Hi.
I am quite new to CNC, and decided to try the Fusion 360 (for Personal Use), since it combines both CAD and CAM, and I do not have any prior experience with any of these, so why not go all in. All hobby. The learning curve is steep I must admit, however, I am a software developer by profession, so I suppose that helps me on the G-code understanding... I hoped. And sorry up-front for a possibly noob and long question...
I have bought a Sainsmart Genmitsu ProVER XL 4030 machine, which uses GRBL as a post processor. I doing pretty simple engraving to start with, and then trying to understand what Fusion 360 does, what it translated into G-code and then how the machine behaves.
Question 1
When I post/translate the instructions to G-code, it seems to be consistent that when executing, the spindle will start, and then move the head in the X and/or Y direction with no Z-move, which - if being too aggressive on the Z-zero - can lead to marks on the stock. I can understand this behavior from reading the G-code, since the following is what is generated at the top of the NC file...
(Engrave1)
T3
S5000 M3
G54
G17
G90 G0 X-34.219 Y4.782
Z15
G1 Z5 F1000
Z-0.001 F333.3
X-33.643 Y5.359 Z-0.578 F1000
So what I normally do it move around these instructions so that it will lift 15 mm then start the spindle, and then travel to the start point. This is naturally pretty tedious, so what am I doing wrong in Fusion 360 or elsewhere?
Question 2
I am doing a simple engrave that writes "Test", and I set the Multiple Depths to enabled and specify a Maximum Stepdown of 0.6 mm. When I simulate or machine the toolpath, then the first pass is alright, but then it plunges to the full depth in its second depth/pass as seen below...

Why is this? I thought that it would increment by depths of 0.6 mm until it reaches the full depth?
Question 3
The bit I have used above is a V-groove bit that is modeled as an Engrave/Chamfer, and it works as expected, however, the bit itself looks more like a Counter sink type when chosen in Fusion 360 than the one above (flat on top so the profile looks like a triangle and not a square as above). However, I do not seem to be able to use a Counter sink type and engraving bit. Why is that and do I have a wrong understanding?
Thanks a lot,
Best regards, Jacob.