Power / Speed conversions

[Michael Ramsey]

As I was reading another thread a question popped into my head. Are there any power and speed conversion charts? I was reading a settings pdf for a product like cermark. Their chart had suggested settings for a 35 watt laser and a 45 watt laser. Is there any type of conversion or rule of thumb formulas to convert to a different laser wattage? Example - 45 watt laser speed 60 / power 40. What or how would that be converted to say an 80 watt tube?

[Mike Null]

In order to do a conversion, you must have the speed of the machine as well as the power. Some machines raster at 140 ips while others may be at 80 ips or even 60 ips.
Converting the settings for a Chinese machine throws a bit of a monkey wrench into the equation as they can't be operated at full power.

[Kev Williams]

Every machine, even identical machines, won't engrave things the same as the next one. The only way to know what your machine will do on Cermark is to run a power grid test, which is a matrix of several columns of power settings and several rows of speed settings. **based on my experience**, if you're using a 40w or less machine, you'll need full power always. However, while running an 80w machine (for example) at higher speeds to compensate for the power works well for some people/machines, I've found Cermark likes some heat-soak time to get the blackest mark and best adhesion. Because some higher power tubes- like my 80w RECI- can actually burn away the Cermark rather than fuse it nicely, I've found that at slow enough speeds to result in good heat soak requires less than full power to get a satisfactory mark.

but- all machines are different, and I'm sure there's likely many high power machines that can run Cermark quite a bit faster than I care to and get satisfactory results- at least in the eyes of their owners

And one last thing I've found over the years- nearly all suggested power/speed settings I've found online are completely out of the ballpark for any of my machines.

Here's a screenshot of a simple power grid anyone can use-
powergrid.jpg
and this is a Corel10 version of the grid - power grid.cdr

This is just a basic starting point, if you're using a glass laser the speeds you'll change to mm/second, and depending on laser power you may not need lower than 100%, or in the case of my Triumph, MUCH lower than 75%... anyway, set up to your preference and run one column at a time--

[Michael Ramsey]

Thanks for the info guys! That helps. So I guess one could run a power grid test on several materials to gather a baseline of starting points for the given materials as well as the desired results. Whilst I wait to purchase my laser I am trying to gather up as many useful bits of information as I can. I've already got most of my workflow figured out going from Sketchup Models, to 2d Planes, to DXF. Making any final designs in my CAD program then import to RDworks. RDworks is a bit crude to say the least. Typical Chinese / Windows 3.1 feel, awkward nomenclature etc.

[Kev Williams]

If you put into your mind that RDworks is NOT an 'editing tool' and is ONLY the necessary evil needed to run the machine and NOTHING MORE, all will be right with the world...

[Robert Bonenfant]

Like others have stated even machines from the same manufacturer are different. We have four of the same lasers and they all vary in power and speed settings (Slightly) . Most Equipment manufacturers will supply you with a basic cheat sheet on powers and speeds, These are mainly starting points and you move on from there. Camfives sheet states we should cut 1/8" plywood at 15 mm/s - We run our machines from 35 - 41 mm/s. Once you get your machine and start testing materiel you'll find sweet spots for most materiels.

[John Lifer]

Test and test some more once you get your machine. And do fergit about rdworks as anything but interface makes life much easier. I'll occasionally size and rotate but really not any more than that, and if you get good, you can import colors and not have to select those.