This bendable metal piece was created using a 2D drawing. The technique used is called kerfing, refer to Aaron Porterfield's study of different kerfing patterns. https://www.instructables.com/id/Curved-laser-bent-wood/
In this instructable I go over how I prepared the laser cut file inside rhino and precisely measured and inserted gaps that would guide me to free hand bend the flat metal piece into the desired curve.
P.S special thanks to the Portland State Mechanical and Engineering Lab Team (MELT) for allowing me to use their laser cutters and providing support along the way esp. with the Kern laser cuter interface.
Step 1: Flat Laser Cut File
I generated this curve from a pavilion project I was working on and wanted to attempt making it using only the laser cutter.
I already knew how deep the "pavilion" would be but to determine the flattened length of the full curve I used the simple length tool in rhino.
-Simply type length into the command line and
-then click on the curve you want measured
- when you press enter, the length will be written at the top (command history location)
Step 2: Subcrv
In order to determine where to place the kerfing pattern and where to insert the gaps, I used the Subcrv* command to find the length of particular segments of the curve.
-type subcrv into the command line
-it will then prompt you to select the curve;
and ask if you want to copy=yes - I chose yes to keep the original curve unchanged.
once you chose yes or no, click on the curve
- selcet the start of the curve
-select the end of the curve segment you wish to know the length of
a new curve will be created and you can take its length using the length command;
it can also be re-shortened as desired.
*If anyone knows of a different command in rhino that allows you to measure segments in a more automated way, please comment below. Do you use a different program that you found has a better command?
Step 3: Final Print
This piece was printed using a kern laser cutter ; the interface and set up is different from the smaller 60W Laser cuter. From experience, it is better to have a .dwg file rather than an illustrator file when working with the interface on this machine.
It was exhilirating to see sparks come out as the machine cut into the thin layer of aluminum.
I did make another print on wood on the 60W laser cuter.
-I think inserting a gap is a great and simple way of achieving double curvature.
-kerfing metal has the advantage of staying in the shape you bend it to,
-but a kerfed wood piece may also achieve the same result if it is soaked in water then left to dry in its curved state. (I will need to do more experimenting with this). this is how I achieved the photograph of the wooden kerfed piece.
-Lastly, be very careful when measuring in rhino and keep in mind the material's thickness when making the base that will hold the object.