Trotec Rayjet Laser Engraver Acrylic Engraving Tests

May 27, 2010 on 8:13 am | In Uncategorized | Comments Off

I recently ran some tests using the Trotec Rayjet laser engraver to see what it could actually do and how I might exploit that to it’s fullest :)

The main experiments were with white 3mm acrylic.  The Rayjet comes with a special commander interface that allows you to assign properties to colours in the drawing you want to cut/engrave.

The basic properties are as follows:

Power: 0 - 100% (how many watts will the laser use in a single pass)
Speed: 0 - 100% (how fast the laser head will move)
Cutting function: Cut or engrave.

All the tests used the engrave function.

I initially conducted the test on the right (see the image below). This test was to establish the cutting depth for each power setting. I kept the power constant at 100% and varied the speed. The notation I’m using is power/speed. The 6 tests, in order were:

Power/Speed Remaining height mm Cut mm
100/100 Inconsistent result *  
100/80 2.7mm 0.3mm cut
100/60 1.98mm 1.02mm cut
100/40 1.7mm 1.3mm cut
100/20 1.49mm 1.51mm cut
100/10 1.25mm 1.75mm cut

*I tried several times to get this consistent, without success.
I suspect either a problem with the commander software or a colour problem in my art work.

Following the the depth tests, I attempted to run tests between 100/10 and 100/1 but the commander software only produced a single power setting, that applied across each colour.

In the end, I found that the most effective technique was to use a single colour for engraving (Black RGB 0,0,0) and to vary the grey level to adjust the height. This means that you decide how deep you want the maximum engraving cut to be by adjusting the power/speed setting, and then use 256 shades of grey to produce your engraving, which actually makes a lot of sense.

The series of gradient tests on the right showed that I could use a gradient to create a particular angle, or curve, depending on the setting. I tested with power/speed settings of 100/2, 100/4, and 100/6. In the end I decided that 100/5 was the best setting that just cut all the way through the acrylic, meaning that I could vary the black (with 256 shades) to get the exact depth I wanted. In fact, I should conduct another test showing steps in 10 percent increments.

My target was to create a 22.5 (or thereabouts) degree angle, in the cut. The tests on the right in the image below shows that 67.5% for the gradient location in illustrator gave me approximately 22.5 degree chamfer.   The gradient location is effectively the position of the midpoint between the two gradient colours, at 50% it is halfway between both colours.

All in all I’m really impressed with the Rayjet, I’m going to miss it when I go back to Australia.

A little more experience with the control interface will teach me what I can and cannot do, as I’m sometimes frustrated by not knowing why certain colours dont engrave.

Test results for the engraving:

Rayjet Engraving Test Results

Oribotics at Ars Electronica 2010

May 26, 2010 on 10:51 am | In Uncategorized | Comments Off

It’s been a long time since I made any updates on this blog. I’ve got some good news. My current generation of oribots, that are very similar in folded design to Oribotics [network] are in full scale production at the Ars Electronica Futurelab. Currently I’m one of the inaugural Australia Council artists in residence at the Ars Electronica Center in Linz.

My workshop here consists of a Dimension Elite 3D printer from Stratasys, and a Trotec Rayjet Laser engraver. I’m using the 3D printer to do direct digital manufacturing of 50 Oribotic blossoms, and the RayJet to engrave and cut paper, and polyester fabric.

The newest generation of oribots have a very robust folded membrane made from polyester fabric. It’s really very flexible, the fold patterns are forming well, and during actuation the fold is clearly defined, not corrupting, and if  someone touches the membrane it wont be damaged, as was the case with the [network] generation of bots.

The video shows a really quick test of the ultrasonic sensor in action. I prototype with arduino, but the actual PCBs are designed by Ray Gardiner, and are currently in production.

Oribotics [AEC] interaction design

May 26, 2010 on 10:44 am | In Oribotics | Comments Off

The following two diagrams explain the interaction concept that I am developing for the installation at the Ars Electronica Festival. The basic concept is “as above so below“, micro interactions with an individual flower have ripple effects out to the macro of the installation.

Intuitive interaction

Through observation over years, the most common interaction gesture, in both children and adults, is to move a hand in front of the oribots “mouth”.

Micro Interaction

Hand push opens the flower
Hand pull closes the flower
(or vice versa)

 Oribotics 2010 interaction concept

Macro effect

Interacting with one oribot affects every other bot on the network – they are interconnected.


Interconnectivity, micro and macro interactions.
Each oribot is interconnected to the entire network of oribots. Interacting with one flower causes the entire bloom of oribots to actuate.  In one flower each of the 1050 folds are actuated by the push pull action of the servo. In a whole network of oribots, one interaction will actuate tens of thousands of folds. This will create a complex moving image. Combined with the RGB lighting in each bot, the installation will be visually arresting. In a simple mathematical sense, a single (micro) interactions, causes tens of thousands (macro) effects.


 Oribotics 2010 interaction concept




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