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Captain Courage And The Courage Cannon! No plan survives first contact with the enemy. |
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The Plan
Plans! Oh, but do I have plans. You can see the initial plans for the 2003 event below. Yes, that's right, I've got nothing to hide, just click on the link below. However, it is worth noting that there are some changes to the plans not reflected in the diagrams. I had initially planed to use bungee cords to propel myself. This plan had worked for some teams (including the winners) last year. This year they are not allowing it. Actually, they weren't last year, but it wasn't enforced. The cannon is now powered by dropping half my team off the dock. Yes, powered by fat.
The Team:
[from left to right]
Brad: Primary Propellant. Brad will provide an important catalyst to
our flight in his role as Primary Potential Energy Source. He also has many
tools and, get this, knows how to use them!
Brian: Another Team Fliegen returning member. In addition to his vast
background in aviation engineering (I'm sure he's built several paper airplanes
and some of them probably flew) he provided a garage for use when we needed to
hack around with power tools. Thanks should also go out to the rest of his
family for putting up with us.
Ken: You know how in every group there's the smart one? Ken's it in this
group (sorry guys). Then again, how smart can anyone be to agree to fall off a
dock. Oh, maybe I haven't told him about that part yet...
Prashant: When I first came up with last years idea about building a
plastic airplane, he was one of the first people to jump in. Expert fabricator
Prashant was systamatic in the creation of last year's wings. And they almost
matched too!
Daryl: That's Pilot-Projectile Fox to you! Usually comes up with stupid
ideas for crazy projects... like getting hurled off a dock into the bay. As an
electrical engineer and hang glider pilot, he is uniquly unqualified to compete
in the flugtag!
Progress so far:
[UPDATE]: New building pictures below!
10 Aug, 2003: The initial plans called for a long box like structure for the cannon wrapped in PVC hoops to make it look round. After calculating what this was going to weigh, a better plan was required. A monocoque structure was proposed and it seems to fit the bill. There are going to be 8 circular forms braced with 1x2s all along the length. It's going to be lighter and look cooler. How much better can you get?
Well, it turns out that the lumber store will not sell you 25' long spars of 1x2. I mean... come on... it's only 25'. Fine, it looks like we need to use two 12' sections. Today we layed-out and cut the first form. The outer diameter is a little just under 4' (the size of the plywood) and the inner diameter is about that much less (highly scientific method of measurement). Now that we have one, we should be able to use it as a template to bang out 7 more next weekend.
On a related note, some people have accused me of only entering the Flugtag so I have an excuse to buy the power tools I want but have no really excuse to have. I'm shocked - shocked - at these baseless attacks on my character. I needed the belt sander and jigsaw (with orbital option) for my... my, well... my other project. You know the one that needs lots of... cutting and sanding. That one. Shut up.
17 Aug, 2003: Wow! This was a long day. I wanted to go flying in the
morning, so I didn't arrive until about 1pm. Then we had to go get lunch. Then
some dog shears. Then we could find some of the supplies. I don't think we
really started until about 2pm. But that's okay, all we were going to do was
make 7 more forms.
Right, so I learned, or relearned, something today. I am not a carpenter. I mean this is really hard work. The garage was sweltering hot and the tools were over heating. We started by screwing the form to a sheet of plywood and then cutting 'around' it. Since they are all made from the same template they should all be the same right? Well, some of our cuts may have had a slight impact on the template. Heisenburg once said that it is impossible to know the size/shape of a piece of wood while transferring the size/shape to another object. I'm almost certain that's what we would have said if he were building a wooden cannon.
So we now have a total of 4 forms... if you count the template. We'll finish it off next weekend then bolt them all together and sand them down until they are all identical.
21 Aug, 2003: To night I had planned to build the wings for the sled
that we were launching. I wanted them to be sort of flimsy things mostly for
show. However, when I checked the supply shed from Der Fliegen Plastik I
found that I had about 40' of left over 1.5 inch ABS. Well, I'd hate to see it
go to waste, so the wings are now going to use it. They will be a little
bulkier than I had planned, but should still be very light. I would have put
them together tonight, but Home Depot was out of .75 inch PVC. Honest. That's
like... like a lumber store without 2x4s or a cheese shop with our Cheddar
(only less funny in a Monty Python skit). Ah, I'll go get some elsewhere
tomorrow.
Something important occurred to me yesterday... I really have no clue how wide the track inside the barrel is. I carefully measured it by making it wide enough to accommodate how I imagined the sled would look. I really hope it is less than 2 feet. If not, the ramp is going to get much more expensive in terms of plywood. I'll bring my measuring tape tomorrow.
31 Aug, 2003: Wow, it finally looks like something other than a pile of
lumber! After a tasty lunch, we got down to building. Brad and Prashant
couldn't make it (something to do with wives) but we picked up Danny to help
build. Actually, I think I only told him we were going to have lunch but then
roped him into building. Sneaky bastards, all of us!
The forms were spaced out and the ribs were hammered into them. Hammer is a little bit of a misnomer in this case though. You see, we had power drills coming out our ears, but strangely not hammers. We fell back on a small 12" bit of 1x2 as a light finishing hammer and a larger 3' length of ABS pipe from Fliegen Plastik as a mallet. As you can see from the picture below, it worked quite well... In sort of a 'four cave men build an air craft' way. "Ug, Not aligned. Hit again!"
Now we are the proud creators of a 12' wooden combine. That's the best way to describe it. I can't believe how quickly this went together. Even considering our lack of tools and wood screws (thanks Ken for picking some up). Next time I want to build the other half of the barrel and lay the ramp. We are in fairly good shape.
Pictures follow.
7-14 Sept, 2003: Two, two, two updates in one! Yes that's right, I was
too busy to update the page last week. Lots got done with a minimum of planning
and documentation. Just the way I like it (but I think it's killing Ken). As a
bonus, Brad showed up to work with broken ribs. Now that's dedication! He
complained that it hurt whenever he laughed. We told many jokes. :)
The cannon barrels now have much more reinforcement and are nearly completed. The base is just getting started but should go fairly quickly. I've got the wings started and am looking at the launch sled assembly. Pictures are below (less than last time).
Early October, 2003: Wow, it's been a while. It's been quite a while
since the last update. Two more big work parties and a few small ones too. We
added two rails for the launch cart and then ripped them out and replaced them
with a single rail. We are defiantly trying to save weight now.
At this point we are effectively complete. That is, we are fully functional and everything else will be extra depending on time. I'm wondering if the auto-deploying wings will make the cut. I hope so, but I don't want to mess everything up for the sake of plastic wings.
Pictures below.
Pictures:
Click on the images to get larger versions. All pictures were taken by Ken who
has more camera stuff that you can shake a stick at and could probably take a
few good pictures of you shaking a stick at it too.
Wow, there are a lot of pictures. From now on I'll me more selective of the
ones I put up. It must suck not to have broadband! Seriously, if you scroll
down to the newer pictures you will see I have been more selective (there were
over 340 pictures total before cutting).
They say everyone is allowed one animated gif in their
life. I really don't think I'm squandering it...
7 Sept Work Party
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The ramp along the bottom
of the barrel was installed. Yup, I bought the cheap plywood for this. No one
will ever see it and it only has to work once. |
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More reinforcements were
added to strengthen the structure. Then Al, the Red Bull guy, showed up so we
took some pictures with the official event poster. As a special bonus, we
left two flats of Red Bull behind! |
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Another set of
reinforcement was added along the top. These make the whole thing much
stiffer. Then we had a mock firing. Just imagine me dressed in a shining
white jumpsuit and helmet... and auto deploying wings... and a determined
super hero/daredevil expression... and with the bay below me instead of a
parking lot... and 30 000 screaming fans. Yup, that's what I see too. :) |
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The cannon will require
some support. This will be built into the base. On the left you can get an
idea of the proportions. The first impression has been "Wow, that's
big" almost every time. On the right is most of the team. |
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Here we are, safely stashed away in the Secret
Workshop. It fits with room to spare!
14 Sept Work Party
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Here's the start of the base. It's even square (for
resonable definitions of 'square').
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Here we see Brad loading up for his role (primary
propellant) in the big event. What's that we sees? It's the air show. Cool!
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Here we are joining the two halves together. They are
held together with six 3/8" carriage bolts. This should work with support
from below.
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(Left to right)Brad drilling blindly and still
hitting a stud. Brian: "How on Earth does he do that?" Patty:
"It's just dumb luck"
Three men with power tools. Danger level: High.
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Strange, it used to fit
just fine. After turning it around a few times it just barely fits. This
could get complicated... |
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Pictures From October
Okay, here's the plan. 2 parts cannon to one part base. Let's not screw this
up.
So then we add these two great big huge (and heavy) guide rails. Sounds easy,
but some of the rails had to be gently coerced into a straight line. Luckily we
had plenty of help for this. Work goes fast when everyone has a power drill.
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Here we are building the
uprights to support the cannon. Much math was done to make these precise. If
there is any justice in the world, the cannon should just drop on op of
these... |
So, how do you get these bolts out?
With a hammer?
What a great idea!
Just fits!
The next weekend we got together to finish the cannon. Loft goal, but we almost
did it! First the crappy rope supports were torn out and replaced with steel
cable by Brad. As you can see, it's practically straight. I mean, it's really,
really close to vertical. Then the supports were beefed up with some 1x2
screwed under them. You can also see Brian pre-drilling like 50 screw holes on
each support. If an asteroid strikes the bay during the event causing a tsunami
that wipes out the entire Bay Area, you can rest assured that these supports
will still be attached to the uprights!
Here is the new rail system. One rail. Much more aerodynamic. :)
Here we go wrapping up the cannon. Prashant looks dizzy! "You're doing
great, just a few more wraps and we're done!"
Done and done! Hmmm, it looks a little more, ummm... That is, we didn't intend
for it to have such a, errrr... You see, the cannon was not intended to look
quite so much like, well... Yeah. Someone keep Brad away from the barrel.
It takes a little bit more work to assemble the two halves when they are
wrapped. Once this was done, the junction was sanded down to give a smoother
transition. Working with a belt sander in a plastic tube in the middle of the
day is not as much fun as you might imagine.
Some people might doubt the highly mathematical calculations involved in the
construction but the cannon fit perfectly the first time. The lower support
only had to have a small force applied to it the make everything line up. Next
up the hang test. Test number one - 165 lbs of pilot hanging on the end:
Passed. Test number two - Primary propellant hanging on the end: Passed.
That's it! The completed cannon. Just have to add the tow supports and finish
the cart (UPDATE: cart is finished). Team photo time!
For what it's worth, Ken sent about 650 pictures from these two events. It's
been hard to whittle it down to the small number you see here. There are
hundreds of shots that are great, but didn't make the cut. If anyone want a
picture of a particular moment, I'm sure either Ken or I have a copy of it.
Drop me some email. As a special bonus, Brad sent some pictures from the last
event. Here they are:
Another shot of the barrel. Um, yeah.
Here we all are. That's me in the cannon and below (left to right) Ken, Brad,
Prashant and Brian.
It's a little more conspicuous now. Pay no attention to the cooling towers
behind the shed!
Okay, so I promised never to make another animated
gif. Well, I lied... Sorry Patty.
