That is what I am really concerned with, the limitations of the lathe along with my novice tool grinding skills and then throw in difficult to machine materials to make matters worse where there is already small "margin for error". I thank everyone for there insight and the comments will be something I will refer to in the future regarding the different types of steels. That is also an area need to develop knowledge in.
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Getting Started With A Lathe
- Thread starter BrianT
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- craftsman 109
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Brian, your little lathe is more capable than you think. I started on a Sherline, which is much smaller than yours and I cut damned near anything I need to on it. You're a hobby guy who can use the appropriate material for the intended use. If you need mild steel then use 12L14 or 1215 instead of 4140. If you need an aluminum spacer then use 6061 instead of 7075. Over time, you learn to use the right stuff for the job and you also learn how to cut each one of them with the lathe you have. Don't stress about it - it will come in time.
If anything, focus on learning to grind tools to reduce cutting forces for each material group you plan to work with. My little Sherline will take a 0.050" deep cut on 12L14 mild steel without even slowing down if I use a modified cutter. I can easily take a 0.10" deep cut on 6061 aluminum (0.20" reduction in diameter). Not that I do this routinely but I can with the right tool. That same tool will take off 0.0005" to size it and will produce a very fine finish. I use a lot of 1144 semi-hardened steel on that little lathe and have no problems at all with it. Same with O-1 and other tools steels and stainless steels. Your lathe, with the right tools, will probably be able to do quite well with most commonly used materials.
The smaller the lathe, the faster you run into the power and rigidity limits of the lathe. Your tools are what will determine what those limits are. I recommend that you stay away from carbide; you cannot run fast enough to use it effectively and cutting forces will be too high. This applies to brazed as well as inserted carbide. Yeah, it will cut but not as well as a good HSS tool will.
I suggest you stay with easily machined materials and learn to grind tools. Learn how your lathe feels and sounds when its cutting happily and what to do when it isn't. Go slowly, learn to be accurate and learn how each material likes to be cut.
You'll be fine - we all started from the same place.
That is some dandy cuts Mikey. I'd be interested to see what you mean by modified tools. I had trouble with the work climbing up in the tool when using my HF 7x. I didn't know much about grinding tools then ether tho.
I ended up damaging the late before I ever learnt to use it & upgraded to a larger lathe that could handle my inability better.
The lathe is still damaged but I still use it at times when I'm working right beside of it & need to spin something. It only gets used for eyeball tolerance cuts anymore.
I ended up damaging the late before I ever learnt to use it & upgraded to a larger lathe that could handle my inability better.
The lathe is still damaged but I still use it at times when I'm working right beside of it & need to spin something. It only gets used for eyeball tolerance cuts anymore.
Thanks for the good advice Mike! And all the advice from everyone! When I got this I was not looking for a lathe though I have always wanted one. After reading much online about these machines you start to get discouraged to even put much effort in to one. What I really wanted was an opportunity to develop some basic skills and it seems this machine will allow me to do that. Funny thing was I was contemplating looking at another, different lathe this afternoon, I really do not want to refurbish/repair another machine as the whole point of this was to learn machining skills and not machine repair. So for the time being I will stick with the 109 and focus on the elements you guys described above...Thanks!
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You might want to take a look at this thread. There are tools I, and other guys, have ground and shown.
http://hobby-machinist.com/threads/turning-tool-and-facing-tool-questions.36687/
You are right. A bigger lathe with more power and rigidity is more forgiving of tool geometry but a modified tool will cut even better, even on that bigger lathe. I have an Emco 11 lathe now but still use the exact same tools I used on my Sherline and they work great.
Tool geometry makes a difference because cutting forces are cutting forces and when we shape the tool to reduce those forces we cut deeper, size more accurately and finish finer. Quite often, a good tool will enable the user to double the depth of cut he can normally take on a small lathe like a Sherline.
I honestly feel that tool grinding is becoming a lost skill. Only us hobby guys do it much anymore so its sort of up to us to keep it alive. Dunno - you think?
The last statement is my thoughts exactly! I have worked with people that were amazed I could sharpen a drill bit on a grinder, in the past they just told the boss they need new drill bits. An old timer showed me how to do that and I have practiced through the years and have gotten good at it. So learning those skills and keeping them alive is of much interest to me as well.
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Uh oh, I agree with all for starts but respectfully disagree Mikey with your views on carbide (per one of my my previous posts) especially all the diff. grades of brazed on carbide (cutting forces too high...will cut but not as good)...??
...generally slower rpm (for harder, tougher steels depending on the stock diameter of course) or mid to higher rpm ("softer" steels) and a little different speeds and feeds (all sfm practice and use) and with a little nose radius you won't chip em' even with a somewhat "sloppy" spindle....perty much the same relief angles as using HSS per material (on steels) and they stay dead sharper many times longer (as pertaining to cutting forces)...boring, OD and ID grooving, parting (cut off), OD and ID threading...I again say yes to carbide!... (But for starters and not having to have a diamond wheel, yes to HSS)... and HSS much less hard on the edge of a diamond wheel ifn' one likes to snag on a chip breaker...Smiley Face here.
...generally slower rpm (for harder, tougher steels depending on the stock diameter of course) or mid to higher rpm ("softer" steels) and a little different speeds and feeds (all sfm practice and use) and with a little nose radius you won't chip em' even with a somewhat "sloppy" spindle....perty much the same relief angles as using HSS per material (on steels) and they stay dead sharper many times longer (as pertaining to cutting forces)...boring, OD and ID grooving, parting (cut off), OD and ID threading...I again say yes to carbide!... (But for starters and not having to have a diamond wheel, yes to HSS)... and HSS much less hard on the edge of a diamond wheel ifn' one likes to snag on a chip breaker...Smiley Face here.
I too sharpen those cheap carbide tools with happy results but not knowing this guys actual lathe & sharping carbide is a whole subject to itself.
I wish I knew something about sharpening carbide when I first started using the little HF 7x. But I didn't try until after upgrading lathes. I believe all I've ever used in that little lathe is carbide. I didn't till recently get done hhs that small.
I wish I knew something about sharpening carbide when I first started using the little HF 7x. But I didn't try until after upgrading lathes. I believe all I've ever used in that little lathe is carbide. I didn't till recently get done hhs that small.
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Cheap!? LOL (Smiley face here)...HSS cut plastic good and make for good little parallels (Smiley face here)
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Sorry Chris, we'll have to agree to disagree. On a small lathe with limited rigidity, HSS will outperform carbide consistently. If we are talking about 5-7 degree relief angles and little to no back or side rake, then maybe a HSS ground like that will be similar to a brazed carbide or inserted carbide tool. BUT if I grind a 15 degree side and end relief and maybe 15-16 degrees of side rake and 10-15 degrees of back rake on a HSS tool with a 1/64" nose radius I bet you money it will out cut that brazed carbide tool on steel, aluminum, brass, Delrin or stainless. It will stay sharp a good long time and takes a few seconds to hone back to paper-slicing sharpness.
Too many of us think of a HSS tool as a tool with standard angles; I don't. I am not saying carbide won't cut. I am saying that a properly ground HSS tool will outperform it on a small, less rigid lathe. Of this, I am certain. Here is a HSS tool that is taking a 0.050" deep, chatter-free roughing cut in mild steel on a little Sherline lathe. Not only did it cut it easily in one pass, it was accurate. I ran the same test cut with a very high quality inserted carbide tool and a standard HSS tool ground specifically for steel and both struggled to make this depth of cut on this lathe.
So, big, rigid CNC lathe running at 10K rpm, yeah, carbide would work great. Small little lathe with 1/4HP - no, not as good.