Re: re: as simple as 1,2,3... ENCODER/JOG

>Message: 5
> Date: Tue, 14 Nov 2000 18:16:02 -0800
> From: Alan Marconett KM6VV <KM6VV@...>
>Subject: re: as simple as 1,2,3... ENCODER/JOG


>What if I setup my rotary table and a tail stock on the Sherline mill,
>and use a 60deg. conical point (or something else?), by driving the
>rotary table and the 'X' axis, I should be able to cut threads on the
>mill! Although other then the obvious code to simulate a "back gear
>ratio" between rotary table and 'X' axis, I haven't sat down to figure
>out how to do it in CAD/CAM.
>

1) If your machine supports helical interpolation ( G17 plane and a G02/G03 with a Z value for example) You can program the thread directly. Just make sure which plane is which.

2) If not (and many of the low cost machines don't support it) use the wrap cylinder function in Vector to produce an interpolated spline representation of the thread tool path. The rotary 4th axis will output X-Z-A code to cut the thread, and it will also allow you to define multiple passes if needed. Just draw a flat line in X-Y that represents the projection of the thread as if you unwound it and layed it out flat. Starting at X=-1 and Y=0, Draw the line to the end coordinates equal to Length_of_thread*Minor_diameter * PI * TPI. For a 1/4-20 thread over a 1 inch length this would be approx = 1*.188*PI*20. The end coordinates would be X=0, Y=11.8124. Just type it in the Y end coordinate dialog box in Vector to get the calculated value. PI is understood to mean the value of pi. As Ballendo described, you could use the Y axis to cut the line drawn if you are just swapping the Y axis to drive the rotary table. You can also use the scaling in the Vector coordinate configuration, but it is much cleaner to adjust this to unitary in the controller parameters.


Best Regards, Fred Smith- IMService
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