Just a note. Im playing with my laser today to see the differences between modes of the panel
to ensure its working as I wanted. Ive modfiied it a bit in Darwin. Heres a definition of how each mode
works.
Diags Mode:
Used ony for testing, nice to see how many shots and at what power it takes to piece
a particular material.
CNC ModE:
In this mode, if the PWM spindle is on, during any motion the laser shoots. The power is
set by the S word, ( S(SpindleMax) is equal to max power. BUT, the power is distance/time corrected.
Let me explain that last term. Lets say you have a feedrate of 4000mm/min. Thats 66.6mm/sec.
My laser shoots 5000hz, so 5000 times a second it can shoot. SO if Im moving at 66mm/sec, thats
5000 shots over 66mm at top speed or about 75 shots per mm. My system has 250 steps/mm so thats
75 shots over 250 motor steps.. so I only get about 30% of each fullpower shot over any 1 step
of the motor.
But what if Im still accelerating ? I may be moving much slower than 66mm/sec as I speed up, so the
CNC mode takes account of how many steps Im currrently taking this second, compares it to the fastest
I will go as determined by the F word, and scales all outpu8t to that max. This way, you dont get more
energy per mm at acceleration or deceleration. This is very handy at smoothing out acceleration articfacts
and stopping burning in corners.
Its important to understand this as you must try to set a feedrate that isnt higher than you can go.
For example setting a feedrate of F25000 when the fastest your drawing can get to is 250 will mean you
will always have no more than 1% of your expected power.
Engrave Mode
My favorite mode. In this mode the laser will NOT shoot unless a) its moving and b) its a G1 move.
This means once you turn on the spindle, you can jog and it wont cut, run a Gcode program that uses a spindle,
and the G1's will cut, while the G0's wont. this means you dont need a bunch of M3 and M5 to slow
you down or have to edit to get that. A normal Gcode program for mill will cut on a laser fine with
no editing. Also, in this mode you can link a photo for photo engraving, the laser will then vary power in
realtime as a ratio fo Photo density.
I have found though, that I wanted the distance/time fix as mode CNC above. So today I added that to the
Engrave mode. Im testing it and all seems very good in all three modes. (Im cutting a XMas card for my wife
as a test. ( Christ Im cheap.. or perhaps I just hate shopping that much...
So I used VCarve to vector a Card graphic, posted for mill, and its cutting it fine from Bristol board.
Gotta love lasers. So this latest update makes the Laser cut fine from Milling GCode. Love it..
Anyay, just a Laser update.. Enjoy the holidays.
Art