First CNC Lathe for Home Shop - Recommendations

[dhrider123]

Hello,

I apologize for the wall of text below. I tried to be as thorough as possible. Thank you in advance for taking the time to read!

About 2 years ago I started a similar thread seeking advice on my first (real) CNC mill. I got a lot of great feedback and ended up with a Fadal VMC-15XT. It's been a great machine and I have really enjoyed using it!

I've been looking for a Lathe (on ebay, Craigslist and the PM Classifieds) for the past 9 months. I'm experiencing some mental blocks and am seeking some wisdom on my options. I have an idea of what I want in a lathe and why I want that. I've also tried to do my own research on specific machines, which hasn't so much ruled any out, but maybe just changed the order of preference between machines.

Here is what I want/need from the lathe:
* Live Tooling with Y-axis.
* Sub Spindle.
* Bar feeder (at least an interface).
* Parts Catcher.
* Chip Conveyor.
* Minimum 1.75" bar capacity (to fit stock for a current part I'm making on the fadal).
* Main spindle fast enough to turn non-standard 10-32 304ss shoulder bolts.

As you can probably see from my above wants/needs, I'm trying to have a lathe setup that is truly automated with the ability to perform a second op.

My shop space is limited, and a barfeeder obviously eats up a lot of that. I'd rather not have two lathes which take up even more space, so I'm really looking for a "do it all" lathe that can make my current parts without much operator input. But can also pinch hit for the smaller diameter parts as well.

My last want on spindle speed is where I'm running into my first mental block. I have zero lathe experience and I realize I'm asking for a lot of machine which will likely present some fun and frustrating learning challenges. With this lack of experience, I'm having a difficult time deciding what my minimum "max spindle speed" should be. Do I need 4K? 5K? 6K? I understand the faster I can got the faster I can "make money" especially with the smaller diameter parts. I also understand that a 4k spindle is not going to be fast enough to use Carbide inserts on those stainless bolts and that a faster spindle simply gives me more options on tooling. Will I eat through HSS tooling trying to turn 304 on a "slower" spindle?

My next mental block is on the machine brand/model. Here is what I've been looking at in my preferred order:
1 Okuma - I've heard amazing things about Okuma lathes, but have had a very difficult time finding one with all the features I want.
2 Daewoo/Doosan - The little Puma machines seem to check the boxes, and I've heard good things.
3 Mazak - Also heard good things.
4 Mori Seiki - I actually just missed a ZL-154 on Craigslist that was 4hrs away from me.
5 Nakamura

I'm mostly stuck on the machine brand because they all seem like they would be great machines. With the exception of the Okuma machines, is there any one brand on this list that is appreciably better than the others? And, are there any brands to stay away from? I think I'm mostly stuck on this because I haven't found many "stay away" posts on any of these machines, and I'm afraid I'm just missing those posts/experiences and might buy a bad machine.

With the above machines, I've been looking at late 90 to early 2000s.

My final mental block is on the price and age of machine. I'm hoping to find something around 30-40k, and I feel like that is very realistic (at least for the era of machines I've been looking at). I know finding newer machines with all the bells and whistles I've listed is a lot easier. So, should I increase my budget and get a newer machine? Or are these older lathes just as trusty and reliable as the older VMCs (Fadal in my experience)?

I know that's a lot to digest, and I really appreciate the help!

Thanks for taking the time to read!
Shane

 

[James H Clark]

I would be leery of 20 year old electronics.

JH

 

[Mcgyver]

I would be leery of 20 year old electronics.

JH

double that concern if its Mitsubishi

 

[DouglasJRizzo]

Well, Okuma is the best IMO, but pricey and live tool Y axis versions are rare in the used market as they get snapped up VERY fast. The machine is just top drawer all the way.

Doosan rocks pretty good and is a good value. Not an Okuma, but doesn't cost like one and can make you money! I'm biased as I used to work for Doosan, but it's a great value. Plenty of good examples abound.

Mazak and Mori are also top drawer machines and can do the trick.
Nakamura, less common but very nice. I think Methods handles those.

My advice is keep searching the used machinery sites - it's like that mint condition car you want. When it pops up, you have to spring on it right away.

 

[Garwood]

I've known a few guys who have tried to setup a sub spindle live tooled lathe at home for products or side income and never run a single part.

VMC's are probably the most versatile machine you could own.

Could you bar feed a small VMC?

Could you run an air powered collet closer on a Cat40 shank in a VMC and use your vmc as a gang tooled lathe?

Robot or gantry load?

Barfeeders eat a ton of room.

Geometric die head for 10-32 threads or thread rolls?

 

[Gobo]

Mazak made about a billion of their SQT-15 Y models, and there are still many, many out on shop floors. Their conversational Mazatrol make them great starter machines. We have several. Parts are still available.

 

[dhrider123]

I have seen a lot the the QT and SQT Mazak lathes around!

Where do you buy your replacement parts from? And, in your experience, is there anything that is a common failure point on the Mazak lathes?

Aside from verifying the machine is being properly lubricated, are there any special maintenance items to be aware of?

 

[dhrider123]

Completely agree. My VMC has been incredibly versatile and I have no intentions of ever replacing it.

Right now I'm running my (let's call it "lathe part") on my VMC with a set of pallets for a total of two operations. I built two sets of pallets for each operation, so while a set is being machined (which takes about 45min) I'm unloading/reloading the offline 1st/2nd Op. pallets which leaves me about 35-40min of free time to get other stuff done. It's reasonably efficient, and does not take a lot of physical time to swap pallets. However, it does mean that I need to be available to keep the machine moving. Right now this means about one weekend a month is dedicated to keeping the machine going (I'm still working my day job). I'd love to have this part run on it's own through the night/day while I'm sleeping and working.

I could setup a pneumatic chuck to hold the 1st/2nd op part and have a robot feed it. Which, may be a great option down the road, especially for future parts.

I still find a lot of appeal to a lathe for turning instead of getting it done on a VMC. It just seems like it would be a headache to build custom fixturing for a VMC to do a job that a lathe can do with a chuck/collet swap and spindle liner.

The other appeal to the lathe is that I would then have two machines making parts.

 

[Garwood]

Don't under estimate the time and expensive tooling it can entail to get what is essentially two lathes and a mill in one package working like you want.

 

[kb0thn]

Don't under estimate the time and expensive tooling it can entail to get what is essentially two lathes and a mill in one package working like you want.

I am contemplating a shiny new Mazak QT250MSY. And that is the big thing holding me back. To effectively use it, it looks expensive. Mazak includes a fairly decent looking selection of tool holders with the new machine. And I could imagine you could get a well tooled used machine with a bunch of tool holders. But I could also imagine getting a used machine without tooling and spending 2x or 3x to put quality tools and holders on it.

 

[dhrider123]

Questions now on tooling.

For Live tools, are there any brands/manufactures to either stay away from or to go after?

I planned on spending about 20k on tooling (live tools, static holders, collets, inserts). For live tools, I need 1 radial and 5 axial live tools to machine my current parts. on static tools, I figured 1 OD/Face turning tool, 1 ID, 1 boring and an undercut. hopefully I can get some decent live tool holders with a used machine, but also plan on those tool holders wearing out fairly soon.

From the little looking I've done, I've gathered live holders can vary wildly in price... Are used live tool holders even worth the time?