The Idea for the warpack was born out of nessecity while planning on participating in the Defcon 12 wardriving mini-contests, all of which were on foot. Having done some warwalking in the past with my laptop jammed in my laptop bag, or a backpack, I knew how quickly it would heat up in there. As well, with it in the case, it was impossible to watch the screen and look for the target AP's. Walking around with the laptop in Vegas heat in a black padded/insulated bag with no ventelation was not something I would have expected to help it's lifespan. And so, the idea came about to build some other sort of mount or case that would solve these problems.
Ordinarily I'd buy an Ipaq and rig it up with a high gain external and be done, but the Renderlab has no budget to speak of, and cheap was the operative word. As you will see, the end result was cheap, useful and very memorable.
Various Ideas were tossed around between RenderMan an 0ktipus (Renderlab partner in crime), such as a 'peanut vendor' type of shelf with a strap around the neck, however this idea wa not something I relished because I was sure it would become very heavy and uncomfortable. One of the contests had the possibility of walking over a mile, so comfort was a primary factor.
Another factor was pure arrogance. This thing had to earn me major geek points at the con and even if I did'nt win, I wanted to have it remembered. So I decided it should also be able to hold my AMP and a UPS for power, not that I needed them, but having them was for pure arrogance and show.
Since the Contest allowed for 2 people on a team (presumably so that equipment carrying could be spread around), a backpack design was agreed upon that had the laptop facing backwards for my partner (know from now on as 'operator') to view and direct me (hearafter known as the 'mule') where to go. This also left 4 hands free to carry a directional, GPS, notepad, anything else we would need. It also allowed for a huge amount of airflow in the Vegas heat and keep the laptop cool.
The easiest way to do this was to use an existing backpack frame. My old hiking backpack was perfect. The 'bag' came off easily since it was held in place with locking pins that were easily removed, so I was'nt destroying the pack.
Looking at the frame and discussing with Oktipus, we figured 1/2" PVC pipe was the best material to build the laptop mounting frame. It's cheap, easy to work with, and with enough fittings, not much different than playing with lego (which we both have a thing for).
20 feet of 1/2" pipe was less than $2 (CAN). The fittings were about $0.50 each, depending on the style, but average about $0.50. Total cost was'nt more than about $20 for everything.
The pins holding the top of the shoulder straps were long enough to provide a decent mounting point for the PVC by passing the pin through a "T" fitting and buiding off that. We finally sketched out the final design that had the laptop at a 90 Deg angle (as if sitting on a table), a securing pipe across the bottom of the screen, a mount below for the UPS, and the AMP strapped to the underside of the 'tray' part of the laptop area.
Construction went on for about a week in my spare time. I learned a new appreciation for tiger saws thanks to Oktipus and his funky power tool kit. Once assembled and test fitted, it was glued together and holes were drilled to connect the PVC to the backpack frame at 3 more points.
In addition, I also got an old hardhat and riveted a piece of 90 deg metal flashing on to the top and back, to give me a place to mount my magnetic mount Omnidirectional antenna. The idea being, The omni would pick up more at once and be used to get into the general area, then the directional would be used to ferret out the specific direction.
Unfortunatly the basement of the Renderlab flooded while I was in NYC for the HOPE conference and my UPS got drowned, so the UPS was out of the picture. That was fine since I decided that the AMP was un nessecary and would cause more problems because it would tighten the beamwidth on my Vagi and make it less useful in the contests as I would have to swing it around alot more and slower to find signals initially.
The final product looked truly bizzare and was a bitch to pack since the laptop 'tray' stuck up and made it hard to pack around in the truck we drove down in, but we dragged it down there successfully.
Upon arrival in Vegas, the warpack was kept under wraps until the contest (I am a showman by heart), one exception was to show my friend Thorn, one of the contest orginizers. I showed him in our hotel room and I put the laptop in place, only to hear a *CRUNCH* of the tray swinging from horizontal to vertical. The glue apparently did'nt like the heat or there was'nt enough and it let go. The laptop was fine, it was just now splayed open flat against my back. The securing pipe did it's job just fine and everything was still secure, just not as I had planned. This turned out to be a benifit because it moved most of the weight forward towards my center of gravity and made it more comfortable. I decided not to repair it and leave it as it was
The laptop was mounted, the Omni was mounted on my head, Panthera follwed and we took off for the contests. The moment we stepped into the courtyard of the hotel, everyone wanted a picture. That part of the project, was a success.
Over the contest, the pack proved to be a dream to use. For the Tag-me game, we found the AP in 10 minutes, and the pack was very useful as a mobile desk for when we had to root the contest server (that part of the contest is a whole other story). For the running man game it was great because it was self contained and allowed me to manuever through crowds easily, as well as giving the operator a nice big display to work with. The Running man was also where we found the first problem. The pack is very warm against the back and shoulders and causes the mule to sweat profusly (not fun). The hands free nature of the rig proved to be the source for cooling the mule down, I went into the hotel bar and ordered a drink, during the contest. The bartender looked and looked, trying to figure out WTF I was doing. Drink in hand, we continued the contest (though the mule started a distinct list to the right as the cooling system kicked in)
The pack really shone for the Fox&Hound contest. Having a nice big SNR graph on the laptop made direction finding very easy. We found the Fox in 36 minutes which was in a hotel room about a 1/4 mile from the hotel. We had to go into the hotel and scanned each floor. Fortunatly we did'nt have hotel security chasing us or anything. After the end of the contest is when we found another deficiency; You look absolutely rediculous wearing this thing. We took the mirror walled elevator down and I got my first look of what I looked like wearing it and I burst out laughing. The elevator stopped on the 2nd floor for a young lady. The look on her face was the definition of 'I'll take the next one'.
Overview pic of the warpack
Overview of the warpack with laptop
Overview of the warpack with laptop in the collapsed position
Front View - Collapsed poition
Front View, Upper detail
Front View, Upper detail with laptop
Front View, Lower detail with laptop
Side View - Collapsed position
Side View - Collapsed poition with laptop
Detail pic of the upper "T" fitting-to-frame mounts
Detail pic of the lower pipe-and-tiewrap-to-frame mounts
After building this, I have become very interested in the idea of
improving this design for next year. Despite the success of the pack,
there Several Observations made at DC12 that will be corrected in the Mark
II version. Some of which are:
- Lack of drink holder!
- Lack of convertability to one man operation.
- Lack of battery backup/supplemental power limiting power life to 2-3 hours (had been planned for, but not implemented)
- In-ability to close laptop increasing power drain and vulnerability of expensive screen
- Lack of Mule viewing of the screen. Total reliance on verbal instructions to Operator
- Lack of holster for antenna(s)
- Lack of dissasemblability for transport
- Needs to have an omni mounted to the pack frame, rather than the Mules' head
- Convertability from 'shelf' to 'flat'
- Weight distribution needs to move down
The major conclusion to be drawn from this is that there is something leeching into the water at the Renderlab and that 2 geeks, a tiger saw and 20 feet of PVC pipe is a dangerous thing.
I am going to continue to improve this design for next year and hopefully have the Mark II done by the new year and a Mark III for DC13's wardriving contests.
I'd like to solicit ideas, comments, improvments, anything you can come up with that would improve this design. If
you make your own rig, I'd love to have a pic. If your feeling REALLY generous, I could use some donations of equipment
for future improvments. Anything from this list would be nice :)
- Small office UPS with decent batteries (350VA range)
- Pole mount Omni antenna (5-8db gain)
- $2000 for eye mounted HUD display
- Any old PDA's
- Any Wi-Fi gear your disposing of anyways
- perl scripting assistance
All questions, comments, donations and especially links to pictures of me in the pack, should be directed to render AT renderlab DOT net