3 phase lathe question..

[Rick Fisher]

I was at this auction, they had 2 x single phase lathes and 4 x 3 phase lathes..

I looked hard at the single phase lathes and found Variable Frequency drives inside a compartment..

So I assume.. A single phase lathe is a 3 phase with a VFD ?

The single phase lathes went for $1600.00 ..

I bought 2 x 3 phase lathes for $700.00

Am I wrong here ? Is there any other difference ?


One of the lathes is a General 20-260 .. I am going to keep it .. I have 3 phase in my garage so I am cool with that ..

The other is a General 10-160 .. It has a 3/4hp motor .. A VFD is what ? $150.00 ?? for a motor that size ? Or I could find a 3/4 hp single phase motor, not sure how the VS works.. is it the motor or some gear system ?

http://i335.photobucket.com/albums/m455/jokerbird_photo/Courtenay-20120531-00565-1.jpg

http://i335.photobucket.com/albums/m455/jokerbird_photo/Courtenay-20120531-00567.jpg

http://i335.photobucket.com/albums/m455/jokerbird_photo/Courtenay-20120531-00564.jpg

Any advice would be great. I know nothing about turning .. Always thought it was cool.. I figure its a pretty safe way to start .. Can always sell it used.

Is the difference between a 3 Phase and single phase lathe just a VFD ?

[Clint Baxter]

I was at this auction, they had 2 x single phase lathes and 4 x 3 phase lathes..

I looked hard at the single phase lathes and found Variable Frequency drives inside a compartment..

So I assume.. A single phase lathe is a 3 phase with a VFD ?

The single phase lathes went for $1600.00 ..

I bought 2 x 3 phase lathes for $700.00

Am I wrong here ? Is there any other difference ?


One of the lathes is a General 20-260 .. I am going to keep it .. I have 3 phase in my garage so I am cool with that ..

The other is a General 10-160 .. It has a 3/4hp motor .. A VFD is what ? $150.00 ?? for a motor that size ? Or I could find a 3/4 hp single phase motor, not sure how the VS works.. is it the motor or some gear system ?

Is the difference between a 3 Phase and single phase lathe just a VFD ?

Your motor will either be a single phase or a 3-phase type. The VFD allows a three phase motor to be run from single phase power with the addional benefit of being able to control to motors rpms. The variable speed on your lathes appears to be a Reeves drive, which, though not a gear system, is a mechanical type of speed changer. A gear driven pulley sheave on one end of a belt coupled with a spring loaded sliding sheave on the other end allows you to vary the speed of your lathe.

Clint

[Olaf Vogel]

These are pretty good lathes, especially if you're just starting out
Very common in the high schools around Toronto. So I've used them many times.

Just bolt it to the floor well - they have a narrow footprint. For out of balance pieces, they tend to rock back and forth which is unnerving.

If you have 3ph in your shop and the General has basic speed control, I'd suggest just hooking it up and playing around. The swing is limited, so you won't need much speed control. Save you $$$ until you think you really need it and just have fun for now.

[Robert Champagne]

Hey Rick,
Nice lathes. I just set up my lathe with a vfd. It is an Oliver 159 and has a 3/4 hp motor. I got a TECO vfd rated for 1 hp, 220v input (single phase). The Oliver is a Reeves drive variable speed similar to yours. I have three phase and could have run it without the vfd, but the Reeves drive alone provides a range of speed from about 800 rpm to 2500 rpm. I got the lathe specifically because it has a 3 phase motor and I could set it up with a vfd. The VFD allows me to slow the lathe down to allow for roughing larger blanks, etc. The main issue is that when you slow down a motor with a vfd you also tend to loose power. The 3/4 HP motor is fine at full speed, even at half, but at low speeds it is fairly easy to slow it down while turning. Perhaps an advantage of your lathe is that you can probably mount a variety of sized motors in your cabinet, allowing you to install a larger 3 phase motor to be powered with a VFD. VFD's for smaller motors are pretty cheap (mine was $75 of so before shipping), and I found the one I got to be pretty easy to set up, though I did have help from my friends on owwm.
Rob

[Mike Cruz]

Sorry, I don't have time to read through the other posts, so I don't know if this is redundant or not...

3 phase plays a huge part in lathes. It allows variable speed. Single phase motors won't allow it. Not sure about VFDs that come with lathes, but if you get, say, a TECO FM-50 for a 3 phase motor, a huge advantage (other than being able to conrol your speed) is that you can also use the VFD to give you soft start, and use it as a brake, too. There are many other functions to the as well, but those are the main ones.

As for a VFD for a 3/4 hp motor, the TECO FM-50 is $100 or under for that hp.

As for those lathes, sorry, can't help you there too much. They are solid machines. But I'm not versed in the Reeves drive for it (if it has one). Some manufacturers made good ones, some didn't. Do you have any idea of the age of each machine?

[Eric Holmquist]

Since you have three phase in your shop, and the lathe has a Reeves drive, for now I'd just use as is. In the future, you may wish to add a VFD to allow you to get a broader speed range and reverse capability. Adding the VFD is easy, but not necessary for now, just hook it up and have some fun first!

[Mike Cruz]

Eric is right. You don't "need" a VFD to convert to single phase since you have 3 phase in your shop. Since you haven't turned yet, here's a little insight. Your lathe's low end speed is probably around 300-400 rpm. That is a little fast for out of balance blanks over 12" in diameter (meaning for bowls and hollow forms). For spindle work, that speed is plenty slow enough. The VFD would allow you to slow your lathes rpms down from the 300-400 range to whatever you need below that (1 rpm if you want...but who would?).

What is the swing (largest diameter blank) you could mount on the lathe? Measure from the spindle to the bed, and double it. So, if the distance is 6", that means you have a 12" swing.

On another note, the lathe in the first pic USED to be a gap bed lathe, but someone filled that area in...

[Trevor Howard]

I have no knowledge to say anything about the lathes but would like to add about VFD's
As Mike stated a 3 phase motor can be electronically speed controlled using a VFD, a single phase motor cannot.
When VFD's first came out (many years ago) they where only available with 3 phase input which allowed controlled 3 phase output.
I guess manufacturers eventually realized not everybody had access to 3 phase power, and realized they could reach a bigger market by making a single phase input VFD to control 3 phase output. I have no proof of this and is only my assumption.
Most single phase input VFD's max out at 3HP whereas 3 phase input I have seen up to 450HP :eek:
Factorymation and Automationdirect sell reasonably cheap and reliable VFD's I have no affiliation with them but have installed several of them.

[Rick Fisher]

Thanks kindly for all the responses..

At this auction, I was asked to buy a lathe for a buddy as well.. so I bought two..

He asked specifically for single phase.. I have a full blown workshop .. he is starting out.. He is a very good woodworker, but went through a divorce.. Its like a fire except you don't get the big trucks and flashing lights..

I picked him up a 160-10 in 3 phase for $700 .. These General lathes in Canada are well regarded, I knew I could sell it for probably $1000 or more if he didn't like it .. So no big deal ..

Afterwards of course I wondered if I did the right thing for him .. I saw those FM-50 VFD's . I could order one and wire it up for him .. Simple enough ..

The variable speed on these is a big silver drum with a belt around it .. if that is a reeves drive .. then that's what it is .. lol

In my shop I have a 20hp Digital phase converter with a 3 phase panel. It runs 3 x 3 phase tools. My curiosity is that in Canada, a Siemens 3 phase breaker and the Tec cable I use for the 3 phase tools costs more than a VFD for a 1hp motor .. Kinda silly..

I am shocked how little I know about lathes.. I may look for turning classes.. The lathe came with some round screw on parts .. no idea what they are .. A bunch of rods with points and chucks.. again.. I figure they go in the tail stock.. I need to learn some stuff before I put power to it.

[Mike Cruz]

Rick, great idea...take some classes!;)

[Harry Robinette]

Rick
I have a General 160-12 there 12" lathes. I put new castings on mine and made it an 18" lathe I also put a DC volt drive on mine and left the reeves system, you can lower the reeves drive speed and raise the motor speed to keep the torque up it works great.
The General like mine and yours are great lathes,the General International is the one you have to watch out for cause there made in China.

[Michael Kellough]

Rick
I have a General 160-12 there 12" lathes. I put new castings on mine and made it an 18" lathe I also put a DC volt drive on mine and left the reeves system, you can lower the reeves drive speed and raise the motor speed to keep the torque up it works great.
The General like mine and yours are great lathes,the General International is the one you have to watch out for cause there made in China.

Can you tell us more about how you increased the swing on your old lathe Harry?

I just bought an old Oliver 51-D and I'm interested in increasing the swing.
It has a 3/4 HP 3 phase motor. How much swing do you think it could handle.
(Moving up from a 1/2 hp (so-called) baby Rikon)