Were you doing a 0.100" depth of cut or was it a 0.100" diameter reduction? It looked more like a 0.050" DOC Feed rate is for finishing, roughing would be closer to 0.010"~0.020"/rev. The relationship between nose radius and feed rate is what will give better surface finish plus the overall surface speed (rpm+feed rate) Speed is also way too low, that's the sort of rpm you use with carbon steel tooling and which is why you were not getting good chip formation, material was being 'rubbed' off If chips are not turning colour, your going too slow to use carbide effectively (you want chips 'brown' at minimum and blue' is 'better, it isn't pushing machine or tooling with 12L4 and coolant) Negative rake tools require a larger more powerful machine, the things you are doing would actually be better with HSS, using 'industrial' tooling isn't actually the best idea for almost all hobby machinists. (use positive rake tools even if you don't get double the cutting edges) I was hoping you would go into the 'grades' of carbide, most Chinese stuff is for general purpose/cast iron (grade C6) and around 65 Rockwell C, 'chrome steel' bearing housings are often about the same hardness or harder but can be easily machined with correct tools which will even cut HSS quite easily if machine and set up is rigid enough 'Micrograin' carbide inserts are often much harder but machine rigidity is more important as carbide will chip very easily if there is vibration/machine/tool flex
I totally agree with you. On the back of the insert boxes show what material the insert is good for along with the suggested Surface footage and chip load. Also the lead angle of the second cutter is 45 degrees ,lengthening the chip.
It has been my experience that few insert boxes from china have the alpha-numeric code from the Black Book or any other book for that matter printed on them. Once in a great while but most haven't had it. Most tool holders also do not coincide with western nomenclature. It is one of the great difficulties using chinesium.
Looks like at about 8:50 your live center begins to not rotate consistently and at the same rpm as the workpiece. Which could possibly explain the chatter. If the piece slides into the chuck towards the headstock that will happen. Or it could just be from the camera.
Great info. Although, it's not a fair assessment/comparison. Snmg is using a 90* tool holder vs the wnmg is using a rh tool holder. The cutter attack angles are different. If you were to cut left to right with the wnmg rh tool holder, you would get much better results. 👍✌️🤙
You clearly have never heard of positive or negative tool geometry... Comparing those two tools in the same operation is nonsensical. What cuts better a chef knife or a chainsaw? It depends what and how you are cutting.
Great tip, I have that handbook too. Way more convenient than online or Machinery's Handbook tome. May want to use a camera mount that is not connected to the lathe. Even small amounts of shake get translated very efficiently to the video, unfortunately. Some folks with more massive lathes get away with this, at least with a well-behaved objects, but even they have a problem if the part being turned is not radially symmetric. Other things to consider: I notice that in several videos you introduce the next 'test', but then insert clips of other information (thermal imaging or close-ups showing surface finish) from the prior operation before you actually go to the next 'test'. Because you describe what's being shown, it is clear, but simply splicing in the other scenes before announcing the transition would be clearer. Perhaps this happens because your narration is mostly real-time and not separate voice over. Anyway something to consider as you generate more content...
Thanks so much for the advice Steve. I am ALWAYS trying to improve things. Glad you enjoyed the video and appreciate you taking the time to send a comment my way. Have a great day!
Interesting. In my old school opinion the best thing you can do with inserts is to use high speed steel instead. 50 years machining and rarely was carbide actually needed for a job. Inserts were created for and are best at high volume high speed Production factory work. There is nothing that was done here that couldn't be done with HSS tool bits and a LOT cheaper.
Time is money and inserts are cheap and repeatable. Even if you are quick, the 10 mins it takes you to regrind and find the new zero position for the tool is more than an order of magnitude longer than it takes to flip an insert. What is your shop's rate per hour? How much is that ten minutes worth? A lot more than one insert's edge I hope.
i get CHATTER !!!!!really hard when trying the SNMG as a groove tool ??SNMG insert 16-4d holder maybe i am not supposed to use that but it seems like the only way to create that V (90degress) groove but i get chatter anythoughts?
Hello Fred thanks for the comment. So if you can manage to go in with a parting tool and cut close to the depth of the groove then go in with the SNMG I bet you would get better results. Even better if you can only cut one side a time. Also, be sure you are on center with a minimum of stickout. You may also want to try increasing/decreasing the speed or feed to see what changes. Sometimes like with parting (Although it seems counterintuitive) feeding faster will eliminate chatter. Are you working as close to the chuck as possible and between centers? Can you use a steady or follower rest to support your work? I would also say check you spindle bearings and end play. Start simple and move to the more time consuming things. Mainly rigidity is your friend. Make sure everything is as solid as possible. Best of luck and thanks for watching! I have a video coming to address some of these things as well. Take care.
I watched one minute of your video and ordered the book
So glad to help you out. Enjoy some time in the garage!
Were you doing a 0.100" depth of cut or was it a 0.100" diameter reduction?
It looked more like a 0.050" DOC
Feed rate is for finishing, roughing would be closer to 0.010"~0.020"/rev.
The relationship between nose radius and feed rate is what will give better surface finish plus the overall surface speed (rpm+feed rate)
Speed is also way too low, that's the sort of rpm you use with carbon steel tooling and which is why you were not getting good chip formation, material was being 'rubbed' off
If chips are not turning colour, your going too slow to use carbide effectively (you want chips 'brown' at minimum and blue' is 'better, it isn't pushing machine or tooling with 12L4 and coolant)
Negative rake tools require a larger more powerful machine, the things you are doing would actually be better with HSS, using 'industrial' tooling isn't actually the best idea for almost all hobby machinists. (use positive rake tools even if you don't get double the cutting edges)
I was hoping you would go into the 'grades' of carbide, most Chinese stuff is for general purpose/cast iron (grade C6) and around 65 Rockwell C, 'chrome steel' bearing housings are often about the same hardness or harder but can be easily machined with correct tools which will even cut HSS quite easily if machine and set up is rigid enough
'Micrograin' carbide inserts are often much harder but machine rigidity is more important as carbide will chip very easily if there is vibration/machine/tool flex
I totally agree with you. On the back of the insert boxes show what material the insert is good for along with the suggested Surface footage and chip load. Also the lead angle of the second cutter is 45 degrees ,lengthening the chip.
It has been my experience that few insert boxes from china have the alpha-numeric code from the Black Book or any other book for that matter printed on them. Once in a great while but most haven't had it. Most tool holders also do not coincide with western nomenclature. It is one of the great difficulties using chinesium.
With that speed and feed you could use high speed tools , a lot more practical and economical .
Looks like at about 8:50 your live center begins to not rotate consistently and at the same rpm as the workpiece. Which could possibly explain the chatter. If the piece slides into the chuck towards the headstock that will happen. Or it could just be from the camera.
Great observation. You might be exactly correct on that. I'll have to pay closer attention in the future. Appreciate the support my friend
Great info. Although, it's not a fair assessment/comparison. Snmg is using a 90* tool holder vs the wnmg is using a rh tool holder. The cutter attack angles are different. If you were to cut left to right with the wnmg rh tool holder, you would get much better results. 👍✌️🤙
You clearly have never heard of positive or negative tool geometry... Comparing those two tools in the same operation is nonsensical. What cuts better a chef knife or a chainsaw? It depends what and how you are cutting.
Great info, thanks
Great tip, I have that handbook too. Way more convenient than online or Machinery's Handbook tome. May want to use a camera mount that is not connected to the lathe. Even small amounts of shake get translated very efficiently to the video, unfortunately. Some folks with more massive lathes get away with this, at least with a well-behaved objects, but even they have a problem if the part being turned is not radially symmetric.
Other things to consider: I notice that in several videos you introduce the next 'test', but then insert clips of other information (thermal imaging or close-ups showing surface finish) from the prior operation before you actually go to the next 'test'. Because you describe what's being shown, it is clear, but simply splicing in the other scenes before announcing the transition would be clearer. Perhaps this happens because your narration is mostly real-time and not separate voice over. Anyway something to consider as you generate more content...
Thanks so much for the advice Steve. I am ALWAYS trying to improve things. Glad you enjoyed the video and appreciate you taking the time to send a comment my way. Have a great day!
It's because of the highly positive lead angle. The WNMG has a slightly negative lead angle.
Interesting. In my old school opinion the best thing you can do with inserts is to use high speed steel instead. 50 years machining and rarely was carbide actually needed for a job. Inserts were created for and are best at high volume high speed Production factory work. There is nothing that was done here that couldn't be done with HSS tool bits and a LOT cheaper.
Time is money and inserts are cheap and repeatable. Even if you are quick, the 10 mins it takes you to regrind and find the new zero position for the tool is more than an order of magnitude longer than it takes to flip an insert. What is your shop's rate per hour? How much is that ten minutes worth? A lot more than one insert's edge I hope.
Wow, now I know the inserts I’m gonna stock up on for my new lathe :-) Thanks!
I get this book.
i get CHATTER !!!!!really hard when trying the SNMG as a groove tool ??SNMG insert 16-4d holder maybe i am not supposed to use that but it seems like the only way to create that V (90degress) groove but i get chatter
anythoughts?
Hello Fred thanks for the comment. So if you can manage to go in with a parting tool and cut close to the depth of the groove then go in with the SNMG I bet you would get better results. Even better if you can only cut one side a time. Also, be sure you are on center with a minimum of stickout. You may also want to try increasing/decreasing the speed or feed to see what changes. Sometimes like with parting (Although it seems counterintuitive) feeding faster will eliminate chatter. Are you working as close to the chuck as possible and between centers? Can you use a steady or follower rest to support your work? I would also say check you spindle bearings and end play. Start simple and move to the more time consuming things. Mainly rigidity is your friend. Make sure everything is as solid as possible. Best of luck and thanks for watching! I have a video coming to address some of these things as well. Take care.