feed rates and drilling and G00 question?

[frankd]

Does G00 travel at the last feedrate specified by a F command?
Or does it travel at the fast speed set by the controller.

I want to do some fake peck drills.
I am at a SafeHeight of say 0.5 inch above the material.
I want to plunge FAST from SafeHeight to the surface.
I then want to plunge SLOW say 0.25 inch into the material
I then want rise FAST to the just above the surface.
I then want to plunge FAST 0..24.
I then weant to plunge SLOW to say 0.5
And then fast out

G90
G00 Z0.5 <-- fast to safeheight
G00 X1Y1 <-----fast to startpoint
G00 Z0.0 <----- fast to surface
G01 Z-0.25 F1.5 <--- plunge slow into material
G00 Z0.1 <--- Will this be FAST or F1.5? to just above surface
G00 Z-0.25 <--- will this be fast or F1.5
G01 Z-0.5 <-- will this be SLOW as its G01 and F1.5 was last feed rate sent

In short, does only G01 travel at the last F command or does G00 also

[Switcher]

In short, does only G01 travel at the last F command or does G00 also

Not all controls are the same.

I think most hold the last rapid/feed (G00 / G01) in memory.

.

[jackson]

My question is why dont you just use a high speed peck

[frankd]

Not all controllers support Peck drill.

Our software is Generic and doesnt know if it is driving an advanced GCode controller, micky mouse one or an HPGL router.
No peck drill in HPGL.

We are trying to develope a FAKE peck drill that acts like a real one for machine that dont have a G73

[Switcher]

frankd,

Are you writing the software?



.

[jackson]

Oh ok well im not familar with that but if it has the basic G code function then G00 should alway be a rapid and G01 needs to be suppoted by an F and G1 will pick up the Last F it read.

[Switcher]

I work with a 5-axis, Siemens control (840D), you have to program a feed value (F=whatever) no matter If it's G00 or G01.

So I couldn't move an axis (X,Y,Z,A,C) unless I write F=whatever for each line containing an axis move.

.

[frankd]

Yes we write the software.
I write the drivers for the various machines.
We would like to have a generic simulated peck drill that any machine that supports xyx axis can use.

The motion is easy.
Its gettting the speeds right for going to the surface between pecks.
We want Fast UP and FAST back down to last peck before switching to Slow plunge velocity for second part of the peck.

I think its controller specific with GCODE if G00 is allways RAPID travell at fastest speed or uses last sent F command.

Was hoping some GURU could say its 95% Fastest speed/5% last sent F command.

[jackson]

ok well on you 5 axis then what is the dif. between G00 & G01

[Ozemale6t9]

On Fanuc and Okuma, controls G00 is controlled by a parameter, and is usually set at Servo RPM x Drive ratio x Ballscrew Pitch. In otherwords, maximum rate of travel. Sometimes on vertical machining centres, the Z rapid will be lower than maximum speed, depending on whether the head is counterbalanced. I believe Mazatrol also uses a parameter for G00.

regards, Oz

[warfreak]

im a nooby so i have not much knowledge but im being taught that G00 is always a non cutting move ....


(feel free to smack me upside the head anytime by the way)

[riverrat]

jackson is right on.
if it were me, i would seriously consider putting
some clearance on my rapids to the top of the part
and, on resuming the peck on the bottom of the hole.
there might be a chip left at the bottom of the hole,
operator loads the part on a chip, etc....