[QuinnSjoblom]

So here's where I'm at right now, 7 months ago I decided I wanted to start designing and milling my own rc helicopter parts. Since then I've learned cad/cam, designed and built a 3 axis cnc, and then designed and am about 90% done milling parts for a complete helicopter airframe. Pretty proud to say I'm holding a tolerance of .01mm with my machine that I have about 2k into.

Anyway, I would now like to add turning to my capabilities. I was able to get by without it so far, but it would be a huge advantage for a lot of parts. 3 axis milling my main rotor grips was a challenge and they still aren't perfect. Would have been a breeze by turning some of it.

All of my parts are either 7075 aluminum or delrin. The largest parts I would need to turn would only be maybe 6 inches long at the most, couple inches in diameter, maybe larger diameter if i wanted to turn a delrin main gear but that did fine milling. So really even a 7 x 12 is overkill. I would prefer something even smaller if it gets me better quality for the money but it seems 7 x 12 is the common mini lathe size.

So what are my options? Is there good options smaller than a 7x12? If I'm limited to that size, what would be a good choice? I see a lot in the 400 to 600 price range. Are they all garbage? Could I expect .01mm tolerances with one? What is they next step above that? I would be willing to pay more like 1000 to 1500 if it's a significant step up in quality.

Another thing I'm thinking about is utilizing my existing cnc for my lathe. My work envelope is 18x26x8 inches and 95% of my work fits in my 6inch kurt. So lots of room on my table to slap a lathe next to my vice. I was thinking I could modify my z plate for mounting turning tools and have a cnc lathe. Could use x and z axis to have cutting tool come down vertically, or x and y to come in horizontally. My machine is very rigid for being aluminum. Indicating from table to spindle, I get a couple thou of deflection when pulling on the spindle quite hard. Couple tenths with moderate pulling.

Just trying to figure out what my best option is. Size, brand, cnc control or not, etc. If I did go with cnc control using my existing 3 axis cnc, I imagine I would still have to by a fully capable manual lathe and remove half the parts to do it the way I want to, unless there's a way to purchase only the parts needed.

Open to any suggestions, thanks

[ianagos]

Look for a used 9x20 lathe if you can fit it. I’ve owned a grizzly and a harbor freight one and the harbor freight was 10x the machine the grizzly ever was. I’ve never owned a mini lathe but I’ve seen them at harbor freight and they were awful.

[QuinnSjoblom]

Look for a used 9x20 lathe if you can fit it. I’ve owned a grizzly and a harbor freight one and the harbor freight was 10x the machine the grizzly ever was. I’ve never owned a mini lathe but I’ve seen them at harbor freight and they were awful.

I saw one at our harbour freight and the ways were horridly sloppy. Wasn't all that cheap either, like 599. Can't remember what size it was, pretty sure just a 7x12. That's what scares me about ordering any of the 500 dollar range ones. They claim good tolerances but you never know until it shows up.

I would definitely consider buying something used, but I really would prefer to stay 7x12 or less. I'm hoping someone here chimes in that has experience with a decent quality small lathe.

[ianagos]

Since harbor freight hasn’t sold the 9x20 for at least 5 years I’d say you saw the 7x12. Goodluck In your quest. By the way I’ve seen 7x12 lathes on Craigslist for $100.

[pippin88]

What spindle do you have?

You can use a mill spindle for small lathe work, with tools mounted to a block on the table.

[QuinnSjoblom]

What spindle do you have?

You can use a mill spindle for small lathe work, with tools mounted to a block on the table.

Yeah, I actually posted about that a while ago and it would work fine for tiny parts, maybe up to 1/4 inch. I have a 2.2kw, 6k rpm minimum. I really need the capability of a lathe for bigger parts than that though

[Turbo442]

One problem with the mini lathes is that they have very little spindle power. Try and find a used 9x20, 10x22 or even 12x36. You will be much happier in the long run.


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[QuinnSjoblom]

One problem with the mini lathes is that they have very little spindle power. Try and find a used 9x20, 10x22 or even 12x36. You will be much happier in the long run.


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I didn't think about that. I guess I would probably be limited to pretty tiny cuts with one of those. I'll only be running aluminum, but 7075 specifically, quite a bit harder than the usual 6061. On my cnc I've noticed the spindle grunts quite a bit more on the 7075. Would be nice if there was something in a small package with decent power but that's probably not likely.

[warrenb]

DO NOT buy the Harbor Freight mini lathes. They are junk. As many said, look for a used quality brand.

[QuinnSjoblom]

DO NOT buy the Harbor Freight mini lathes. They are junk. As many said, look for a used quality brand.

Ok, thanks. Yeah it was pretty obvious after the 5 minutes of fiddling with one at our harbour freight. Definitely won't go that route. Price wasn't even low enough to be tempted by it