In this video, I will show you how easy it is to stop breaking carbide inserts when you are parting off a workpiece in your lathe. Parting tool and insert source: www.ebay.ca
Brilliant. I have a Colchester Chipmaster which is a rigid lathe but I have never succeeded at parting with it. No matter what I use - HSS or carbide, it would end in breaks or chipped inserts. I will be trying this for sure.
I'm a big advocate of really finding the true On Center measurement and using an Indicator to set your tool. I've done the usual Eye Ball, Ruler tricks but for "Has To Be Right On" nothing beats it.
Thanks for the advise. I got mine to not break insert by basically backing the tool inside the 4 way tool post, but those without a 4 way toolpost can't do this, and the support really helps. I found the support size is critical, too little and it doesn't support, too much and it shifts the center point too high. Will need to make more than one, or have a way to adjust the length. Problem is these things are designed for CNC... where they're not oriented like a manual lathe but backwards (it means your took faces downwards, and the lathe turns backwards). Doing this somehow improves stiffness for some reason, and on a lighter lathe that can't use parting tool without chatter mounting it backwards can eliminate the chatter. If you look at every CNC lathe video you will know what I mean, the tool faces the wrong way compared to a manual lathe. Edit: Most parting tool holders sticks far too much out to use in a manual lathe, and was wondering perhaps you have to mill the quick change tool holder to allow you to back the insert holder inside the holder slot...
Thank you for your kind comments, Tyler, no I did not have to mill my cutoff tool, it fits just fine in my older Botsford lathe and yes, I heard that if you mount a cut off tool upside down and behind the workpiece in a CNC lathe for example there is less chance of breaking a carbide insert.
What a great project! I have an idea similar in concept but different in execution. I’m pretty well covered in the parting department as of last week but if and when boredom strikes I have another project :)
As i experienced in my chinese mini-lathe, after having broken a lot of parting-inserts, the goal is to use the tool upside down and - of course - opposit revolution direction. Using this configuration helps the chips falling down for gravity, so leaving the work free from them, allowing the insert to freely cutting. I have no risk of un-screwing the mandrel, as it is fixed to the lathe nose with three 6 mm screws and nuts ( 4 screws for 4 jaws mandrel ), the only risk is for the compound that could be snapped out, but only if too far much strenght would be applied ... ( i don't really fear of this chance ... ) Just three tips : 1 - be aware of construction steel, it is not so omogenous inside as silver steel or lead-steel can be, and so it gives variabile stress on the carbide tip, leading to broke it. So advance with hight attention ... 2 - if you hear a noise twistle, your tip is not cutting, but just touching your piece, this can lead to harden the piece, better have a bit heart and give a bit more turn of the knob. 3 - as i saw in many videos, enlarge the cut on both sides to give more space to the chips to fall down and get a more free space for the tip ... Using upside down tool and opposit direction, i was able ( this time using an HSS tool, 3,0 mm large, from Proxxon ) to part a 45 mm piece of steel ...
I'm old. My lathe is old and my tooling are old too. That's a great idea for QCTP but my old 4 way turret tool-post doesn't need it. For those hard to reach operations I still have my (even older) Lantern style TP. It and its tool-holders are plenty rigid and offer minimum overhang. Wakodahatchee Chris
Yep, I don't understand the upside down thing. The parting tool doesn't know or care which way it's facing. Your workplace doesn't know or care that it rotates in a certain direction . The end result is the same, the insert is gauging/cutting a piece of rotating stock. Am I missing something?
The theory is that in reverse the forces move the parting cutter away from the cut if your carriage lifts, in forwards it tends to dig in. (Due to the v way being on the front)
Interresting aproach! However, what's that on @4:12 ? the tool holder was not locked solid so it twisted, That way, the tool is not perpendicular to the workpeace.. Normally that's a recipe for disaster when parting off..
Thats NOT a parting tool.... A grooving tool, yes. Can be used as a parting tool for small diameters and even a turning tool if small cuts are taken. A parting tool it is not!!
I think it would have been much easier just to thread the bottom of the tool, and put a screw in it long enough to reach down to the bed of the cross slide, and used a nut to tighten it, Think it would have done the job?
I like having a wide solid base under the parting tool, you might be able drill and tap the bottom of the parting tool to fit a larger diameter screw then use a jamb nut to prevent it from loosening from the parting tool, thanks for your suggestion.
A truly excellent solution. Nice video.
Thank you! I just broke another carbide and decided to see if anyone on youtube had a solution. Your solution is beautiful
Your welcome, I am glad that it helped you.
Anything that improves a process has to be worth it's weight in gold......no matter what.
Your channel deserves more subscribers. I really like the slideshow approach over videos. It's far easier to see the important details.
Thank you David, much appreciated!
Thank you. What a great idea. I am going to make one as soon as I can.
You are welcome!
Brilliant. I have a Colchester Chipmaster which is a rigid lathe but I have never succeeded at parting with it. No matter what I use - HSS or carbide, it would end in breaks or chipped inserts. I will be trying this for sure.
That was a great video. Simple solution to a perennial problem, presented very clearly. I will have to make one for my lathe! I also subscribed.👍👍
I implemented a version of your parting tool support thingy. Works really well, so thanks for sharing.
Great idea. Thanks for the video.
what a great idea, looks like a great problem solver for my shaky compound slide...thank you, cheers from down in Florida, Paul
I'm a big advocate of really finding the true On Center measurement and using an Indicator to set your tool. I've done the usual Eye Ball, Ruler tricks but for "Has To Be Right On" nothing beats it.
Thank you for your support, Sir.
I have the same issue. Thank you so much for sharing your solution to this problem. I’m going to do the same.
Your welcome, I am glad it helped you too.
Thanks for the advise. I got mine to not break insert by basically backing the tool inside the 4 way tool post, but those without a 4 way toolpost can't do this, and the support really helps. I found the support size is critical, too little and it doesn't support, too much and it shifts the center point too high. Will need to make more than one, or have a way to adjust the length. Problem is these things are designed for CNC... where they're not oriented like a manual lathe but backwards (it means your took faces downwards, and the lathe turns backwards). Doing this somehow improves stiffness for some reason, and on a lighter lathe that can't use parting tool without chatter mounting it backwards can eliminate the chatter. If you look at every CNC lathe video you will know what I mean, the tool faces the wrong way compared to a manual lathe.
Edit: Most parting tool holders sticks far too much out to use in a manual lathe, and was wondering perhaps you have to mill the quick change tool holder to allow you to back the insert holder inside the holder slot...
Thank you for your kind comments, Tyler, no I did not have to mill my cutoff tool, it fits just fine in my older Botsford lathe and yes, I heard that if you mount a cut off tool upside down and behind the workpiece in a CNC lathe for example there is less chance of breaking a carbide insert.
at 4:13 when you test the tool on thhe mystery metal, your whole tool holder moves considerably
I just may do that, greetings from Canada.
What a great project! I have an idea similar in concept but different in execution. I’m pretty well covered in the parting department as of last week but if and when boredom strikes I have another project :)
Thanks for your kind comment!
As i experienced in my chinese mini-lathe, after having broken a lot of parting-inserts, the goal is to use the tool upside down and - of course - opposit revolution direction. Using this configuration helps the chips falling down for gravity, so leaving the work free from them, allowing the insert to freely cutting.
I have no risk of un-screwing the mandrel, as it is fixed to the lathe nose with three 6 mm screws and nuts ( 4 screws for 4 jaws mandrel ), the only risk is for the compound that could be snapped out, but only if too far much strenght would be applied ... ( i don't really fear of this chance ... )
Just three tips :
1 - be aware of construction steel, it is not so omogenous inside as silver steel or lead-steel can be, and so it gives variabile stress on the carbide tip, leading to broke it. So advance with hight attention ...
2 - if you hear a noise twistle, your tip is not cutting, but just touching your piece, this can lead to harden the piece, better have a bit heart and give a bit more turn of the knob.
3 - as i saw in many videos, enlarge the cut on both sides to give more space to the chips to fall down and get a more free space for the tip ...
Using upside down tool and opposit direction, i was able ( this time using an HSS tool, 3,0 mm large, from Proxxon ) to part a 45 mm piece of steel ...
now THAT is perfect! i have the EXACT same issue! thank you sir!
Thanks mister.
I'm old. My lathe is old and my tooling are old too. That's a great idea for QCTP but my old 4 way turret tool-post doesn't need it. For those hard to reach operations I still have my (even older) Lantern style TP. It and its tool-holders are plenty rigid and offer minimum overhang.
Wakodahatchee Chris
❤
Just found your channel and Subscribed. Very nice work. I agree totally with your channel name. Good job
very much like my solution on my small lathe, i use a machinist jack, yours is more permanent and elegant
Interesting... ill give it a try. After I replace the tool holder. Last carbide tip mangled it on the way out
Genius! I'm doing this now. Or tomorrow when I wake up. LOL
Great idea……I’m on it! You don’t try it you will never know!
Good idea, glad it worked for you - I don't think my lathe will be suitable for that mod.
cool idea. i noticed your tool holder moved during the first test cut.
Thanks, there is a good chance that my tool post holder was not tightened properly.
Saw some people ran the lathe in reverse with the parting tool upside down. Supposedly breakage can be mostly avoided.
How would that help?
@@DandiOffroad e.g. search on CZcams "The Ultimate Trick: Cutting off with the Mini Lathe".
Yep, I don't understand the upside down thing. The parting tool doesn't know or care which way it's facing. Your workplace doesn't know or care that it rotates in a certain direction .
The end result is the same, the insert is gauging/cutting a piece of rotating stock.
Am I missing something?
The theory is that in reverse the forces move the parting cutter away from the cut if your carriage lifts, in forwards it tends to dig in. (Due to the v way being on the front)
Interresting aproach! However, what's that on @4:12 ? the tool holder was not locked solid so it twisted, That way, the tool is not perpendicular to the workpeace.. Normally that's a recipe for disaster when parting off..
You are one of a few people who caught my mistake, thank you for your comment.
@@practicemakesbetter7132 Cheers!
Having a crappy toolpost is not helping.
Thats NOT a parting tool.... A grooving tool, yes. Can be used as a parting tool for small diameters and even a turning tool if small cuts are taken. A parting tool it is not!!
Bored to tears befoe1/3 of the way.BYE
pity, the rest of us learned something.
I think it would have been much easier just to thread the bottom of the tool, and put a screw in it long enough to reach down to the bed of the cross slide, and used a nut to tighten it,
Think it would have done the job?
I like having a wide solid base under the parting tool, you might be able drill and tap the bottom of the parting tool to fit a larger diameter screw then use a jamb nut to prevent it from loosening from the parting tool, thanks for your suggestion.
I'm sure that works, but.....
It's a one tool solution, when in reality all of your tools are being effected by the lack of rigidity.
You are right of course, we can tolerate some lack of rigidity with most lathe tools, a parting tool is more delicate, thanks for your input.
thanks. stay away from Chinese parting tools is the first rule.
Even if you follow rule number 1 you can break parting tools if you have an unstable base, thanks for your comment.