Re: Lathe CNC retrofit

> Date: Mon, 28 Jan 2002 20:06:53 -0500
> From: "Carlos Guillermo" <carlos@...>
>Subject: Lathe CNC retrofit
>
>Hi All -
>
>I've been thinking about CNC'ing my Sharp 13x30, and I'm wondering
>what the max loads are that the leadscrews see during typical
>cutting? By the nature of the lathe design, it seems the majority
>of the cutting forces are directed downward against the ways. I
>don't remember feeling the same resistance at the handwheels while
>"lathing" as I do on my mill.

Carlos, the "work" done by a lathe is usually considerably more than a mill. In a commercial setting it is not uncommon to see a CNC lathe with 20-30 hp and CNC mills with only 10. This is particularly important if you want to drill any holes over about 3/8 inch (which a 13 inch lathe should be very capable of doing)

Look at the size of the lead screws on your lathe and figure that if you want to use the capacity of your lathe, you will be sizing motors with shafts to match.

If you are only working in soft materials, you might be OK with small motors, but there is a lot of resistance just to move a lathe and a lot of losses from the leadscrew and gearing.

> I'd like to see about using
>spring-loaded anti-backlash nuts instead of trying to mount
>ballscrews, but I need some sort of load rating to go by. OTOH,
>could I adjust the half-nuts to eliminate the backlash?

Most people have trouble finding a place to put an antibacklash nut on a lathe. They are hard to fit under the apron and crossslide (X direction).

Best Regards, Fred Smith- IMService

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