Showing posts with label Double Decker Bicycle. Show all posts
Showing posts with label Double Decker Bicycle. Show all posts

Thursday, March 14, 2013

Recumbent Madness pt. 1

Various real life things like taxes and an attempt at finding a real job prevented me from posting last week (see "Dear Readers"), and for that I apologize and have written a ludicrously long post to make up for it.

After the successful proof of concept of the top level, it was time to begin constructing the lower, recumbent level of the Pariahcycle. So, I put on some metal, 

and, having never built even a normal bicycle in my life, got to work.


I began by laying it out on the shop floor in order to get a sense of the placement and scale of the parts I would need.
The result is that the upright portion is six feet from hub to hub, and the recumbent portion is ten feet from hub to hub.

I started by cutting the crank-set off of this thing so that the two parts could be used separately.

I was also using more of the horrible plumbing parts that I appear to have an endless supply of.
The ends of the tubing were too large of a diameter to be directly welded to the rear fork.

So I fired up the scary home-made forge that was built by a couple guys named Chris and Aaron. This involved turning on the gas with that red knob in the corner, then getting around to the front as quickly as possible to light it with a propane torch.

With that done, and with considerably less arm hair than I started the day with, I began shrinking the ends of the pipes down to make a better fit.

Then I did the same with the parts that connect to the middle crank, creating a thing that looked like this,


and one that looked like this.

Because of the way that the crank had to be cut off, I was left with this enormous gap.

To remedy this, I found a piece of scrap that was kind of the right shape, but which didn't fit very well.

Fortunately, thanks to some guys called Thomas, Hrayr and Karine, I was able to sort that out with a quickness.

Next, I cut the rear fork off this black BMX,
and began constructing a new back end for it that would connect to the low-profile frame I would have to build.

This was a little complicated.
I cut two pieces of tubing and beveled and shaped the ends so that they would fit snugly against the curved surfaces of the BMX bike. Once I'd done this, I welded them into this triangular shape.

Then I had to create a V-shaped component to match the angle of the parts I had built earlier.
In order to do this, I had to take two pieces of tubing and merge them to the diameter of one piece of tubing so that I could weld them to the triangular structure at an angle for strength.

Because the angle I had to cut out of these pipes was so acute, the chop-saw didn't have a setting for it. As a result, I was forced to cut it out with an angle-grinder.
It turned out pretty sloppy, and required a huge nasty weld that is going to have to be in an unfortunately visible place.


The next thing I had to do was straighten everything out so I could tack weld it all together. I didn't really have a straight-edge that was long enough to be of any use, but that didn't matter because the frame had nothing to use as a reference point anyway. For this reason I resorted to just sighting along it, straightening everything out by eye. Once I thought I had it straight enough I tacked it all together, then stood back and looked at my work.

I had forgotten to double-check it.
It's probably hard to tell from this picture, but it was quite crooked.

I had to cut it apart and try something else.
On my next try, I clamped a long piece of rectangular tubing I had found to it, and tack-welded it again.

There was no really good place to do the clamping however, so it turned out crooked a second time.

I was again forced to cut it apart.
At Kai's suggestion I used string and C-clamps to stretch a line along which I could sight the frame. This worked great (helpful bastard), allowing me to weld it together for the third and final time.

With that, the frame was completed.
All ten feet of it.

Tuesday, February 19, 2013

The Rise of Frankencycle

Last weekend I got bored with planning and decided to start actually putting some stuff together, so I went out to the bike pile and extracted a red bike frame,


and my old nemesis the gray bike frame.

I also gathered up a collection of nasty looking pipes that were laying around the shop.

I think these pipes may have been part of a fire-sprinkler system from an old building. They were all coated in some kind of thick, impermeable paint. In order to clean the paint off I first tried using a chemical paint-stripper, which did effectively nothing except make me feel a little unusual. Next I tried sand-blasting them, but the sand-blaster that I had access to turned out to be next-to-useless.


After that I tried using a wire-wheel on the bench grinder,
which only managed to smear the paint around and take up a lot of time.

Finally I was relegated to painstakingly scraping the majority of the paint off with a razor blade until I could again use the bench grinder to polish off the excess.


 Eventually I managed to get them to a relatively useable state of cleanliness.


The next thing was to cut up some bike frames.

I had no use for the rear fork of the red bike, so I cut it off,

setting myself on fire in the process.
This would be okay, except that the sweater I was wearing belongs to my friend Jesse. So Jesse, If you're reading this, I've hired a team of plain-clothes guards to monitor your whereabouts.

Next, I put on some leathers and proceeded to grind off the bits of tubing and weld that were left behind.


 This adorable pink bike probably made some little girl very happy once,

and yet I dismembered it in a shower of sparks.

Once I had prepared all the parts I needed, I laid them all out to see what would be the best configuration.

When performing metal work that has a structural function, it's important that joints fit together snugly so that the welds are in less danger of being thin. In order to get all the parts to fit the way I wanted them to, I cut each one to the size I needed, then contoured and bevelled the ends so that they would fit solidly against the curved surfaces that I had to weld to.

Next, I shimmed the pieces up using fire bricks so everything was straight and properly aligned.

I then tack-welded it together,
corrected a mistake or two,

then welded all the joints.

 Once finished, I put on some seats and handlebars, assembled the crank sets,

and put on some wheels and tires.

Then I attached the chains using my newly (and reluctantly) acquired chain breaker ($17.95 plus tax).

At which point it was time for a test ride.
I managed to convince my friend Caitlin to help me out. As if riding a home-made tandem bike wasn't scary enough, her handlebars came loose while we were moving. She's fine, but informs me that we're taking a break from the friendship while she recovers.

The test ride of the Tandem-Frankencycle was really only meant as a proof-of-concept for my gearing system, making sure that it didn't slip or rub. Ultimately, this frame will be the upper portion of the Pariahcycle. It won't have wheels, only a coaster-gear at the back with another chain leading down to the gears and rear wheel of the lower, recumbent level.

This was surprisingly successful, but the next step is the hard part.

Wednesday, February 13, 2013

A Pre-do Re-do



After a lengthy discussion with Kai, we've had a bit of a rethink and decided that the original design for the pariahcycle is both unstable and structurally unsound. Among other problems, these are two fundamental flaws that can't be ignored for pretty obvious reasons. The outcome of this brainstorming session was this redesign:




We decided that the center of gravity of the original design was much too high and could cause balance issues. We believe that this flaw could be overcome by redesigning the bike with the riders on the lower level in a recumbent position rather than an upright position. This would solve several additional problems I had been facing with the earlier iteration. First it lowers the center of gravity of the bike, second it reduces the overall height of the bike by about two and a half feet meaning that the riders on the upper level have less of a distance to fall in the event of a crash, third it provides more space for supports and latices which will improve the bike's structural integrity. Another perk is that it prevents the riders on the lower level from being kicked in the face by the riders on the upper level. 

We will also be adding outriggers, which are basically just giant training wheels that will parallel the rear wheel. Ideally these will be retractable so they can be raised once the bike gets moving, but this may turn out to be a greater test of my ingenuity than I can handle. We shall see.

The drawback is that it's going to be a lot more complicated to construct, and therefore require a lot more planning than I generally put into things,

so I got some tools, a box of Equal Exchange Organic Chocolates, put on some Mythbusters,

and set to work turning said box of chocolates into a cardboard model.

I then went out to the shop and used some bike parts and other stuff to lay out a full-scale mockup on the floor.



This was to help give me a sense of scale so I could estimate the amount of material that I will need, and in doing so, what I've realized is that, despite the two and a half feet that the redesign eliminates from the Pariahcycle's overall height, it is still going to be about seven and a half feet tall. This is still ridiculous, but not unmanageable, and still better than the nearly ten feet that it was originally going to have to be.
Additionally, according to my measurements, and (probably incorrect) math, I am going to need about 40 feet of steel tubing and 30 feet of bike-chain, which is a lot.

Friday, February 1, 2013

Dismantling Competence

This week I began disassembling all the bicycles that I obtained from my ad in order to find out what was usable and what wasn't.

Along the way I encountered some problems.
 Like never having the right size hex key

in a box of hex keys this size.

I also discovered some typical aspects about the way bicycles are built that would not have been a problem had I possessed the proper tools.
This, for instance, would have been extremely easy to handle with a $5 chain breaker, but of course I don't own one.

I managed to solve this, however, in one of my (extremely rare) moments of brilliance, by using a hammer, a punch and a nut.


I also had to contend with my own ignorance about how certain types of hardware work.
 I struggled with this little silver thing on this green bike for much longer than I care to admit, trying to unscrew it or wiggle it out. I even tried banging on it for a little while with a ball-peen hammer to no avail

 before giving up and cutting it off with an angle grinder. 

Not long after I did this, however, Kai of Burning Beard Fabrication strolled into the shop to see what I was working on. I showed him all the bikes and explained that I was harvesting parts from them. He saw what I had done with the green bike and asked why I had decided to cut it rather than just take it apart, to which I replied that this little silver thing was some kind of permanent factory fixture made from an indestructible material of indeterminate origin, and that neither I, nor anyone else on planet earth, could possibly remove it. Kai then picked up the frame, looked at the silver thing for a second, tugged on it once and it came out in his hand while the other side fell out onto the floor.

By this point I was down to the last bike in the pile, and I was feeling pretty accomplished until I encountered this:
This nut was so badly rusted that it and the crank arm were both essentially welded to the spindle of the crankset making it impossible for me to twist it. Eventually, with a lot of WD-40, swearing and a dead-blow hammer I was able to get the nut loose, but the crank arm was still impossibly stuck. 

so I put the arm in a vice and found a piece of wood, which I used to try and pound the spindle through.
 It didn't work.

So I improvised. This also failed. 

At almost that very moment Kai came in for a second time and picked up a monkey wrench. He used this and his not-inconsiderable strength to disassemble the crank-set while his girlfriend Lisa and I held the frame steady. Once it was out, all it took was sticking it in the Hardy-Hole of the anvil and one little tap on the end with a hammer and the spindle popped right out of the crank arm accompanied by a shower of ball-bearings. And thus, after 20 minutes crawling around on the shop-floor looking for, and miraculously finding all of said ball-bearings, disassembly was finally complete.

In the end, it took me just shy of ten hours
 and this many tools

To reduce this

To this. But I succeeded. (with help)

These bikes had some sand in them,

and some rust,

but despite all this and the fact that most of them had been sitting in someone's back yard for an indefinite number of years, I was able to salvage a surprising number of usable parts from them. These parts will find new purpose as the Pariahcycle and other dangerous machines of marginal practicality soon to come.