Week 3

LASER CUTTER

KERF

Kerf is defined as the width of material that is removed by a cutting process. It was originally used to describe how much wood was removed by a saw, because the teeth on a saw are bent to the side, so that they remove more material than the width of the saw blade itself, preventing the blade from getting stuck in the wood.

When talking about CNC shape cutting with typical cutting processes, kerf is the width of material that the process removes as it cuts through the plate.

Over the years I’ve heard some people use the term when referring to the angle on the edge of the part, but that would be an incorrect use of the word. The “cut angle” on the edge of the part makes measuring the kerf width sorta tricky, but for consistency, the word “kerf” should only be used when talking about the actual cut width.

The laser cutter machine

The model of laser cutter machine we have in ours Fablab is a 100w laser 1390 from China.

To control the laser i use Rdworks V8 laser software

Laser Kerf test

To test the Kerf on my machine i made a Kerf Laser file in Rhino

Exported the file from rhino as a illustrator .ai format and opened it in Rdworks V8.

The file format that i usually use for the laser is .ai and .dxf

Here i can control the speed and power of the laser. I define where i want to cut with red color and use black color for the Scan(Raster)

Download to the machine and select the file one the laser control box

After that you push the ORIGIN button to make that you new zero position and then you can push the FRAME button to see the size of your project on the material.

Here is the Kerf cutout test

I put the to picese to gether and found out that the best fit was 3.8 mm so my laser Kerf cutout with is 0.2 mm or 0.1 mm from center line in both directions

The portable water turbine

I have a little fishing hut by a river in a rural part of south Iceland. This hut is quite primitive with no running water and almost no electricity. When I say almost, its because I have solar cells on the rooftop to engine a few lights to help over the darkest hour. As for other equipment, I have a gas stove to cook and a gas heater to keep warm and prevent the hut from molding. Some might say that this hut is to primitive to use but for me its quite the opposite. Sometimes the only therapy you need is to get away from the hectic everyday life and experience the peace and quiet, and that is what I get in my hut.

That said, of course here are some aspect of my hut that I would like to adjust. The solar cell for example does not function as it could due to scars sunlight in the winter time in Iceland. That, combined with the long dark days, makes it hard to rely on solely.

Like I said before, the hut is situated by a river. In Iceland we have a long history of harvesting rivers and streams for electricity. Iceland gets about 71% of its electricity this way and another 22% from geothermal harvesting. These facts are part of the Icelandic culture and shape the way we think about our nature. Therefore, it was a natural step to try to harvest the river by my hut to make my own electricity with some kind of a water turbine.

But I didn’t want to stop there. As much as I love my hut, I also enjoy traveling through the wilderness of Iceland, by cars, horses and on my feet. And as much as I enjoy the peace and quiet, I also know that the weather in Iceland can change rapidly and you should always have a fully charged phone or an emergency locator of any kind. This, as well as the fact that the Icelandic wilderness is full of rivers and water streams got me to the idea to find a way to make a small, portable water turbine, efficient enough to charge a phone, a radio or similar.