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I haven't even got to the complicated bit yet, but yes I agree this is not for everybody although there has got to be some other wacko's, like me, out there somewhere.



Tweakie.

Great build so far Tweakie!
I have a question about the un-focused beam length. After the first mirror running down the Y axis before hitting the second mirror. Does the length of that run have any effect on the power of the beam. Lets say you are etching a 4 foot board would the end closest to the tube have a darker burn because the beam is closer then when its at the far end of the run?
What kind of power can you get with this size tube? What can you cut with it in comparison to say a diode laser.
BTW that tube looks super scifi cool!
Keep up the good work

Hi Mark,

Yes indeed sir, the total distance the beam has to travel does affect the power.

In practical terms a variation in distance of 4’ or so will not produce any noticeable variation in power but if this distance is increased to say 8’ then it may start to show. For this reason the larger commercial machines (bed size 8’ x 4’) actually mount the laser tube ontop of the gantry so it travels with the Y axis then the beam distance variation is back to within the 4’ or so.

I have no way of actually measuring my laser power at it’s smallest focussed point but, just as a guess, I would suspect it to be approaching a kilowatt.

Things you can cut with a laser will depend on the laser beam’s wavelength.

Just as an example the beam from a ‘visible beam’ laser will travel straight through clear Perspex, glass etc. whereas an Infrared laser (not visible) of the same wattage will cut into Perspex and etch the surface of glass.

The cool looking tube was manufactured in the USA. Unfortunately, when it eventually reached the end of it’s useful life, it could not be replaced with like so I had to turn to a China manufactured tube instead – still looks cool though.


Tweakie.

Thanks for the information Tweakie, I have always wandered about the losing of power over distance on these tube lasers.
So with your set up now, everything is in place that if you want to you could buy a larger tube and have a more powerful laser, say 40 kw 40 watts for cutting though ply, etc..?
BTW I like the square tubing that you put around the beam on the new set of pics you added great idea.
Thanks again

I have never actually seen a 40kW laser but I don’t think it would even go in through the door of my workshop. Perhaps best if I keep to 40Watts.

Tweakie.

Whoops 40 kw 40 watts

Thanks Michael,
Very valid points that you have mentioned, I think most of them will be covered as the build progresses but I just haven't had time to write it all up yet. Stay tuned folks

Tweakie.

Wait a minute I thought the test cut for Mach was the RoadRunner not Wile E
Cool video Tweakie

Tweakie.

Chicken's egg shells

Tweakie.

Nice job Tweakie!

Thanks Mark.

Tweakie.

Perhaps one of the greatest advantage in adding a CO2 laser is it’s ability to cut acrylic.


Acrylic is one of those materials which will easily sublimate (change state from a solid to a gas without going through the liquid stage) and as a bonus, it also has the property to act as a waveguide at the 10.6 um wavelength of the laser beam. This enables acrylic up to 10mm thick to be cut with reasonably straight sides and have near perfectly polished edges which require no additional finishing.


This Open Builds Logo keyfob took just 45 seconds to cut from 6mm Plexiglas and was made, just as an example, to illustrate laser cut acrylic.


Tweakie.

Here is a link to the Lasersaur project by Nortd Labs. I think these are the guys that started the original DIY CO2 http://www.lasersaur.com/
Also here is a link to the manual
http://www.lasersaur.com/manual/

Laser beams do not actually contain any heat, they are just a coherent stream of photons. It is the reaction of the molecules in the material laser beams come into contact with that generates the heat.

Tweakie.

These little bikes were laser cut some time ago and they are perhaps a good example of the edge finish that can be expected when working with acrylic. Unfortunately not all plastics behave the same way - with Polycarbonate, for example, it is doable but the edge finish is extremely poor in comparison.


Exactly what a laser can and cannot do is to a large extent determined by its operating wavelength – for example my 40 Watt CO2 laser (operating a 10.6 um) will find almost all metals to be excellent reflectors, the laser beam just bounces off leaving the surface totally untouched. With different types of laser (YAG / Fibre etc.) operating at far shorter wavelengths the situation is entirely different and almost all metals are easily etched. So it is basically ‘horses for courses’ and a bit of trial and error soon reveals the strong and the weak points of any particular type of laser.


Tweakie.

Nicely said, an I would add that this holds true for most if not all machines.

Hi Manuel,

Welcome to the forum, its very nice to see another CO2 laser user here.

Tweakie.

@Manuel García this would make a great addition to the software resources.
http://www.openbuilds.com/resources/categories/software.2/