I will start by admitting that I am a professor and have a PhD in an area of Applied Mathematics, so you may discount my comments. However, I am reacting to some of the comments on this video. I think that this is a well organized and thoughtful video that attempts to show tradeoffs. When someone says 'we do not need the math' or 'just use the charts' I immediately think "why don't you want to understand the basic idea so that you can do it yourself, rather than just rely upon what someone else has written?" The hobby machinist will, no doubt, face a variety of situations that may not be readily available in a chart. Suppose, for example, that I want to learn how to make my own HSS+Cobalt tools and want to turn some stainless steel rod for a bicycle project (actual example). This TH-cam video helps me to understand the tradeoffs and the basic ideas behind what RPM to run my lathe and what cut depth and feed rate to apply. So, I very much appreciate the approach that the video takes and I subscribed to the channel PRECISELY because I want to learn the basic, underlying principles. Great job!
For the record, carbon steel cutters are not mild steel, mild steel has very low (Wikipedia says 0.05-0.25% ) carbon content and is basically unhardenable. Just throwing that out there, in case someone tries to make a cutter out of mild steel. Loving your video series otherwise, very well produced, informative and entertaining, you've been making me want to get a Sherline mill and lathe again.
Thank you very much for the feedback, I should have been clearer and more precise in my terms used. I need to do a few videos later on the specifics of materials and identification, so much I still want to cover :). Carbon steel cutters vary widely in quality and can indeed be made of very soft mild steel. Some imports are made out of mystery metal, and can be very poor or low quality steel if intended for frequent use. If you want good quality then you will pay for it and it should include a specification of what material was used to produce the cutter. You used to be able to purchase "low carbon steel" cutters specifically as high carbon steel (HCS) and high speed steel (HSS) were more costly. Now I think you get mystery metal, HSS (sometimes also a bit mysterious), and various grades of carbide as manufacturing costs have dropped over the years. In the video, regarding cutter materials, I'm using mild steel very broadly to include most un-named steels since many cheap cutters are indeed un-named in what they are made of (low carbon, high carbon, alloy, etc). Don't expect good steel in the 600+ piece lathe/mill/drill cutter set you find on sale for $9.99 with free shipping ;)... yes I'm sorry to admit I've tried them, and it is about the only time I've been able to bend steel with my bare hands like superman LOL. Have to be careful with names like carbon steel and mild steel as they are very generic and will be applied differently depending on who you talk with, the industry you are talking in, and what part of the world for the discussion. Best bet when possible is to reference the AISI, ASTM, SAE or other standard for the material if you really want to get accurate. Case in point is 1018 steel. Per SAE standards all steels beginning with 1xxx are carbon steels, while the "18" indicates it contains 0.18% carbon making it a mild steel (per wikipedia's numbers). So it is then a mild carbon steel. And it is indeed able to be hardened to Rc42 in the case of 1018, much depends on other elements present in the steel although higher carbon certainly does make for better hardening in most steel alloys). And I'm not sure if there is a standard on what "mild steel" officially is, you mention wikipedia as listing 0.05-0.25% but for contrast some of the cutter manufacturer charts shown in the video list "Mild" with up to 0.50%??? And I love wikipedia but have to be careful on their references as they are community generated, the citation of the 0.05-0.25% is to another non-standard body website... which then actually lists the range as 0.05-0.30% LOL. And even in the wikipedia article I found it shows "definition needed" for Mild steel. Low/Medium/High carbon steel are probably more accurate, but still a little fuzzy without a specific percentage listed. The fuzziness on these names are why the SAE and AISI wrote standards beginning in the 1940s to help clear up what material is what. Technically you can make perfectly good cutters out of *some* "mild" steels... if you want to make a one-off short-use cutter for aluminum, brass or other "mild" steels you can use mild steel, not to mention for wood, plastic and other materials. Now those cutters are not going to last very long without resharpening (but resharpening will be relatively easy), and that mild steel cutter will last all of a couple milliseconds if you attempt to use it on a high/super-alloy material. en.wikipedia.org/wiki/Carbon_steel
Well the app is now $9.99 and I don't see a free version. Which I don't mind paying for the app. because, it looks like it's a great app. I'm planning on buying it. It beats sitting with a pen and paper and a calculator. The company I work for does not want to buy a cad cam program. So, I program everything on the machine using canned Cycles. And feed and speed is essential for turning or milling. It really sucks because now that I'm looking through the old programs they already had. They had somebody that didn't know what they were doing, and just put 2000 RPMs limit with a G50. Then just put s650 with a G96 for everything. Most of the material is 304 SS. So, I am constantly having to grab a pen and paper and figure the correct feed, and spindle speed. Thank you for the video. I didn't think they had good cnc calculators for the phone. Honestly I never bothered to look. So again thanks for the video and thanks for the heads-up about the calculator.
Good introduction. I don't think we need detailed math........other than how it might relate, in general terms, with things like SFM (surface feet per minute), decreasing radius, etc.
I will start by admitting that I am a professor and have a PhD in an area of Applied Mathematics, so you may discount my comments. However, I am reacting to some of the comments on this video. I think that this is a well organized and thoughtful video that attempts to show tradeoffs. When someone says 'we do not need the math' or 'just use the charts' I immediately think "why don't you want to understand the basic idea so that you can do it yourself, rather than just rely upon what someone else has written?" The hobby machinist will, no doubt, face a variety of situations that may not be readily available in a chart. Suppose, for example, that I want to learn how to make my own HSS+Cobalt tools and want to turn some stainless steel rod for a bicycle project (actual example). This TH-cam video helps me to understand the tradeoffs and the basic ideas behind what RPM to run my lathe and what cut depth and feed rate to apply. So, I very much appreciate the approach that the video takes and I subscribed to the channel PRECISELY because I want to learn the basic, underlying principles. Great job!
For a hobbyist wishing to learn the basics, for me, this is a sensational start. Thank you.
Looking forward to the next video
I’m liking it so far, this was 2016, where’s the rest of this?
For the record, carbon steel cutters are not mild steel, mild steel has very low (Wikipedia says 0.05-0.25% ) carbon content and is basically unhardenable. Just throwing that out there, in case someone tries to make a cutter out of mild steel. Loving your video series otherwise, very well produced, informative and entertaining, you've been making me want to get a Sherline mill and lathe again.
Thank you very much for the feedback, I should have been clearer and more precise in my terms used. I need to do a few videos later on the specifics of materials and identification, so much I still want to cover :). Carbon steel cutters vary widely in quality and can indeed be made of very soft mild steel. Some imports are made out of mystery metal, and can be very poor or low quality steel if intended for frequent use. If you want good quality then you will pay for it and it should include a specification of what material was used to produce the cutter. You used to be able to purchase "low carbon steel" cutters specifically as high carbon steel (HCS) and high speed steel (HSS) were more costly. Now I think you get mystery metal, HSS (sometimes also a bit mysterious), and various grades of carbide as manufacturing costs have dropped over the years.
In the video, regarding cutter materials, I'm using mild steel very broadly to include most un-named steels since many cheap cutters are indeed un-named in what they are made of (low carbon, high carbon, alloy, etc). Don't expect good steel in the 600+ piece lathe/mill/drill cutter set you find on sale for $9.99 with free shipping ;)... yes I'm sorry to admit I've tried them, and it is about the only time I've been able to bend steel with my bare hands like superman LOL. Have to be careful with names like carbon steel and mild steel as they are very generic and will be applied differently depending on who you talk with, the industry you are talking in, and what part of the world for the discussion. Best bet when possible is to reference the AISI, ASTM, SAE or other standard for the material if you really want to get accurate.
Case in point is 1018 steel. Per SAE standards all steels beginning with 1xxx are carbon steels, while the "18" indicates it contains 0.18% carbon making it a mild steel (per wikipedia's numbers). So it is then a mild carbon steel. And it is indeed able to be hardened to Rc42 in the case of 1018, much depends on other elements present in the steel although higher carbon certainly does make for better hardening in most steel alloys).
And I'm not sure if there is a standard on what "mild steel" officially is, you mention wikipedia as listing 0.05-0.25% but for contrast some of the cutter manufacturer charts shown in the video list "Mild" with up to 0.50%??? And I love wikipedia but have to be careful on their references as they are community generated, the citation of the 0.05-0.25% is to another non-standard body website... which then actually lists the range as 0.05-0.30% LOL. And even in the wikipedia article I found it shows "definition needed" for Mild steel. Low/Medium/High carbon steel are probably more accurate, but still a little fuzzy without a specific percentage listed. The fuzziness on these names are why the SAE and AISI wrote standards beginning in the 1940s to help clear up what material is what.
Technically you can make perfectly good cutters out of *some* "mild" steels... if you want to make a one-off short-use cutter for aluminum, brass or other "mild" steels you can use mild steel, not to mention for wood, plastic and other materials. Now those cutters are not going to last very long without resharpening (but resharpening will be relatively easy), and that mild steel cutter will last all of a couple milliseconds if you attempt to use it on a high/super-alloy material.
en.wikipedia.org/wiki/Carbon_steel
Thanks for clarifying
Thank you!!
learned so much.
Thanks for the useful explanation
Well the app is now $9.99 and I don't see a free version. Which I don't mind paying for the app. because, it looks like it's a great app. I'm planning on buying it. It beats sitting with a pen and paper and a calculator. The company I work for does not want to buy a cad cam program. So, I program everything on the machine using canned Cycles. And feed and speed is essential for turning or milling. It really sucks because now that I'm looking through the old programs they already had. They had somebody that didn't know what they were doing, and just put 2000 RPMs limit with a G50. Then just put s650 with a G96 for everything. Most of the material is 304 SS. So, I am constantly having to grab a pen and paper and figure the correct feed, and spindle speed. Thank you for the video. I didn't think they had good cnc calculators for the phone. Honestly I never bothered to look. So again thanks for the video and thanks for the heads-up about the calculator.
nice.
Good introduction.
I don't think we need detailed math........other than how it might relate, in general terms, with things like SFM (surface feet per minute), decreasing radius, etc.
Awesome 😎 👏 video. Subscribe!
Sucks I’m 3 yrs late 😔
I never can get that I need at least a few lesson to get it good don't get it