In the golden age of British model engineering (between the two world wars) a common modification to a lathe was a "rear tool post" on the cross slide. It exploited the same cutting geometry your video shows (the rear of the workpiece is of course moving upwards). The rear tool post was normally fitted permanently with a parting tool. This was also the days before QC toolposts, so not having to swap a parting tool into the main tool post was a double-win. There are a few videos on youtube of present day rear tool posts used for parting off.
Thanks for the excellent suggestion Latheman, I just tried this on my 7x16 Mini Lathe which has a forward/reverse switch and I was able to part a 20mm dia bar of aluminum for the first time ever! This note is for the doom and gloom merchants: The carriage didn't fly off killing a nearby fluffy white kitten, mainly because it can't, being totally captive to the bed, and the chuck didn't unscrew and race across the floor smashing into my wooden crate full of jars of nitroglycerine, because on my mini lathe the chuck is bolted to the spindle, it doesn't unscrew. I suspect that Latheman knew all this about the Mini Lathe when he made this video titled 'Cutting off with the Mini Lathe'. Cheers
You did this video 8 years ago but I have just washed it. It is very interesting and your way of talking and description is so much fun. And your idea here looks extremely useful i'm going to try the upside down approach. Much appreciated thank you
I saw this a couple of days ago and wondered out accurate it was. Today I was trying to part a 3/4" metal bar and kept having all kinds of problems and not getting my piece cut off. I decided to give you recommendation a trial run. 1) Had to invert the cutoff tool in the tool holder. 2) Had to recenter the cutoff tool in the quick change tool holder, had to go to the maximum of the adjustment to get it close. 3) Had to remember to reverse the lathe before starting the cutoff. Very happy to say that it worked well for me. Did three cutoffs and finished up the project that I was working on.
You can also get the same or even better results by using a rear tool post and running forwards with the tool upside down. When I was an apprentice (many years ago) the reason for the increased rigidity was explained to me as being because the reaction on the spindle from the tool forces is directed vertically downwards into the spindle bearings where the weight of the spindle has already taken up any small clearance that there must be in order for the spindle to rotate. Wether this is true is debatable, however it should be noted that all capstan lathes have rear toolposts and upside down part offs.
Just ordered my first lathe and I was wondering about this. Always thinking it would be difficult to not break tooling. Glad I was fortunate enough to stumble across your video. Probably just saved me countless hours of frustration. Thanks for a great video.
I had thought this method would work having seen rear tool post parting done. The best and most graphic demonstration of how effective this method works is when you used a profile (round) tool. the results speak for themselves. Cheers from John Australia.
With regards to your simulation it’s shows the cutting tool at the same height in both directions. If you run your lathe in the conventional anticlockwise direction as you look at the chuck the tip of you cutter should be just below center then it wount pull the tool in like the simulation showed. This may be where you had problems in the first place. Hope this helps
Perhaps the best solution is to get a back-side parting tool post. Many people like these better because you can leave both your cutting tool and parting tool mounted at the same time. I have to remove my cutting tool to mount the front-side parting tool and even have to remove the work because it is in the way of replacing posts. My stepper motor mount prevents me from removing the T-Slot posts from the front side. Also, with a back-side parting tool post you get the benefits of a down-facing cutting edge (as you describe) without having to run the chuck backwards and risking it unscrewing itself. Having both parting and cutting tool posts mounted at the same time means a CNC-user can turn and part all in the same program without stopping.
+Latheman666 I dont like the simulation because you did not change the tool height when you ran the lathe in normal cutting direction. That way the tool was much more offcenter than in the reverse scenario and that causes the difference. I have a c2 mini lathe with a hss mini cutoff tool from ebay and using aluminium I found for getting a good cuttoff you need your tool height on centerline and feed consistent so your tool doesnt rub on the workpiece.
Thanks - wonderful suggestion - really helped - I lost all hopes that I would ever do a reliable parting with Grizzly G0765 mini lathe in the normal way even after all fine adjustments - the very sight of tool digging underneath work was a horror to see - this trick came in handy - finally peace reigned
I used this method today on my mini lathe. Once the tool height was set properly, it worked on brass and small diameter steel like a knife through butter. No chatter or digging in and a smooth progressive cut Thanks for the video
Did'nt realize this vid is 9 years old but I did this today its the first time Ive parted without the hair on my neck standing up.Very useful Vidiso Thanks
Thank you for this tip, I have a C2 mini lathe and parting off has been all but impossible till now. Such a simple solution that never occurred to me. I can now part off quickly and cleanly without fear of the tool digging in. Thanks again and keep up the good work.
Thank you Latheman! I have always dreaded parting on my lathe. This tip works like a charm even with slower RPM and slow cross feed. Getting the tool height correct is important as with any lathe tool. I took my time and learned on scrap pieces. Works beautiful! Thanks !!!!!!!
parting in a mini lathe, I thought it was not possible. What kind of magic is this?!? After pulling out my hair and eventually giving up on parting, I will seriousy give this a try!!!!
I just found this video and it solved a problem I have lived with for years! Previously I resorted to a bar clamp between the bottom of the saddle and the slide holding the tool holder tightening it only enuf to stabilize the tool but still allowing the cross feed slide to work. This was not the best solution. But the solution shown here is WONDERFUL! I tried it on a piece of scrap brass and the tool slid thru that brass like a hot knife thru butter! I use the quick-release tool holders and with the adjusting nut all the way down against the holder the holder is still not high enough to center the upside down tool. I will mill the top surface of the quick release holder down a bit to allow enough vertical adjustment to center the tool. I will paint the top of the tool holder RED to remind myself to run the spindle backwards. THANKS for the video!
I saw you video years ago and have been cutting off in reverse ever sense I saw you video. My mini lathe was new from the factory when I bought it. To date I haven’t had any problems with it like in the comments below. I have found also other thing That helped. Locking down your saddle so it would move when cutting. Thanks for sharing again
Yeah it seems like there is a brotherhood of man--sharing information--talking to people you have never met and getting along like a house on fire...It really is a wonder of the 21st century and the information stream is huge..There is so much trouble in the world with extremism and we have youtube which by and large is the opposite--we all get along and we encourage each other....win win win..
Thanks i needed that .the biggest problem i have on my machine is parting.even with a large machine i break parting tools cutting wide diameter pieces. I hope this works cutting large stock
My last lathe was a 10x24 Jet which is a full function machine with right/left carriage feeds, in/out cross feeds, full gearbox and back gears. It was almost 700 pounds (317 kg); kind of a beast for its capacity. I knew nothing of rigidity problems with it. I sold it because of a long distance move and bought a sub-500 pound (226 kg) 11x26 which is closer to a mini-lathe in its construction. It has taught me the meaning of a less than rigid lathe. I'll certainly give this a try!
I would not do this on a taig mini lathe because the chuck will come off the threaded spindle, but when you use a cut off tool on the backside of the workpiece (with the tool upside down) you will achieve the exact same thing.
I have a 1936 atlas 10d and chuck will screw off if I run backwards and I don't have reverse anyway but it does a good job on cut off if I turn the tool up side down and feed from the back side sense the atlas d does not have power cross feed I made one with a windshield wiper motor and a pwm and it cuts of like a champ
Hi when I was apprentice in the late 50 's I worked on a BRM 150 Italian make lathe and it had a back tool post on the end of the crosslide for parting off upside down. The back tool post was mainly to have a parting tool always available. The front tool post was a QCTP type.
Well done, that was a very practical explanation of what happens. I don't have a machine but have considered it. It's nice to know this information. Thank you.
A friend on one of the engineering forums gave me a good explanation as to why latheman is correct that the parting blade is knocked clear of the work piece if a problem arises,,, he explained it kinda like this,,the blade is indeed pulled into the work piece when it jams while the machine is running forward but when the machine is in reverse any 'play' that exists in the toolpost holder and compound slide ect,will open out and allow the tool to be pushed clear,but in forward mode the same 'play' is compressed tighter by the force of the work piece pushing downward..thus everything jams up....at least I think thats what you guys are trying to explain to me...Ian,model engine making is a quite recent hobby of mine and where I live I don't have anyone else nearby who has the same hobby so utube has been a great source of info for me as it lets me see things actually being done which is always better than just reading 'how to' in a mag or on a forum..any new tasks I have to do I check utube first to see if someone has posted a video of themselves doing that particular job...its a really good resource for novices like myself..
There's more to it than that -- the geometry of the tool post drives this effect. Because the support for the tool isn't directly beneath it, cutting pressure exerts a bending/rotating force on the tool post and lathe bed. With the normal arrangement any such bending causes the tool to hog deeper into the work, but if you run the spindle the other way the bending force relieves the tool instead.
Thanks, I will be trying this technique! I'd like to add, I read somewhere that cutting a small notch in the center of the HSS parting tool will help with chatter. I tried it myself, and it does seem to help to reduce chatter on a smaller lathe, in forward rotation. The notch was cut using a thin dremel cut off wheel. The groove runs parallel to the sides of the cutoff tool, making a small V shape in the top edge of the parting tool. It seems the shearing action of the V groove helps remove chips, and there's less surface touching the work. That said, I think your idea is better for larger forming tools.
Parting is such sweet sorrow that I'll say good night until tonight becomes tomorrow: Shakespeare. I agree with that for sure. Your video is so helpful. Many thanks.
nice one, dude. shakespearean lathe puns.....we live in fascinating times, man, fascinating times. i really appreciated that, prolly in the vein it was meant. excellent coup de gras with the saddle thing, too.
Thank you for sharing, you are using the same technique that I was thought in technical school using a South Bend 9, it works and it is faster. We made our own cutting tools, and we did not have inserts. Thank you and have a good day, be safe.
Dear Latheman666: Thank you, thank you, thank you. You have really showed me a great trick to make it easier to work some difficult pieces on the mini lathe. And I really appreciate the explanation also. I have just subscribed to your channel!
Just a small tip for a C2 lathe. If you have a standard parting tool holder you might get it to fit if you turn the standard toolpost upside down and use grub screws to hold the parting tool. This trick allowed me to mount my standard parting tool holder and get it on center to try out this process - it worked great, allowing me to part off a 3/4 dia brass rod with one smooth cut. I intend to make a custom toolpost to hold three sizes of parting tool so I can just drop it on and use the required size of tool.
You can do this without going into reverse by mounting the cut off tool upside down on the back of the cross slide. Many CNC lathe have a static cut off tool on the back side and the primary tools on the front side.
russianwolf1972 Yes, that would work too. Unfortunately on many mini lathes (including mine) there ist not enough space for a a tool on the back of the cross slide.
Latheman666 Maybe. Mine is a Sherline, so I have a good amount of room and can swap on a 13 inch cross slide table from a mill easily enough if more room is needed.
Good tip: I have a Big Dog Lathe and lost a blade during a cut due to the lack of rigidity of the machine. Vielen Dank für diese einfache und rationelle Lösung.
I have a diy 80mm chuck mini lathe with a small cross slide. I was unable to cut off aluminum part. But with that reverse cutting technique Im able to cut off 30mm steel with hss tool. Thank you...
From what I can see, place the tool below the center line in the forward direction and you'll achieve the same thing. You will always have a decreasing angle which is key to the tool not digging in.
***** You can also look at Machineries Handbook as well as some good online calculator's, one that I have used is called The Engineers Toolbox. Cheers from John.
the actual reason it works better is due to the spindle bearings in your headstock. excessive bearing clearance allows the spindle to lift and bounce causing chatter. never cut slow slow with an inserted tip these tips need speed friction and pressure to achieve a proper cut. if you want to run slow use high speed steel tools
brilliant, really useful information, il be using this on our lathe at work, that animation is a great tool (pun intended). Just as you cut through the final little bit of material you got an audible noise that sounded like it was colliding with tool can you confirm that the part was ok
even after a lifetime of machining I learn the correct way, only on problem , you can't do this reverse run if you have threaded chuck, it will unscrew.
Invert the tool and cut from the backside of the part. That way you don't have to run reverse. Sherline actually makes tool holders for this. I wasn't convinced until I tried it. Works way better this way.
No I do not have a number for oxtools but I geared up my lathe today to part using that advice and I never had a failure--I am quite chuffed,I put the tool upside down,switched the lathe into reverse rotation and and magic happened--beautiful cuts-no trouble.. If you do not have the luxury of reverse rotation on your lathe you will have to go to the other side of your lathe upside down
Ian, from "chuffed" I'm guessing you're from the UK. You might enjoy/find useful L. H. Sparey's _The Amateur's Lathe_, published in at least five editions since 1948. My 1976 hardback lies flat very nicely whilst opened; my 1991 paperback has slightly crisper print and photos. If I haven't got my memory mixed up Sparey was the model for the main character in Nevil Shute's _Trustee From The Toolroom_.
HI, thanks, but isn't the reason the cutter is drawn into the piece (when running in forward) because you have the cutter quite a bit above the center of the piece being cut?
Gom Bart Thank! I noticed this error after I uploaded the video. I forgot to set it at center for the presentation, after I simulalted it at center height, below center height and above center height. Reverse operation did always work better in the simulated flexible lathe.
The exaggeration on the computer makes it much more clear. Have you already done one one reducing chatter? When any of the angles of the triangle between the top slides and the cut is greater than 90- presto, you've got bad chatter.
Excellent video.... thanks so much for taking the time to post it! Very helpful. Question: The tool shown @ 2:18 ... exactly what I've been looking for. Who makes it?
+Rice Crash I think a downside is that you don't see the cutting edge. Especially when touching off it is important to see the tiny chip that forms. Built-up edges also couldn't be seen.
With normal rotation and tool orientation the force of the cut forces the carriage down onto the bed. Running in reverse like this can damage the carriage and the bed.
+Rasmus Hansen modern ones have a locking mechanism or pins to prevent this. It's not good advice to run a lathe backwards there is a reason they run anticlockwise
good video, thanks. This trick is known since a long time and works particularly well for mini lathes which all suffer from low rigidity. However there is a safety risk for lathes with a chuck mounted to a threaded main spindle. By reversing the spindle direction those chucks can work loose and jump in the face of the user. Such lathes should NEVER user reversed spindle directions.
I really cracked up when you said "that's a cloud going by"! Laughed my socks off - brilliant!
8-)
@@Latheman666 I liked the cloud too.
In the golden age of British model engineering (between the two world wars) a common modification to a lathe was a "rear tool post" on the cross slide.
It exploited the same cutting geometry your video shows (the rear of the workpiece is of course moving upwards). The rear tool post was normally fitted permanently with a parting tool.
This was also the days before QC toolposts, so not having to swap a parting tool into the main tool post was a double-win.
There are a few videos on youtube of present day rear tool posts used for parting off.
Thanks for the excellent suggestion Latheman, I just tried this on my 7x16 Mini Lathe which has a forward/reverse switch and I was able to part a 20mm dia bar of aluminum for the first time ever!
This note is for the doom and gloom merchants: The carriage didn't fly off killing a nearby fluffy white kitten, mainly because it can't, being totally captive to the bed, and the chuck didn't unscrew and race across the floor smashing into my wooden crate full of jars of nitroglycerine, because on my mini lathe the chuck is bolted to the spindle, it doesn't unscrew.
I suspect that Latheman knew all this about the Mini Lathe when he made this video titled 'Cutting off with the Mini Lathe'.
Cheers
your computer simulation was amazing.
I'm about to buy my first lathe and I think I just learned something many professionals wouldn't know, thank you, this is high quality content.
You did this video 8 years ago but I have just washed it. It is very interesting and your way of talking and description is so much fun. And your idea here looks extremely useful i'm going to try the upside down approach. Much appreciated thank you
I saw this a couple of days ago and wondered out accurate it was. Today I was trying to part a 3/4" metal bar and kept having all kinds of problems and not getting my piece cut off. I decided to give you recommendation a trial run.
1) Had to invert the cutoff tool in the tool holder.
2) Had to recenter the cutoff tool in the quick change tool holder, had to go to the maximum of the adjustment to get it close.
3) Had to remember to reverse the lathe before starting the cutoff.
Very happy to say that it worked well for me. Did three cutoffs and finished up the project that I was working on.
Good video. Inspired me to sort out my rear toolpost this evening and it just completely fixed all my parting off chatter. Good man!
You can also get the same or even better results by using a rear tool post and running forwards with the tool upside down. When I was an apprentice (many years ago) the reason for the increased rigidity was explained to me as being because the reaction on the spindle from the tool forces is directed vertically downwards into the spindle bearings where the weight of the spindle has already taken up any small clearance that there must be in order for the spindle to rotate. Wether this is true is debatable, however it should be noted that all capstan lathes have rear toolposts and upside down part offs.
Just ordered my first lathe and I was wondering about this. Always thinking it would be difficult to not break tooling. Glad I was fortunate enough to stumble across your video. Probably just saved me countless hours of frustration. Thanks for a great video.
I had thought this method would work having seen rear tool post parting done. The best and most graphic demonstration of how effective this method works is when you used a profile (round) tool. the results speak for themselves. Cheers from John Australia.
With regards to your simulation it’s shows the cutting tool at the same height in both directions. If you run your lathe in the conventional anticlockwise direction as you look at the chuck the tip of you cutter should be just below center then it wount pull the tool in like the simulation showed. This may be where you had problems in the first place.
Hope this helps
Complete newb on the lathe here. Tried parting off first time today with Grizzly 7x14. Will definitely try this next time!
Perhaps the best solution is to get a back-side parting tool post. Many people like these better because you can leave both your cutting tool and parting tool mounted at the same time. I have to remove my cutting tool to mount the front-side parting tool and even have to remove the work because it is in the way of replacing posts. My stepper motor mount prevents me from removing the T-Slot posts from the front side. Also, with a back-side parting tool post you get the benefits of a down-facing cutting edge (as you describe) without having to run the chuck backwards and risking it unscrewing itself. Having both parting and cutting tool posts mounted at the same time means a CNC-user can turn and part all in the same program without stopping.
Thanks. The simulation with the spring models was the best part.
Shannon Price Glad you enjoyed it. Thanks!
+Latheman666 I dont like the simulation because you did not change the tool height when you ran the lathe in normal cutting direction. That way the tool was much more offcenter than in the reverse scenario and that causes the difference.
I have a c2 mini lathe with a hss mini cutoff tool from ebay and using aluminium I found for getting a good cuttoff you need your tool height on centerline and feed consistent so your tool doesnt rub on the workpiece.
Very good trick !! longtemp the fact that I have not seen anything so convenient for turning on a lathe , thanks !!
For beginner machinist out there your "Phun" example is a good visual, well done
Thanks!
Thank you Latheman. This video provides very useful information, especially it provides a clear explanation and simulation for how it works.
Just happened across your video. I went and tried this on my mini lathe and it worked great. Thanks.
I also like the fact that it sheds the chips downward. Great idea!
Thanks - wonderful suggestion - really helped - I lost all hopes that I would ever do a reliable parting with Grizzly G0765 mini lathe in the normal way even after all fine adjustments - the very sight of tool digging underneath work was a horror to see - this trick came in handy - finally peace reigned
You are welcome. Glad I could help you.
Quality demonstration with good humour. Top stuff.
I used this method today on my mini lathe. Once the tool height was set properly, it worked on brass and small diameter steel like a knife through butter. No chatter or digging in and a smooth progressive cut Thanks for the video
Did'nt realize this vid is 9 years old but I did this today its the first time Ive parted without the hair on my neck standing up.Very useful Vidiso Thanks
Very interesting. The simulation made it more clear. I'll have to try it because it is such a pain to part with my mini-lathe.
I learned something new on youtube today. I'll be running my next cutoff in reverse.
Thank you for this tip, I have a C2 mini lathe and parting off has been all but impossible till now. Such a simple solution that never occurred to me. I can now part off quickly and cleanly without fear of the tool digging in. Thanks again and keep up the good work.
Thanks for the info man! Parting has had me in fits for a few days and your method I will try in the morning out in the shop! Have fun!
Gerry
Sense of humour appeals, nicely done.
Very useful and helpful info, thanks for sharing.
+Aaron DC mediA
zomg the cloud cracked me up. I think the deadpan narration is perfect.
Great video, and the clouds deserve their own thumbs up as well.
Thank you Latheman! I have always dreaded parting on my lathe. This tip works like a charm even with slower RPM and slow cross feed. Getting the tool height correct is important as with any lathe tool. I took my time and learned on scrap pieces. Works beautiful! Thanks !!!!!!!
parting in a mini lathe, I thought it was not possible. What kind of magic is this?!? After pulling out my hair and eventually giving up on parting, I will seriousy give this a try!!!!
I just found this video and it solved a problem I have lived with for years! Previously I resorted to a bar clamp between the bottom of the saddle and the slide holding the tool holder tightening it only enuf to stabilize the tool but still allowing the cross feed slide to work. This was not the best solution. But the solution shown here is WONDERFUL! I tried it on a piece of scrap brass and the tool slid thru that brass like a hot knife thru butter! I use the quick-release tool holders and with the adjusting nut all the way down against the holder the holder is still not high enough to center the upside down tool. I will mill the top surface of the quick release holder down a bit to allow enough vertical adjustment to center the tool. I will paint the top of the tool holder RED to remind myself to run the spindle backwards. THANKS for the video!
I saw you video years ago and have been cutting off in reverse ever sense I saw you video. My mini lathe was new from the factory when I bought it. To date I haven’t had any problems with it like in the comments below. I have found also other thing That helped. Locking down your saddle so it would move when cutting. Thanks for sharing again
You are welcome. I'm glad I could help you.
Great use of humor and your videos keep up the good work.
It worked great on my mini lathe too thankyou very much for a much easier way to part off...
You're welcome.
Yeah it seems like there is a brotherhood of man--sharing information--talking to people you have never met and getting along like a house on fire...It really is a wonder of the 21st century and the information stream is huge..There is so much trouble in the world with extremism and we have youtube which by and large is the opposite--we all get along and we encourage each other....win win win..
thank you for posting this very helpful tip for parting off work in mini lathes. This will be put into action on my lathes as from now.
Thanks i needed that .the biggest problem i have on my machine is parting.even with a large machine i break parting tools cutting wide diameter pieces. I hope this works cutting large stock
I tried parting in reverse and it works well, thanks for the tip!
My last lathe was a 10x24 Jet which is a full function machine with right/left carriage feeds, in/out cross feeds, full gearbox and back gears. It was almost 700 pounds (317 kg); kind of a beast for its capacity. I knew nothing of rigidity problems with it. I sold it because of a long distance move and bought a sub-500 pound (226 kg) 11x26 which is closer to a mini-lathe in its construction. It has taught me the meaning of a less than rigid lathe. I'll certainly give this a try!
I would not do this on a taig mini lathe because the chuck will come off the threaded spindle, but when you use a cut off tool on the backside of the workpiece (with the tool upside down) you will achieve the exact same thing.
I have a 1936 atlas 10d and chuck will screw off if I run backwards and I don't have reverse anyway but it does a good job on cut off if I turn the tool up side down and feed from the back side sense the atlas d does not have power cross feed I made one with a windshield wiper motor and a pwm and it cuts of like a champ
Hi when I was apprentice in the late 50 's I worked on a BRM 150 Italian make lathe and it had a back tool post on the end of the crosslide for parting off upside down. The back tool post was mainly to have a parting tool always available. The front tool post was a QCTP type.
Very interesting, I never heard about cutting in reverse direction. I'll giving a try, thanks!
Awesome method thanks, I have never thought of this. I will be using this from now on. A huge thumbs up for you.
Well done, that was a very practical explanation of what happens. I don't have a machine but have considered it. It's nice to know this information. Thank you.
Thank you,solved my parting off problems straight away.
Thanks for this tip. I am going to buy a mini lathe so this will certainly help.
A friend on one of the engineering forums gave me a good explanation as to why latheman is correct that the parting blade is knocked clear of the work piece if a problem arises,,, he explained it kinda like this,,the blade is indeed pulled into the work piece when it jams while the machine is running forward but when the machine is in reverse any 'play' that exists in the toolpost holder and compound slide ect,will open out and allow the tool to be pushed clear,but in forward mode the same 'play' is compressed tighter by the force of the work piece pushing downward..thus everything jams up....at least I think thats what you guys are trying to explain to me...Ian,model engine making is a quite recent hobby of mine and where I live I don't have anyone else nearby who has the same hobby so utube has been a great source of info for me as it lets me see things actually being done which is always better than just reading 'how to' in a mag or on a forum..any new tasks I have to do I check utube first to see if someone has posted a video of themselves doing that particular job...its a really good resource for novices like myself..
There's more to it than that -- the geometry of the tool post drives this effect. Because the support for the tool isn't directly beneath it, cutting pressure exerts a bending/rotating force on the tool post and lathe bed. With the normal arrangement any such bending causes the tool to hog deeper into the work, but if you run the spindle the other way the bending force relieves the tool instead.
Thanks, I will be trying this technique! I'd like to add, I read somewhere that cutting a small notch in the center of the HSS parting tool will help with chatter. I tried it myself, and it does seem to help to reduce chatter on a smaller lathe, in forward rotation. The notch was cut using a thin dremel cut off wheel. The groove runs parallel to the sides of the cutoff tool, making a small V shape in the top edge of the parting tool. It seems the shearing action of the V groove helps remove chips, and there's less surface touching the work. That said, I think your idea is better for larger forming tools.
"Happy little clouds; this is a feature that most "serious" simulations don't have- . classic
Parting is such sweet sorrow that I'll say good night until tonight becomes tomorrow: Shakespeare. I agree with that for sure. Your video is so helpful. Many thanks.
Oh, and don't forget to lock down the saddle as well.
nice one, dude. shakespearean lathe puns.....we live in fascinating times, man, fascinating times. i really appreciated that, prolly in the vein it was meant. excellent coup de gras with the saddle thing, too.
Thank you for sharing, you are using the same technique that I was thought in technical school using a South Bend 9, it works and it is faster. We made our own cutting tools, and we did not have inserts. Thank you and have a good day, be safe.
Dear Latheman666: Thank you, thank you, thank you. You have really showed me a great trick to make it easier to work some difficult pieces on the mini lathe. And I really appreciate the explanation also. I have just subscribed to your channel!
+Angelo Zucco Thanks, I'm glad that I could help you.
Just a small tip for a C2 lathe. If you have a standard parting tool holder you might get it to fit if you turn the standard toolpost upside down and use grub screws to hold the parting tool. This trick allowed me to mount my standard parting tool holder and get it on center to try out this process - it worked great, allowing me to part off a 3/4 dia brass rod with one smooth cut. I intend to make a custom toolpost to hold three sizes of parting tool so I can just drop it on and use the required size of tool.
Very well explained, now I know, thank you. I will watch more of your videos but I'm sure it won't be a waste of time, thanks again.
Makes you wonder if we should always run the lathe in reverse order for all normal cutting. Even the chips won't fly around that much.
You can do this without going into reverse by mounting the cut off tool upside down on the back of the cross slide. Many CNC lathe have a static cut off tool on the back side and the primary tools on the front side.
russianwolf1972 Yes, that would work too. Unfortunately on many mini lathes (including mine) there ist not enough space for a a tool on the back of the cross slide.
Latheman666 Maybe. Mine is a Sherline, so I have a good amount of room and can swap on a 13 inch cross slide table from a mill easily enough if more room is needed.
Good tip: I have a Big Dog Lathe and lost a blade during a cut due to the lack of rigidity of the machine. Vielen Dank für diese einfache und rationelle Lösung.
I have a diy 80mm chuck mini lathe with a small cross slide. I was unable to cut off aluminum part. But with that reverse cutting technique Im able to cut off 30mm steel with hss tool. Thank you...
From what I can see, place the tool below the center line in the forward direction and you'll achieve the same thing. You will always have a decreasing angle which is key to the tool not digging in.
That puts the workpiece in a climbing situation. It's an eye-opening experience when that happens!
Not only is this a great tip, and a great video, but this guys voice is cool as fuck. Sounds like Werner Herzog.
Totally brilliant, now why didn't I think of that? Thank you sir!
Thank you for the video. Where is the best place to look up RPM's for what diameter/material to part off?
Toms techniques made a good video about cutting speeds (I recommend all his videos)
***** You can also look at Machineries Handbook as well as some good online calculator's, one that I have used is called The Engineers Toolbox.
Cheers from John.
the actual reason it works better is due to the spindle bearings in your headstock. excessive bearing clearance allows the spindle to lift and bounce causing chatter. never cut slow slow with an inserted tip these tips need speed friction and pressure to achieve a proper cut. if you want to run slow use high speed steel tools
I tried this myself. What a difference. I run most of everything in reverse
Very good! It is the way most cnc's cut . Does it work on steel??
Amazing trick. Thanks for sharing 💪
Looks like a good tip will try
brilliant, really useful information, il be using this on our lathe at work, that animation is a great tool (pun intended). Just as you cut through the final little bit of material you got an audible noise that sounded like it was colliding with tool can you confirm that the part was ok
+nathan hellyer I don't remember.
going to try this tonight, thanx
thank you for showing the technique.
I have been doing this wrong for 30 years. Thank you!!
Thank you for the video. Among the benchtop lathes, which do you recommend?
Werner Herzog owns a mini lathe?! Awesome!
"This is a cloud going by" - tremendous. :-)
Does anyone have an explanation on why it doesn't vibrate? With downwards pressure (convecional turning) the setup should be more rigid
even after a lifetime of machining I learn the correct way, only on problem , you can't do this reverse run if you have threaded chuck, it will unscrew.
Invert the tool and cut from the backside of the part. That way you don't have to run reverse. Sherline actually makes tool holders for this. I wasn't convinced until I tried it. Works way better this way.
Great tip. Thank you for sharing.
I'm curious, do you not get the same effect in forward rotation by just lowering the tool below the center axis of the part?
The tool will dive under the part and either get stuck or shatter.
Nicely done!
I'll be trying this.
No I do not have a number for oxtools but I geared up my lathe today to part using that advice and I never had a failure--I am quite chuffed,I put the tool upside down,switched the lathe into reverse rotation and and magic happened--beautiful cuts-no trouble..
If you do not have the luxury of reverse rotation on your lathe you will have to go to the other side of your lathe upside down
Ian, from "chuffed" I'm guessing you're from the UK. You might enjoy/find useful L. H. Sparey's _The Amateur's Lathe_, published in at least five editions since 1948. My 1976 hardback lies flat very nicely whilst opened; my 1991 paperback has slightly crisper print and photos. If I haven't got my memory mixed up Sparey was the model for the main character in Nevil Shute's _Trustee From The Toolroom_.
HI, thanks, but isn't the reason the cutter is drawn into the piece (when running in forward) because you have the cutter quite a bit above the center of the piece being cut?
Gom Bart Thank! I noticed this error after I uploaded the video. I forgot to set it at center for the presentation, after I simulalted it at center height, below center height and above center height. Reverse operation did always work better in the simulated flexible lathe.
The exaggeration on the computer makes it much more clear. Have you already done one one reducing chatter? When any of the angles of the triangle between the top slides and the cut is greater than 90- presto, you've got bad chatter.
Great video and concept
Excellent video.... thanks so much for taking the time to post it! Very helpful.
Question: The tool shown @ 2:18 ... exactly what I've been looking for. Who makes it?
I bought it on this steam show: ua-cam.com/video/evl10GZHGxs/v-deo.html
Unfortunately I don't remember the dealer nor do I know the manufacturer.
Rob Stachowicz I bought this tool on Ali Express
Great demo. Thank you!
I tried this method but my results didn't seem to be any better. Looks like your setup works pretty dang good though!
Neat trick, and well explained.
Interesting. The simulation with the cloud was priceless. What simulation software is that?
Thank you! I'm going to try this!!
tool are not in the center of the piece in the simulation....
Did they look pretty centred in the actual footage of tools and spinning metal though?
very informative . thank you
really useful! how did not know this, thank you!
Unreal thank you so much!
I'm gonna have to try this. parting off is the thing I hate most with my machine
great work, great tip and tricks. great info. thanks for sharing.
sam yeates I'm glad you liked it. Thanks!
Makes sense, why then wouldn't all lathe tools be used in this fashion. Is their a downside to general lathe work running in reverse ??
+Rice Crash I thought the same thing... why not just do all your turning backwards with the tool upside down? Ill try it on my next project.
+Rice Crash I think a downside is that you don't see the cutting edge. Especially when touching off it is important to see the tiny chip that forms.
Built-up edges also couldn't be seen.
+Latheman666 smaller lathes have the chuck fixed with thread. it can therefore unscrew.
With normal rotation and tool orientation the force of the cut forces the carriage down onto the bed. Running in reverse like this can damage the carriage and the bed.
+Rasmus Hansen modern ones have a locking mechanism or pins to prevent this. It's not good advice to run a lathe backwards there is a reason they run anticlockwise
good video, thanks. This trick is known since a long time and works particularly well for mini lathes which all suffer from low rigidity. However there is a safety risk for lathes with a chuck mounted to a threaded main spindle. By reversing the spindle direction those chucks can work loose and jump in the face of the user. Such lathes should NEVER user reversed spindle directions.
Neat idea! I'll try it too.