Re: [CAD_CAM_EDM_DRO] EMC Continuous Contouring

Andy Olney wrote:

>
> > This program pauses at the end of each quadrant, which is no good for
> > a flame cutting machine. I have G64 turned on for continuous cutting
> > mode.
>
> I notice you have never set a feedrate (Fnnn) anywhere in the program.
> That is pretty odd, but I guess there is a default feedrate set at startup.
> That could be a cause of the problem. When you say it pauses, do you
> mean you have to hit a key to manually continue, or that there is a
> hesitation,
> and then it continues the move? How do you start the program? With
> the R key while in AUTO mode? (The S key steps through the program
> one block at a time.)
>
> Jon
>
> I must have edited the program on the machine to add the feed.
> By pause, I meant hesitation, but enough to ding the cut. I was starting
> with the R key.

> Jon - I am using the version of EMC that came with the BDI, steppermod.o on
> a Dell 166 mHz machine.

> Motion is smooth and the cut quality good.

> For your information, I am running the G340s at their 10x setting and a
> little less that 2000 steps per inch. Max speed is less than 30 in/min.

Well, I can't explain it. I am using the 20-Dec-1999 version of EMC, because
it seems to be the most stable. The 166 MHz machine may be too slow to
run properly with the X10 multipier on the G340. That may have something to
do with the problem. I make circular arcs all the time, and always do it as
4 90 degre sectors, because the program I use already does the 90 degree
sectors when making the spirals. I use the R parameter in the arc rather than

the I and J, maybe that has something to do with it. You might try out one of

my programs :

http://pico-systems.com/gcode.html

The first program there, makebore, will start at the center, spiral out, and
finally
make a finishing pass at the desired diameter (compensating for tool radius,
of course). You might try this and see if it performs differently.

Here is a toolpath that was run through that, to make a 1.8" OD bore, using a
.248"
end mill. (The .248 is partially to compensate for tool deflection, too.)

N10 G01 F10.000 X0.7660 Y0.0000
N20 F1.667 Z-0.0640
N30 F10.000 G03 X0.0000 Y0.7660 R0.7660
N40 X-0.7660 Y0.0000 R0.7660
N50 X0.0000 Y-0.7660 R0.7660
N60 X0.7660 Y0.0000 R0.7660
N70 G01 F10.000 X0.7660 Y0.0000
N80 F1.667 Z-0.1250
N90 F10.000 G03 X0.0000 Y0.7660 R0.7660
N100 X-0.7660 Y0.0000 R0.7660
N110 X0.0000 Y-0.7660 R0.7660
N120 X0.7660 Y0.0000 R0.7660
N130 F5.000 X0.0000 Y0.7760 R0.7760
N140 X-0.7760 Y0.0000 R0.7760
N150 X0.0000 Y-0.7760 R0.7760
N160 X0.7760 Y0.0000 R0.7760
N170 X0.0000 Y0.7760 R0.7760
N180 G01 F50 Z0.1
N190 M02

If this one also has the pauses, then you have some kind of problem in the
handling of motion in your particular setup, as the program is OK. I don't
know if that is a BDI problem or what.

Jon