That is fantastic, Art!!

What is the visible red dot? Did you also build the hardware??  

Dan

All G1's.. I turned off rapids for that test

Art

An echo from the past. 

https://www.flickr.com/photos/tweakie-cnc/27822699768/in/dateposted/

This demo was made in the early days, before the M62/M63 commands were included within Mach4. The laser was switched using the A axis direction pin and machine control was by the LPT parallel port using Darwin.

Tweakie.

Hi Spandex,

Depth control is a weak point.
Comparative depth and repeatability is generally good but trial & error is usually used to arrive at the correct initial settings.

Tweakie.

Still thinking about depth quality. Do you think a laser that's reasonably priced would have a depth of cut accuracy to be able to take off a layer of paint? So I'd I have a few coats of primer and then a few layers of top coat, would it be reasonable to expect to go through the top coats and say half way through the primer?

I am sure it is possible but it is not something I have ever tried.
I suspect that the final result would be far from satisfactory as there is bound to be some scorching / charring of the edges of the topcoat and the entire surface (and quite possibly the entire thickness) of the undercoat.
Perhaps a subject for experimentation ?

Tweakie.

I am sure it is possible but it is not something I have ever tried.
I suspect that the final result would be far from satisfactory as there is bound to be some scorching / charring of the edges of the topcoat and the entire surface (and quite possibly the entire thickness) of the undercoat.
Perhaps a subject for experimentation ?

Tweakie.

Spent a few hours researching this, couldn't find an answer thus far so perhaps experimentation might be the order of the day.

What's your take on Fiber lasers? I'm only starting looking into them, but they appear to be superior to CO2 lasers at least for thin materials. Although they appear to be a fair bit more powerful than CO2 lasers which doesn't bode well for simple engraving work. The main thing that interests me with fiber lasers is the fact that you don't need to spend a long period of time setting up all the mirrors (and are therefore also more reliable in exploitation) and they appear to last longer as well, so these seem to be a much cheaper alternative all around.

Fiber lasers open up a whole new chapter, their different wavelength enables metals engraving and many other things that can’t be done at the CO2 wavelength. However, CO2 lasers can do many things that Fiber lasers can’t so best to decide on the final product required before choosing the laser type – or perhaps have both types, after all it’s only money 

Tweakie.

Hi Tweakie, do you have any info in relation to laser wavelength selection?

It's such a broad subject and documents I have seen only cover limited aspects of photon properties at various wavelengths so best to Google the subject and see what you find. The various laser manufacturers websites will often detail what their machines are capable of so that should be a start.

Tweakie.

I think I found the answer, looks like it's as simple as, the optimal wavelength is the wavelength that is absorbed by the material.