This video discusses the basic setup of a parting tool for the best results. I'll show you different types, grinding tips, and a few suggestions for saving some time.
When my old man had to make a bunch of washers/spacers,he would plunge in almost to the diameter of the bore,then make a finish pass on the bore,and the parts would 'plink'.... end up on the bar. Try it
Joe, fantastic video. You are a very good machinist but your best quality is your ability to communicate. You are amazing. Parting has been a challenge for me but I came up with a method that works every time without fail (with power feed). In my opinion (and I suspect you will agree) the very biggest reason for failures while parting tool movement. When something isn't solid you get chatter and sometimes it grabs bad enough to break the blade etc. The reason an upside down tool helps is that if something moves it climbs out of the cut rather than into the cut. When you cut from the front the amount of back rake can amplify the problem. A negative back rake will be much less likely to dig into the work but does not cut very well. I have small old lathes with screw on chucks that are not very solid but what I came up with is nearly fool proof. Oh... and I used the same blade profile you do, absolutely the best! Leave me a comment and let me know what you think. Thanks! ruclips.net/video/HGAQHjzgs9c/видео.html
You BOTH are great. Since I have subscribed to your channels I have learned so much. We need people like you. Thanks and should you come to Florence let me know, I will show you my city and offer you a REAL Italian coffe. Take care and stay save
Hey Joe, Great video with plenty of important tips, HOWEVER, there is a VERY important one you missed out. That is, NEVER grind a top rake or chip breaker into the top of the blade. Because the blade is either tapered or hollow ground, as soon as you cut deeper than the grind depth, the tool will bind. That is because when you grind the tool top, the blade becomes thinner in width and will cut a narrower slot, and when it tries to cut past the grind depth, the tool being wider will jam and may break. Some other great tips for the un-initiated users out in RUclips Land are as follows :- When parting off bolts / all thread, initially only have enough blade sticking out to just get past the thread depth. When the tool is ground with a slight taper as you showed to not leave a pip on the finished part, it will want to try and follow the thread helix, causing the tool to flex sideways. Once you are cutting a smooth diameter, then extend sufficient blade to finish cutting off the part. When parting off a large diameter, say 2 inch, start off with only a short length of blade sticking out. Then as the cut gets further in gradually pull out more blade. Because the tool is at an angle in the holder, you will need to lower the tool holder height slightly to bring the cutting edge back onto center height. When parting off, try and not be too timid with the hand feed, once it starts to cut, keep the feed going at a constant rate. Hope this helps, keep up the great video’s and well done for getting over 3,000 subscribers so quickly.
Thanks Dave. The top rake is a very tedious thing to do and not for new comers for sure. You can get away with it, but you have signed a death warrant for the tool. When grinding that top rake, you can only go to the very front top edge and no further. Don't forget to grind the front first, or the tool is already doomed. The the taper starts to come into play. Its a narrow window of success. I usually keep a hand ground HSS tool bit handy when doing bolts to start my part off track. Those threads will dominate the parting tool everytime. Its amazing just how much they can flex side to side. Thanks for your input and well wishes. Always welcome.
Thank you for your tips. Thoughtful and educational. I too have had some parting tool nightmares. Couple comments though. For an older lathe, one with wear, I have had much better success with the parting tool 1/64 to 1/32 above center. Anything less causes the parting tool to be drawn into the work due to excessive backlash in the top slide for cross slide. I too like the truncated triangular HSS parting too. Chatter is significantly reduced or eliminated by grinding a "u" into the front of the parting tool. Chatter seems proportional to the width of the parting tool. The "u" grind gets the job done especially on ductile Iron or stainless. I expect a V grind would be better but my diamond wheel does not have sharp edges anymore! Top rake or clearance, I've had better success with 5°. Front rake, yes 12° seems good. I also put a India stone to the cutting edge, prefer a rounded cutting edge as opposed to sharp. My go to engine lathe: clausing Colechester 13x36. I've got two, vintage 1956, and 1968. Again really appreciate the effort knowledge and experience you provide.
I make my parting tools from old carbide tipped saw and dado blades. Parting tools in my price range were disappointing at best. I was sceptical at first but it works well for me. This is about the best basics video I have seen. You have a knack for teaching. There are a handful of people on youtube that are good at both machining and teaching. You are one of them. Keep it up.
I very rarely comment on videos but the 2 i've watched (so far!) of yours are brilliant. have you done any teaching? if not you should as you are very good at explaining things clearly. Takes me back to being at uni, only with a better teacher. cheers
Thanks Nick. That's a great compliment. The only teaching I've ever done was as an in house instructor at my last company teaching University of Texas engineering students a course called 'Design for manufacturability. It was very rewarding to all involved. I had a bunch of apprentices under my wings many time as well.
Never set a parting blade above centre. If it takes extra pressure to get the tool to cut it will deflect down and grab the work. The work will ride over the blade and break or spit the job out of the machine. Parting blades set on centre height QED.
And above center height the tool holding side rotates into the work instead of away, perpetuating the feed in + chatter and breaking the blade before you have time to back off the feed....I broke blades constantly while following the above center advice. Then I tried a few thou below, and haven't broken a blade since.
I started watching your various videos and have learned a lot, although I have been machining for over 30 years, these are basics that every wannabe machinist should know if they are to be successful at machining.
Joe, I had quit using my parting tools altogether. I just couldn't get it right. I saw you video and took notes and now..no problem! I still can't get over how smooth it works! I originally got to your videos by accident while researching threading. I formerly had a gunsmith business and for years stayed puckered up when threading to a precise shoulder I had just meticulously created where the barrel and action mated. Since learning your reverse threading procedure it is super simple. So logical, wonder why I never heard of it before. Now I try to watch all you videos for the shear entertainment and knowing I will pick up some tip. You are unselfish with your knowledge and it is appreciated! God Bless!
As I expected Joe - your subs have climbed fast. Great.:) Thank you for an excellent video - indeed there are so many variables and it was super useful to have you go through them all - many we don't necessarily remember - I know I don't always, even now!
Joe To clean up chatter put the lathe in neutral and turn off. Offer tool to surface needing remedying and turn chuck slowly by hand. Use chuck key for extra leverage and adjust depth of cut to suit. Initial cleanup may need be quite heavy (Deep cut). Works with every type of tool. Much faster than flipping tools. Remember lathes are designed to have cutting forces react downward on to bed, not against bolt of flimsy retaining plates.
I have had an old lathe for only few weeks now... - You have teached me a LOT of with your videos. Must be a worth of several months or even year in vocational school. Thank you very much and looking forward for Your 2020 videos!
To cut a long story short, I mat some teachers that they know their stuff in a extraordinary way, like you do, but with the difference that they can't transmit knowledge. You instead have BOTH...good on you..!!, and THANK YOU.
Fantastic Video Joe!!!! just like all your other videos that I have watched so far. I also watch Abom79 (Adam), Tom's Techniques & Halligan142 just to name a few but you and mrpete are the first ones on my list & watch the most often. I prefer your guys way of teaching and NO I am NOT saying that there is anything wrong with any of the other guys lol ( I learn a lot from them as well.) Thank You for taking the time & effort to do these videos-Two Thumbs Up Sir!!!!
Hello Joe! The parting tool that you didn't know the name of, is called a" T-type" I have bought some of them myself from Littlemachineshop.com . They have them in sizes as small as 1/32 wide.
Hi Joe in uk. After getting small lathe few months ago have found your videos brilliant. You are a great teacher. You are bit of fun not to serious but safety conscious always. Your drawings on board with commentary then practical on machine really cover things. My point is that when using my machine your experience and showing processes do really help and stick in your head lol👍😃 thanks. Nigel
Great presentation. I know the danger of using the tail center for support, but I use it to advantage until I get near the end of the cut. I also frequently back out the tool to widen the slot in case it is not set absolutely square to the work.
Thank you Joe, for the great videos. I heard you apologize in a previous video about sharing info that someone else has previously shared. DO NOT worry about that! Whatsoever!! Teach what you think people need to learn, never mind anyone else. Love your great vids Cheers
Joe, I am not a machinist but a hobbyist and you're right, parting operations are a nightmare; busted a cobalt blade just yesterday! Your videos are not overlong and I find that if you understand the theory you can better understand the practice. Keep it up!
To get stuff that is tricky, sticky to come out even power feed parting is required. Sometimes a rpm reduction for the last inch on big parts. Most common fault of hand feed is too light a cut. Flood coolant, powerfeed, let that big dog eat. They make new holders everyday
Parting has always been a love/ hate thing for me. I love doing it, but like you said- that sound when it goes wrong. I have successfully powerfed the tool, in the neighborhood of 200-250 rpm and .002 per rev, but I don't make a habit of it. Everything has got to be PERFECT for it to go well. Anyway, I learned a few more things from this video, thanks again.
I almost always power feed when parting, especially with stainless steel (which is mostly what I work with). The critical thing to get just right is the feed rate. Too fast doesn't end well as you would expect but too slow and the tool can not sustain a steady chip and can work harden the stainless. As always, keep it wet. Thanks for you tips you provide as there is always someone that knows something that we can all learn from.
The only thing I would add is... Always make sure when you advance the tool, that you're getting a chip. If a situation comes up where you advance the tool, and you don't get a chip, you get rubbing or chatter or anything other than a chip, back out and find out why. If you crank harder on the cross slide wheel, you'll break the tip off the parting tool, and cause a very exciting few milliseconds. This usually happens because the tool is a bit above center, and when the diameter has been reduced sufficiently, the cutting edge is above the part and you're just pushing a thin HSS wall into your part. It will rub until you push hard enough to deflect the tool or part to where the tool catches and it will dig in hard and catastrophically. I never set my parting tool above center for this reason. I've had too many episodes of parting tools diving into stock because of the side load caused by an angled cutting edge, so I don't do that anymore either. I put up with the bur, it's better than grinding another tip onto the parting tool. Once you get over being "gun-shy" of the bang, you will be amazed at how fast you can jam a .06 or .09 cut off tool into steel, as long as it's straight, short, square, and sharp.
best metal working videos I've seen anywhere on the web Joe!.. and I knew about a minute and a half into the first one I watched. thanks for posting them!
I could tell Joe! not a "know it all" here, but always know what I'm looking at, haha... I've actually had several good instructors over the years, first in my general machining program and then a few years later in my automotive machinist program
Thanks for the great tutorial ….used this today and parted off 4 identical parts and countersink the end of each ….without taking the material out of the chuck ….. I’m starting to think about things more …previously would have done 1 at a time
Need to do this today and it's normally a disaster. Gone through your video list to find how you do parting off. Belated congratulations on getting 3000 subs! I'm only 5 years late 🤣🤣 Cheers Neil
Hi Joe, I enjoy your videos since you explain everything so well (I'll be subscribing). I've been a toolmaker for most of my 45 years working, and soon to retire (I hope!). An easy way I've come up with for squaring the tool to the work, assuming an ALORIS tool post is used like you have, is I'll extend the tailstock quill enough to bring the front of the ALORIS post in contact with the quill and tighten it there. The Aloris posts are square and can easily be set this way. I also use this technique when setting the thread chasing tools and won't bother with a thread gauge.Regards, Steve
I do the same thing. I also have one tool holder I dedicated to threading. The inner wall of the tool holder is ground true to the block once the block is true to the lathe. Its a good quick technique. Thanks for your subscription. Much appreciated.
Another great video! Absolutely enjoy the way you explain the topic! Thanks and you are almost to 4000 subscribers by the time I got around to watching! Congrats!
Another video with great information!!! The one thing I learned the hard was is if you plunge the parting tool in too quickly the tip will break off in the up direction with the tip going strait up past your face. Luckily it missed. Chris
1/4" wide tool, 3" diameter aluminum, 4500 RPM. rapid feed in. BOOOOOOM. That was day 1. The tool flew past my head and stuck in a sheetrock wall 15 feet away like a commando dagger. HSS steel doesn't mean high RPM. My bad.
Hey Joe, Thanks for video. You explained parting very well and I as a beginner learned a lot. I just do this as a hobby on a 7x12 mini lathe, but have see all the points you pointed out. Thanks for the insight. Dave
Hi Joe, a very in depth tutorial, I find using a DTI to square up the parting tool , which is much more accurate and easier.I agree that your preferred blade is the best and yes they usually have a cobalt content they are made in the uk by JJ Churchill and I believe Somma tools in the US. Thanks.
Mr. Joe, I really love your videos and you are a very good teacher. As I asked Keith Fenner years ago, " Please more light on the operation " I know it is a hassle but we would all like to see better detail of your explanation and demonstration. Thank you so very much. Richard
Joe, after adjust my cross slide and compound to make my mini lathe rigid I was fallow your recommendation, and finally I was able to cut 1 inch of 6061 without chattering and tool filling. Thank you again! Before, parting was stressful!
Important stuff like this was never taught to me in dental school. Your videos are really helping me with all my self taught machining on my various projects. Thanks!
It makes my skin crawl when these tools break. I think that fear holds us all back just a bit. Keep it sharp, lubricated and keep the pressure constant. Thats a good place to start. (watch the RPM too)
Thanks for all the pointers on the parting tool. It has always been the worst tool for me to use on the lathe. I have had a few failures and have been using the saw since the last one. But after your pointers I parted off a 1.25 steel slug with zero issues. Thanks Keep up the good work.
Thanks, being self taught this was great, covered all the errors I have done so far trying to part, and hopefully saved me from new ones in the future.
I blew up a parting tool in school doing a very deep cut and part of the tool hit me in the forehead. Fortunately the scars of youth get covered up by wrinkles of old age.
Chicks dig scars. But you may wish to lie about how you got it. When these tools blow up, they do tend to send a nice chunk straight up and slightly to the rear. Safety glasses when parting....ALWAYS.
Thanks Joe, I am finding your videos helpful and practical. My shop is mostly for super-dense hardwoods, so I use metal tools for the precision. I do cut a lot of delrin and have to clean-up casts of silver and bronze. My main parting tool is the most el-cheapo chinese thing. I use it for delrin, it's hopeless on metal. One thing I DO like about it is that it has a taper from the tip to the body such that the perpendicular alignment is a bit more forgiving. That way I get a little more latitude when adjusting the leading-edge bias. The nemesis of parting hardwood is the grain - most saws and parting tools will chip-out the OD or ID on a wooden part - usually ruining it. Unlike metal, wood has grain. Woodgrain is never perfectly straight and the last thou of the cut can ask the grain to go splitting-off wherever it wants - specially with cuttoff operations. So, for anyone who is parting wooden cylinders - the way to avoid the chipping is to have the tool speed extremely high .. you can't do that with RPM of the lathe - the wood will fly-apart, so I mount a high-speed Dremel kinda thing into the toolpost with a circular saw rotating the opposite of the lathe-spin. The reason this works is because you have to overcome the weakness of grain by leveraging the inertia of the actual grains themselves. Woodgrains are about 4 microns, so to get the inertia in that tiny thing, you got to have extreme impact-speed from the tool to break the grain without the grain-cleavage getting involved. It works in all other ways as you have described Joe - the rotary saw-blade acts exactly like a high-speed parting tool - and the alignments are critical. I know this is wood, not metal, but please consider: Lignum Vitae (the second-hardest wood) was used for bearings on submarine prop-shafts. And wood blunts tools faster than steel does - because wood has a lot of silicon in it .. and I have seen it produce sparks off of the tools in some cases. Anyway - thanks! Subscribed.
I missed this one when it was first published. Must have been out on the road at that time. The biggest improvement to my parting occurred when I checked and adjusted the big bearing on the headstock. I adjusted it from .006 "lift" to .002, and 98% of the parting problems I was having went away. Of course the results of standard turning improved as well. The rest, that is not related to the nuances of setting the tool up properly, is caused by a lantern tool post that needs retirement. I'm working on a solution to that at the moment. In short, those that are running older machines need to make sure that they are in adjustment. A few thou loose will allow the work to climb the tool, changing the center and allows the spindle to rattle around, causing chatter.
Thanks Joe for the great Sunday morning sermon for me, I thought I was the only one that wasn’t parting ways properly. I agree, it’s a nasty tool when you don’t use it correctly ! 7:00 I use the face of the chuck for my perpendiculars . 18:40 nightmare pattern, that’s funny!
I bought my first lathe 2 weeks ago, an old South Bend 9" clone. Trying to teach myself some lathe work, I have a few projects I need it for. I had real trouble parting of bits, my tool (new "bought" parting tool) kept wandering off to the left. After seeing this video I figured out the the tool wasn't sitting exactly straight or didn't have the right angle to begin with. The tool post isn't exactly mint.... But a small touch of on the grinder and the tool now goes straight! Thank you! I like the white board explanations, it gives me "aha moments". :)
Joe, speaking of holders and inserts, you spoke of one of your favorites as the Kennametal NSR-123-B and said you weren't sure if it was still available. The manufacturer still sells it for about a hundred bucks. I purchased mine through E-Bay for $31.00.
Will be buying my first lathe and mill (hobby size) for my home shop soon and just want to send a big thanks for all your vids I have seen so far and I'm learning lots. Thanks Joe
Frank Hoose ruclips.net/video/UNfUI9uo4L0/видео.html Or mrpete222 has good vids on older lathes. Here is another smaller one that I would love to have. ruclips.net/video/ypMOts-EWbU/видео.html
One of the best lubricants after a mishap using the power feed for parting is a 1/2 pint of whisky. It will get you back in the saddle in no time. Kerosene mixed with mineral oil AKA ISO 46 is one of my go to homemade lubricants from homing stones, emery cloth, locks to cutting, parting and threading. It even kills aphids, web worms to fleas on a dog and mites on a hog. Dog needs bath after treatment. Another in depth video by Joe that went far beyond the average RUclips video on the subject. Job well done. Worth Bastrop Texas.
Hi Joe, This is well explained by taking all the elements separately and describing every variations and effects. There is a thing that affects the performance of those tools is the rigidity of the machine itself, small lathe owners are finding it much more difficult than us with the sturdier machines, trying to part stainless on a little Atlas is something else, this is where small kerf blades will save the day... ;) I must have had excellent teachers cause parting blades never scared me, meaning that I got no more mishaps with those than with any other tools. Cheers, Pierre
It's a joy watching your work, your ability to explain is sublime. I wish teachers of this watch you and get some tips of how to do it properly. Thanks for all the work you put in to all these videos.
Great tutorial as usual. I do a LOT of parting at work almost exclusively with 1/8" wide insert tooling, the geometry of the insert curls the chip in making it narrower than the groove which helps a bunch! Parting ALWAYS leaves a burr no matter how slight and angling the tip only makes the tool want to crawl sideways as you aptly demonstrated. What I do, on parts with a hole in them, is only drill or bore the hole .01" + the nose radius of the tool if you are boring, deeper than the part length. This leaves a very minimal burr which is easy to remove. You can then continue feeding to the center or minor diameter of the stock, rise and repeat..... Another trick, if you need to make several washers, cut multiple grooves slightly smaller than the finished ID then drill or bore the parts off they end up on your drill or boring bar with minimal burrs. I always power feed parting tools, usualy about .002 per rev in steel, gives a very consistant chip, keeping them flowing is key! PS looking forward to getting my puzzle LOL
I use a .095" Tantung parting tool and I always run a flat top, with no rake. I power feed when parting, doing as many as 100 parting cuts in 4140 steel per batch. I never have any problems. Tantung is amazing, so much better than HSS or even carbide. I had to build my own holder. The tool blanks were surplus screw machine tooling and commercial holders were not available. It makes parting a breeze!! Try it if you get the chance.
Really good, thanks very much, will try again, had just given up and gone to rear tool post upside down setup, but still not happy. Do you have any comments about the backlash in the cross slide feedscrew being an issue, and/or the size/rigidity of the lathe?
Great video. I really like these types of videos. Really appreciate how you take the time to present the topic in detail and then go out to the shop and show us the process.
Joe - thanks for the tips - just starting on the lathe and had no luck parting - Going to try your suggestions and see how it goes. Well presented, clear and logical.
Parting tool performance is without a doubt the most developed " feel" you will ever have to master on a lathe. ALL of your info on tool shape and set-up is exactly correct. You have saved many less experienced machinists hours of misery at the hands of a parting tool. The most important piece of advice is NEVER to use the power cross feed. Develop the feel for the feed. You can avoid a lot of chatter problems by feeling the cut.
I used power feed with one of the carbide insert cut off tools successfully a couple of times. One of the next couple of tries I crashed. Broke the tool, ruined the part. Hand feed from now on, but it's still scary now, seems like I'm always clenching teeth when parting off.
Great video and info (especially for a newbie like me). I have a question though...If you setup an inverted cutting tool with the lathe in reverse (which is the reason I ended up here, I read about it and the search brought me here) anyway. I got confused now I see this video, you talk about the upper rake on the parting tool but then mentioned that you love inverted parting. If you mount the parting tool upside down the rake now (if you use the holder with the angle) would be the wrong way around isn't it? Sorry for my ignorance. And if there is more info on upside down parting I would love to read about. Thanks!!!!
Could you do a video on how to identify the best tool manufacturers? You mentioned Morse Cutting Tools. Are there others? Where would you find a good manufacturer of taps or drill bits? Is Somma Tool Co. a quality manufacturer?
I have a small shop where i do a little bit of everything . And can't remember how many times I wished I had a lathe an a mill so I could make the part I needed. I have just gotten myself a lathe an mill and I'm so glad I found your channel. I appreciate you taking the time to explain everything in such detail . I have learned a lot. Again thanks.
Great vid! I've been trying to get my HSS parting blade to work efficiently without shattering for around 5 years; half an hout watching this vid & no more issues, cuts great every time; Thanks Joe
Good video joe ,but i would have preferred to see you parting steel.I have no problem with soft materials ,plastic,brass etc. but steel is suicide for me.
Again thank you. Every time I get stuck on the lathe with something that I don't get I wind up back here, spend 30 minutes learning and moving. This time it was parting last time it was using microdrills. See ya next time for a new solution ;-)
One thing to pay attention to when making your parting tool leave the little stem on the main piece of stock and not on the part taken off is the concave shape it can give to the part being cut off. As you showed at the end of the video the end of the stock was crowned, this shows that the very possibly the part that came off may be concave, this means that it won't pass inspection... The solution is to run some tests and reshape the parting tool until you find the spot you feel happy with, most of the time you can find a happy medium that will give you a clean part with a straight back.
This was just a demo. I covered many of your observations in another video. I agree with the blade walking, but rarely finish a part I'm making with a parted off surface There is always a second side face cut. When thats not an option, I'll part several pieces of material until the parting tool tracks to my liking. the I'll run actual parts. thanks for the comment.
I'm always amazed at how eloquent you deliver your experience, for such an amateur as myself! Just toasted 2 hrs of lathe work to a bad parting job: now I see why! Thanks for the fabulous and helpful advice:))
Buy nice or buy twice - I love it! My motto also, I've been there done that - bought nasty, got nasty! I have tools over 30 years old and still work fine because I bought quality. Note: when you do a clean out, the old idiom:if you haven't used it in 6 months, throw it out" this does not include tools! I will qualify this: if you know you won't use (because you bought newer/better/etc, then give it to someone who can use it, or 'pass it round' through Joe or Adam or the various Keith's (and others) out there - they will greatly appreciate it!
It is amazing that a slight variance can actually make that much difference when a part is cut off. Do you have a video on how to grind and what to use for grinding the tips ?
Thanks Joe. Exactly what I require. Can't. Wait to get to the garage tomorrow and put your ideas to work. Many thanks. You have an excellent site and are a very good instructor. I am 76 and learning machining as a hobby and to support my wife's small business tooling requirements. Your videos and my machinist handbook answer my questions. Well done.
Joe, I found that if I angle the tip of the tool any, it makes a chip that is wider than the slot which makes for a lot of friction on both sides of the chip and much more prone to weld in the slot if it runs out of lube for even a second of two. This characteristic of an angled grind gave me my worst parting tool experience and permanently ruined the accuracy of a nice 3 jaw chuck.
On my 1943 South Bend I put her in back gear, and part under power feed. This is the only way I've been successful. In my experience I would say if it ever chatters you have to get "under" the chatter and keep a chip going.
I found that with over about 1.5" dia. if I feed in slowly to be "safe," the sides of the slot winds the fragile chips into a tight ball which gets jammed and cases a growling dig in. Going in faster, making a stronger chip solves he problem.
I have 2 lathes. On one of them, the parting blade holder's base is parallel to the cross slide table. No induced relief angle. The other does angle the blade up slightly. I have parted a lot of of stuff in both lathes with the same blades - i cannot tell a difference. Tool height is much more critical!
Hi Joe. I'm now using a KT3.2 Tanjential brazed carbide tool.. I made the toolholder myself and adjust the rake with a wedge below it. Goes very well and feeds fast.
Very good info, you can never know to much. Joe I like the way you speak or teach what you have learned threw the years! You pick up on the important things that you should know about being a good machinist and staying safe. I watch your videos when ever I can good stuff keep keep en on! O when parting off your work put a wood dowel in the tail stock bring it up into hole if there is to catch the part if no hole use a tube to do so. save your fingers you will need them later people. hope this will help maybe Thanks for the info Joe
Awesome video. I had bad experiences as well when I first started, but it taught me sooo much! One thing I never used were the insert parting blades, so I was wanting to know your opinion
All learned the hard way Thanks WHen the part is just too big a hack saw in the cut with the chuck turned slowly, by hand works too. Cut off wheel in a 4' grinder not so well, more clean up
What sets you apart from all the rest is the excellent "why" in addition to how. Thank you
Thanks. I think it helps.
When my old man had to make a bunch of washers/spacers,he would plunge in almost to the diameter of the bore,then make a finish pass on the bore,and the parts would 'plink'.... end up on the bar. Try it
I have, it does work. Cool trick.
That sounds like an awesome idea.
Joe, fantastic video. You are a very good machinist but your best quality is your ability to communicate. You are amazing. Parting has been a challenge for me but I came up with a method that works every time without fail (with power feed). In my opinion (and I suspect you will agree) the very biggest reason for failures while parting tool movement. When something isn't solid you get chatter and sometimes it grabs bad enough to break the blade etc. The reason an upside down tool helps is that if something moves it climbs out of the cut rather than into the cut. When you cut from the front the amount of back rake can amplify the problem. A negative back rake will be much less likely to dig into the work but does not cut very well. I have small old lathes with screw on chucks that are not very solid but what I came up with is nearly fool proof. Oh... and I used the same blade profile you do, absolutely the best! Leave me a comment and let me know what you think. Thanks! ruclips.net/video/HGAQHjzgs9c/видео.html
You BOTH are great. Since I have subscribed to your channels I have learned so much. We need people like you. Thanks and should you come to Florence let me know, I will show you my city and offer you a REAL Italian coffe. Take care and stay save
I named my parting tool "Satan." I may have to rename it after I try a new grind on it. Thanks for the info........
Thats a good name. If the tool doesn't perform well, its talking to you.
Hey Joe, Great video with plenty of important tips, HOWEVER, there is a VERY important one you missed out. That is, NEVER grind a top rake or chip breaker into the top of the blade. Because the blade is either tapered or hollow ground, as soon as you cut deeper than the grind depth, the tool will bind. That is because when you grind the tool top, the blade becomes thinner in width and will cut a narrower slot, and when it tries to cut past the grind depth, the tool being wider will jam and may break.
Some other great tips for the un-initiated users out in RUclips Land are as follows :-
When parting off bolts / all thread, initially only have enough blade sticking out to just get past the thread depth. When the tool is ground with a slight taper as you showed to not leave a pip on the finished part, it will want to try and follow the thread helix, causing the tool to flex sideways. Once you are cutting a smooth diameter, then extend sufficient blade to finish cutting off the part.
When parting off a large diameter, say 2 inch, start off with only a short length of blade sticking out. Then as the cut gets further in gradually pull out more blade. Because the tool is at an angle in the holder, you will need to lower the tool holder height slightly to bring the cutting edge back onto center height.
When parting off, try and not be too timid with the hand feed, once it starts to cut, keep the feed going at a constant rate.
Hope this helps, keep up the great video’s and well done for getting over 3,000 subscribers so quickly.
Thanks Dave. The top rake is a very tedious thing to do and not for new comers for sure. You can get away with it, but you have signed a death warrant for the tool. When grinding that top rake, you can only go to the very front top edge and no further. Don't forget to grind the front first, or the tool is already doomed. The the taper starts to come into play. Its a narrow window of success. I usually keep a hand ground HSS tool bit handy when doing bolts to start my part off track. Those threads will dominate the parting tool everytime. Its amazing just how much they can flex side to side. Thanks for your input and well wishes. Always welcome.
Thank you for your tips. Thoughtful and educational. I too have had some parting tool nightmares. Couple comments though. For an older lathe, one with wear, I have had much better success with the parting tool 1/64 to 1/32 above center. Anything less causes the parting tool to be drawn into the work due to excessive backlash in the top slide for cross slide. I too like the truncated triangular HSS parting too. Chatter is significantly reduced or eliminated by grinding a "u" into the front of the parting tool. Chatter seems proportional to the width of the parting tool. The "u" grind gets the job done especially on ductile Iron or stainless. I expect a V grind would be better but my diamond wheel does not have sharp edges anymore! Top rake or clearance, I've had better success with 5°. Front rake, yes 12° seems good. I also put a India stone to the cutting edge, prefer a rounded cutting edge as opposed to sharp. My go to engine lathe: clausing Colechester 13x36. I've got two, vintage 1956, and 1968. Again really appreciate the effort knowledge and experience you provide.
I make my parting tools from old carbide tipped saw and dado blades. Parting tools in my price range were disappointing at best. I was sceptical at first but it works well for me. This is about the best basics video I have seen. You have a knack for teaching. There are a handful of people on youtube that are good at both machining and teaching. You are one of them. Keep it up.
I very rarely comment on videos but the 2 i've watched (so far!) of yours are brilliant. have you done any teaching? if not you should as you are very good at explaining things clearly. Takes me back to being at uni, only with a better teacher. cheers
Thanks Nick. That's a great compliment. The only teaching I've ever done was as an in house instructor at my last company teaching University of Texas engineering students a course called 'Design for manufacturability. It was very rewarding to all involved. I had a bunch of apprentices under my wings many time as well.
I think parting tools were almost everyone’s first bad experience in a machine shop! 🤣
It was mine. I thought a High Speed Steel parting tool meant run it it at high speed. BOOM
Never set a parting blade above centre. If it takes extra pressure to get the tool to cut it will deflect down and grab the work. The work will ride over the blade and break or spit the job out of the machine. Parting blades set on centre height QED.
And above center height the tool holding side rotates into the work instead of away, perpetuating the feed in + chatter and breaking the blade before you have time to back off the feed....I broke blades constantly while following the above center advice. Then I tried a few thou below, and haven't broken a blade since.
I started watching your various videos and have learned a lot, although I have been machining for over 30 years, these are basics that every wannabe machinist should know if they are to be successful at machining.
Joe, I had quit using my parting tools altogether. I just couldn't get it right. I saw you video and took notes and now..no problem! I still can't get over how smooth it works! I originally got to your videos by accident while researching threading. I formerly had a gunsmith business and for years stayed puckered up when threading to a precise shoulder I had just meticulously created where the barrel and action mated. Since learning your reverse threading procedure it is super simple. So logical, wonder why I never heard of it before. Now I try to watch all you videos for the shear entertainment and knowing I will pick up some tip. You are unselfish with your knowledge and it is appreciated! God Bless!
As I expected Joe - your subs have climbed fast. Great.:)
Thank you for an excellent video - indeed there are so many variables and it was super useful to have you go through them all - many we don't necessarily remember - I know I don't always, even now!
Thanks Chris. The subs are climbing quickly, I am flattered at the support. Thanks for watching.
Chatter recovery, running in reverse!! Crazy, brilliant. Always worth watching your work, thanks for sharing your hard won experience.
Its a creative setup to do that, but it works.
Joe To clean up chatter put the lathe in neutral and turn off. Offer tool to surface needing remedying and turn chuck slowly by hand. Use chuck key for extra leverage and adjust depth of cut to suit. Initial cleanup may need be quite heavy (Deep cut). Works with every type of tool. Much faster than flipping tools. Remember lathes are designed to have cutting forces react downward on to bed, not against bolt of flimsy retaining plates.
Sounds much simpler now the basics have been explained thanks for answering so many questions Brisbane Oz
Make sure you buy a good tool. Thanks for watching.
I have had an old lathe for only few weeks now... - You have teached me a LOT of with your videos. Must be a worth of several months or even year in vocational school. Thank you very much and looking forward for Your 2020 videos!
To cut a long story short, I mat some teachers that they know their stuff in a extraordinary way, like you do, but with the difference that they can't transmit knowledge. You instead have BOTH...good on you..!!, and THANK YOU.
Thank you very much.
Fantastic Video Joe!!!! just like all your other videos that I have watched so far. I also watch Abom79 (Adam), Tom's Techniques & Halligan142 just to name a few but you and mrpete are the first ones on my list & watch the most often. I prefer your guys way of teaching and NO I am NOT saying that there is anything wrong with any of the other guys lol ( I learn a lot from them as well.) Thank You for taking the time & effort to do these videos-Two Thumbs Up Sir!!!!
Hello Joe! The parting tool that you didn't know the name of, is called a" T-type" I have bought some of them myself from Littlemachineshop.com . They have them in sizes as small as 1/32 wide.
Anyone else lean their head to see the gap with the white paper?
I foegot to add, if you would see my presentation #10 Tail Stock Aligment, you may find it interesting. Old Bob
very good instructor, easy to understand.
Thanks
Hi Joe
in uk. After getting small lathe few months ago have found your videos brilliant. You are a great teacher. You are bit of fun not to serious but safety conscious always. Your drawings on board with commentary then practical on machine really cover things.
My point is that when using my machine your
experience and showing processes do really help and stick in your head lol👍😃
thanks. Nigel
Thanks Nigel. Thats good to hear.
The blade you like is referred to as a T profile.
Great presentation. I know the danger of using the tail center for support, but I use it to advantage until I get near the end of the cut.
I also frequently back out the tool to widen the slot in case it is not set absolutely square to the work.
The tool will let you know if its not happy. You just have to listen.
Thank you Joe, for the great videos. I heard you apologize in a previous video about sharing info that someone else has previously shared. DO NOT worry about that! Whatsoever!! Teach what you think people need to learn, never mind anyone else. Love your great vids
Cheers
Joe, I am not a machinist but a hobbyist and you're right, parting operations are a nightmare; busted a cobalt blade just yesterday! Your videos are not overlong and I find that if you understand the theory you can better understand the practice. Keep it up!
To get stuff that is tricky, sticky to come out even power feed parting is required. Sometimes a rpm reduction for the last inch on big parts. Most common fault of hand feed is too light a cut. Flood coolant, powerfeed, let that big dog eat. They make new holders everyday
Parting has always been a love/ hate thing for me. I love doing it, but like you said- that sound when it goes wrong. I have successfully powerfed the tool, in the neighborhood of 200-250 rpm and .002 per rev, but I don't make a habit of it. Everything has got to be PERFECT for it to go well. Anyway, I learned a few more things from this video, thanks again.
Great format for learning. Thanks for taking the time to make videos. 👍
I enjoy it Billy. Thanks for watching and taking the time to comment.
I almost always power feed when parting, especially with stainless steel (which is mostly what I work with). The critical thing to get just right is the feed rate. Too fast doesn't end well as you would expect but too slow and the tool can not sustain a steady chip and can work harden the stainless. As always, keep it wet.
Thanks for you tips you provide as there is always someone that knows something that we can all learn from.
The only thing I would add is... Always make sure when you advance the tool, that you're getting a chip. If a situation comes up where you advance the tool, and you don't get a chip, you get rubbing or chatter or anything other than a chip, back out and find out why. If you crank harder on the cross slide wheel, you'll break the tip off the parting tool, and cause a very exciting few milliseconds. This usually happens because the tool is a bit above center, and when the diameter has been reduced sufficiently, the cutting edge is above the part and you're just pushing a thin HSS wall into your part. It will rub until you push hard enough to deflect the tool or part to where the tool catches and it will dig in hard and catastrophically. I never set my parting tool above center for this reason. I've had too many episodes of parting tools diving into stock because of the side load caused by an angled cutting edge, so I don't do that anymore either. I put up with the bur, it's better than grinding another tip onto the parting tool. Once you get over being "gun-shy" of the bang, you will be amazed at how fast you can jam a .06 or .09 cut off tool into steel, as long as it's straight, short, square, and sharp.
47 years in and I still stand waiting for that "BANG". I hate that sound.
best metal working videos I've seen anywhere on the web Joe!.. and I knew about a minute and a half into the first one I watched. thanks for posting them!
Thanks Guy. Been at it for a long time.
I could tell Joe! not a "know it all" here, but always know what I'm looking at, haha... I've actually had several good instructors over the years, first in my general machining program and then a few years later in my automotive machinist program
Thanks for the great tutorial ….used this today and parted off 4 identical parts and countersink the end of each ….without taking the material out of the chuck ….. I’m starting to think about things more …previously would have done 1 at a time
Need to do this today and it's normally a disaster.
Gone through your video list to find how you do parting off.
Belated congratulations on getting 3000 subs! I'm only 5 years late 🤣🤣
Cheers Neil
I value every one of my subscribers. Thank you all.
And about one hundred and fifty thousandths off🧐🤔
Hi Joe, I enjoy your videos since you explain everything so well (I'll be subscribing). I've been a toolmaker for most of my 45 years working, and soon to retire (I hope!). An easy way I've come up with for squaring the tool to the work, assuming an ALORIS tool post is used like you have, is I'll extend the tailstock quill enough to bring the front of the ALORIS post in contact with the quill and tighten it there. The Aloris posts are square and can easily be set this way. I also use this technique when setting the thread chasing tools and won't bother with a thread gauge.Regards, Steve
I do the same thing. I also have one tool holder I dedicated to threading. The inner wall of the tool holder is ground true to the block once the block is true to the lathe. Its a good quick technique. Thanks for your subscription. Much appreciated.
One word says it all -- "Excellent".
Thank you Bob.
How about trying a pieces of 2 inch 316 stainless bar? :-)
Just as soon as I replace that small Morse blade....Not a problem. Constant pressure, low RPM, keep it wet.
I may have to buy a 6 jaw chuck so the demo goes well !
Another great video! Absolutely enjoy the way you explain the topic! Thanks and you are almost to 4000 subscribers by the time I got around to watching! Congrats!
Better late than never John. Thanks for checking in. I am glad you enjoy the videos. Stay tuned.
Another video with great information!!! The one thing I learned the hard was is if you plunge the parting tool in too quickly the tip will break off in the up direction with the tip going strait up past your face. Luckily it missed. Chris
1/4" wide tool, 3" diameter aluminum, 4500 RPM. rapid feed in. BOOOOOOM. That was day 1. The tool flew past my head and stuck in a sheetrock wall 15 feet away like a commando dagger. HSS steel doesn't mean high RPM. My bad.
Hey Joe, Thanks for video. You explained parting very well and I as a beginner learned a lot. I just do this as a hobby on a 7x12 mini lathe, but have see all the points you pointed out. Thanks for the insight. Dave
Thanks David.
Hi Joe, a very in depth tutorial, I find using a DTI to square up the parting tool , which is much more accurate and easier.I agree that your preferred blade is the best and yes they usually have a cobalt content they are made in the uk by JJ Churchill and I believe Somma tools in the US. Thanks.
I have to get some more. Great cutoff tool.
Mr. Joe, I really love your videos and you are a very good teacher. As I asked Keith Fenner years ago, " Please more light on the operation " I know it is a hassle but we would all like to see better detail of your explanation and demonstration. Thank you so very much.
Richard
Thanks for watching Richard.
The shape of the parting tool blade is called a P type blade it looks like T.
Joe, after adjust my cross slide and compound to make my mini lathe rigid I was fallow your recommendation, and finally I was able to cut 1 inch of 6061 without chattering and tool filling. Thank you again! Before, parting was stressful!
Glad I could help!
Important stuff like this was never taught to me in dental school. Your videos are really helping me with all my self taught machining on my various projects. Thanks!
Thanks for watching.
Sometimes the simplest operations get overlooked.Thanks, for taking the time to explain. :) Fred, UK
Thanks for watching Fred.
Should have been a teacher Joe, you have a way of reaching people. Great video
Just for shits and giggles you could lock the carriage.
Thanks Dennis. Locking the carriage is a very good tip. I don't think I do that. I will now.
Great info& demo Joe cant wait for the next one.
Got some great tricks coming. Stay tuned.
Joe
Good Video. I rember in school way way back that this was one of the hardest things to do. Very good.
Cheers
It makes my skin crawl when these tools break. I think that fear holds us all back just a bit. Keep it sharp, lubricated and keep the pressure constant. Thats a good place to start. (watch the RPM too)
Pretty good primer on parting, I'm sure it will become a standard, a must watch for beginners
.
Thank you.
Nice demo. The only comment I would add is: Keep the parting tool cutting. Tool pressure is your friend here.
100% agree.
Thanks for all the pointers on the parting tool. It has always been the worst tool for me to use on the lathe. I have had a few failures and have been using the saw since the last one. But after your pointers I parted off a 1.25 steel slug with zero issues. Thanks
Keep up the good work.
All situations can be different, but parting tools like to cut. Moderate RPM and constant pressure usually yield goo results. Thanks for watching.
Thanks, being self taught this was great, covered all the errors I have done so far trying to part, and hopefully saved me from new ones in the future.
Buy a good tool and keep the grind mild. you're half way home.
I blew up a parting tool in school doing a very deep cut and part of the tool hit me in the forehead. Fortunately the scars of youth get covered up by wrinkles of old age.
Chicks dig scars. But you may wish to lie about how you got it. When these tools blow up, they do tend to send a nice chunk straight up and slightly to the rear. Safety glasses when parting....ALWAYS.
Thanks Joe, I am finding your videos helpful and practical.
My shop is mostly for super-dense hardwoods, so I use metal tools for the precision.
I do cut a lot of delrin and have to clean-up casts of silver and bronze.
My main parting tool is the most el-cheapo chinese thing. I use it for delrin, it's hopeless on metal. One thing I DO like about it is that it has a taper from the tip to the body such that the perpendicular alignment is a bit more forgiving. That way I get a little more latitude when adjusting the leading-edge bias.
The nemesis of parting hardwood is the grain - most saws and parting tools will chip-out the OD or ID on a wooden part - usually ruining it. Unlike metal, wood has grain. Woodgrain is never perfectly straight and the last thou of the cut can ask the grain to go splitting-off wherever it wants - specially with cuttoff operations.
So, for anyone who is parting wooden cylinders - the way to avoid the chipping is to have the tool speed extremely high .. you can't do that with RPM of the lathe - the wood will fly-apart, so I mount a high-speed Dremel kinda thing into the toolpost with a circular saw rotating the opposite of the lathe-spin.
The reason this works is because you have to overcome the weakness of grain by leveraging the inertia of the actual grains themselves. Woodgrains are about 4 microns, so to get the inertia in that tiny thing, you got to have extreme impact-speed from the tool to break the grain without the grain-cleavage getting involved.
It works in all other ways as you have described Joe - the rotary saw-blade acts exactly like a high-speed parting tool - and the alignments are critical.
I know this is wood, not metal, but please consider: Lignum Vitae (the second-hardest wood) was used for bearings on submarine prop-shafts. And wood blunts tools faster than steel does - because wood has a lot of silicon in it .. and I have seen it produce sparks off of the tools in some cases.
Anyway - thanks! Subscribed.
I missed this one when it was first published. Must have been out on the road at that time.
The biggest improvement to my parting occurred when I checked and adjusted the big bearing on the headstock. I adjusted it from .006 "lift" to .002, and 98% of the parting problems I was having went away. Of course the results of standard turning improved as well.
The rest, that is not related to the nuances of setting the tool up properly, is caused by a lantern tool post that needs retirement. I'm working on a solution to that at the moment.
In short, those that are running older machines need to make sure that they are in adjustment. A few thou loose will allow the work to climb the tool, changing the center and allows the spindle to rattle around, causing chatter.
Lots of great information here. I've had plenty of problems with this operation and your video will help a lot.
Keep a constant pressure on the tool and reduce the RPM. You should have better results.
I use a short piece of ground hacksaw blade as a parting tool for making washers out of delrin. It works great and is virtually for free.
I've seen that done. It does work.
Thanks Joe for the great Sunday morning sermon for me, I thought I was the only one that wasn’t parting ways properly. I agree, it’s a nasty tool when you don’t use it correctly !
7:00 I use the face of the chuck for my perpendiculars .
18:40 nightmare pattern, that’s funny!
I bought my first lathe 2 weeks ago, an old South Bend 9" clone.
Trying to teach myself some lathe work, I have a few projects I need it for.
I had real trouble parting of bits, my tool (new "bought" parting tool) kept wandering off to the left. After seeing this video I figured out the the tool wasn't sitting exactly straight or didn't have the right angle to begin with. The tool post isn't exactly mint.... But a small touch of on the grinder and the tool now goes straight!
Thank you! I like the white board explanations, it gives me "aha moments". :)
Joe, speaking of holders and inserts, you spoke of one of your favorites as the Kennametal NSR-123-B and said you weren't sure if it was still available. The manufacturer still sells it for about a hundred bucks. I purchased mine through E-Bay for $31.00.
Will be buying my first lathe and mill (hobby size) for my home shop soon and just want to send a big thanks for all your vids I have seen so far and I'm learning lots. Thanks Joe
Frank Hoose ruclips.net/video/UNfUI9uo4L0/видео.html
Or mrpete222 has good vids on older lathes.
Here is another smaller one that I would love to have.
ruclips.net/video/ypMOts-EWbU/видео.html
One of the best lubricants after a mishap using the power feed for parting is a 1/2 pint of whisky.
It will get you back in the saddle in no time.
Kerosene mixed with mineral oil AKA ISO 46 is one of my go to homemade lubricants from homing stones, emery cloth, locks to cutting, parting and threading.
It even kills aphids, web worms to fleas on a dog and mites on a hog.
Dog needs bath after treatment.
Another in depth video by Joe that went far beyond the average RUclips video on the subject.
Job well done.
Worth Bastrop Texas.
Thanks for the laugh!!!!
I was on a plane that blew an engine on takeoff last friday in Ft lauderdale fla. Whiskey cures many ills.
Hi Joe,
This is well explained by taking all the elements separately and describing every variations and effects. There is a thing that affects the performance of those tools is the rigidity of the machine itself, small lathe owners are finding it much more difficult than us with the sturdier machines, trying to part stainless on a little Atlas is something else, this is where small kerf blades will save the day... ;)
I must have had excellent teachers cause parting blades never scared me, meaning that I got no more mishaps with those than with any other tools.
Cheers, Pierre
Keeping the tip buried is really important as well.
It's a joy watching your work, your ability to explain is sublime. I wish teachers of this watch you and get some tips of how to do it properly. Thanks for all the work you put in to all these videos.
Thank you very much.
Great tutorial as usual.
I do a LOT of parting at work almost exclusively with 1/8" wide insert tooling, the geometry of the insert curls the chip in making it narrower than the groove which helps a bunch!
Parting ALWAYS leaves a burr no matter how slight and angling the tip only makes the tool want to crawl sideways as you aptly demonstrated.
What I do, on parts with a hole in them, is only drill or bore the hole .01" + the nose radius of the tool if you are boring, deeper than the part length.
This leaves a very minimal burr which is easy to remove.
You can then continue feeding to the center or minor diameter of the stock, rise and repeat.....
Another trick, if you need to make several washers, cut multiple grooves slightly smaller than the finished ID then drill or bore the parts off they end up on your drill or boring bar with minimal burrs.
I always power feed parting tools, usualy about .002 per rev in steel, gives a very consistant chip, keeping them flowing is key!
PS looking forward to getting my puzzle LOL
Check the tracking number. Its on the way.
You offered good tips! Constant feed is very important. I have done the drill trick too.
I use a .095" Tantung parting tool and I always run a flat top, with no rake. I power feed when parting, doing as many as 100 parting cuts in 4140 steel per batch. I never have any problems. Tantung is amazing, so much better than HSS or even carbide. I had to build my own holder. The tool blanks were surplus screw machine tooling and commercial holders were not available. It makes parting a breeze!! Try it if you get the chance.
Great vids Joe, love your direct, no nonsense style. Best wishes from the UK.
Thank you Doug.
Really good, thanks very much, will try again, had just given up and gone to rear tool post upside down setup, but still not happy. Do you have any comments about the backlash in the cross slide feedscrew being an issue, and/or the size/rigidity of the lathe?
Hi Joe, another great tutorial saves making a lot of frustrating mistakes.
Thanks.
Thanks. Keep the pressure on the tool. Keep the chip growing and wet.
Great video. I really like these types of videos. Really appreciate how you take the time to present the topic in detail and then go out to the shop and show us the process.
Some of us like the board, and some of us gotta see it done. I like knowing why something works.
This stuff is as good as we got in trade school....or better. Thank you.
Thanks Glenn.
Joe - thanks for the tips - just starting on the lathe and had no luck parting - Going to try your suggestions and see how it goes. Well presented, clear and logical.
Good luck!
Parting tool performance is without a doubt the most developed " feel" you will ever have to master on a lathe. ALL of your info on tool shape and set-up is exactly correct. You have saved many less experienced machinists hours of misery at the hands of a parting tool. The most important piece of advice is NEVER to use the power cross feed. Develop the feel for the feed. You can avoid a lot of chatter problems by feeling the cut.
"The Feel" is so important. Good comment. I also never use power feed for parting, but some guys swear by it. I'm not one of them.
I used power feed with one of the carbide insert cut off tools successfully a couple of times. One of the next couple of tries I crashed. Broke the tool, ruined the part. Hand feed from now on, but it's still scary now, seems like I'm always clenching teeth when parting off.
Great video and info (especially for a newbie like me). I have a question though...If you setup an inverted cutting tool with the lathe in reverse (which is the reason I ended up here, I read about it and the search brought me here) anyway. I got confused now I see this video, you talk about the upper rake on the parting tool but then mentioned that you love inverted parting. If you mount the parting tool upside down the rake now (if you use the holder with the angle) would be the wrong way around isn't it? Sorry for my ignorance. And if there is more info on upside down parting I would love to read about. Thanks!!!!
Jow, thank you for anexcellent video. I am a machinist new guy and learned so many valuable points here. Keep the good work coming.
Could you do a video on how to identify the best tool manufacturers? You mentioned Morse Cutting Tools. Are there others? Where would you find a good manufacturer of taps or drill bits? Is Somma Tool Co. a quality manufacturer?
I have a small shop where i do a little bit of everything . And can't remember how many times I wished I had a lathe an a mill so I could make the part I needed. I have just gotten myself a lathe an mill and I'm so glad I found your channel. I appreciate you taking the time to explain everything in such detail . I have learned a lot. Again thanks.
Great vid! I've been trying to get my HSS parting blade to work efficiently without shattering for around 5 years; half an hout watching this vid & no more issues, cuts great every time; Thanks Joe
Good video joe ,but i would have preferred to see you parting steel.I have no problem with soft materials ,plastic,brass etc. but steel is suicide for me.
Again thank you. Every time I get stuck on the lathe with something that I don't get I wind up back here, spend 30 minutes learning and moving. This time it was parting last time it was using microdrills. See ya next time for a new solution ;-)
One thing to pay attention to when making your parting tool leave the little stem on the main piece of stock and not on the part taken off is the concave shape it can give to the part being cut off. As you showed at the end of the video the end of the stock was crowned, this shows that the very possibly the part that came off may be concave, this means that it won't pass inspection... The solution is to run some tests and reshape the parting tool until you find the spot you feel happy with, most of the time you can find a happy medium that will give you a clean part with a straight back.
This was just a demo. I covered many of your observations in another video. I agree with the blade walking, but rarely finish a part I'm making with a parted off surface There is always a second side face cut. When thats not an option, I'll part several pieces of material until the parting tool tracks to my liking. the I'll run actual parts. thanks for the comment.
I'm always amazed at how eloquent you deliver your experience, for such an amateur as myself! Just toasted 2 hrs of lathe work to a bad parting job: now I see why! Thanks for the fabulous and helpful advice:))
Buy nice or buy twice - I love it! My motto also, I've been there done that - bought nasty, got nasty! I have tools over 30 years old and still work fine because I bought quality. Note: when you do a clean out, the old idiom:if you haven't used it in 6 months, throw it out" this does not include tools! I will qualify this: if you know you won't use (because you bought newer/better/etc, then give it to someone who can use it, or 'pass it round' through Joe or Adam or the various Keith's (and others) out there - they will greatly appreciate it!
Great material again. My first lathe crash was a cheap dry parting tool.
Mine too. Scared the shit out of me. I thought HSS needed to be run at high speed. I was young.
It is amazing that a slight variance can actually make that much difference when a part is cut off.
Do you have a video on how to grind and what to use for grinding the tips ?
Thanks Joe. Exactly what I require. Can't. Wait to get to the garage tomorrow and put your ideas to work. Many thanks. You have an excellent site and are a very good instructor. I am 76 and learning machining as a hobby and to support my wife's small business tooling requirements. Your videos and my machinist handbook answer my questions. Well done.
Brilliant tutor, very methodical explanation.
Glad you liked it!
Joe,
I found that if I angle the tip of the tool any, it makes a chip that is wider than the slot which makes for a lot of friction on both sides of the chip and much more prone to weld in the slot if it runs out of lube for even a second of two. This characteristic of an angled grind gave me my worst parting tool experience and permanently ruined the accuracy of a nice 3 jaw chuck.
On my 1943 South Bend I put her in back gear, and part under power feed. This is the only way I've been successful. In my experience I would say if it ever chatters you have to get "under" the chatter and keep a chip going.
I found that with over about 1.5" dia. if I feed in slowly to be "safe," the sides of the slot winds the fragile chips into a tight ball which gets jammed and cases a growling dig in. Going in faster, making a stronger chip solves he problem.
I have 2 lathes. On one of them, the parting blade holder's base is parallel to the cross slide table. No induced relief angle. The other does angle the blade up slightly. I have parted a lot of of stuff in both lathes with the same blades - i cannot tell a difference. Tool height is much more critical!
Hi Joe. I'm now using a KT3.2 Tanjential brazed carbide tool.. I made the toolholder myself and adjust the rake with a wedge below it. Goes very well and feeds fast.
Very good info, you can never know to much. Joe I like the way you speak or teach what you have learned threw the years! You pick up on the important things that you should know about being a good machinist and staying safe. I watch your videos when ever I can good stuff keep keep en on! O when parting off your work put a wood dowel in the tail stock bring it up into hole if there is to catch the part if no hole use a tube to do so. save your fingers you will need them later people. hope this will help maybe Thanks for the info Joe
Awesome video. I had bad experiences as well when I first started, but it taught me sooo much! One thing I never used were the insert parting blades, so I was wanting to know your opinion
Thanks Joe,
I parted without having to clean up the part today! Happy 4Th!
All learned the hard way
Thanks
WHen the part is just too big a hack saw in the cut with the chuck turned slowly, by hand works too.
Cut off wheel in a 4' grinder not so well, more clean up
Great stuff....keep them coming please.
Thank you