Here's the list. Guess what i'm making.
3x 625g tins of rice pudding
2x small tins sweetcorn
2x value treacle sponges (in tins)
2x tins chopped tomatoes
1x can value grapfruit segments
(pic to follow)
No, its not a weird dessert for 15 people. It's my (Elliot's really, he'll be paying for it in the long run) jet engine.
Basically, sheet metal is a bitch to buy and form into tubes considering the closest I have to a (arc) welding kit is rusted solid and erratic enough to either not melt the stick or to melt through 3mm of metal at first contact, leaving a decent sized hole complete with flying chunks of molten metal. Welding anything as thin as the 1mm sheet steel I'd be using would be like trying to cut paper neatly with a schitzophrenic chainsaw.
My solution is to rivet and crimp and hose/jubilee clip (you know, the metal version of cable ties you do up with a screwdriver) the preformed cylinders into something vaguely resembling the pulse jet design I mentioned earlier. Like this. (pic to follow) The choice of cans was based on size and whether they would stack properly. And on whether I'd actually eat the contents; so much for my diet. i'll get some eating in and hopefully you'll see something kinda like a jet engine by this time on tuesday next week.
Beyond the problem of materials is getting a vapourised/nebulised/gaseous propellant into the engine. I'm either going to use BBQ/camping bottled gas as it comes with loads of safety features already fitted, or R/C car petrol which is badassly flammable and easily dispersed using a spraypaint gun. The ignition is one of those long kitchen lighters which will simply be wedged into the chamber, or a spark plug, whichever is cheaper/easier.
My lunch is over now, so anyone whose lunch isn't over (or is really bloody bored) go look up how to X-ref in autocad LT 2007 without it f***ing the f***ing hell up. And then tell me! Or just provide me with a bucket of patience and one of those stress relief squidgy shapes.
Peas out!
24/08/2008
19/08/2008
Eastbourne and weather
I'm sitting here waiting for an A1 document to print, so I shall comment on the dark clouds rolling in across the sky for yet another day. THIS WEATHER SUCKS! Partly cos it's rubbishy weather, mostly because I can't really get much practice in for Eastbourne. The Major race in the UK; the IGSA World Cup at Beachy Head. The local council are well up for this as oyu can read on the site; they've resurfaced the hill with race grade tarmac, and are provding floodlighting for night-time riding.
As I'm competing I feel it'd be a good idea to get some practice in, but I dont really want to have to do it in the pissing rain. I even have my full leathers required for safety; average speed is 30 miles per hour, max is 50mph if you're clever. I've hit the 30mph average (on St Johns hill for those of you that know Sevenoaks) but thats only over 0.8km, and it has no techical corners. The technical aspect of cornering is where I'll most likely fall down (not literally I hope!); there's no substitute for practice, but there's no substitute for good weather either. I need to build up my strength aswell: the leathers and full face helmet are heavy and provide a significant resistance to normallly easy and comfortable movements. The tuck position is also a little uncomfortable aswell, so i need to be able to hold that for about 2 minutes 30 seconds to get to the end of the course still in the aerodynamic pose (Pics to follow).
Anyway! I'm off to print some more drawings now autoCAD has stopped failing so miserably at fast processsing.
BYE!
As I'm competing I feel it'd be a good idea to get some practice in, but I dont really want to have to do it in the pissing rain. I even have my full leathers required for safety; average speed is 30 miles per hour, max is 50mph if you're clever. I've hit the 30mph average (on St Johns hill for those of you that know Sevenoaks) but thats only over 0.8km, and it has no techical corners. The technical aspect of cornering is where I'll most likely fall down (not literally I hope!); there's no substitute for practice, but there's no substitute for good weather either. I need to build up my strength aswell: the leathers and full face helmet are heavy and provide a significant resistance to normallly easy and comfortable movements. The tuck position is also a little uncomfortable aswell, so i need to be able to hold that for about 2 minutes 30 seconds to get to the end of the course still in the aerodynamic pose (Pics to follow).
Anyway! I'm off to print some more drawings now autoCAD has stopped failing so miserably at fast processsing.
BYE!
Bets, Pickles and Meths: pulse jets
Bets
The story behind it comes from a drunken bet. Well it wasn't that drunken, but as those of you who know me well will agree, if you give me some utterly geeky or silly or engineeringy challenge I have to accept. It went something like this:Me: "stirling engine blah blah"
Elliot (a righteous longboarder and water polo-er): "Cool...blah... but JET ENGINES"
Me: "Yes, but want to build a stirling engine like so"
Elliot: "CHALLENGE: I bet you £100 that you will not build a working jet engine in 2 years from today."
Me: "... GODDAMMIT!" *shakes on the bet, agrees terms*
And so it was decided. The terms of the bet are pretty simple. I must make, not just purely from a kit, a working jet engine that generates thrust. The bet is off if I build a steam powered longboard. Which is kinda fair, cos either would be totally awesome.
Pickles and Meths
The most basic form of jet is the "pulse jet" as used on the doodlebug bombs during WW2. Valveless are the simplest to make, but harder to make work as efficiently as valves. The simplest one however is like so. I however used a large pickle jar (not the picture, thats just to show you what the concept looks like), and a very crude hexagonal hole I got by jamming a whole screwdriver through the lid then twisting the handle around. Using methylated spirits I managed to get one good 3 second jet, with roughly 5" of jet out the top of the jar. I didn't measure the experiment in any way really, but as a proof of concept it works. I also produced a 2 foot high jet of flame at one point. That was interesting.
The idea here explained on the website but as a quick summary:
Jet works by causing an explosion i.e. a wave that goes out in all directions. Directing the forward chunk of the blast backwards increases forwards thrust. making this redirected blast take a much longer/shorter route compared to the backwards blast means that when the first blast in over air will rush back into the blast chamber faster from one of the jet nozzles, making the other jet much more efficient at providing thrust.
This example is one I chose because thats what I basically did with a coke can and a baked bean tin; the coke can had the ringpull end opened fully to the can walls, the sides crushed so the cross-section of the can was square at the ringpull end to allow air in, and a hole in the bottom, which was going to be the jet nozzle. I then flipped the can uside down, nozzle aimed at the sky, poured meths into the bean tin, and wedged the coke can into the bean tin. Together they formed the chamber, the nozzle was simply the hole in the can, and the gaps between tin and can walls were the gaps around the chamber.
Shaking up and lighting it worked. Not as well as the jar, but it worked for a few gentle revvs. I intend to build a larger, more refined version (from tin cans) powered by butane camping gas, or possibly spray-gunned meths.
Yes I did wear goggles,yes they did do nothing, but thats because nothing tried to asplode my face. Thankyou and goodnight!
Pulse Jets
The next part of the experiment was based on the Tharratt design (thanks to this site, although the pics don't work here anymore):The idea here explained on the website but as a quick summary:
Jet works by causing an explosion i.e. a wave that goes out in all directions. Directing the forward chunk of the blast backwards increases forwards thrust. making this redirected blast take a much longer/shorter route compared to the backwards blast means that when the first blast in over air will rush back into the blast chamber faster from one of the jet nozzles, making the other jet much more efficient at providing thrust.
This example is one I chose because thats what I basically did with a coke can and a baked bean tin; the coke can had the ringpull end opened fully to the can walls, the sides crushed so the cross-section of the can was square at the ringpull end to allow air in, and a hole in the bottom, which was going to be the jet nozzle. I then flipped the can uside down, nozzle aimed at the sky, poured meths into the bean tin, and wedged the coke can into the bean tin. Together they formed the chamber, the nozzle was simply the hole in the can, and the gaps between tin and can walls were the gaps around the chamber.
Shaking up and lighting it worked. Not as well as the jar, but it worked for a few gentle revvs. I intend to build a larger, more refined version (from tin cans) powered by butane camping gas, or possibly spray-gunned meths.
Yes I did wear goggles,yes they did do nothing, but thats because nothing tried to asplode my face. Thankyou and goodnight!
18/08/2008
Work, or the lack thereof
So I sit here, at my desk, killing a few minutes while we wait for architects and similar to hit us back with the info we need. Gary Gabriel Associates took me on as a summer placement 6 weeks ago now; in that time I've learned tons about drainage, levels, drawings, and masses of Autocad. No Uni course could prepare you for the CAD-tastic nature of the work; X-refs, completing whole chunks of drawing with just the keyboard, layer control and management, not using layer 0... The list goes on, so I will not bore you further. Suffice to say that AutoCAD is paramount.
My specific role is currently Quality Assesment boy; The next audit is today so I have been attacking the filing cabinets like a viking on acid. Ive removed over 3 full binbags of now archived A1 sheets, sorted through hundreds of job folders, and refiled them. Fun. But necessary, so i'm really not bothered doing it.
The rest of the time I'm designing and checking drainage schemes for new designs, and drawing it up on autocad. There's a lot of man-hours put into getting your rain and poo to their specific endpoints; gradients have to be met, ground conditions, existing sewers, existing services, permissions for putting more sewage into the existing system, CCTV surveys. Its design and its interesting. Each project is a different set of parameters. Every one is a desgn nightmare...I mean challenge: I'm enjoying the work.
Its probably time to stop slacking and go find somethign to do...
Keep it surreal!
My specific role is currently Quality Assesment boy; The next audit is today so I have been attacking the filing cabinets like a viking on acid. Ive removed over 3 full binbags of now archived A1 sheets, sorted through hundreds of job folders, and refiled them. Fun. But necessary, so i'm really not bothered doing it.
The rest of the time I'm designing and checking drainage schemes for new designs, and drawing it up on autocad. There's a lot of man-hours put into getting your rain and poo to their specific endpoints; gradients have to be met, ground conditions, existing sewers, existing services, permissions for putting more sewage into the existing system, CCTV surveys. Its design and its interesting. Each project is a different set of parameters. Every one is a desgn nightmare...I mean challenge: I'm enjoying the work.
Its probably time to stop slacking and go find somethign to do...
Keep it surreal!
A brief history of XSS etc part 2
The lush summer session happened in the Hope valley and the surrounding countryside deep in the rainiest backroads of the Peak District. Si, Kim and I arrive and get ferried straight to one badass slide hill, where we proceed to chill with 20 odd other sliders, and throw the first of some wicked sick tricks. Back to the bunkhouse, shotgun our beds, Lush do dinner (pasta I think) and the local garage does cider.
Sharing cider has never been so fun; the invention that was produced out of the necessity to share cider between 50 longboarders on opposite sides of the large room, and the desire to not waste a drop allowed the almalgamation of sports drink technology with the finest 2 litre Wrongbow(Trampagne, strongbow, call it what you will). SPORTS CIDER (brand name sportsbow) is a 2 litre bottle of the apple-based drink with a sports cap on it. This was amazing, we spilt none, and it was thrown merrily around the room with no fear of spillage. Try it, you might just get drunk!
So the first full day of riding dawned; 9am we shook off the slight hangovers and looked out on inclement weather. Kitting out with pads, gloves, and at least 2 boards per person we ventured into the unknown. Stuff happened in thins kind of order:
Skate, rain, skate, lunch, skate, skate, skate, drink, food, drink, drink, sleep.
Sunday morning welcomed us with pouring rain. Pouring pouring rain. So we did these:
Skating skating skating, complaining about the weather, skating. Then lunch! The end of the day for me as i got 3 fingers shut in the van door. Fun!
Even with dented nails throbbing regularly, it was an aweosme experience that brought the three of us riders closer, and made us all better; gave us a bigger picture and skills to aspire to. The details are hazy, but this was over a year ago now so all thats left is the sense of euphoria, the feeling of Longboard brotherhood, and good memories. including sledging down the face of an earth embankment dam covered in sheep poo. Good times! Respect to Lush and everyone that was there!
Sharing cider has never been so fun; the invention that was produced out of the necessity to share cider between 50 longboarders on opposite sides of the large room, and the desire to not waste a drop allowed the almalgamation of sports drink technology with the finest 2 litre Wrongbow(Trampagne, strongbow, call it what you will). SPORTS CIDER (brand name sportsbow) is a 2 litre bottle of the apple-based drink with a sports cap on it. This was amazing, we spilt none, and it was thrown merrily around the room with no fear of spillage. Try it, you might just get drunk!
So the first full day of riding dawned; 9am we shook off the slight hangovers and looked out on inclement weather. Kitting out with pads, gloves, and at least 2 boards per person we ventured into the unknown. Stuff happened in thins kind of order:
Skate, rain, skate, lunch, skate, skate, skate, drink, food, drink, drink, sleep.
Sunday morning welcomed us with pouring rain. Pouring pouring rain. So we did these:
Skating skating skating, complaining about the weather, skating. Then lunch! The end of the day for me as i got 3 fingers shut in the van door. Fun!
Even with dented nails throbbing regularly, it was an aweosme experience that brought the three of us riders closer, and made us all better; gave us a bigger picture and skills to aspire to. The details are hazy, but this was over a year ago now so all thats left is the sense of euphoria, the feeling of Longboard brotherhood, and good memories. including sledging down the face of an earth embankment dam covered in sheep poo. Good times! Respect to Lush and everyone that was there!
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