Hi Kevin,
Yes, I plan to use laser engraving and cutting. There is a local
community maker workshop that charges $2 per minute of cutting time for
using their machine with exactly the setup you describe - I choose line
colours in my PDF depending on whether I will want the areas or line
rastered, etched or cut, and then I configure the laser to fire at
different powers for each colour. I've taken to writing my programs in
Javascript - there's are code libraries for Javascript that allow
drawing directly into PDF files.
I think I own some of your work - aren't you the KWK who produced Fred
Sawyer's Universal Nomographic Sundial handed out at a recent NASS
conference? The details in that piece are much finer than I have been
able to achieve on the machine at the workshop. They have a measuring
device that hangs loosely from the head of the machine. The train us to
raise or lower the bed until the measuring device only just touches the
work piece. To my mind that should bring the cone of laser light to a
perfect point and allow very fine lines - but in practice I've never got
a line to come out narrower than, I guess, about .5mm even at the lowest
power setting of the machine. I have the line widths set to .1 mm in my
PDFs.
I'm starting to suspect that the people who run the facility I use
aren't very good at calibrating the machine. The guy in charge seems to
think that it's working a well as can be expected but your work is much,
much finer. The machine is one of these: http://fslaser.com/Product/Pro3624
I'd welcome your thoughts and advice about this.
Cheers,
Steve
On 2017-02-26 5:39 AM, Kevin Karney wrote:
Dear Steve
I do not know how you are planning to cut and fabricate your plastic
sheeting. But if you have not looked, there are many many bi-colour
double layered UV resistant acrylics used by the sign-writing
industry. See, for example,
https://www.engraving-supplies.co.uk/laser-materials/trolase.html. The
advantage of these materials (or single colour acrylics) is that they
can be either cut and engraved with great precision and minimal cost
by laser-cutting. All you need is a good .pdf graphic made to
appropriate specs for your laser-cutter. Typically, text - which is
raster-engraved - will be one colour. While vector lines and curves
will be lines of a certain thickness and of different colours (one
colour for a cut, others for different depths of engraving).
One of the great advantages of the laser cut approach is that you can
try endless designs cut/engraved on cardboard - costing virtually
nothing, before committing to your more expensive final material.
Laser cutting is cheap these days and if you live anywhere near a big
city, you may find that there is a 'FabLab', where you can go and do
it yourself - see www.fablabs.io/labs/map <http://www.fablabs.io/labs/map>
Having started designing sundials by laser-cutting in Cardiff
University's FabLab - I am now actually employed there part-time to
teach others in laser-cutting. So I am happy to elucidate further if
anyone is interested.
cheers
Kevin
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