Re: EMC and a lathe

[Brian Pitt <bfp-at-earthlink.net>]

Hi Scot

EMC as it stands now is mainly for mills I keep hearing rumors about 
adding lathe threading but I dont know how far along it is

so heres MY view of the steps needed for an EMC-Lathe control

first put everything done for mills on the shelf ,it will do nothing but
make a mess of things to try to convert it

now focus on the primary axis of the lathe ,the spindle
everything on the lathe is a slave to the spindle ,everything.

add encoder position feedback to the spindle ,this will need to be
able to track and reset the position on the index pulse and not just 
keep counting up or down forever

once that works the other axes can be slaved to interpolate motion
relative to the spindle for constant surface feet on X ,feed per rev on X & Z
and threading/scroll cutting on X & Z (these are all related anyway)
feed per minute is rarely used in the lathe

once that the motion primitives are worked out the interpreter would
need some major rework for the lathe functions and canned cycles
for turn,face,grove/cutoff,bore/face grove,thread,scroll (face threading)
roughing cycles ,finishing cycles 
(both using the same profile-definition-blocks/subprogram)

and add the tool orentation directions and tool nose radius comp

whew... as you can see this is NOT a trivial task 

Brian -yes ,I do work in a turning/screwmachine shop ,how did you know ;-)


On Wednesday 13 February 2002 07:40, you wrote:
> Hey there,
>
> I was just wondering if there was an EMC based controller in the works for
> a lathe or if there's a set of steps for altering EMC to be more like a
> slant bed conrol.
>
> Scot
>
>
>
>
> /?*$#-at-%!&*
> -------------------------------------------
> Give me open source, or give me open sores!
> -------------------------------------------