a faster way to do this identical task. This video was great as usual and a serendipitous event for me. Thanks so much for sharing your effort and expertise
Hey Joe. Seeing your channel for the first time. Former (90%... ish) manual machinist and enjoy seeing a skilled tradesman at work. Almost miss the smell of cutting oil and dykem... almost. Legitimate question. Is there a reason you used a relatively wide trepanning (plunging) tool for the OD on the square stock? And for all of the frightened non-machinists... This is not a super safe cut, but it's a fast way to get a part out the door. Speed in turn around on jobs is the name of the game. If you ever really want your pucker factor upgraded, watch an old VTL machine with some stringy material cuts. Keep making those 6's and 9's for the rest of us, you definitely have a new subscriber.
The ideal tool for this operation would have the cutting profile on the outside of the tool. That would allow for a thinner grind. With the tip positioned to the inside, ( like this one ) the underside relief weakens the tool considerably if the top is too narrow. Plus the material was soft enough to allow for a wider tool.
If the workpiece can have a center hole, start by drilling center partway through with standard 60 degree center drill. Then pressure turn between that (tailstock live center) & the chuck plate. The workpiece is positively held throughout the process. To center already cut-round work, clamp work lightly & HAND TURN spindle while letting toolholder rub against work and slowly feeding in. Setup works like wiggler finder; the work tends to center itself unless you overfeed the tool. When manually centering work, use small mallet to tap work on center. Movement is much more controlled and there is less tendency to offset tailstock.
The larger the pressure pad, the better. On a part this size, you can be assured a single center would let the part slip under load. If you are allowed a center hole, make a cap with a recess and bolt it securely
Nice. You'd be impressed with a vacuum chuck on your lathe for work like that. It was on a CNC but the custom setup I tested trepanned no problem and then held .1 doc at .006ipr facing on a 14" sq alum plate. I don't know if there's anything commercial out there, yet, boss saw something somewhere and wanted to try it so I made it happen.
Saw a guy who used double sided sticky tape on the face of his chuck,he set the stop so the tool just touched the tape, when he cut through the off cut stayed there and took some prying to get it off, he also used the tail stock center to apply pressure.
I've done a similar operation quite a few times, and you're totally right to warn people of the potential hazards. Might I add a third method you might find handy? I usually add a few drops (6 on something that size) of superglue. Don't overheat the part while cutting, and a quick blast with a heat gun removes the part easily. Hope this is of use :) Great vid as usual!
Nice technique, never used paper in between. I work in a shop with mainly CNC, Foreman gave me a piece of 321, 3/8 round and said make these three pins and motioned to the small mazatrol lathe next to me. Two minutes later I was putting the collet chuck on the ONE manual lathe that we have, the Foreman came over and asked what I was doing. When u told him he was like, OK if you think you can hold two tenths with this. I responded with 'It turns things round don't it?' Really, bore jaws, set tools and write a program for three pins. Sad really. Took ten minutes on a manual and would have taken twice as long to do on CNC.
Sorry for the loss of your friend. This was a great tribute to your friend as his memory will live on through this video.
Thanks. He was a good guy.
Hi Joe,
I tried this as an experiment at work today. My workshop foreman was pissed beyond all repair but when I showed him the results he was very satisfied and grateful to learn a new technique.
Thank you.
Glad it worked for you.
Nice Joe, i'm a french Canadian and i spent 40 years in machine shop and it went by like a flash i am now retired. I used this setup all the time but to center my piece i just put a little pressure on it and centered it using a piece of wood in the tool holder and manually turning the chuck to rub on the piece of wood and it would center very precisely when i needed precision suppose i had only like .010-.050 to take off on the already round part. Thanks a million Joe you give me nostalgia....have a nice day!
thank you. Same to you.
Man, thanks for sharing your skills. I watch all your videos and always get something new from them, and I have been machining for 42 years!
In having my students do this over the years I have also discovered if you use a tool bit with a 45 degree lead angle rather than a rather abrupt 90 degree lead, that you reduced cutting pressure on the work piece dramatically. And as Joe points out, anything you can do to help out in this type of operation is to your benefit. This is the same thing that takes place in face milling when you use a face mill (insert style) with a 45 degree lead angle vs. A face mill with a 90 degree or square shoulder. If you are trying this for the first time I would recommend you bandsaw the rough circle out.
Be careful putting angles on the nose of your tool. An 1/8 inch wide 45 degree nose tool has more surface contact than a blunt 90. If I understand you correctly, the part would have a large sharp burr on it once the corners fall away.
Hi joe, nice job. I've been machining since I was a kid, what you did I have done, and seen done plenty of times. As with any job, there are times when you hold your breathe especially while parting off large parts. We have a hydraulic copy lathe for machining the OD of rollers for hot steel mills, we grip them between a stepped mandrel in the chuck and a stepped puck in the tail stock. We use a pressure centre, it has a large spring inside the live centre and a resistance gauge to show how much pressure has been applied by the tailstock. The pressure live centre is a store brought item, worth you looking into if your doing a lot of this stuff, if the tailstock moves a fraction, the spring still holds some pressure, and the gauge shows you straight away.
Keep up the information on your channel, don't listen to the haters.
Meant to tell you, Joe, you are an eloquent speaker with excellent diction and meter. My Mom likes listening to you but she hasn't a clue what you are talking about. I 'translate'.
I'm can't think that anyone with any machining ability has a difficult time with following your directions. The whiteboard and shop demo are an excellent combination.
My brother purchased my old 1754 Standard Modern lathe and is experimenting. He's never cut a thread in his life! I sent him a link to you and told him to learn your method. He's subscribed!
Thank you for your comment and for sending your brother my way. Much appreciated. Tell your Mom thanks and hello from Austin Texas for me!
Joe Pieczynski: Last nite I got a message from my brother about lathe threading said, "I did it!, just like Joe!!" I'm trying to teach him outside the traditional box and you're helping. He's 1200 miles away and you're helping me to teach and keep him safe. Thanks.
Great " how to " video, there will always be some nay sayers no matter what, the smart ones will learn from this
It's nice to have a friend like you who keeps the memory of a buddy alive.
John
I had to make a batch of discs for an order. They were trepanned out of rough cut octagons of sheet metal. Just the squares with the four corner excesses chopped off. The discs were secured to a face plate that was modified to allow vacuum to hold them in place. Also used a similar pressure block like you did but had a layer of rubber sheet 1/8" bonded too it. The vacuum chuck idea came from my woodworking, wood turners use this technique quite often and some bigger wood lathes like those by Jet have a built in vacuum chuck system. Great work mate.
Over the 40-plus years I've been a machinist I've done a fair amount of this I think handling Dynamite is safer.
I got a piece that was sheared to more of a rectangle than a square once. Right at the end of this operation, the material broke through and broke off. It came off in a string of 4 curved triangles with razor sharp radiused inner surfaces and needle sharp points connected by a remnant burr you could shave with. It was about 2 feet long and 1/8" thick. It was no doubt the most potentially damaging swarf I've ever seen ejected from a machine ever.
@@joepie221 my first experience with this was a piece of plexiglass that was 12 in in diameter and about a quarter of an inch thick. In addition to being brittle it wasn't uniform in thickness and I did not know this until I started to cut it about 400 RPM. The part ended up melting in front of the tool and the tool quit cutting. The outside diameter the part proceeded to explode in all directions and a moment later the part completely cracked and came out of the machine in three pieces. Do not turn plexiglass this way.
it is, it's actually quite hard to set off dynamite by accident
ask me how I know
instaBlaster.
I have a project coming up & on the way home from work tonight i thought how can make a disc that doesn't have a hole in it?
Well googled it & you were there with a solution to my dilemma you always seam to have a solution that just seams to work with the minimal of equipment but the maximum of results.
Thank you Joe you are such a wealth of knowledge.
Hey Joe, I've done this over the years (40). I've opted for a thinner profile bit, made of carbide, with larger face relief, to form a sharper point. Works very well... I've had my moments. Thanks for spreading the knowledge to all the newbies....they need it!
Nice video, Joe. I used to do that in the same way.
We manufactured farewell gifts out of a brass plate combined on a wooden blazon.
We high-gloss polished the brass and the electricians used their special tools to etch our coat of arms into the brass plate.... That was a great time back in the days in the German Air Force.
P.S.
I preferred the second option. To lazy to spent to much time at the band saw ;-)
Awesome vid! My addition, I attached .030 EPDM roofing rubber to the back plate and my puck. Never had any issues. I also mark where my center was on the material when I drew my circle with a protractor. When I initially place the material against the back plate, I reference my center mark with the live center point. I suppose I could draw an additional circle that would be the same size as the puck for easy aligning... Finally, I clip off the corners around the perimeter with the shear. Thank you for spending time to make your informative videos!
As always, yet another informative and well-thought out video, thank you so very much! Guys like yourself, This Old Tony, and Abom 79 are setting the standard for all us fledgling hobbyists out there who might be struggling with the math, order of operations, and other machining issues. I have heard of pressure-turning, but the first time I've seen it, and it looks like a viable option when my fly cutter just simply won't make the larger diameters on flat, thin stock. Thanks again and NEVER stop preaching safety and respect for running equipment! (60 year old and still have all my fingers....)
Wow sir, I completed my apprenticeship in '90, done everything from medical valves to battleship prop shafts in a variety of shops and had never seen nor heard of this. Now a simple hobbyist with a fairly complete home shop, I will certainly use pressure turning when the opportunity arises. Seems like smaller diameter pieces wouldn't even induce much terror and yes what a time saver. Thanks!!
Very rarely, RUclips suggestions do work. Glad I found your channel sir. Thanks for sharing.
Very sorry to hear about your friends passing joe. I am sure he fought the good fight and is in a better place now.
My sincere condolences to his family and friends.
Thanks Joe for just being you.
Thanks. Joe was a good friend and is sorely missed.
Thanks for all that you do for your viewers.We appreciate it
I appreciate you guys watching.
Good demonstration, Joe. I appreciate your emphasis on the safety aspect of this kind of work. I have occasion to do this kind of turning a few times a year, and my method is almost exactly the same as the way you show, even including backing paper. Usually it is a precursor to making rolled end caps from brass sheet, and I use the same turning method when I go to roll the brass circle over a former, using a roller tool to form the flange part of the end cap.
Again, your emphasis on safety is well received, Joe!
Most excellent. Used the technique for years. Brilliant idea with the paper if it does slip the piece will not get scratched or welded to the stock. Thanks for posting that . I see so much rubbish on RUclips is good to see something one can respect.
Thank you.
Russell Cresser and
this guy has such great tips and shows so much. I think its really nice that a pro machinist like him is willing to share his way of doing things, and also to "teach" other people thing trough the internet. It probably cotst him some valueable time, but i havent come across a more skilled machinist on youtube yet that is sharing so much information.
Thats a great compliment. Thank you very much.
Wow. Thanks for that. These videos can be time consuming, but its nice to know they are helping.
Love it please don't stop showing us dangerous lathe tricks
First of all, thank you for share your knowledge with the people. What really moved me is the kind of person you are. Your friend Joe was a lucky person to have you as a friend. God bless you!
Thank you for that comment. Joe DeCarlo was like a brother to me. he was the kind of friend you only find once or twice in a lifetime if you are lucky. His illness was unexpected and sad. He is sorely missed by all that knew him.
Joe, you are a valuable resource in my toolbox! I would not call myself a machinist but I have had a few lathes. I have seen more recent tutorials where you demonstrate this technique. I came back to this video. I just built an ammo box stove and made 2 1/2" stove pipe and needed a damper plate. Not satisfied with making one out of ductwork sheet metal, I used pressure turning and trepanning to cut the damper from the centre of an octagon box cover. I owe you man!
Glad to hear it worked.
I feel like I've watched every youtube machinist video possible. You Joe are the real deal.
Thank you for the compliment.
I moved to the side of my computer when you were cutting with the last method. :-)
Good idea.
First time I put on safety squints when watching a machining video!
I use spray glue on the driver. I've also used spray glue on a back plate when removing the pattern from chequer plate without using the tailstock. It works extremely well as long as the part stays cool.
Joe, I appreciate your emphasis on safety! And, I appreciate your attention to detail.
Great video Joe! Very informative. I have no idea who the haters are giving the thumbs down, but please ignore them and keep up the fantastic work.
I never heard of pressure turning or trepanning. But, I have been doing it for many years. I thought I may be the only one, first time I have seen anybody else do this. I devised method 2, trepanning, but my tool also has a profile on it too. It always lets you know it is about to break off with the noise you hear in this video. I devised the set up with a backing plate just a little smaller than the part. Never had any problems. I figured someone else must be doing it, logic says, and finally, here it is. I was doing 20 pcs about 3 times a year, but less frequent now. Definitely a great setup to loose body parts, seriously injure other parts, possibly even get to see if there is life after death.
56 years ago in the university machine shop (taking a class) we had a wood lathe. A wood plate (face plate) and a wood push plug attached to the tailstock. The normal tool bar was off and we had a post. We used an axe handle in wax - thrusting coper plates like the round you had and turning candy dishes. The handle pressed on the copper (or brass) as you moved outward stretching the metal. The bar was used as a lever point. A bit death defying if you know what I mean. Enjoyed the show and thanks for the memory recall.
Thank you for this lesson, especially your SAFETY WARNINGS. All your videos are enlightening and interesting.
Thank you.
I am a manual lathe machinist at a Rotary Lip Shaft Seal manufacturing facility. We pressure spin metal blanks over "roll forms" we machine to a specific diameter, and harden. We use a machinists wheel loaded in the tool block to center the blanks while clamped by pressure, much like in this video, then use the same wheel to form a blank into a case using the before mentioned "roll form". It is a very effective way to get the job done fast, so long as you feel comfortable doing this. Our metal blanks are punched out by a press though, or cut out using a circle shear.
Nice video by the way!
Forgot to mention, we have customized our tailstocks on our lathes. Instead of the standard point tip seen in this video, we have like a half inch cylindrical knob type tailstock. And have custom "drivers" we make, that vary in diameter depending on what size seal we are making, with a half inch hole in the middle. Makes for a much easier and quicker time when loading blanks, since our driver is already mounted on the tailstock, and can be easily interchanged.
Wow!
9th grade shop 1965 we were taught to cut the Aluminum alloy disc round before putting it in the lathe.
Joe Pieczynski is my new shop teacher.
As a 9th grader, that was probably a good piece of advice. Maybe liability insurance had something to do with it. Thanks for the comment.
Wow that was intense Joe! I have never seen that done before, thank you for demonstrating, and the hint about the crush was worth it big time! Thanks again, Joe
Thank you for the great video. I have done this before on a wood lathe, but have never seen it done on a metal lathe. And yes, I have no doubt it is very dangerous. But it was still very interesting to watch. I appreciate all of the videos you have done for all of us. I have learned a lot from you. Your years of experience really stands out in these vids. I work in a CNC shop full time and have not seen anyone doing some of the methods you have shown. I'm really sorry to hear your friend passed. I lost both of my parents like that and it's hard to see anyone go like that. My prayers are with you and your friend's family. Thank you Joe. Dan
One thing on centering your parts. You already used a compass or trammel to layout the OD. layout a second circle that matches you outer pressure plate OD. Then use either two sided tape or spray adhesive to apply your gripping material to the pressure plates. And I agree that turning the square material can be unnerving at times. Plus feed with the compound set parallel to the ways. You have a lot more control on the feed with the compound than with the apron hand wheel
When centering the part, use a small hammer tapping on the edge rather then manually pushing. Not only is it easier to make small adjustments, it does not tend to off-center the tailstock end.
If work can have hole in center, use center drill to make cone-hole in work, and put tailstock center directly into that. You can turn thicker pieces this way, safely, and centering is automatic. To improve traction, turn a raised rim on the headstock end at its outside edge.
If you drill hole small through work, and center drill it on both sides, you can flip work over for access to both sides.
Pressure turning a thicker solid part is OK with a live center and centerdrilled hole, but for thinner material, a centerdrilled hole driver will distort the part and lead to it slipping. I don't endorse that method. Try to have as large of an od on your driver and locators as possible. It helps to deliver more surface contact.
Another great, informative video, with lots of small but significant practical and safety tips as usual. Sorry to hear about the loss of your long-term friend.
Oh goodness, Joe, that was frightening! That's something I'll keep in the back of my mind in case I ever need to do that, but I sincerely hope I never need to do it. Thanks for another great video.
I used a similar technique a while ago to take a disk out of a 3mm thick mild steel sheet. I chopped it down to rough size and shape, used a backing plate like you did and a gripper plate. The big difference is that I cut a series of eccentric grooves in the backing plate and used super glue to stick the metal to before advancing the gripper plate. i cut the disk over size so i cut break off the rough edges when the part was part way through (Cutting toward the chuck into the sheet). I then finished to size with fine cuts and deburred the plate. I have to say I was not comfortable and kept well out of the axis of the plate while it was turning - I have since bought a plasma cutter!
Sorry - concentric not eccentric!!!
Hi Joe, Sincere sympathy and condolences on the passing of your friend Joe DeCarlo . You can take some comfort in the knowledge that he had a great friend in you. PS Well done on your video of the "o" ring groove in stainless steel. Keep up the good work. Regards Ian
Thank you. Joe was a good friend. It was too soon.
I'm self taught and have done this but not with paper or a holding piece like yours, some very useful advice and I thank you for this video.
You had me holding my breath on the second part!- Sorry to hear of your loss, I lost my wife of 25 + yrs to brain cancer (in 2011) and I don't know if I could have kept the same up beat attitude and smile every day like she did knowing that you are not going to be around to see your youngest daughter Graduate High School she was the strongest person I have ever know or met.
For the Trepanning, I think I'd probably build a plywood arch over the chuck area (to catch any flying pieces), start in automatic feed, then retreat to the far end of the workshop, until the cut has been completed.
Joe, I really appreciate your videos and techniques. I'm a mechanical engineer who designs and analyzes parts for aerospace and defense, and all too often we have bureaucratic and/or contractural walls put up between us and the manufacturers. So getting manufacturability advice from machinists during the design cycle can be really tough.
Your videos have taught me a lot, made my initial designs much better, and probably made life easier for dozens of unknown machinists around the country. :D
I have over 40 years in manufacturing and had the opportunity to teach a "Design for Manufacturability" Course to 3rd year mechanical engineering students at UT Austin. It Really helps when the engineers talk to, and listen to, the machinists that have to make the parts. If you ever have a specific question...ask. Its Ok to listen. They will respect you for it.
Joe Pieczynski couldn't agree more. I've been seeking out machinist advice for nearly all of my 20 years and I haven't been let down or given bad advice yet. This latest job has made it tougher to find out who to talk to, but that's where you've been very instructive. Again, thanks for all the work you put into your videos. Great job!
thank you for the demo. knowledge is always valuable, particularly when you can gain it without harm to your self. Thanks for the ongoing education.
Avoiding injury is always on top of my list.
I don't know how I got to see this video but Thank you So much for being so thorough, I am a CMM technician and have no Idea what's going on in the machining process. So very much happens amazing. Thank you very very much for posting this.
When I do this type of turning, I attached the plate or sheet metal to the driving plate with double-sided tape. Then I apply the pressure with the tailstock. Never had an issue doing it that way and it seems as though you would need less pressure to keep the part from flying off. And you generally wouldn't be doing enough machining to build up enough heat to break it loose from the tape.
Joe, I was holding my breath on that last cut. Listening for that crunch was a really good thing to know as a stop tool.
I had never seen this technique before. I appreciate the new addition to my arsenal, and in particular the heads up on the dangers of trepanning this way. Excellent video for which I am very thankful. Yet another good one! Sorry about the sad loss of your dear friend.
Thank you. I miss him.
Thanks for sharing this useful operation with us. A second circle slightly larger than the diameter of the pressure disk would help to locate the larger disc on center.
If you back plate was large enough, a series of short dowel pins could be added as locators and drivers for the various blanks you use regularly. It would help, but ( downside) the burr / cutoffs would come towards the tool and not the chuck.
I was nervous on that one ...nicely done, thanks for the video.. and lesson.
We pressure turn aluminum tubes between centers. 22” diameter x 40” long x 1.25 wall. There is a center at each end, supporting a 1” thick plate at each end. The plates have a step that fits loosely to the bore (.2 loose or so) just to stop the tube from walking out sideways. Just in case. The OD is four pointed at each end, six inches in, at the soon to be steady band locations. The tailstock is tightened and matching steady bands are cut on the OD. Prep for this is faces get trimmed true at the horizontal. If there is some wobble in the faces, the plates at each end absorbs the effect, and the steady bands come out nice and round for the next operation.
Sir I have to congratulate you on your video you are concise to the point and informative no BS no aaaaaaahs every third word. Thanx.
I appreciate the comment. thanks.
Scary as hell, but expertly demonstrated. Thank you Sir.
I have one suggestion for you. Try using 3/4" phenolic material. Turn chucking surface on phenolic . mount in lathe and skim face of phenolic to remove slick surface. Thus will give you a great gripping surface and if your part spins, it will not gall your finished part. I used to make fixtures for punching flared holes that required od turning the entire length of part with no place to chuck. Its a good stable set up. I've turned up to 15 lb parts. Definately dangerous like you said but a Chuck shield helps keep your butt from clinching shut!! BTW. Never heard the term pressure turning. I just called it friction drive. Now I know right name.
I have some LE phenolic laying around. I may have to try that. Thanks.
Came across this now, but did this type job 6+ years ago, on 15 mm thick square plexiglas to be 150 mm round. Also machined flat bottomed groove for 'O' ring x
2 off. Didn't know about the paper 'grabber'. Survived. But knew it could go pear shaped, was careful. Thanks for this teaching.
Joe, you should be running training courses for budding machinists. Your knowledge is both practical and impressive. Well done.
Thank you very much.
John Gates I think he is...
Very Interesting. I have to do this kind of job several times a year with 1/4" thick material. I cut the blank square and hold it by the outside edges in a four jaw chuck.....so not pressure turning....when I cut through (or almost) I stop and tap the circle out later once removed. Joe's method here will make me think next time about trying it! Thanks Joe.
We did pressure turning on 28" diameter 100 lb manhole covers....crazy what you can do sometimes... thanks Joe Pie
Be safe. Thats a lot of weight.
yet another great lesson Joe . very informative.
Thanks for sharing Joe. I could have used this 3 days ago, but now I'll know for next time!
Wow. That second procedure made me nervous just thinking about those parts flying across the room. I built a attachment for my 4" grinder to attach to my lathe to take off the square corners before I turn a part. It takes a couple of minutes to get those sharp corners off, but I feel better afterwards when I machine the part.
I freaking love all your tricks and tips on top of all the techniques you're showing. Thank you so much!
Hi Joe - Very neat information - at some time I am going to make a larger throttle butterfly, after I enlarge the the throat of the inlet manifold of my car. The bit that has thus far stopped me was how to machine the butterfly - you have answered the question. Thank You
Those butterflies should have 2 center holes in them to hold them to the shaft. Put those in first and screw the blank to the face of a soft arbor. Basically work backwards.
glenn whitchurch Just a note Glenn. Most butterflys aren't round. I machine them for carburetors and injector stacks fairly frequently. Most of them are 8 or 9 degrees. Mount your workpiece to an arbor milled to the appropriate angle and tapped for the necessary screw centers. Use a backer piece to mount the butterfly to the arbor. Stack three or four discs to the arbor. The middle ones will be burr free. Check your diameter only at the screw/ shaft centerline. Turn the butterflies 4 to 6 thou smaller than housing bore. It's kind of a wobble plate nightmare when you are machining it but that's the only way to get good closure on the throttle housing. Check the edge of your existing butterfly when you get it out, if it's not square to the plate read the angle and go for it.
Thank You Bob for the information
Since it technically seals in a radial trajectory about the shaft centerline and is driven by the bore diameter, you may be surprised at what you find if you inspect it closely. Different on each side I bet.
15:20
Safety Squints Fully Engaged
I have relied on those many times over the years. Great comment.
Nice @aVe reference
I've done this on a small dia but this size, well - sure gotta be careful. Really great demo Joe.
Great demo Joe, this looks like an operation for professionals only
Hi Joe thank you for a very interesting / numerous topic on pressure turning . Yes I've had some near do's performing this operation. I'm a retired mechanical engineer but have always loved the engineering side . At 74 years old I still love it and thoroughly enjoy your engineering videos. All the very best for Christmas and New year. Best regards Brian
Thank you sir. Best wishes for a happy holiday to you and yours as well.
Early in my career I knew some manual metal spinners some of them were missing digits from this exact type of work. Indeed wise to use extreme caution when this work is necessary.
Yet another great video, Joe. But trepanning that freaked me the heck out! Thanks for sharing.
Joe, you must be psychic! I was doing this very technique, on a smaller scale, as you posted this video yesterday. 1/8 inch steel on a live centre, with a 2 inch ally hub in the chuck. I did chicken out a little with a superglue back-up.
Slow, and steady, wins the race. Nice video.
I have always called it friction turning and it sure is a handy technique for a lot of jobs.
Looks like a table-saw. This is one of your techniques I won't be using...
Ps - thank you for the series of incredible instructional videos. You're my hero!
Thanks for watching them. I appreciate it.
Joe,
You are the man.,now I know you've done this before....great job, you got a lot of confidence.whew.....great video waiting for the next one..
Really simple tip. When you're marking your stock out, mark driver pad diameter too.
Thanks Joe, I am really learning new things from your videos, even after 35 years of occasional lathe work
We used to make orifice plates like this for measuring water flow using stainless plate. We called it friction turning and used emery tape glued to the face plate to drive the stainless plate when turning the OD and facing, and then put it in the 4 jaw to turn the ID :)
nice!
This Old Tony Tony!!!
Thanks for stopping by.
You the man joe, I'm learning alot from your videos, keep'um coming.
Thanks, will do!
Great demo Joe, we do some 12 X .250 6061 discs with the friction method. Works well.
Two sided tape is another option
*Thanks Joe!*
METHOD #2 IMPROVEMENT
Takes *pressure* off getting injured.
*IDEA #1*
For safety's sake - I can't see why you couldn't make a dedicated square *_backplate,_* that has holes, _starting at each corner,_ drilling four straight lines toward the center, at half inch intervals.
Make the square *_backplate_* at the maximum size, _that you can get away with,_ for your particular lathe. This will allow you to turn a variety of workpiece sizes.
Square the workpiece with the *_backplate,_* then clamp together.
Drill a minimum of two holes on each corner of the workpiece, so the holes line up with holes in the *_backplate._*
Use the *_backplate_* as a drill guide, or make a dedicated drill guide.
Secure the workpiece to the *_backplate_* using eight nuts, bolts; and Loctite® - then remove clamps.
This will allow a cut to be made all the way through the workpiece - virtually preventing you from being impaled by an injurious flying Ninja Shuriken.
*IDEA #2*
EASY CENTER ALIGNMENT
Do this when not using a dedicated *_backplate._*
Drill a small hole all the way through the center of the *_driver puck._*
Prior to pressing the workpiece against the faced off *_backplate,_* mark the center of the workpiece with pencil, or Sharpie® marker.
Align the hole of the *_driver puck_* with the center marking which has been drawn onto the workpiece.
Hold the *_driver puck_* firmly as you mark its circumference onto the workpiece.
Use this circle to center align the workpiece to the *_driver puck,_* thus virtually eliminating having to eyeball the concentricity of the part, then having to fidget with aligning it multiple times.
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- edit -
fixed typos
add beginning comments
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Securing those loose corners is a fantastic idea.
Great video, I can see how useful this would be for turning thin walled parts that a chuck might warp in order to grip it as well.
It's actually quite amazing what you can do friction and it continually surprises me how diverse it's applications are becoming.
To get a better idea of how strong friction can be, a quick an easy experiment one can do at home is to take two books of about 100 pages each and interleave each page as far into each other as you can all the way through both books. Once that's done, see if you can pull them appart by the spines.
JSYK, the correct term for a throwing star is shuriken and hails from Japan ;)
Anyhoo, I love all the sound advice, techniques, tips and tricks you empart, I value it all highly as a relatively new and eager home shop machinist.
keep up the awesome work my man, I'm loving every minute of it :)
Thanks. Thats why I do it.
I had to Treepan a 1x1x.125 thick x12od angle outta a 1 x12 square hunk of aluminium, for an airplane shroud....in a situation with nothing but scribe marks, a mill and a lathe with no DRO or vetical saw or rotary table. I managed it.
But yes, in the end I had to Pressure hold it all, not unlike what you have described.
Thanks for the vid, it helps anyone in a difficult situation, plus you add a little teaching about it.
Wow! This is amazing. I've been searching for a faster way to do this identical task. This video was great as usual and a serendipitous event for me. Thanks so much for sharing your effort and expertise
Hope it works for you.
I just love your presentation and your tips and tricks. Martin in the U.K.
Thanks Martin. Be careful with this one.
Hey Joe. Seeing your channel for the first time. Former (90%... ish) manual machinist and enjoy seeing a skilled tradesman at work. Almost miss the smell of cutting oil and dykem... almost. Legitimate question. Is there a reason you used a relatively wide trepanning (plunging) tool for the OD on the square stock? And for all of the frightened non-machinists... This is not a super safe cut, but it's a fast way to get a part out the door. Speed in turn around on jobs is the name of the game. If you ever really want your pucker factor upgraded, watch an old VTL machine with some stringy material cuts. Keep making those 6's and 9's for the rest of us, you definitely have a new subscriber.
The ideal tool for this operation would have the cutting profile on the outside of the tool. That would allow for a thinner grind. With the tip positioned to the inside, ( like this one ) the underside relief weakens the tool considerably if the top is too narrow. Plus the material was soft enough to allow for a wider tool.
Joe Pieczynski That makes sense. I appreciate the response. Hope you have a great week.
Thanks Joe -cool video. I suppose we could say "Joe Pie master of the one jaw chuck!"
Regards John Spargo in Cape Town
Jaws, I dont need jaws....
Hi Joe,
Good timing Joe. Scary videos right before Halloween.
Steve
If the workpiece can have a center hole, start by drilling center partway through with standard 60 degree center drill. Then pressure turn between that (tailstock live center) & the chuck plate. The workpiece is positively held throughout the process.
To center already cut-round work, clamp work lightly & HAND TURN spindle while letting toolholder rub against work and slowly feeding in. Setup works like wiggler finder; the work tends to center itself unless you overfeed the tool.
When manually centering work, use small mallet to tap work on center. Movement is much more controlled and there is less tendency to offset tailstock.
The larger the pressure pad, the better. On a part this size, you can be assured a single center would let the part slip under load. If you are allowed a center hole, make a cap with a recess and bolt it securely
Nice. You'd be impressed with a vacuum chuck on your lathe for work like that. It was on a CNC but the custom setup I tested trepanned no problem and then held .1 doc at .006ipr facing on a 14" sq alum plate. I don't know if there's anything commercial out there, yet, boss saw something somewhere and wanted to try it so I made it happen.
Saw a guy who used double sided sticky tape on the face of his chuck,he set the stop so the tool just touched the tape, when he cut through the off cut stayed there and took some prying to get it off, he also used the tail stock center to apply pressure.
You can just superglue it to a flat aluminum plate with a.couple rings cut into the face a few mil. Warm it slightly and superglue gives.up its bond
I've done a similar operation quite a few times, and you're totally right to warn people of the potential hazards. Might I add a third method you might find handy? I usually add a few drops (6 on something that size) of superglue. Don't overheat the part while cutting, and a quick blast with a heat gun removes the part easily. Hope this is of use :)
Great vid as usual!
Someone suggested screwing the corners down. I like that one too.
I don't know what I'm doing here but I like it!
Awesome video. Pressure turn a lot at work. Never thought about the sandpaper. My “new learn” for the day. Thanks Joe!
If your doing production quantities it may make sense to work up a quick removable alignment jig. Thank you for all the knowledge and wisdom.
Nice technique, never used paper in between. I work in a shop with mainly CNC, Foreman gave me a piece of 321, 3/8 round and said make these three pins and motioned to the small mazatrol lathe next to me. Two minutes later I was putting the collet chuck on the ONE manual lathe that we have, the Foreman came over and asked what I was doing. When u told him he was like, OK if you think you can hold two tenths with this. I responded with 'It turns things round don't it?'
Really, bore jaws, set tools and write a program for three pins. Sad really. Took ten minutes on a manual and would have taken twice as long to do on CNC.
Jeremy Tenorio sorry bud unless you polished it in and checked it with indicating mic's at the least. No you didn't hold "2 tenths" on a manual lathe.
I've done it a thousand times. You have to be aware of the heat of the part and use the correct measuring device, but many manual lathes can do it.