CNC Lathe Shopping....Where to start?

[griffithbuilt]

We are looking for a CNC Lathe that is for the most part very basic. I want something that I can use to mildly modify crankshafts, produce serpentine pulleys and a number of other smallish - 8" max diameter, 36" max length projects.

I am focusing more of our budget on our VMC so the lathe I am hoping to find cheap. Aside from the crankshaft work, most of what we will be doing is aluminum, so extreme hp probably isn't a necessity. accuracy would be nice, with the sloppiest accepted around +/- .001 tolerance.

Curious what peoples opinions are and where I can start looking in the PacNW for something of this caliber. Specific machine names, etc would be appreciated. I will be learning on an Okuma cnc lathe next fall and plan on purchasing within the year so time is certainly not a factor.

Jason

[ViperTX]

Like turning journals on crankshafts....those are very not your normal CNC lathe.

[HuFlungDung]

I don't know if I would pick cnc at all for modifying crankshafts. Perhaps if I had a big run of them to do. But about all you can hope to do is modify the end journals or pulley/flywheel mounting surfaces. I don't know what your planned operations would be.

A 36" long center distance is quite long, so far as turning centers go. This might put you more in the field of manual type machines that have been retrofitted.

So far as horsepower goes, cnc lathes need a good sized motor to produce adequate turning torque at low rpm, for larger diameter jobs. Most cnc's do not have a vast gear selection such as you would find on a manual lathe. This wide range of gears is what allows manual lathes to run with relatively low horsepower motors.

[griffithbuilt]

Well honestly I don't even see us doing any crankshaft work at all, that was simply the largest item I could fathom putting in a lathe in the first place. THat was also what was defining the length requirement. Really we're probably looking at around 6" dia x 12" long maximum with the parts we are focusing on.

And I was thinking knife edging the counterweights.

Jason

[little bubba]

These guys were helpful when looking for a couple of machines in the southwest. http://www.premierequipment.com/. We never bought anything from them, but they deal in used equipment all over the country and can at least let you get a feel for going prices.
I would suggest looking for any area machine dealers, not just in your town but that cover a couple of states. Our local mazak distributor also deals a bit in used machines, and since their salesmen are in shops for hundreds of miles around, they know when something is going up for sale, and what kind of condition it is most likely in.
I've noticed that not all dealers are the same, most won't call you back, most don't even care. I've had good expieriences with both our local mazak distributor and Premier in Florida up above, as far as looking for used machines, even if they aren't Mazaks.