I’m enjoying the current videos and running through the archives. My girlfriend may think that I have a TH-cam addiction. I respectfully blame you. Thanks Tom.
Great project, very interesting and informative. One benefit to 4 feet over 3 feet is that if one of the feet becomes non-coplanar, (burr, dirt, etc.), the base will rock, indicating that there's a problem.
Great video Tom. Please discuss the mandrel with collet you used on the lathe to hold the part when you polished it. I’ve not seen that before. Also, you used a clever gizmo with a dial indicator to measure the feet height on your master square, but I couldn’t see enough of that indicator holder to understand what it was. If you could show that again in a closeup that would be nice. Glad you are back baking videos aster your winter break.
Well ... I like to see different ways a layout processes is done. I am an infant in the machining world. Nothing to do but learn all I can, and practice. I appreciate your explanation, detail, and the way you go about it. Looking forward to meeting you next month. At 59 I’m still having a hard time controlling my excitement for what I am about to learn.
Grinding, honing and lapping that "bowl" should definitely produce interesting results. Unnecessary and unacceptable results but that's what will be interesting. "Pretty" isn't "performance".
I have those bits too. Love them, especially for stuff where i'm not particularly sure what i'm cutting other than a general idea. Of which, i have a lot since i'm only slightly above hobby.
Form cutting big radii on manual machines: grandma gear, keen tool, spring tool holder, plenty of lard(!) oil with an evaporative coolant component like alcohol. PITA but if successfully done, it leaves a satin finish, and the chip are like tinsel - plus it's quick once you have the equipment on hand.
Are you sure you don't need the dried wing membranes from cadaver flies mixed in with choice single malt alcohol that to make it work? Always good to hear from you Forrest. All the best, Tom
oxtoolco The spring tool was the main message but I failed to emphasize. Another minute on the ass-kicking machine for me. Actually gin works pretty good.
I never see form tools with any positive top rake, is there a reason besides keeping the grind as simple as possible? Or, even, negative top rake form tools?
Zero top rake makes it easy to grind a relieved cutting profile. Add rake and interacting tool and work geometry gets far more complicated if profile accuracy is a major factor. If a positive rake is desired you can always grind in a chip breaker with a formed wheel or a mounted point in a die grinder. Very delicate work if done by hand but not that difficult on a Monoset or equivalent. My career shop of 600+ machinists had a fine tool grinding department up on the mezzanine. They routinely ground chip breakers on single point radius tools that worked very well especially if you had spring or gooseneck toolholders to mount them in. Tinsel chips on the final stages of form cutting seemed to be the gold standard for attaining satiny finishes in difficult materials. My approach was to select a somewhat larger radius tool (for external radii) and, with with travel indicators to track X and Y, hand circular interpolate a small radius tool path. This resulted in a far narrower chip, proportionately lower cutting forces, and a finished radius that was very slightly bumpy. A distinct advantage when forming a 2" radius on a deep drawing die. Bear in mind this is Stone Age manual machining. CNC can buzz out finely finished radii tangent to surfaces in a single tool path, the spoiled bastards.
"it grinds like cream cheese"... I totally knew what you meant until i actually pictured a machine grinding cream cheese. Not sure it would work. Could be a new trend like the putting vegetables in the lathe/mill thing a while back.
Hi Tom, after enjoying the manual layout method, which is the one I enjoy most, I'm thinking why didn't he use the mill? Nice seeing both methods. Looking forward to Pt-3 !!
Paint would be cool, but since you're going to case harden it anyway I would send it to Doug Turnbull of Turnbull Restorations, he does some of the most beautiful color case hardening you'll ever see and he does one off parts all the time. Give it the look of an old Starrett instrument. Just my opinion, I enjoy your videos. Godspeed!
Single point boring? Honing improves hole roundness and diameter but not position. Single point boring locates holes in position best. Hope this explains your question. Cheers, Tom
You've said it before.. roughing with a drill is called roughing for a reason :) Wondering about your thought process on honing the bore / lapping the feet perpendicular as best you can prior to assembly. In other words what will you be doing to try and reduce the amount of geometry adjustment required once assembled? Great project! Thanks
Thanks for all the amazingly well done and informative videos! I love them! I do have an out of sequence question though. In the Russian optical flat video, you use both surfaces of the flat to generate interference patterns. Are both surfaces flat to the spec sheet specs? I thought that only one of them was. Thanks again for helping me educate myself.
Usually one surface is the optically flat surface. In some cases both are optically flat and in further cases both surfaces are parallel. The Russian ones are one surface that is indicated with a mark or line.
CCGP? I think you meant CCGT? I might have to try those trigons, CCMT/GT is what I run and love, but having 3 times the number of edges would be nice. Not sure if our 10" could run a negative insert even with that chipbreaker. Also, plenty of table to the side of that vise. :)
Tom -- I love the design . Why case harden the foot ?? The work to grind it in will be extensive. It's not going to be moved around a hell of a lot . Most likely only the parts will be moved. It would take a bazillion years to create the slightest wear . Here is a suggestion from the peanut galley.Have it stress relieved then finish it up .. no stress no movement . Amen
Hey Jim. The grinding is the fun part for me and will make great video. I could insert small hardened feet but I decided to make it monolithic and permanent.
I could insert small hardened feet -- " That's a Great Idea." Monolithic and Permanent. -- Wow what big words -- What are you smoking ??? I've heard of "Legal Ease" -- is this called "Machining Ease" I think that California smog has effected your thinking . That is one tall unit -- It must be dead square with the surface plate. If it's off .0001-.0002 At the bottom -- It will be a mile off at the top Hold the round hardened feet in with flat head screws . If it is out of square you can remove the hardened feet and lap them accordingly . I'm talking about function -- your talking aesthetics / pretty. What good is Pretty Hooker without a Vagina -- Pretty but not functional. Useless as Tits on a Bull. --- Kisses and Hugs from your adoring fan ,
This is a traveling squareness comparitor, I'm sure it's not going to be used on anything that's not perfectly flat or it won't work at all, 4 feet are perfect.
Tom, as you explained, you have eschewed the more pure “kinematic” option of having just three feet on the base of the cylindrical square because it provides a compromised support base and therefore is less stable. However, given you are opting for a non-kinematic design, why not adopt a narrow continuous rim rather than four discrete feet. A thin continuous rim would certainly maximize the stability. Also, I assume that the defects in a clean surface-plate are more likely to be divots and hollows rather than lumps, in which case, wouldn’t a continuous rim perform better than discrete feet, in that it would tend to span across such defects? Would a thin continuous rim be harder to lap co-planar than discrete feet, assuming the same total area for both? I guess a continuous rim would have to be bigger in area than the discrete feet in order to not to be too delicate. Is it that correction of out-of-square will be easier with discrete feet, although I cannot see why it should be?
6 feet, grind a thou, or just a few tenths off every-other foot. That prevents tipping, but you have perfect 3-point contact. Hah! Never mind. I paused the video to type the above, then re-start it and it's the next idea out of your mouth.
Hi Tom. Can you please make an insert codes de-coding video for us, the novice? I would love to learn more on these carbide inserts. Thank you in advance!
good stuff mate , but whats the reason when you use the stone , every couple of strokes you rub it against the other stone - does this refresh the grit or keep the stone flat ?
Precision ground flat stone. Cleans the surfaces and knocks off hangers and embedded metal. Not the same animal as regular stones. These are lapped flat to better than 50 millionths. Check out Professional instruments precision ground flat stones for a better explanation.
Would it be a better way to do as you did with the copper spaces or would it be better to open the jaws out until it could drop down to the next step closer to the chuck could someone please tell me what is best and why please
Tom, why did you put the 123 block on top of parallels? Is the base of the vise not accurate enough? Also, maybe a green hammered metallic finish be nice.
I found the discussion about the three vs four feet interesting, though I was wondering why not just have small relief slots like what I’ve seen on cylindrical squares. Any particular advantage with the small contact area of the four feet versus something like that?
Drill bits far larger than that "little" one are available but "boring" is the way to make big holes. Your "drill" is deflecting alright. The one that drill bit is powered by.
The idea behind the device is its not adjustable therefore not subject to random twiddling or getting out of adjustment. Otherwise you need to qualify it every time you want to use it. Cheers, Tom
Thanks for the Q&A, would be nice if you incorporated time in to each video for it, what better way to share your wealth knowledge. this may be stating the incredibly obvious, but, you could just as easily not have indicated the original scribe lines, rather just indicate the part insuring the original scribe lines fall in the quadrants to be machined away, just sayin.
Not a realistic explanation on the drill wobble. I really am a faithful viewer and also a proper machinist with many years experience. A properly ground drill will not perform as yours did. Both flutes will cut nearly the same. True, a boring bar will be used for the finish cuts. A lot of beginners are watching. Please take this as constructive criticism. You are adding much value to the machining community. Thanks for doing what most of us do not have time to do. George
Big drill was brand new with a factory grind. Most likely the pilot hole was not centered well which will start a wobble. 99% of tailstocks are low on anything but a brand new lathe. I agree theoretically a proper grind should act like a boring bar but in my limited experience its just not the case and you can't count on it.
It looked to me that the magnitude of the drill "movement" was more of a camera artifact from the vibration, than actual movement. Same as it goes with airplane propellers, etc.
I had to think the same, a "jell-o" product of image stabilization or rolling shutter. It looked like the pilot hole was a little off center, but I can't believe that drill would look like spring steel.
Yep; drill for the hole, bore for concentricity, and ream for size. (This last is, of course, not practical for large holes in most shops; careful boring and perhaps lapping/sanding must suffice.)
I can tell you now you are doing it all wrong.........when you are wanting to form a radius with a full form tool...flat top.... you first hone the cutting edge on the face and top then after you've roughed the radius out with another tool you run the lathe DEAD SLOW with just a bit of coolant.....10 rpm would be good ( I have back gear on my old Colchester Bantam lathe)........and you will get a almost chrome plated finish. I have formed radii of 25mm and using HSS form tools.
Wow! Another old tin knocker turned machinist. Transitions, square to rounds, round elbows, we learned to lay all that stuff out on paper at actual drawing boards. These days all that stuff gets laid out on a screen and burned out b laser or plasma.
Case-hardening steel "grinds like Swiss cheese" AND you're going to get case hardening .080" deep? Of all the things you make, no sense is what you're best at.
Hey Deer in the headlights, Not following your comment here. My comment was 8620 specifically grinds easily and I will specify case hardening .080 deep. Didn't think it was that hard to follow. I apologize if you were confused. Cheers, Tom
I’m enjoying the current videos and running through the archives. My girlfriend may think that I have a TH-cam addiction. I respectfully blame you. Thanks Tom.
Tom, you are not a Bozo!. I enjoyed both methods of layout. You are a clever guy. Keep up the good work.
Great project, very interesting and informative. One benefit to 4 feet over 3 feet is that if one of the feet becomes non-coplanar, (burr, dirt, etc.), the base will rock, indicating that there's a problem.
Great video Tom. Please discuss the mandrel with collet you used on the lathe to hold the part when you polished it. I’ve not seen that before. Also, you used a clever gizmo with a dial indicator to measure the feet height on your master square, but I couldn’t see enough of that indicator holder to understand what it was. If you could show that again in a closeup that would be nice. Glad you are back baking videos aster your winter break.
The beauty of precision is a joy forever! looking forward to the next installment
Be honest sir, the fussy layout was fun, and it was fun to watch. And we all know several methods of skinning cats.
There is always a lesson to be learned when you make a video. Thank you.
Well ... I like to see different ways a layout processes is done. I am an infant in the machining world. Nothing to do but learn all I can, and practice. I appreciate your explanation, detail, and the way you go about it. Looking forward to meeting you next month. At 59 I’m still having a hard time controlling my excitement for what I am about to learn.
Coming along nicely. Interesting to see the squaring process after heat treat.
Excellent Tom! waiting for Grind hone & lap video.
ATB, Robin
Grinding, honing and lapping that "bowl" should definitely produce interesting results. Unnecessary and unacceptable results but that's what will be interesting. "Pretty" isn't "performance".
I found your lay out interesting, and useful,, thanks for the video and lesson,,
What bozo move? Clearly you were verifying the accuracy of your layout against the DRO.. Masterful as usual.
Enjoyed immensely thanks Tom. Very nice tool build. Excited to see the honing.
I love this video! You do great work! I also love the fact that you mention Abom in the video he is awesome and I happy that I found your channel!
Really cool as always!!!
Thanks for the video. I was just beginning to have DTs from OXTOOL withdrawal.
I have those bits too. Love them, especially for stuff where i'm not particularly sure what i'm cutting other than a general idea. Of which, i have a lot since i'm only slightly above hobby.
And Tom, Free 8620 is always better than cheap!
Great video. Keep 'em coming.
Eric
"Dopesicle". Haha, that's one I haven't heard before. Great stuff as always!
Form cutting big radii on manual machines: grandma gear, keen tool, spring tool holder, plenty of lard(!) oil with an evaporative coolant component like alcohol. PITA but if successfully done, it leaves a satin finish, and the chip are like tinsel - plus it's quick once you have the equipment on hand.
Are you sure you don't need the dried wing membranes from cadaver flies mixed in with choice single malt alcohol that to make it work? Always good to hear from you Forrest.
All the best,
Tom
oxtoolco The spring tool was the main message but I failed to emphasize. Another minute on the ass-kicking machine for me.
Actually gin works pretty good.
I never see form tools with any positive top rake, is there a reason besides keeping the grind as simple as possible? Or, even, negative top rake form tools?
Zero top rake makes it easy to grind a relieved cutting profile. Add rake and interacting tool and work geometry gets far more complicated if profile accuracy is a major factor. If a positive rake is desired you can always grind in a chip breaker with a formed wheel or a mounted point in a die grinder. Very delicate work if done by hand but not that difficult on a Monoset or equivalent.
My career shop of 600+ machinists had a fine tool grinding department up on the mezzanine. They routinely ground chip breakers on single point radius tools that worked very well especially if you had spring or gooseneck toolholders to mount them in. Tinsel chips on the final stages of form cutting seemed to be the gold standard for attaining satiny finishes in difficult materials. My approach was to select a somewhat larger radius tool (for external radii) and, with with travel indicators to track X and Y, hand circular interpolate a small radius tool path. This resulted in a far narrower chip, proportionately lower cutting forces, and a finished radius that was very slightly bumpy. A distinct advantage when forming a 2" radius on a deep drawing die. Bear in mind this is Stone Age manual machining. CNC can buzz out finely finished radii tangent to surfaces in a single tool path, the spoiled bastards.
Looking good Tom. Thanks
Doing the dishes by hand is the best way to get your hands really clean. Other advantages too :)
Nice. Thanks for the video.
"it grinds like cream cheese"... I totally knew what you meant until i actually pictured a machine grinding cream cheese. Not sure it would work. Could be a new trend like the putting vegetables in the lathe/mill thing a while back.
Looking good Tom.
Steve
Interesting video, thanks.
Nice to show the alternative way for those who don't have a DRO.
Great point, and thanks for pointing out your "Bozoness" lol. Great video as always, thanks Tom
love the follow ups!
Tom , good discussion about 3 vs 4 feet. I was going to ask but I see 4 can work quite well w/o the tipping issue.
Regards,
Eric
Hi Tom, after enjoying the manual layout method, which is the one I enjoy most, I'm thinking why didn't he use the mill? Nice seeing both methods. Looking forward to Pt-3 !!
Sure miss your work Tom
Paint would be cool, but since you're going to case harden it anyway I would send it to Doug Turnbull of Turnbull Restorations, he does some of the most beautiful color case hardening you'll ever see and he does one off parts all the time. Give it the look of an old Starrett instrument. Just my opinion, I enjoy your videos. Godspeed!
Awesome videos Tom, keep them comming! What is the difference in concentricity between single point threading and honing?
Single point boring? Honing improves hole roundness and diameter but not position. Single point boring locates holes in position best. Hope this explains your question. Cheers,
Tom
You've said it before.. roughing with a drill is called roughing for a reason :) Wondering about your thought process on honing the bore / lapping the feet perpendicular as best you can prior to assembly. In other words what will you be doing to try and reduce the amount of geometry adjustment required once assembled? Great project! Thanks
Thanks for all the amazingly well done and informative videos! I love them! I do have an out of sequence question though. In the Russian optical flat video, you use both surfaces of the flat to generate interference patterns. Are both surfaces flat to the spec sheet specs? I thought that only one of them was. Thanks again for helping me educate myself.
Usually one surface is the optically flat surface. In some cases both are optically flat and in further cases both surfaces are parallel. The Russian ones are one surface that is indicated with a mark or line.
20:00 Layout is half the fun though, plus it gives you time to visualise wtf is going on and let the pink squishy do some thinking
CCGP? I think you meant CCGT? I might have to try those trigons, CCMT/GT is what I run and love, but having 3 times the number of edges would be nice. Not sure if our 10" could run a negative insert even with that chipbreaker.
Also, plenty of table to the side of that vise. :)
enjoyed....
Tom -- I love the design . Why case harden the foot ?? The work to grind it in will be extensive.
It's not going to be moved around a hell of a lot . Most likely only the parts will be moved.
It would take a bazillion years to create the slightest wear . Here is a suggestion from the peanut galley.Have it stress relieved then finish it up .. no stress no movement . Amen
Hey Jim. The grinding is the fun part for me and will make great video. I could insert small hardened feet but I decided to make it monolithic and permanent.
I could insert small hardened feet -- " That's a Great Idea."
Monolithic and Permanent. -- Wow what big words -- What are you smoking ??? I've heard of "Legal Ease" -- is this called "Machining Ease"
I think that California smog has effected your thinking .
That is one tall unit -- It must be dead square with the surface plate.
If it's off .0001-.0002 At the bottom -- It will be a mile off at the top
Hold the round hardened feet in with flat head screws . If it is out of square you can remove the hardened feet and lap them accordingly .
I'm talking about function -- your talking aesthetics / pretty.
What good is Pretty Hooker without a Vagina -- Pretty but not functional.
Useless as Tits on a Bull. --- Kisses and Hugs from your adoring fan ,
Never Mind you convinced me.
Totally unrelated, but how did the big Etching Press turn out?
Green is good, a nice dark bottle green..
No bozo , I enjoyed the layout , Not all of us have a DRO .. ENJOYED ..
This is a traveling squareness comparitor, I'm sure it's not going to be used on anything that's not perfectly flat or it won't work at all, 4 feet are perfect.
my old dog had four feet, he was real stable. he slobbered aaaaalot though
Why don't you use the space next to the vise to clamp things to the table on your milling machine?
Great video! May I ask what the lathe toolholder is that holds the WNMG insert?
Painted Green? Make it Extreme, Make it Your Own!
Tom, as you explained, you have eschewed the more pure “kinematic” option of having just three feet on the base of the cylindrical square because it provides a compromised support base and therefore is less stable. However, given you are opting for a non-kinematic design, why not adopt a narrow continuous rim rather than four discrete feet. A thin continuous rim would certainly maximize the stability. Also, I assume that the defects in a clean surface-plate are more likely to be divots and hollows rather than lumps, in which case, wouldn’t a continuous rim perform better than discrete feet, in that it would tend to span across such defects? Would a thin continuous rim be harder to lap co-planar than discrete feet, assuming the same total area for both? I guess a continuous rim would have to be bigger in area than the discrete feet in order to not to be too delicate. Is it that correction of out-of-square will be easier with discrete feet, although I cannot see why it should be?
Easier to lap for perpendicularity with four feet. A rim is nice but a lot of surface area to lap and correct for squareness errors.
6 feet, grind a thou, or just a few tenths off every-other foot. That prevents tipping, but you have perfect 3-point contact.
Hah! Never mind. I paused the video to type the above, then re-start it and it's the next idea out of your mouth.
Hi Tom. Can you please make an insert codes de-coding video for us, the novice? I would love to learn more on these carbide inserts. Thank you in advance!
Saar Tal check out the engineers black book. Has a great breakdown of all insert tooling nomenclature
tom my cat has 4 feet and she says its the way to go,thanks for sharing
good stuff mate , but whats the reason when you use the stone , every couple of strokes you rub it against the other stone - does this refresh the grit or keep the stone flat ?
Precision ground flat stone. Cleans the surfaces and knocks off hangers and embedded metal. Not the same animal as regular stones. These are lapped flat to better than 50 millionths. Check out Professional instruments precision ground flat stones for a better explanation.
Thanks , checked them out - now i get it .
He said he has another tool which is the turning tool. What's the first one? What's the difference between turning and what he did in the first video?
Nice rad tool.
how do you go finishing the rad tool after grinding it?
How about black oxide instead of paint?
Then all my scratches will show more prominently. Deep scratches and high polish is my middle name.
Best,
Tom
Would it be a better way to do as you did with the copper spaces or would it be better to open the jaws out until it could drop down to the next step closer to the chuck could someone please tell me what is best and why please
Paint it red it makes everything good faster
Hey Tom, quick question why do you use copper unter your lathe tools to clamp them, just random or has it to do with vibration reduction or something?
Twist Drills need to be flexible thats why a Centerpunsh works
Tom, why did you put the 123 block on top of parallels? Is the base of the vise not accurate enough?
Also, maybe a green hammered metallic finish be nice.
Hi Matt. I wanted the through holes in the block so I could put the holdown studs all the way through. Needed room underneath for the nuts.
Or you could paint it pink, like the baby bullet vise. :-D
I found the discussion about the three vs four feet interesting, though I was wondering why not just have small relief slots like what I’ve seen on cylindrical squares. Any particular advantage with the small contact area of the four feet versus something like that?
Easier to lap four feet for perpendicularity with the vertical post. Nothing wrong with slots at all.
oxtoolco Thank you Tom. I really learn so much from your videos (and old blog posts). Thanks for your time producing them, truly.
Even an old round carborundum stone would improve that.
HI tom was the high speed steel radius tool ground by hand?
I’m sure you don’t want to get into the color conversation again but I’m voting for burgundy ish color.
that master square reminds be of a bottle of whiskey.
If you're not going with 3 feet, what would be the problem with just lapping the entire base coplanar? That would be maximum stability, yes?
Harder to lap the entire base for correcting perpendicularity to the post.
Drill bits far larger than that "little" one are available but "boring" is the way to make big holes. Your "drill" is deflecting alright. The one that drill bit is powered by.
(( PUCE )) :-) OR LEAVE THE CASE HARDENED COLOR ??
How do you make an external radius cutter?
Do you mark the dull cutting edges somehow when you rotate those insert cutters?
cool
Hi, is that CCGT insert not only for aluminium ?
They'll cut others, but they're fragile. I use CCMT for general purpose.
I was wondering why you didn't make the feet adjustable and is Bob really your uncle?
The idea behind the device is its not adjustable therefore not subject to random twiddling or getting out of adjustment. Otherwise you need to qualify it every time you want to use it. Cheers,
Tom
Isn't wnmg a neutral insert? ... That gets cutting geometry from tool holder?
The N in WNMG means negative. Negative inserts have straight sides and can be molded as opposed to ground.
Tom why 4 feetsies? Why not the incontestably stable 3?
nevermind
mmmh......drill bad sharpened or previous hole runout..
Hey Boss. Brand new drill. Sorry. Previous hole runout, sure I'll buy that.
Now i know, what "free machining steel" means, lol
I wish I had a drill that big. I hear it's all genetics though...
Why four feet instead of three. Three points is always best????
John Miller, but with four feet you can feel when something is under a foot or the surface it's on isn't flat
Turn on the audio and listen to his explanation.
Thanks for the Q&A, would be nice if you incorporated time in to each video for it, what better way to share your wealth knowledge.
this may be stating the incredibly obvious, but, you could just as easily not have indicated the original scribe lines, rather just indicate the part insuring the original scribe lines fall in the quadrants to be machined away, just sayin.
Where were you on Sunday? You could have saved me a minute or two. You are totally right.
Not a realistic explanation on the drill wobble. I really am a faithful viewer and also a proper machinist with many years experience. A properly ground drill will not perform as yours did. Both flutes will cut nearly the same. True, a boring bar will be used for the finish cuts. A lot of beginners are watching. Please take this as constructive criticism. You are adding much value to the machining community. Thanks for doing what most of us do not have time to do. George
Big drill was brand new with a factory grind. Most likely the pilot hole was not centered well which will start a wobble. 99% of tailstocks are low on anything but a brand new lathe. I agree theoretically a proper grind should act like a boring bar but in my limited experience its just not the case and you can't count on it.
It looked to me that the magnitude of the drill "movement" was more of a camera artifact from the vibration, than actual movement. Same as it goes with airplane propellers, etc.
I had to think the same, a "jell-o" product of image stabilization or rolling shutter. It looked like the pilot hole was a little off center, but I can't believe that drill would look like spring steel.
Yep; drill for the hole, bore for concentricity, and ream for size. (This last is, of course, not practical for large holes in most shops; careful boring and perhaps lapping/sanding must suffice.)
I can tell you now you are doing it all wrong.........when you are wanting to form a radius with a full form tool...flat top.... you first hone the cutting edge on the face and top then after you've roughed the radius out with another tool you run the lathe DEAD SLOW with just a bit of coolant.....10 rpm would be good ( I have back gear on my old Colchester Bantam lathe)........and you will get a almost chrome plated finish.
I have formed radii of 25mm and using HSS form tools.
"co-plained-ness" ? LOL
My advice: 5 feets, its better than 4, may even be better than 6 feets...
Why are they better than 1 feets? (lap the entire base coplanar).
Wow! Another old tin knocker turned machinist. Transitions, square to rounds, round elbows, we learned to lay all that stuff out on paper at actual drawing boards. These days all that stuff gets laid out on a screen and burned out b laser or plasma.
I don't feel like this counts as a Bozo visit. Nothing bad happened. You just overlooked something, nothing biggie.
Case-hardening steel "grinds like Swiss cheese" AND you're going to get case hardening .080" deep? Of all the things you make, no sense is what you're best at.
Hey Deer in the headlights, Not following your comment here. My comment was 8620 specifically grinds easily and I will specify case hardening .080 deep. Didn't think it was that hard to follow. I apologize if you were confused.
Cheers,
Tom