Anyone figured out a workaround for overcooked corners?


#1

The other day I needed to mark text on some cardboard, so I turned the text into outlines and marked it at high speed and low power.

Of course, around a corner the head slows down and so you get a darker mark. Has anyone figured out a workaround for this, without moving to a much slower engraving process? I would love to quickly mark letters with even coloration.


#2

Slow it down and lower the power accordingly is your best bet. Like 125-150 speed.


#3

And multiple passes if necessary to get it dark enough.

Here’s to hoping that GF eventually figures out braking & acceleration / dynamic power modulation for dwell time on corners.


#4

That would be great! I’d roll with a manual ramp and be happy. That should be one of the strengths of the power supply and tube type.


#5

Yeah, I would hazard an educated guess that the power supply can already do this, it’s just not fully implemented yet. This is based solely on the non-linear dynamic power settings vs full power settings.

I really would like to see auto-default speeds in the corners with the ability to manually increase the speed a certain percentage, as well as include a required user input value for the distance from the corner to increase the speed (if a non-default corner speed was specified). This of course would require them to call another variable which is the degrees of deviation from existing toolpath. eg. how sharp of a turn is it, how much to change the speed, and for how long.

That being said the Bystronic laser I ran didn’t have a set distance, but did have Corner Angle, Braking and Acceleration values (the last two could be either positive or negative).


#6

In this case it’s cardboard, so speed was already maximized. Power was about 5… Any lower and the lightest parts were too light.

I couldn’t find a combination that yielded even coloration.


#7

Oh for sure; 3D engraves are the perfect example of it currently modulating power (albeit by a different method)


#8

You want the speed slower. Not faster. That way you have less deviation between maximum and minimum speeds and therefore more even burning.


#9

Good point!


#10

As long as you are not using full power the laser is being modulated by the pulse file so it would be trivial to ramp it during acceleration to make it inversely proportional to speed.

It might need a material dependent mapping to get the corners perfect but I suspect a default mapping would be better than the current situation.

It is probably worse on GF than other lasers because it uses such low acceleration.


#11

Another thing you can do that may help is to round the corners when you turn into paths. Just a little bit of radius buys you a lot.


#12

Good call, thanks.

I look forward to the day when there is a button that makes this all magically easy!


#13

Was there a discussion somewhere about a rounded Hershey-style font?

There’s an interesting design irony here. Serifs supposedly began as a way of getting chisels in and out of letters without looking stupid, but now what we want is not just sans serif but a sort of anti-serif.