I am just looking into getting a small lathe like the Jet 14"x40" Geared Head Lathe. I have a Bridgeport Mill running off a phase converter. If I get the lathe should I just get a single phase motor or use the lathe through the phase converter? I know the Jet is no Clausing, does anyone else know of a low cost lathe besides Grizzly?
If I was you (and I was a year or so ago) I'd check out eBay, or CraigsList (or it's equivelent where you are) for a used American built machine. You can find SouthBends, Clausings, Sheldons, Logans etc in the $2000.00 price range. You own a BP so you KNOW how good old iron is, trust me you'll be disapointed my anything new and imported. FWIW the SF CraigsList has some VERY nice lathes up right now, most under 2K.. there is even a LeBlond for under 2K (Damn wish I'd seen that a year ago...)
No reason to use single phase if the "new lathe" comes with a three phase motor. If, and it may very well be, this 14 X 40 has a larger motor than your existing phase converter uses (I'm assuming a Rotary Phase Converter), and the lathe does not have a "clutch", you may have a bit of a problem. But, if the RPC you already have would be large enough to start the lathe you want to buy, then in operation ANY motors running off the RPC will only INCREASE the capacity of the RPC circuit.
In other words, say you have an RPC just large enough to run the "new lathe", and while you have it running "someone else" wants to run the Bridgeport, or that you have the Bridgeport running and "someone else" wants to use the lathe, you are OK because the second motor running is an additive to the RPC capacity.
While what I'm writing may well be true, I would also assume that the existing RPC has, to this time in your shop, only been required to run a Bridgeport vertical mill, of probably (what?....), a maximum 2 or
3HP, and therefore probably has only a 5HP motor on the RPC, while the normal size motor for a 14 X 40 lathe would nominally be in the 5 to
7.5HP range. So your existing RPC alone may well be not large enough to start the geared-head lathe, and might require a 10HP on the RPC.
What I have done to accomplish this, in a similar situation to yours, is to install a number of "three phase wall outlets" in my shop, to power some various stuff in a given location on the shop floor at any given moment. So then I bought a second 5HP motor for my RPC. It is mounted on a 4 wheel cart (so I can store it out of the way) and with it's own disconnect. If I want to run my larger lathe, I start the existing RPC, plug in this "second motor" and turn it on, then I can use the larger lathe, as I have in fact "doubled" the size of the RPC effectively so it can handle the 7.5HP lathe's starting load.
PLEASE NOTE: All that being said, you must have the proper ampacity in the wiring to handle the additional load(s).
First, I'd say that a 14" lathe really isn't a small lathe.
Second, I once bought a 14 1/2" Southbend for $2000, and a 12" Chinese lathe from Harbor freight for $2000, and I think the Chinese lathe was a better lathe. Though the castings looked crude and the hand dials are crap, at least the ways are hardened and have no wear. Same with the chucks.
The Jet, and the Grizzly and the Central Machinery and the Enco and the Vetrax and the Turn-Pro etc are all mostly the same crap painted different colors.
A GOOD used lathe on ebay or Craig's list would be the best deal. But some "good old iron" isn't that good.
I would use a lathe through a rotary phase converter, but perhaps not a static due to the high starting torque.
Thanks for everyones replies! I was also looking at a 1340VS made by Sharp. Maybe be a better choice than Jet. I know there all the same imports and since this machine has a variable speed controller, I may not get that major load (dimming of lights) when I turn on the spindle.
Carb> I am just looking into getting a small lathe like the Jet 14"x40"