Prop: Sign “Rund” for the larp Do Androids Dream?

IMG_20170204_023729IMG_20170204_023728
For the larp Do Androids Dream we needed a lot of small props to give a Blade Runner feeling of the scene.
Small lit up signs would give that Hong Kong look that is so common in Blade Runner. Carl Nordblom, the set designer, had some ideas about how the sign should look, and had found some sample pictures.

IMG_20170204_023730IMG_20170204_023756
From the sample pictures I got an idea of how to produce a design. And from that idea I started to make a CAD-design.
The finished design ended up being almost exactly like the CAD-design.
Here is the Drawing of the Round Sign (Do Androids Dream).pdf

IMG_20170204_023731
IMG_20170204_023732IMG_20170204_023733
Small wooden block for holding a aluminium plate in a slot.

IMG_20170204_023735
IMG_20170204_023736IMG_20170204_023737IMG_20170204_023738IMG_20170204_023739IMG_20170204_023740
IMG_20170204_023742
The wooden blocks attached on to a sheet of flexible PET plastic.
The sheet is bent around the round aluminum plate with the help of the slots.

IMG_20170204_023743
The PET ring is transparent with a blue tint which would not be fitting in a light fixture. So we painted the PET ring in black to make it opaque.

IMG_20170204_023744IMG_20170204_023745IMG_20170204_023746IMG_20170204_023747
Warm white 5050 LED strip was glued on to the aluminium plate.
9×6 strips with 54 LED’s on each side makes 108 LED’s in total
108 * 20mA = 2.16A
2.16A * 12V = 26W

IMG_20170204_023749
IMG_20170204_023748IMG_20170204_023750IMG_20170204_023751
The LED strips is driven by 12V that comes in from JST-connector.
But the sign is supposed to look like an old florescent light, so to give that look the light should look like it flicker occasionally.
I hooked up an N-channel MOSFET IRLML6344 and connected it to a Arduino Nano for timing the random flickering.

IMG_20170204_023752
A big steel angle attached to the heavy aluminium plate of the sign, this is used for screwing the signs to a wall. Also the JST power connector, hidden in black heat shrink tubing.

IMG_20170204_023755
IMG_20170204_023753IMG_20170204_023754
In the outer sides of the sign round white acrylic plates will be inserted. They will rest against the wooden blocks and hold back by small sprints.
Each side of the sign is mirrored, so one sign have two faces.
The light is powerful enough to project through the white acrylic plastic. And with opaque paint on top will make a huge contrast perfect for a sign.

Prop: Dragon in Noodle Bar for the larp Do Androids Dream?

IMG_024056
For the larp Do Androids Dream we needed a lot of small props to give a Blade Runner feeling of the scene.
An iconic part of the movie is the dragon sign above the Noodle Bar. I thought i could be made out of el wire and it could, it even looked like neon. The light emitting from the el wire was really low doh, I would prefer to have stronger light.

IMG_024057
I started out by placing steel wire in the dragons shape by hand.

IMG_024058
Attaching el wire around the steel wire frame was quite easy, just a matter of placing some transparent tape around it.

IMG_024059
When trying out the outer shape I know I was on the right track, it looked great!

IMG_024060
IMG_024061IMG_024062IMG_024063
The dragons tongue is animated in the movie, it’s animated in segments. I was after the same look, so I created two segments for the tongue and had the idea the enabling each segment by turning on and off the high voltage el wire transformers.
I connected a couple of N-channel MOSFET IRLML6344 and connected it to a Arduino Nano.

IMG_024064IMG_024065IMG_024066

Interactive LED balancing board

A video posted by Tim Gremalm (@timgremalm) on


IMG_6636
IMG_6637
An interactive game were the visitors can build complex structure with help from an interactive LED balancer.
The installation was part at Vetenskapsfestivalen.

It’s a project by Stig Anton Nielsen read more about it in this post.

TeiSteadyBuilds from stig anton nielsen on Vimeo.

IMG_6645

A video posted by Tim Gremalm (@timgremalm) on

IMG_6638IMG_6643IMG_6644

The loadcells is build from 16 layers of conductive carbon packaging film. The recistance ranging from 500k to about 450 Ohm loaded at 8kg. Because it’s a so huge range the loadcells can be directly hooked up in a voltage divider, no amplifiers needed.
3 load cells us used to detect the direction and force of the balance. They are really sensitive to touch, small pressures from fingertips will be easily detected. A backside is that the film tends to be squashed so that it takes long time form the form and resistance to return.
The value from the 3 loadcells is arranged in 3 forces 120 degrees apart. The Forces is calculated into a resultant that is describing a thrust vector.
The thrust vector is indicated with a led strip of addressable WS2812 LED light. The stronger the force, more inbalanced, the greater the red marking will grow.

Att this Google Drive document I’ve collected som measuring data from the loadcells. There’s also some information of how the resultant is calculated.

DIY Moving Head Spotlight PAR RGB-LED

There’s a small festival up in Uddevalla (Sweden) called Elinorspelen. It’s a non-profit festival with the goal to have fun and spread culture. Unfortunately the festival have a very low budget and can’t afford all the equipment that it needs, and lighting has especially been down-prioritized.

Two friends of mine, and I, decided to do something about it. We got together and started discuss what kind of stage light that would be possible to buy/make.

We all agreed on that moving head spotlights would probably the cheapest alternative that gave the most visual effect.

Research

We started out to search for cheap LED-diodes to make our own spotlight.
But after a day or so we quickly found out that to just build the a LED-array would cost as much as a commercial spotlight. For example this LED PAR 56 black 151 LEDs RGB 16W for 296SEK.
We soon gave up the idea of making our own LED spotlights.

But we found out that all the cheap LED-spotlights had a very wide beam angle, and we wanted a very narrow beam.

Making an RGB spotlight on a tight budget

We got back to the idea of making an spotlight ourselves. Picking out narrow 10-13° viewing angle LED’s from Ledz.com.

As I started to pick parts to the project, the list grew longer and the price were raised by big numbers.

I managed to find really cheap geared stepper motors from eBay for a really cheap price; 28BYJ-48 DC 12V, plus controller, for around 26SEK a piece. After some research it looked like that model i widely used in different DIY- and Arduino-projects.

After a few weeks of picking components forward and back I’ve come closer to a final budget on 450SEK per spotlight, and that excluding some material prices like polycarbonate. I suspect that the final price per unit will end up on 500SEK. That’s at least 3 times cheaper than any commercial light.

You can find the budget for the spotlights here (Google Drive).

Electronics

I’ve just a basic idea of what components the electrical design needs. Some micro-controller based up on the STM32 series should work well.
Some mosfets to drive the LED’s.
The LED’s should be connected in series to 12V, and have the same pinout as the popular LED-strips that are so widely available now. This should make the testing very easy.

Designing the chassis and mechanics

The designing process were making its way alongside with the budget, a design-change could radically change the budget.

I had a pretty basic idea how I wanted the final product to look like.


A LED-array soldered on to a PCB, the PCB should be mounted directly on an axis that were attached in a U-shaped arm.
The PCB would make the LED-array really lightweight and it should not be a problem for the geared stepper motor to move it.

I also thought of having the cabling layed inside the axis, so why not make the axis into a tube instead of a solid rod?

Moving the U-arm

But how would the U-arm move? I knew that a central shaft would be the focus in this problem. It should be able to move a pretty heavy weight, PCB + Stepper motor + alot of polycarbonate.

I also think that the moving head spotlight should be able to be mounted in several ways; placed on a flat surface shouldn’t be a problem. But be able to hang upside in a ceiling, or hanging from the side of a wall, that’s tough.
The center-axis mus be able to take on forces from many directions.
One thing was for sure, we needed alot of bearings.

With the bearings a shape took form, centered around the axis.

4 bearings are used on the center axis. 2 axial bearings to make it spin easy upside down and standing. And 2 bearings up and down to make the center-axis stiff and prevent it from leaning.

And around the bearings, the framework took place.

Somewhere here the pieces started to place them selves in the big puzzle, it was much easier to design now.

Around the framework we needed a casing to hold out dirt and to keep it pretty.
It’s hard to make a nice chassis by yourself, so  I started to look around for a cheap case designed for another purpose.

I found this cheap water bawl for dogs for around 17SEK. It’s about 200mm in diameter and should house the mechanics and the framework nicely.

Designing in CAD

It’s one thing to have you design in your head and on paper, but it’s hard to grasp if it will fit or not. It’s here CAD-design comes into the picture.
I started to draw the different parts needed. As I draw the parts I could easily adjust lengths of parts to fit each other. Make puzzle-slots for the different pieces in the U-arm.

I try to make an easy design that could easily be milled out in our CNC-machine. The most parts are made so they could be cut out in X-Y-axis. I’m also trying to make as long and narrow pieces as possible, because long pieces are easier to fit narrowly on to a big polycarbonate-sheet.

The last part of the CAD-design was to put it all together, attach bearings to the shaft, build the U-arm.

The first design is now complete. We’ll have to make several adjustments to the design in iterative steps.

But for now, I’m thinking it’s starting to look good!