No new progress.

Velomobile Stitch and Glue

I am trying to make time to work on the seat. Haven't been able to get to my dad's house where the material is. I am guessing I might take a few times to get the seat profile down.

I am thinking about how to apply stitch and glue boat building techniques into velomobile building. For my first project I figure I want to make the body as inexpensive as possible, since I can always reuse the mechanical parts for another velomobile later. I have been thinking of simple but decent shapes for the shell.

I read that the angle on the rear end should be 12 degrees or less. The idea I have drawn up has a 13 degree angle. Pretend there is an imaginary line that extends along the edge of the velomobile and you measure at the point the rear begins to narrow. The angle from the imaginary line to the point the body curves to the rear should be less than 12 degrees, which makes for a long body if it has any width to it.

I drew two lines to represent the angle that is being measured for a visual. Like the old saying goes, a picture is worth a thousand words.

I decided to play with different roof lines to see what kind of effect it gave. A lower roof line in the front gave a pretty neat effect. Will need to verify measurement to see how low the top can comfortably be. I think my ideas are within being able to use the stitch and glue technique. My drawing has a width of 38 inches and a length of over 9 feet. I am hoping to make room for a back seat.

Seat Design/ Building Process

Well, I have been doing some research to make a seat. I want to have a seat that might be used to do some mock ups. I want to do some mock ups to help me better determine space requirements. This is something that could probably be done on the computer, but I have a hands on personality. Besides, building the seat at this stage just means one less thing to build later.

I think I have found a pretty good method for using plywood as the seat material. The process is pretty straight forward. You shape three pieces of plywood to the given contour of the seat and fasten 2x4 in between the three shaped pieces of plywood as a form. The 2x4 run the length and up the sides of the plywood with the 4" sides perpendicular to the plywood/ horizontal. Once the form is built you can make your seat.

You use two or more sheets of plywood to make the seat. Sound like 1/4" plywood was the choice of many builders. You glue the two or more sheets of plywood together and fasten them to the mold with clamps/ straps. Use spare material to place in between the seat and the fastening method of your choice to not scar the seat surface. Make sure the plywood being formed is larger then your desired seat; you will later trim the seat to size.

Let the seat sit an appropriate amount of time for the glue to harden, usually twenty-four hours. You wouldn't want to remove the seat to early and waist all your work.

I am thinking I might make a fiberglass or Kevlar seat later on, Kevlar is just laying around. I might try and put a backseat for my wife or one son to ride with me. I might have to get creative on how to work that out. I am figuring a few extra pounds for a seat wouldn't break me. Besides, the seat can always be made removable.

Forum: http://www.bentrideronline.com/messageboard/showthread.php?t=35802&highlight=plywood+seat

Seat-Fiberglass?

Well, I last spoke about possible methods for making the fairing. I am trying to throw out any ideas that come to mind. Nothing is dumb, some ideas are just better.

Fore instance, far north, might have been Canada, head people for an electric company were trying to find ways to remove ice from the overhead power lines in the middle of the wilderness. Everyone threw out ideas from adding heater to melt the ice, to having bears scratch their back on the poles, which would shake the ice from the wires. They played with the idea of bears scratching their backs on the poles and said what would make a bear itch their backs on power poles. They figured they could hang meat or find something that attracted the bears. Once they thought of how to get the bears to scratch their backs on the poles they tried to figure how do we get the stuff to the poles?

The first thought was to use dog sled, then snow mobiles, then finally someone says we could use helicopters. How would we get the helicopters close enough to the wires to fasten the item to the poles. They discovered the turbulence from flying helicopters over the power lines would shake the ice from the power lines. This was an exercise we used in a management class I took at the local community college and apologize for any inaccuracies.

Now to the point, I think a fiberglass seat could be built similar to this persons: http://buckybikes.blogspot.com/2008/04/seat-building-finished.html
He made a plaster shape of his own back and use that as a mold for the seat. Very cool! I think that building a wooden seat out of thin sheets of plywood and gluing them together could make a decent seat as well, if the shape is right. I think I will post on bent riders to see what a lot of the builders on their forum are doing.

Velomobile Fairing

I was thinking about different methods for building the fairing that might be more easily shaped for an aerodynamic benefit. One method would be to use a foam core that is ruff cut to the desired shape, fiberglass and smoothed. Here is an example that shows someone using foam to shape their bike's exterior in foam. http://www.wisil.recumbents.com/wisil/barracuda/barracudafairing2.htm

Another method would be to build foam ribs and fasten thin strips of foam across the ribs to for the outer shell. A really good example is here: http://www.adventuresofgreg.com/HPB/2006/12/dec-4-2006deck-covering-until-just.html

I think both ideas would work. The rib method would probably be lighter than leaving all the foam in the velomobile, but the extra foam would allow for more impact resistance in the event of an accident. I have to way the difference in safety for weight. The weight penalty should be minimal and this is supposed to be a commuter velomobile.

Rear suspension

Here is a look into the rear suspension. I figured I could either use bushings or bearings for the pivoting point of the suspension. I am not sure what would transfer the least amount of noise to the body of the velomobile. I would think that polyurethane bushings would absorb the impact and disperse any road noise. I am not sure if friction is a critical factor with this part of the suspension. Its not a continuously moving part like the wheel bearings, which require an efficient low friction manner of spinning.

Front Suspension

This is what I have drawn up for the front suspension minus the shock and brakes. I am figuring the steering axis inclination at a 15 degree angle in the diagram. The steering axis inclination is the angle at which the two lines intersect with the bottom patch of tire and the pivoting point of the A-arms. I will do more research on suspension geometry before doing a finally design and mock up. I am trying to keep to simple geometry that should make fabrication easier. I think most of these parts can be built with patients, a drill press and a hacksaw. I will probably use aluminum because it is fairly easy to work with.

Reasonable Top

I figured I would try a different approach on my bubble top idea. I still like the idea of a bubble top, but I would need to build an oven to heat the plastic with. I could always start with no top and then build a simple top that could use the same outline for the bubble top. This would allow for the canopy's to be interchangeable.

I hope to find more people that have home built human powered vehicle and home built velomobile.