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Last weekend we drove up to visit the ice runway at Alton Bay Seaport, B18. Lake Winnipesaukee is a seaplane base most of the year, but in the winter it freezes and the townspeople plow out a 3000′ runway on it. It was wicked cold, but saw some cute planes and helos. Landing on ice is apparently no harder than a grass landing, assuming the crosswind isn’t insane. If you’re landing properly, there shouldn’t be a side load on the gear. Just remember you can’t slam on the brakes

Thought one: Several years ago, Mike P and I built our hovercraft out of simple materials we had around. We powered it with a leaf blower at first, then tried to install my 22″ propeller (you can see the hole cut for it in the pics) but it couldn’t hold the pressure required. The leaf blower kinda worked, but we certainly couldn’t get both of us on it. A little math tells us that 0.3 psi in the skirt of a 3′x4′ hovercraft will hold 500lbs - about the range I want. But how do we get that volume?

Thought two: A lot of people at home build jet engines using turbochargers from cars: the primary builds 3-8psi in the combustion chamber, which rockets the gas out the exhaust turbine, spinning it faster and stuffing more in, etc etc. These guys hardly produce much forward thrust, BUT they push a very impressive volume of air of at least 1 psi.What can we do with that?

Exactly! Put them together! I’m going to build the only jet hovercraft that I know of. As long as I can get it floating nicely, I have a 24″ prop and motor I can use for forward propulsion also.

I’ve managed to summon some extra motivation and find time recently to do some things I’ve been meaning to do for a long time. For one, I got a new driver for the mill that will run the larger motors. I got it set up and everything works beautifully, I’m just waiting until I have parts that need to be made.

On a more exciting note, I’ve been doing flying lessons at Danbury Airport (DXR) with Arrow Aviation and at Vansant Airport (9N1) in PA. Here’s the nice J-3 Cub I flew at Vansant:

I was happy to find that it flies *exactly* like my own little plane (which makes sense since my plane is a J-3 replica). In any event, I’m trying hard to get my license done this month (unlikely) or next month (more likely) so as soon as it starts warming up I can go off and adventure without hindrance.

Finally, the least exciting - I’ve been coding algorithms to deduce coming events from sudden volume changes in stocks and options. As with all my previous exploits, it will make a ton of income if it works however I’m not convinced I can find the right trends. Nonetheless the risk of wasted time isn’t huge compared to the return of significant gains.

Let’s cut to the chase: I have two flying vehicles

My plane is a Fisher 202 “Koala” single-person ultralight based on a Piper Cub. It has a single-cylinder single-ignition 277cc Rotax, and it very cute.

My other flying vehicle is my hang glider, a Gemini 134:

I’ve flown the hang glider a good few times at Susquehanna Fligh Park where I took lessons and camped out for a few days. They’re in Cooperstown NY, and I’d highly recomend them.

I’ve been working on the plane with my good freind Chris David, just getting everything perfect and peachy. We cleaned out the motor and it now runs perfectly, so we’ve have it out for taxi practice. We still need to do balance checks, but should be ready for short hops down the runway soon.

For flying practice, I’ve been flying the 2-33 (a glider) with Chris. I landed Fitchburg the other weekend and it was very epic. Here we are up over Sterling, MA:

I set up a Wordpress blog for my girlfriend and I last night to track the growth of our garden (you can check it out at http://plants.crepinc.com/). I was only 10 minutes into explaining that pictures had to be resized so as not to wreck the page, then uploaded via SCP and put in the right place with the right permissions, then finally linked in the proper manner when I realized that the whole process was way more complicated than it needed to be.

I hacked up the following two php pages to solve the issue. They allow you to upload an image (no fooling with ftp or scp), have it converted, named, and moved automatically, and generate the code to paste into Wordpress.

The comments in uploader.php explain everything, but the only thing you really need to know is that you need imagemagick installed.

The code is here: http://anna.crepinc.com/wordpress-uploader.tar.gz

Happy Blaggin’

As you can see below, I spent a huge amount of time last year getting to know different virtualization setups. I got quite good at it in fact… and I came to realize that I could run a Virtual Private Machine service better and cheaper than what’s currently out there. I totally need more to do, right?

Thus, in November I started getting hardware and planning out a company. I didn’t know what it was called or quite how to go about it, but I knew that I had the technical aspects down pat. And 3 months later here we are…

This month I started Paraproc Internet Services (Paraproc). You can get all the details from the site if you’re interested, but suffice to say I provide better packages for less money than what’s currently out there in addition to some services not offered by other providers.

While we’re at it, I’m offering a 2-3 week free VPS for enthusiasts. This helps me load test the system, and in exchange you just tell me if things aren’t working. When your free period is up, you can either give up your access or become a customer. To request a free VPS, fill out this form: http://www.paraproc.com/?request

Over the past two weeks I’ve been doing some work with virtualization in the context of Virtual Private Server setups - one physical host machine houses several “nodes” that do the actual processing.There are really two types of setups in this field: shared kernel and and separate kernel.

In a strictly shared kernel setup (like FreeBSD), the root kernel simple creates a new process tree for its nodes, and marks each process with both a process id (pid) AND it’s node id. This is obviously quite efficient, however it lacks the ability to do some of the handy things a separate kernel system provides.

In a separate kernel system (like Xen on linux, or even VMware), much more ram is neccesary since separate copies of all the binaries are loaded into memory. However, that means you can have different kernel version in different setups for testing, as well as better control over “virtual” hardware presented to those node kernels (I am keanly reminded of the networking restrictions FreeBSD jails have, as shared kernel nodes).

Most real operating systems support one setup or the other, however there are a few libraries out there that run on several OSs to allow for both options. Here’s what I’ve found.

Linux - After installing the Xen package, linux supports separate kernel nodes quite well. Despite some of the inherent inefficiencies of such a system, this setup is widely used and provided by companies such as slicehost and linode.

FreeBSD - Out of the box, FreeBSD includes support for Jails. This concept was written in 1995 to basically extend the functionality of a chroot environment. However, there are quite a few shortcomings: each jail is IDENTIFIED by its IP address, rather than a jail id or something of that sort. As such, each jail can have only ONE IPv4 address, and no IPv6. Further, there is no resource control to limit a jail to memory usage, cpu usage, or disk space (see end of paragraph for hacks). Also, a jail cannot do complicated firewalling or tunnels, but that is inherent to a shared kernel system so it can’t be blamed solely on FreeBSD’s implementation. It’s a shame out of the box jails suck so much, since BSD in general is a great system. There are a few patches to provide more jail control, however none are in the current source tree.

Solaris - Supporting 5 different types of virualization, Solaris really takes the cake. Everything works perfectly to any level of configuration. That said, Solaris x86 really is a scary beast. Even if you manage to get it installed, your hardware may still crash it onces a month when it throw a particular hook. If you’re using Sparc hardware however, this is most certainly the way to do things.

In any event, I’m working on getting the patches to FreeBSD installed for jail control, as well as getting some nicer Sparc hardware to use Solaris. With luck, I’ll get good at this virtualization business and perhaps start such a service.

Recently I’ve gotten back into my routing craze… since I can’t get IPv4 space anywhere, I got two 6over4 tunnels and a /48 from Hurricane Electric. My Cisco 7500 is linked up and serves up tunnels to all of my boxes, splitting up the (enormous) address space and doing intelligent routing with BGP in places I have more than one link. It way over engineered, but at least I get to play with such things in case I ever get to work on a large system.

Also, I was bored last night and threw together JustLOLS.com - an aggregator for LOLcats and dogs. Take a look, I’d love your feedback.

I’ll cut right to the chase: I flew!

This picture doesn’t show it well due to the long grass, but I am in fact flying. (I stalled right after this picture was taken, but that’s beside the point!) This isn’t even with good wind - when the wind was favorable, I flew near half way down the hill. Despite the police, high-tension power lines inducing current in the glider frame, and fussy wind, I left the ground. Check out the glider section for video, more pics, etc.

Today I did a lot of math regarding the lift of a non-airfoil wing. From the math and review of the videos, my best bet is that we aren’t properly maintaining the right angle of attack during takeoff. The leading edges aren’t near strong enough either, but that’s something I can’t fix (if anyone knows where to get thin wall aluminium tubes I would love to purchase two…) In any case, I will be in NJ at the end of this week. I have a couple ideas as to increasing the angle of attack. I’ll be sure to post pics, and with any luck video of some flight!

This post is divided into two parts: Things I’ve done recently, and things I’ve acquired recently.

Events

Last Sunday I was up at 6am to do communications for the MS walk in Worcester. I didn’t actually need to do anything.

This Sunday I was up at 5am to get to the MIT Swapfest. Usually Ken and I come back with both more money and more devices. However, this trip was in the interest of emptying the apartment for the summer. As such, I bought nothing, came back with $310 more, and got rid of about 30 cubic feet of computers and routing equipment. I spent most of the money on a new radio, but that’s beside the point…

Monday (yesterday) I was up at 4am to do radio for the Boston Marathon. I was an operator for the medical teams. It wasn’t really the most exciting thing I’ve ever done, but it certainly got me out of the house. It was the biggest event I’ve ever done, but it was also the most organized so it wasn’t that bad.

Tuesdsay (today) I had an interview at Applied Communications in Northborough. They aren’t quite the same as many of the other companies to which I applied or from which I got offers, but it sounds like they have the opportunity for me to travel a good bit and work on some very different projects. They seem to like me a lot. If they can come through with an offer close to some of the others, I’d likely nab the job.

Additions

I’ve got a few small things recently, but the two large additions to the RF section of the apartment are as follows:

An HP 8924C service monitor. This handy device has an RF generator and analyzer, as well as a spectrum and network analyzer. In addition to the analog functions, it does all sorts of encoding models such as CDMA, GSM, EDACS, etc. The reason I could get it for $hundreds not $thousands is it’s title: Cellular Monitor. It was produced for cell phone techs to trouble shoot phones (back when this was done rather than just throwing them away). As such, hardly anyone on eBay found it, and I nabbed a sweet device. Here’s a pic of the analyzer sweeping a duplexer:

A Yaesu FT-8100R mobile radio. This is a dual band (2m/70cm) ham radio that has two features I needed: cross band repeating and wide band receive to 1.3ghz. In general I stay away from ham equipment (versus commercial) since it tends to be much lower quality (ham equipment doesn’t need to pass FCC specs - it’s up to the operator). This is in fact the case with this radio: the deviation is a little high (gets to 6khz), it’s moderatly deaf (opens at -120dBm as opposed to my Motorola’s -158 dBm) and the output frequency is a bit off (1.3khz on VHF and 700hz on UHF, compared to 200hz on my motorola). Regardless, it does several functions on different bands plus wide band receive, which isn’t something commercial equipment is made for. It has a different purpose, and if I need higher performance for a task I’ll just use a Motorola.

I got my pretty new radio a few days ago. My Motorola XTS 2500 is quite nice, I have to say. It’s the second to most epic handheld Motorola makes. In addition to the things my HT1250 does like MDC signalling and whatnot, the XTS series supports APCO Project 25. This standard, P25 for short, is a digital protocol for signalling and voice over radio. It’s mostly used in the public safety bands, since digital works better than analog covereage (in general: if the packets can be pulled out of the noise at all, the original audio is maintainted). Kurt, N1PFC came by and helped me program the radio for all my various Ham things in the area (I didn’t own a VHF handheld before so this list is pretty extensive) as well as his P25 Ham repeater not far away. Yay

In other news, I finally got around to doing my Extra class ham license. I got a new call sign while I was at it, and as such I am now NA1C.

In an effort to promote radio and space to other WPI students and staff, Theo, KC2RMJ and I (KB1OZL) put together an event with WPI Wireless to talk to the International Space Station during a particularly good pass last November. I found the pictures of the event and thought they were nice.

I put together one of our (WPIWA’s) smaller towers for the event, and kept it outside my apartment for a few days leading up to the event. Also, I built a 2 meter J Pole antenna since it had pretty good gain at the horizon to help lengthen our window. I modified it a bit from what hams generally use (I used much larger tubing), but as I expected it made the antenna much more wideband. We got about 6 dBi, at <1.5 SWR across the band. Nice!

Continue reading ‘WPI Wireless talks to ISS’

I heard back in the day of someone building a hang glider from a tarp and bamboo… While I went slightly less ghetto, this Winter break I built a hang glider with the help of several friends. The thing is quite… well… take a look at the project here.

A while ago I posted regarding the network when I moved into my apartment. This winter break we finally got around to working on things and taking it from a cluster of gross to a pretty little network of lights. Internally, we have 3 separate IP segments, bridged by our Cisco 2500 routers. Additionally, we now have VPN tunnels to a few friend’s apartments as well. Since the Department of Defence network is not routable publically anyway, we chose to implement our main backbone on the 11.0.0.0/8 network, with other segments on 172.20.10.0/24, 10.0.0.0/8 and 192.168.0.0/16. I suppose it isn’t strictly neccesary, but at least it was worth implementing since we learned a lot about routing in the process. I can actually configure Cisco devices properly now!