TwitterGalaxy – DIY Google Liquid Galaxy from Recycled Monitors with integrated Twitter Feed

I have been working in the R&D department for the last couple of weeks. One of the projects they were working on was a Google Liquid Galaxy setup. I asked if I could help out with my engineering skills. This is what I got up to…

First off, What is Google Liquid Galaxy? Well Liquid Galaxy is basically Google Earth on a massive screen! It enables you to sync Google Earth across multiple computers, so as you navigate around on the master computer it updates the slave computers.

What equipment do we have? Well we had 32 19″ screens, picked up when clearing out the old Wapping site, which I removed all the stands from. Eight quad core computers each with two quad core dual output graphics cards, also scavenged from the old site.

Prototype setup, the first lot of monitors to be disasembled

The old stands ready for the bin

The monitors stack much easyer with the stands removed

So the first thing I was brought in to do was to build the frames to hold the screens. After a bit of designing and scribbling, I came up with a kick ass design.

It’s quite a neat design if I do say so myself. There are four bases that hold eight monitors in two stacks of four. The bases are also storage cabinets for when the display is not use. The cabinet also holds the two computers and all the required cabling. The frame that holds the monitors is made of 1″ x 1″ steel box section. The frame slots together the cabinet/base with two options for having the monitors straight or at a slight curve.

This was a bit too much too soon, so a scaled it down to basically a wooden Christmas tree…

Each stand can hold eight monitors in stacks of four. There is wooden base plate that uses the computers as a counter weight to the monitors.

This was a much quicker and cheaper design to make for the proof of concept. This is how I built it.

After working out roughly how much wood I would need I headed out to the shops for some woody goodness. In the garage a made up a cut list of all the pieces I needed.

The wood fresh from the shop ready to build the stands for the Google Liquid Galaxy screens

My cut list for the Google Liquid Galaxy stands

Time to cut up the wood from the list. To make the job easy I have “invested” in a new toy for the garage. It’s a bench circular slide saw that can cut box steel as well as wood with the same blade. It has compound cut settings so you can do a 45 degree on a 45 degree cut:

My new toy

I cut up all of the cross beams that would hold the monitors, four per tree. I used the bench saw to cut do the mortice joint down to the right depth. Using a good old hammer and chisel I knocked out the unwanted wood, to make a nice smooth joint:

Cut ready for knocking out the unwanted wood

Using a chisel to knock out the wood to make a nice joint

I cut out a base for each tree out of 1\4″ Ply Wood. I then made up some 45 degree side supports and a larger one for the rear support so that the screws in all the supports would not clash. I used some right-angle squares I use for welding to align the supports for drilling.

Getting a nice collection of cut bits going

Using a right-angel to align the wood perfectly

Then I drilled the base on to the truck (loving the tree comparison for explain this). I then used a large spirit level clamped to the truck to align it and drilled the supports in to the base and the first tree is done:

Aligning the stand for the Liquid Galaxy Monitor Array

Making sure it's all correct in both plans for the monitor array

This is how the legs look attached to the base

The first Google Liquid Galaxy Monitor Array Stand is complete

The first fail came when I tried to put the trees in my Volvo Estate whole… It was late I don’t know what I was thinking either. Not only were they about 2″ too long the base was too high when laid on it’s side. Back in to the garage to disassemble the stands, and try again. The next day I drove in to work and took them up to the lab for assembly.

I had purposely not drilled the holes for the the monitors in to the arms, as they say measure twice cut once! and as I had done most of the measuring of the monitors by eye and then used the monitor specs I had found online I wanted to make sure when all was well with a dry assembly:

All the parts at the lab ready for asemberly

Checking for alignment before drilling

All is good, time to drill, I marked out the vertical center of the branches, and then measured half a monitors width from the centre of the truck. I did this on all of the branches on both sides. I worked out what the hypotenuses should be between to diagonally opposing bolt hols and checked for alignment before I drilled, they were accurate to +/- a couple of mills.

With the drill holes made, and the stand fully assembled, I started to lead it up. First came the computers that sit on the base to act as a counter weight to the monitors. After setting up a stand I found out that one computer is enough to hold the stand up, so it makes swapping then around easier, you don’t have to worry about the stand catapulting a computer a cross the room if you try and lift one off:

Computers on stands to weight them down

Next came hanging the monitors. Each monitor has a backing plate that used to hold it to the stand they came with, this has been very handy. So I simply pushed a bolt though the centre hole before I screwed the plate to the back of the monitor. Then pushed the bolt thought the stand and tightened up the nut. Luckily the clamping pressure was enough to stop the bolt from spinning, and I could tighten up the screens nice and tight. I did add a washer between the nut and the frame to stop it from ripping in to the soft pine wood. Here we go:

One monitro and all is well

Four monitors

Five monitors

Six monitors for the google lequid galaxy

Seven monitors and stand is still holding out

Eight and the first stand is compleat

Now I have the first stand complete, I noticed some small issues that will need addressing in the 1.2 update. First off, the support struts are working well at supporting the main trunk in terms of keeping it upright, but now the main trunk is loaded up with monitors I’m noticing a lot of torsion twist in the wood. As the monitors and hanging either side of the truck if there get knocked they are causing the truck to rotate back and forth. Below is an image to try and demonstrate what I’m badly describing. To solve this I will add a large rear support from the base to as far up as I can reach with a stock length piece of timber, which is 2.1 meters.

Torsion twist on the truck makes the monitors wobble back and forth

Also another twist issue with the branches. There is no problem with the top monitor but as each monitor adds a little bit of weight to the new one and so on down to the bottom, the combined weight is making the branch of the bottom monitor twist, so the top of the monitor hangs forward of the monitor above. This is a reason not to use wood, although it is cheaper and easier to work with then metal it does twist and flex, useful in some project but not in this one. So to fix this I’m going to make some wedges to to the trunk behind each monitor to hold it forward.

Torsion Twist on the branches from the additive wait of all the monitors

Before spacer is put in to stop the monitor droop

Monitor with spacer in place push the bottom of the screen forward

Neither of these are big problems but definitely something to fix. I set up another stand, and wired it all up. In fact we brought all of the power strips in a 1 mile radius of Wapping. This is what it looks like, it’s not pretty, but there is not a lot I can do about it, unless I make custom sized wires and fix them to the frame, not something we have time or budget to do. Here is what 16, 19″ screens look like running Google Earth.

Google Liquid Galaxy on 16 Monitors

Google Earth on a massive monitor array

Whats next?

I need to make up the 1.2 update fixes for the stands and bring them in. Get the other two stands made and link them all together.

I’m planning two more posts, one to cover the software side of things that has been expertly done by David Somers (@jalada). The second will cover the Twitter integration I have been working. At the moment it pulls in the location and latest tweet of all the Times foreign correspondents, and converts it in to a Google Earth Tour to play on the massive monitor array…

Got a question or want to know more details, just ask in the comments below.

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