Getting Started With A Lathe

I wish I could show you guys my set up (tool angles...speeds and feeds) me taking a .075 deep (.150 dia) cut with a big 1/2" 999 carbide brazed Carboloy tool bit in a KDK holder on 3" OD prehard 4140 (Maxell 3 1/2) (scale and all), mounted in a 4 jaw on my old "garage" (10 x 24 or so) Logan...or the same thang' but using the old 883 Carboloy designation but a .125 deep cut (1/4" dia) on some 'ledloy"...but, as I have shpieled around here (this site) a few times: Along with my Jet mill, like a dummy, I sold the Logan (with its 5c collet set up and all collets up to 1"!) and I am now on the hunt again...

Oops it's bugging me so I better peck it here....cutting "scale and all" above: That layer of scale will wear a groove on the cutting angle (face) of even that 999 carbide...(so its best to turn a skim cut under that scale 1st so's you don't have to grind the whole cutting angle face much when "touching up" the cutter (just the end with nose of the cutter) (like some have already said here or there around here (Smiley Face here)
 
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...FYI I do, however, grind my angles (relief) in conjunction with cutting "like a blade" for big cuts, fast stock removal... IE the nose and angle of the cutter is negative (angled towards the tailstock (then just turn the holder to rip away (face) on wherever, whatever shoulder is left...ID boring, cut off and "grooving, threading....form cutter cutting....carbide baby!

Add: Just a liiittle touch up on the cutting angle and nose now and then on that prehard and other tough stuff...and agin', likes I've shpield around here before...gotta' have a diamond (I like a"face') wheel"around 220 grit (I like resin bond..about 1/8" or 3/16" " thick "life") for snagging that carbide and if yoose' take care of it, your kids will be using it (But a face wheel can be made flat and "ungrooved"again (ifn' you hack it up) on a surface grinder with a carborendum dressing wheel (or another diamond wheel!)
 
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As for carbide, the only time I use it on the 109 is for parting. It works MUCH better than HSS. I am not really sure why, but there are a lot of reasons that people post on the Internet. My guess is that they have a better grind. I use one of those often-posted junk circular saw blade homemade tools. This little thing outperforms a generic wedge type HSS tool on a 14X40 lathe. For just about anything else, I would agree with you, Mikey.

Funny, Eric, but I've had the opposite experience. My Emco Super 11 is very tight and handles an Aloris carbide parting tool quite well but my HSS P-type blades will outperform it in almost every case other than really hard steels. On my little Sherline, a rear mounted HSS parting tool mounted upside down will cut at much, much higher speeds and no chatter.

Carbide needs more rigidity, speed and HP to work well. Most of our hobby class lathes can't keep up. Again, carbide will work; it just won't work as intended and especially on a little lathe. Big, rigid, fast lathe in a production environment? Heck, yeah, I would go with carbide in a heartbeat.

It also comes down to preference. I have SECO SCLCR tools that take CCMT and CCGT inserts that will cut most stuff on my Emco Super 11, no problem. But they cannot cut as deep, size as well or finish better than my HSS tooling in head to head tests, at least in my hands at the speeds I have available. I've taken a 0.25" deep cut on my Super 11 in 12L14 steel with a HSS general purpose tool, just to see if it will do it, and the lathe barely slows down. It's fun to see what your lathe can do but quite honestly, I don't turn this way. I use stock that is as close to the finish diameter as I can get and rough only enough to take sizing or finishing cuts. For ME, on my lathes, HSS works better in almost all cases. For others, well, that is of course a choice.
 
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I haven't tried a P type blade on the big lathe. I have had two accidents, and I am kind of gun shy now. This was with an Aloris BXA tool post, but with Chinese parting tool and holder. The problem with a blade shattering is that sometimes the pieces fly at a pretty high speed which makes me unlikely to do much more experimentation. Maybe another try is in order after the rear mounted tool holder is installed. In the blacksmith shop, flying steel is taken extremely seriously.
 
I haven't tried a P type blade on the big lathe. I have had two accidents, and I am kind of gun shy now. This was with an Aloris BXA tool post, but with Chinese parting tool and holder. The problem with a blade shattering is that sometimes the pieces fly at a pretty high speed which makes me unlikely to do much more experimentation. Maybe another try is in order after the rear mounted tool holder is installed. In the blacksmith shop, flying steel is taken extremely seriously.

Flying steel in ANY shop is taken seriously!!

That rear mounted tool will work vastly better for you, I suspect. Keep us posted, okay?
 
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...The general standard (and for brazed on toolbits) and I have various "C" grade (mostly Kennametal C3 through C7) that I have crossed referenced but while somewhat close, I am spoiled with just 3: My old Carboloy 666's (no, not that! LOL), 883's.....and 999's! (Which I have/you can even take small cuts (.oo5 and under) A2, D2, S7 Heat Treated to RC 58-60)

Like HSS toolbits, you can get S7 to RC 62 if'n need harder than 58-60)...after those hardness's, next up, really, is all the carbides)...

Here are a few charts (with some cross referencing) of 3 carbide vendors mostly for machining product (just like ordering steel)...(EDM (Sink and Wire) and Grinding (Diamond Wheel is best)
...as far as lathe tools; I have used plenty of pcs. mostly to Silver Solder onto carbide rod for boring bars and onto tool steel blanks for form cutters (Sometimes pcs to replace brazed carbide on their old steel (Carboloy,Kennametal) ...and then, again of course, snag grind to what I want
http://www.vistametalsinc.com/gradecharts.htm
http://www.basiccarbide.com/grade_chart/grade-chart.html
http://www.innovativecarbide.com/icgrfx2/IC GradeChart FNL.pdf

OK, I'm done with this thread (again! LOL) that kinda' turned into HSS vs Carbide and I'm leaving with another 2 yes's (besides Yes to HSS vs some carbide cutters that I wouldn't give 2 cents for)...
Yes to HSS for Aluminum, plastics (+ micartas etc.) (Just because you can snag those severe rakes (angles) on them...
...and of course Yes to HSS ifn' one doesn't have a diamond snag grinding wheel
...otherwise: Carbide baby!
 
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