Re: [CAD_CAM_EDM_DRO]A question of size managenent.

Hi Bill:
How did the program get to having the arcs broken up into line segments
in the first place?
Was the toolpath generated from a spline or a surface in the CAM software?
Splines and arcs will output as line segments in most CAM software, since
there are very few machine controls out there that can handle NURBS input.
(Splines and surfaces are often described mathematically as NURBS entities).
Sometimes, it's difficult to determine if the entity you see on the screen
is an arc or a spline.
Most programs have some king of "analyze" function that will tell you.

Anyway, back to your original question.
A lot of the guys I worked with, preferred to take a simple 2D profile and
program only the first pass.
They would then "loop" the program to create all the subsequent passes.
That gave them only one short chunk of code to edit.
If you have multiple copies of your profile to cut, it makes for a very
economical program, but you have to know how to set up the loop commands in
your particular controller.
Hope this helps

Marcus
-----Original Message-----
From: BillDarby <ddarby@...>
To: CAD_CAM_EDM_DRO@egroups.com <CAD_CAM_EDM_DRO@egroups.com>
Date: Wednesday, November 29, 2000 7:38 AM
Subject: Re: [CAD_CAM_EDM_DRO]A question of size managenent.

>Hi All
>
> I recently ran a tool path with 36,000 lines of code. (no big deal

in the real world) Now my question is this: This

>path was really only 200 sets of (a line an arc and a second line) or

[line, arc, line, 200 times]. "If" I could have entered the

>summation of the 160 lines of code representing each arc into one common

"arc command" I would have had a total of just 600 lines

>of code.
>
> As it was, there was not enough memory to edit on the CNC. It

could run the program, but if I wanted to change anything I

>had to do the change on my off line program on my PC, then reload by floppy

to the CNC.

>
> Is there any software that could convert all these line commands

into arc commands?

>
>Just compelled to ask!!!
>
>Bill Darby
>
>Also (have never seen my CNC do this before) As these [160 line] arcs

became smaller my CNC began what appeared like a series of

>jerky motions as it rounded these corners and sped up when it hit the

straight-away. The cut looked and felt perfect but there

>definitely some jerking going on as the entire mill set up a rocking motion

on the wooden floor. I almost thought the CPU was

>bogged down. The feed was set at 32 IPM and dropped to less then 1/3 rd on

the corners.

>
>What do you think is going on??
>
>
>