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Show"N"Tell ( What you have made with your CNC machine.) / Re: My first attempts at laser engraving.
« on: May 04, 2009, 07:21:50 AM »
Hey Guys,
I am still learning about this process and don't know all (hardly any really) of the answers myself yet.
The laser I have used was bought last year from Virtual Village, one of the Chinese retailers, and came with its own constant current power source (picture attached) which just requires a standard 5 Volts regulated supply. It cost around £35 (GBP) plus the shipping cost.
The laser is used in CW mode (continious operation) and my GCode file was edited to delete all the +Z moves completely and replace the -Z moves with G4 P3 to give a dwell before moving off from each new starting position. When the G0 moves are made they are too fast for the laser to bite therefore focus was set once, at the start of the job and without any subsequent Z moves using a feedrate of F20 (mm/min) and G0 inbetween the results were as you can see in the initial photos. Increasing the feedrate thins the line width and reducing the feedrate thickens it. (I guess the whole process must be very similar to plasma cutting requiring pretty much the same disciplines).
I did modify the laser to add a focus ring (the clear acrylic part on the front) but all this does is allow me easy focusing adjustment without using any special tools.
This laser does focus well even though it has plastic optics (min. 30mm - max. the length of my workshop) and was originally purchased as an allignment tool for a larger YAG laser which I have been slowly constructing for the last 6 Months or so (not sure if I will ever get it finished though). It was just by chance that I fitted it to my CNC to see how it would cut vinyl. Now it is a whole new ball game and I have so much learning to do (all the laser engraving machines I have seen so far use fast raster scan and pulsed laser operation) CW operation and vector drawing is just like conventional engraving and well suited to relatively slow moving CNC machines such as mine.
Thanks Guys for the interest - I will post more info and pics as things develop.
Tweakie.
I am still learning about this process and don't know all (hardly any really) of the answers myself yet.
The laser I have used was bought last year from Virtual Village, one of the Chinese retailers, and came with its own constant current power source (picture attached) which just requires a standard 5 Volts regulated supply. It cost around £35 (GBP) plus the shipping cost.
The laser is used in CW mode (continious operation) and my GCode file was edited to delete all the +Z moves completely and replace the -Z moves with G4 P3 to give a dwell before moving off from each new starting position. When the G0 moves are made they are too fast for the laser to bite therefore focus was set once, at the start of the job and without any subsequent Z moves using a feedrate of F20 (mm/min) and G0 inbetween the results were as you can see in the initial photos. Increasing the feedrate thins the line width and reducing the feedrate thickens it. (I guess the whole process must be very similar to plasma cutting requiring pretty much the same disciplines).
I did modify the laser to add a focus ring (the clear acrylic part on the front) but all this does is allow me easy focusing adjustment without using any special tools.
This laser does focus well even though it has plastic optics (min. 30mm - max. the length of my workshop) and was originally purchased as an allignment tool for a larger YAG laser which I have been slowly constructing for the last 6 Months or so (not sure if I will ever get it finished though). It was just by chance that I fitted it to my CNC to see how it would cut vinyl. Now it is a whole new ball game and I have so much learning to do (all the laser engraving machines I have seen so far use fast raster scan and pulsed laser operation) CW operation and vector drawing is just like conventional engraving and well suited to relatively slow moving CNC machines such as mine.
Thanks Guys for the interest - I will post more info and pics as things develop.
Tweakie.
