Sunday, February 27, 2011

Heavy Duty Coffee Cart

This trailer will be the frame for Good Bike's coffee vending cart.
The bed is 36"x 48" (3ft x 4ft) and the total width is 46" (3 ft 10 in).



The hitch arm is made from 1" round steel tube with a wall thickness of about 1/8". I made the bend with a JD^2 model 3 bender. The arm sleeves into a bigger beefy steel tube that has an ID of about 1" and wall thickness of about 3/16". Really beefy, as far as bike trailers are concerned. As the photo below indicates, it is held on by 3/8" bolts. These will be replaced by 3/8" lock pins to make hitch mounting/ dismounting quick and tool free.




You may be wondering what the heck those things are at the corners. They look like table legs. That is indeed the purpose they serve. The idea was to have a bike trailer turn into a vending cart with minimal time and effort. The feet drop down at all corners to hold up the cart, then the bike can be disconnected and the hitch arm removed.

Here is a front view of the trailer and it's feet holding me up.


Detail of a leg assembly. The legs are 3/4" round tube with some 1/8" flat stock welded at one end. The leg collar has some notable details. It is 1" round tube with 1/16" wall, it has 1/4" nuts brazed to it, and it is tig-welded to a 3/4" square tube that sleeves 6" into the open end of the trailer frame.









Friday, February 4, 2011

rambling manifesto: Junk Strategy for a Critical Energy Philosophy

Trailer for double bass made from salvaged junk

I have been focused most recently on making things out of new material; this is both good and bad. I am now returning to the idea of making things out of 'junk'.

There is a time and place for new materials that are specifically designed for a certain purpose. There is also a time and place for re-purposing raw materials that have been salvaged from the junk pile.

Using items for applications other than their original purpose can be sketchy, but there is an art and science to it. Just because something was designed to do one thing, doesn't mean that it isn't capable of doing another. In the spirit of direct reuse of materials to save energy and resources, I am obligated to reuse materials when appropriate.



It is easy to think of bicycles as really 'green'--environmentally friendly, sustainable, etc. But behind every new product there is a chain of production that is probably not sustainable. Bicycles are made in factories from raw materials just like anything else. They get shipped across the world in boxes full of disposable plastic. Look in the dumpster of a bike shop and you'll see the mountain of plastic that results from the shipping of bicycles. The end result is a machine that efficiently and cleanly transforms human energy into motion. Thus we title it "green".


But "green" is a relative term. Compared to cars, bikes are green, because they use much less energy and don't pollute like cars do. Well, compared to jumbo-jets, cars must be green, because they use much less energy and don't pollute like planes do. And compared to walking, bikes are bad for the environment, because they were made in factories and shipped across...


Thus, "green" is not an absolute designation like positive/ negative. The term "green" loses meaning without qualification of HOW green something is. But it's hard to put a proportion on "green". If I said" I'm 15% green", would you understand? I'm suffering without a precise definition of "green".


I could say, A is greener than B. That makes sense.

There is difference between appearing green and actually being green. So many companies have jumped on the bandwagon. For example, water bottle companies are claiming that their "new designs" for water bottles are "green" because they use 30% less plastic. By "green" they mean it saves them money in manufacturing? The real question is: by how much is the state of affairs improved by a modified plastic bottle design, all things considered? I hypothesize that the new design isn't significantly greener than the old one, in the long run. (Considering the difficulty of recycling plastics, the litter problem, etc.) Maybe I'm wrong.


A is greener than B. Bikes are greener than cars, but bikes aren't green by themselves. Bikes take energy to move, just like cars. The fuel is the food you eat. Where did that food come from? It took energy to produce and likely it was done in an industrial way that produced trash, consumed energy for climate control and depended on petroleum for delivery. Even if you grow your own food and/or raise your own animals, is that really green?


By far, the energy we invest in fueling our bicycles is much less in comparison to motor vehicles, but it's not negligible; It should not be left out of the equation.

I saw a shirt the other day that had a picture of a bicycle and was claiming that the mpg rating for a bicycle is infinity. Well, that's true (after a fashion) because bicycles don't directly consume petroleum fuel. But if you go down the rabbit hole and trace the energy trail, the human's energy at the bike pedals isn't completely independent of fossil fuels. Thus, the shirt's assertion isn't unequivocally correct.


It can be overwhelming to trace the energy trail on anything we do. For example, I saw huge wind turbine blades carried by trucks on the highway recently, and it made me think of the energy cost of existence. To have a functioning wind turbine that is harvesting energy, a vast, possibly incalculable amount of energy must be consumed. Assembling it requires massive cranes, trucks, etc. Shipping it requires multiple trucks. Constructing it requires raw materials, a factory, etc. How many light bulb-hours were spent on a wind turbine blade? How many diesel engine hours? Computer hours? Going even further, what about the factory that makes the trucks and cranes? Consider the commuting energy of the crane operators, truck drivers, factory workers, engineers, etc. Another infinite branch of the endless energy trail. There must be a logical spot to draw the line when assessing an event's energy consumption. I'm thoroughly overwhelmed.


Moral of the story: reuse things







Fabric, The Final Frontier

Dog Wagon
I spent many hours on this trailer. Specifically I spent many hours at the sewing machine making the fabric enclosure. I am very proud of it. I used cordura fabric for the bulk of it. Cordura is commonly used on backpacks, cases, army boots and in other heavy duty applications. I broke several sewing machine needles before I found the right speed and needle size.
The windows are mosquito mesh.
The fabric enclosure is attached to the frame by an array of straps and snap buttons. It is in two parts: top and bottom. The top can come off leaving a general purpose floor. The door is like a hatch that is held on by velcro and snap buttons. All of it can come off for cleaning. All up and running, the trailer weighed about 25-30lbs, and would be very hard to pedal into the wind. I was aiming for an aerospace trailer that carries itself, but that will be the next one...
It came with reflective strips and even had a strap in the back to hang a bike light on.
I got the black cordura fabric because "black socks, they never get dirty..." but next time I will aim to get a bright color like yellow, orange, or white.
I took it for a test ride with about 100 or 150 lbs. I don't have an exact figure, but I know for sure that it was more weight than I recommend for trailer of this type. The load was junk from my yard: A cast iron sink, bricks, rocks, cinder blocks, gallons of water and motor oil. I took it over curbs at low speeds and on some hills and the trailer passed the test.


After the dead weight test I took TJ for some rides around the neighborhood. He got comfortable in there after he learned that he got snacks for being there. When riding, he even laid down and was looking out the window; Like he was taking a ride in the back seat of a car. I haven't done a complete inquiry into the effects of trailer motion on dogs. It's possible that they can get motion sickness.