Paper vs Pen, paper wins

I wanted to use the laser cutter & my CAD knowledge to make a 3D structure so I made a pen holder out of paper. It seems simple but it was a learning experience. Trying to make a self-supporting rigid structure out of paper, without relying on folds / glue is tough.

Assembled paper pen holder
the pen holder freshly assembled!

Video of the cutting

The joints behave like hinges and I had to take care to load the paper in the right direction. The narrow hole in the top causes the pens to lean at an angle such that the pen’s center of gravity is centered with the holder, otherwise the heavy pen will cause the holder to fall over. It turns out the beam diameter of the laser cutter is a lot larger than the thickness of the paper, so you have to design the joints to an interference fit, because the cut dimension will be smaller & holes larger.

 

Cut Peices
Cut Peices
3D Model
I modeled it using CAD first
Laser Cutting the Paper
Laser Cutting the Paper
Pen Holder Flatpack
Pen Holder Flatpack – All the pieces layed out to be cut

CCCP – Custom Cork Coasters Please

More lasering fun,

After an hour or two of blatent google image lifting & very low amounts of Adobe Illustrator skill, I had 6 designs to cut into some blank cork coasters I got at the Meijer.

Laser settings:
10 mA
raster, 256×256
85% speed

Laser Etched Cork Coasters
DIY Laser cut custom cork coasters

Cork cuts super well, turning deep black similar to a pen&ink drawing. Also: when doing a raster cut, include a small square at each corner to set the bounding box, the software will avoid blank rectangles & only cut to the graphic width (which saves time).

Laser Etching a Cheapass Bamboo Cutting Board

Heh,

TJ Max / Meijer / Target are great places to get cheapish objects to cut & engrave.

 

Cutting Board
Bamboo Laser Etched Cutting Board

All Hands Active recently got a laser engraver / cutter, and I gave it a try.

This was the first attempt.

I found the bamboo cutting board cuts well, but has a wide variation in shade depending on the particular strip being etched.

 

 

My racecars – the Formula SAE days

Back in college the first team I was a part of was Formula SAE and helped build two racecars.  Since then I’ve driven a lot of fast road cars, nothing compares to the acceleration and cornering you get with a purebred racecar like we built in FSAE. After driving for 20 minutes I had bruises on my arms from cornering so hard and my legs were shaking.

It’s an annual engineering competition organized by the Society of Automotive Engineers where university students engineer, build, and test throughout the year and then compete in one of a few events held in the US or Europe.

I’ve always loved car’s and engineering and I was excited to build a car, but it’s been really crazy to realize how much joining that team shaped other major events in my life in the years that followed. I really cant stress enough the importance of college teams like FSAE for students who want to work in industry…. As an engineer for a car manufacture, I can say that pretty much every new engineering hire, especially for the more exciting positions, has experience in either FSAE or the EcoCAR Challenge.

Moving a 10um cell using lasers and a shack hartmann / deformable mirror adaptive optic system

Optical trapping is a really cool fall out of the fact that light can be used to apply forces on objects, albeit really really small forces (around 1E-12 or so Newtons to be precise!)

For really tiny things, like biological cells, this can actually be the biggest force in their little world’s, and by creating a tightly focused laser beam you can actually hold onto them and move them around.

In my masters work at the Adaptive Optics Laboratory, I built a rube-goldberg esq optical trap that used a special deformable mirror and shack hartmann beam phase measurement system to command special phase manipulations to the beam that caused the trap to move and alter it’s stiffness in interesting ways.

The video shows a 10 micron polystyrene sphere trapped in a bath of water, as the controller is fed different commands, it changes the reference positions of the phase measurement. A closed loop controller then generates commands to deform the mirror such that the measurement equal the new reference position, causing the trapped sphere to move.