Lathe retrofit

[toneV8]

This si my lathe on pic1, pic2 which I am interesting in retrofit.What kaind 2 axis control system I need and how strong my motors need to be ( stepper or servo ).Do I need make belt drive system or put motor ( stepper or servo ) directly on axis see pic3 and pic4.
-directly on axis pic3
-belt drive system pic4

[fkaCarel]

For a lathe, you need an active and precise system. I would say max.speeds of 2-5 mtr a minute, although I found anything above 2mtr/min scary. It's different then milling, because everything what goes wrong hits the chuck with a big boom!

You need good acceleration and power for threading to synchronize chuck and tool. I'd say, go for servo's and look for the UHU do it yourself drives. They are discussed here on the forum. For mounting the drive on the Y axle: on your photo#3 it may come into conflict with your family production tools. Maybe you can find a place on the backside. Good luck and keep posting pictures. For some reason they like it here.

Carel

[toneV8]

How much torque for servo motor.

fkaCarel: Can you post link of 2 axis drives discussed here on the forum I can't find.

[fkaCarel]

I can't advise you on torque. It is weight, speed and money related. Google "UHU servo" and you will land there. Beware: it's a long thread.

Carel

[toneV8]

Do you mean UHU Servo controller on this web site.
http://gsst.wikispaces.com/

[fkaCarel]

I meaned this one: (second on Google)
DIY Servo controller

Carel

[RotarySMP]

Look like a great old Lathe.

The bed axis is the Z axis on a lathe. The Cross slide is X.

What is your plan? Replace the entire drive hardware with Ballscrews, or just motorise the existing screws? You really want an anti backlash solution at least on the cross slide of a lathe. If you go the whole way, you could strip out the norton gearbox and probably fit the Z motor, and probably the drives in the gearbox housing. The entire Apron assy could be replace with a nut carrier.

You can remove the top slide and replace it with a tooling plate once you CNC. That will also add some rigidity.

You could drive this machine with modern low inductance NEMA 34 steppers (a single stack on the X axis and a double stack on the Z) driven by Gecko's. Going to 2-5m/min rapids like Carel said is not going to be a great idea, as you will just wear out the bed faster.

Whether you direct drive or gear down with timing belts will depend on what motors your get and whether you fit ballscrews. I used timing belts on my Mini lathe to easy the shaft alignment and make the installation more compact.

[NC Cams]

I can probably sell you a fully functional turn key surplus Fanuc powered CNC lathe that I have on the floor right now, under power, for as much or less than you'll spend to tear up and retrofit the one you have...

A fully functionaly gear driven lathe with a powered cross slide is a very functional and useful and versatile tool. It is already set up to do threading and facing that can be distinct challenges for a full CNC lathe due to timing issues between the axes.

Yes, CNC lathe retrofiting is done but it is not as simple, cheap and as fool proof as that of a well featured quick change gearbox equipped lathe. Some machines are better left as-is and, if this machine were mine, I would not try to CNC it.

[toneV8]

Forget to mentioned turning diameter is 280mm, turning length 500mm.

Now I need to know how much torque for motor.