Code to plunge Z gradually and then retract along length of a profile path.

[Rufe0]

Just out of interest why would you want to arc in and out with the Z?

[Wal]

Just out of interest why would you want to arc in and out with the Z?

In my case it was for aesthetics - I was looking at engraving into 3-ply acrylic (black/white/black) with a ball-nose cutter, using this technique would have given me a variation in line thickness along the path. Kinda like this:



Wal.

[Rufe0]

Ok yeah well if its exactly that shape you want to make (spiral) you should learn some gcode, its very simple to do in gcode. Something like

G0 X10 Y10
G2 X20 R5 
G2 X11 R4.5 
G2 X19 R4 
G2 X12 R3.5 
G2 X18 R3 
G2 X13 R2.5 
G2 X17 R2 
G2 X14 R1.5 
G2 X16 R1

Then it would be trivial to add your Z depth.

If you wanted to use code generated by a program its probably going to be 1000s of tiny straight line moves. I could perhaps make a small program for you that will tack on the Z depth but it wouldn't be as good as hand written code.

[Wal]

Hi Rufe0,

You're right, I should learn some G-code..! You're also right about my G-code being a series of thousands of smaller moves (as output by Vectric's cut 2D) so adding z-variation to existing code wouldn't be as straightforward as perhaps it ought to be. Unfortunately (heh, or fortunately, rather) it's not just spirals I need to do..!

Out of interest - how would you go about adding the z-arc on the code you've used above..?

Wal.

[Rufe0]

Assuming 3mm thick with each ply being 1mm thick and the cutter just touching the surface at 0mm

G21
M6 1
M3 
G0 Z20 
G0 X10 Y10 
G0 Z0.2 
G1 Z1 F30 
G2 X20 R5 F1000 Z-1.2
G2 X11 R4.5 Z-1.4 
G2 X19 R4 Z-1.6 
G2 X12 R3.5 Z-1.8 
G2 X18 R3 Z-1.8 
G2 X13 R2.5 Z-1.6 
G2 X17 R2 Z-1.4 
G2 X14 R1.5 Z-1.2
G2 X16 R1 Z1 
G0 Z20 
M30

[Wal]

Ah - ok, so the Z's still going in manually - wouldn't doing it like this leave each G2 arc on a 'step' (as opposed to a smooth dip in and out along the entire length)..?

Wal.

[Rufe0]

It should look fairly smooth, seems to in the simulation software i'm using anyway. It's because its going smoothly in and out, if you did it in steps like this you would see it

G21
M6 1
M3 
G0 Z20 
G0 X10 Y10 
G0 Z0.2 
G1 Z1 F30 
G2 X20 R5 F1000
G1 Z-1.2
G2 X11 R4.5
G1 Z-1.4 
G2 X19 R4
G1 Z-1.6 
G2 X12 R3.5
G1 Z-1.8 
G2 X18 R3
G1 Z-1.8 
G2 X13 R2.5
G1 Z-1.6 
G2 X17 R2
G1 Z-1.4 
G2 X14 R1.5
G1 Z-1.2
G2 X16 R1
G1 Z1 
G0 Z20 
M30

[JAZZCNC]

Just out of interest why would you want to arc in and out with the Z?

To save cutter wear would be another. It means Not plunging into material but still being able to have Arc lead-in. Something I use often when cutting out of material were tool can't avoid plunging into material and I don't want or can't ramp.