Hackerbot Labs enters the modern age

Hackerbot Labs enters the modern age

Hello interwebbernet, We've been so busy trying to reinvent wireless power that we didn't notice this internet thing growing in popularity. To that end, we are trying to catch up. We are on the brink of many changes here at hackerbot labs, and one of the first major changes we would like to announce is […]

Payload hull building!

Payload hull building!

JonM and I started construction on the payload hull tonight for AHAB3. We had a pretty easy job figuring out where to put everything, given that we only have one camera, a transmitter and some batteries. Then we cut some pink foam to rough size - 3 8" x 12" pieces of 2" foam and […]

High Speed Coin Shrinking

High Speed Coin Shrinking

We recently had a chance to work with the fine folks at Intellectual Ventures to quantify some of what goes on with our coin shrinker. Using a bunch of neat gear (including an extremely high speed camera), we were able to learn all sorts of things about our amazing chamber of shrink. Here is some […]

Frozen bubbles don't show birefringence. But ice sure does!

Frozen bubbles don't show birefringence. But ice sure does!

In our last post we discussed the goal and methods around capturing the birefringence found in frozen soap bubbles.   The good news is that we established a solid method for capturing birefringence, but so far have yet to see any real noticeable birefringence on soap bubbles. Along the way we did capture some amazing photos […]

A couple of months ago, we revived an old project, the Hackerboat. The original project was building a boat to circumnavigate the globe autonomously. This was, to put it mildly, rather a bigger thing than we could chew. So the revival is a bit more modest in scope -- we're building an autonomous boat capable of doing sonar surveys of dive sites in the Puget Sound. Once that's working, we'll go from there. Since Toorcamp was then a couple of months out, we made that our target. The boat was there, but not entirely functional. More on that later.

We chose solar-electric propulsion as the easiest to implement quickly. Truly long distance cruising will require something like sail or wave power, but that's immaterial to our more limited goals for operations within Puget Sound and in near coastal waters.

We bought an old kayak off Craigslist and set about modifying it. We made the following major modifications:

  • Added center, forward, and aft bulkheads
  • Added a keelson to allow us to bolt a keel and other equipment to the bottom of the boat
  • Added stringers under the deck along the rails between the forward and aft bulkheads for mounting solar panels etc
  • Built up the hatch comings to flat surfaces for simple hatches
  • Motor mount for a trolling motor
  • Geared, waterproof steering servo
  • Lead-acid batteries
  • A mounting frame for solar panels
  • A radio mast
  • Control electronics
Hackerboat under modification, showing the motor, radio mast, solar panels, and Jenny.

Hackerboat under modification, showing the motor, radio mast, solar panels, and Jenny.

The physical modifications ended up taking more time than planned, leaving the software and testing than would have been optimal. There was still significant amounts of electronics assembly, all the final integration work, and all but a tiny bit of the software to write when we left for Toorcamp with the boat in tow.

At Toorcamp, thanks to a tremendous amount of help from incidental volunteers, we were able to finish the electrical work, test the solar panels, test the low-level control electronics, test the motor, and add some status lights. We even got the radios up and working.

On Friday, we did a basic float test with an empty boat (no batteries, no solar panels). It floated well and we devised a system of ropes (thanks to Ratha and Trout) to make it easier to lift and carry the boat. There was no problem handling it in the low surf present that day. We also dropped the motor and connected the steering linkage in the waves. While not an ideal operation, we determined that this was a doable thing.

While we were able to get the low level control code up and running, we were not able to get the GPS navigation code or the shore station code running. With the end of Toorcamp fast approaching, we decided to launch anyways on Sunday and use the low level panic mode (run due east) to demonstrate the boat in action. We left off the keel, due to the difficult of beach launching with it in place. Neither of these turned out to be a great decision.

The lack of the keel is what truly doomed the attempt. We took the boat out into the surf, dropped the motor, and maneuvered it out to where Jenny was waiting for us. At that point, we had about ten minutes before the low level control system concluded that all was broken and it needed to run in to shore.

The  weight of the boat more that doubled with the addition of the solar panels and the batteries. We re-arranged the ropes so eight people could carry it, and took it down to the water. When we took it out into the water, we discovered two problems. First, the front hatch was askew. We fixed that. Second, the boat was listing to the right. We re-arranged the batteries (while chest-deep in the surf, naturally) to take care of some of the list. Not enough, as it turns out. As soon as Jenny took the boat under tow and we let it go, it rolled over. We grabbed it, turned it back over, and hauled it out onto the beach, done for the day.

Jenny preparing to take the Hackerboat under tow immediately prior to the capsize. Photo courtesy of Becki Brotman.

Jenny preparing to take the Hackerboat under tow immediately prior to the capsize. Photo courtesy of Becki Brotman.

Hackerboat on the shore after the roll-over. Note the GPS antenna on the bow. Photo courtesy of Zack Archer.

Hackerboat on the shore after the capsize. Note the GPS antenna on the bow. Photo courtesy of Zack Archer.

hackerboat-linkage

Installing the steering linkage in the surf. Photo courtesy Becki Brotman.

hackerboat-recovery

Recovering the Hackerboat post capsize

There was some water in the boat when we got it onto the beach, but not as much as I expected given that waves had broken over the askew hatch and we'd rolled it completely over. Nothing appeared to be broken, but the batteries were loose in their mounts and of course there was salt water on the outside of the electronics boxes.

Our current plan is to work to correct the mechanical, stability, and software deficiencies and get the boat back in the water at the end of August. We'll do it in far more protected waters this time.

Hello interwebbernet,

We've been so busy trying to reinvent wireless power that we didn't notice this internet thing growing in popularity. To that end, we are trying to catch up. We are on the brink of many changes here at hackerbot labs, and one of the first major changes we would like to announce is the launching of our meetup group.

  • The meetup group enables us to communicate much more clearly when we are open and operating.  We've been doing stuff, but.. umm. forgot to tell anyone else.
  • It helps us make new friends better.  We need new minds, many of us have gotten old and cranky in the 9 years we've had the space open.
  • It might help dispel some of the myths and rumors spread far and wide about hackerbot labs.
  • Some day it might help us pay the bills.
  • The other day our website went down.  For 2 months.  Nobody noticed.   Yes, we are doing it wrong.   The meetup site might have a better uptime.  :)

Regardless, please join the meetup group, and RSVP for any meetings you see posted there you'd like to join.  If they are posted there, you are welcome to show up if you RSVP.

Cheers, -3ric

PS. I hear there is an infestation of cats on the internet.  However, I was highly, highly disappointed in the selection of long-haired cats playing with van de graaff generators.  Please help.  Meow.

Everybody loves angry birds. We had a creative bird who really wanted to build nests around hackerbot labs. We found three of them in time and had them removed, but then the sneaky angry mamma bird formed a nest and eggs in our fastener container. As punishment, we've decided to pull a truman show and make these little baby angry birds famous.
Best we can tell, these eggs got laid sometime around May 26.. and we expect them to hatch sometime between now and June 9th. This totally beats the flying toast screensaver.

In our last post we discussed the goal and methods around capturing the birefringence found in frozen soap bubbles.   The good news is that we established a solid method for capturing birefringence, but so far have yet to see any real noticeable birefringence on soap bubbles.

Along the way we did capture some amazing photos of soap bubbles in several different states of frozen, and finally just shot some images of just ice crystals forming.  We have some videos of the growth of crystals which we might post later.

In order to capture images such as these, you need to polarizing sheets.   One covers your light source (flash, led, etc), the other over your camera. It is important that the polarizing sheet is the last optical element before the subject you wish to photograph.

First, more photos of "ice crystals we really wished showed birefringence ".  We have a few theories about why this doesn't work (including: thin film from glycerine causing scatter, too many layers of ice, etc).  At this point it's still unknown, any comments welcomed!  The good news is that the soap is showing it's lovely colors!

Well, that sure was neat, but we didn't really get the birefringence in water crystals we wanted. So it was time to just try old fashioned ice crystals and liquid nitrogen. The results where spectacular:

Here's where it got interesting. By rotating the polarizing film different parts of the crystals would show birefringence based on the changing angles interacting with each other.



Transparent solids can show birefringence when they are under mechanical stress. This stress can be present in a part after it's manufactured (in the case of plastic) or present due to thermal expansion. You can view these birefringence patterns if you view it between two crossed polarizers.

These patterns can also be found in ice. I decided, on a whim, that would attempt to photograph birefringent (cross polarized) crystals in frozen soap bubbles. This is what is hopefully going to be short set of posts with attempts to do so.

For starters, making frozen bubbles has it's own challenges. When air cools, it compresses. This would likely lead to a fracture of the bubble. The first attempt to make frozen bubbles confirmed this - if you inflate a bubble using (warm) air from your lungs, it pops the moment it gets close to something cold. In this case, we tried this with a pool of liquid nitrogen - -  it fractured well before hitting the liquid. We did manage to make some 'broken half bubbles', which floated around on the gaseous nitrogen. I don't have any photos of this, but let's just say it didn't work so well. After some trials and tribulations we developed the following method to make frozen bubbles:

  • Take a short (12") copper pipe
  • dip one end into a "bubble solution", adding additional glycerin may help.
  • Make sure that there is bubble solution coating the outside of the pipe; a thin film will work fine.
  • Submerge the other end into a cup of liquid nitrogen.
  • The warm copper will cause a phase change in the nitrogen, which will inflate the bubble with chilled nitrogen.
  • Before it pops, gently shake the pipe such that bubble 'slides' down to the pipe.
  • Take the pipe and hold it carefully over a pool of liquid nitrogen. There will be a thermal gradient there which enables the bottom of the bubble to freeze.
  • With some luck and skill, you can "thaw" and "refreeze" your bubble many times before it bursts.

Here are some photos of our first round of testing.  At the time we didn't have a good setup for capturing the birefringence in the crystals then we ran out of liquid nitrogen!. We will have to try again. On the next post I'll provide more information about how to capture birefringence using a camera.

A nitrogen filled bubble:

Frozen bubbles!

A shot of an old fashioned ice-cube under cross polarization (you can see birefringence!!):

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