Paint work on the rear half

As announced in the previous post, I painted the rear half of the body.

I used a light green with pearl effect for the edges, and give the rest of the body a second layer of clear coat.

The front half has to be changed in some points and is therefore not painted yet.

First of all, I have to change slightly the position of the jackshafts under the bench.

Then I can remove the idlers, which actually prevent the chain from rubbing against the bench.

 I have used small idlers from a normal derailleur, 

which can't withstand the forces of the chain for a long time.

These idlers are attached since 100km or a bit longer and ruined now.

To give a better view of the shape of the body, here is a short video:

Almost complete !!!

The front hood is read now.

A windscreen and a soft top will be the next steps.

The body has actually one layer of clear paint, must be sanded and painted again. 

Hundreds of screwheads must be filled and smoothed, then the edge will get a green color.

Kai

Streamliner tail box for the steel tandem

Hello folks,

It's a long time since the last posting, so here is an update:
To find out, how the numerous 3d-sketches will look in reality, I've scrapped the old ugly rear box of the steel tandem and build a new tail with a more sophisticated shape and enclosed rear wheel wells.
To reduce the increase in weight, the drivers seats are now an integral part of the tail box.
With this much more massive body, the weight is just 4kg/8pounds higher than before.
For a racing velomobile this would be a catastrophe, but for a cargo-tandem like this it's acceptable.
I have used 4mm birch plywood, except the sides, which are pine (left over from an abandoned project)

structurally integrated bench

internal partition with wheel wells

top panel is on

A look in the trunk, childs backrest not in place

My first test drivers

the attached retro rear lights 

Although it looks really wide, it's just 119cm/3 ft, 10inches in width.

The entire box is attached to the frame via 4 bolts and can be easily removed if maintenance or repair is necessary.

There is not enough space to make any repair on the wheels or even to adjust the derailleur or brakes, as long they are inside the wells, so easy removing is essential.

We have driven 100km since the modification and are very happy with the new tail.

It provides a lot of space behind the backseat (ca. 100 litres/ 4 cu.ft.), our childs are much more protected from the airstream than before, it's rock solid and looks way better, so the pluses outweights the few drawbacks in our opinion.

Next building projects are a front hood and a light soft top to make it a fully faired retro pedal car.

I had made a paper model two years ago, which I had given a pointy nose, instead of the more blunt front of the CAD designs:

Pointy front

Pic from previous post for comparison

Which looks better in Your opinion ???

Kai

More improvements of the design

Here is my latest sketch.
It shows the convertible top version with the childs backseat and luggage space behind.

 

 

 

As shown below, the luggage space of the convertible is around 90litre/3,17cubic feet, the space for the childs has twice the volume.

 The translucent bodys represents the space provided for childs and grocery.

With a disassembled backseat the space in the rear is around 270litre/10 cubic feet.
 

 

The same partition of the space behind is also possible with the formerly shown Kamm tail.
 

 

Kai

 

CAD design #2 in three versions

I changed the lines and measurements of the previous design slightly,
the most important as follows:

Bottom bracket height: 40cm/16"
Seat height: 20cm/8"
Backrest angle: 40° from horizontal
Min. distance heel to ground: 7,5cm/3"
Car body height at crank position: 75cm/30"
Car body height at knee position 80cm/32"
Maximum height of soft top: 105cm/42"
Width: 120cm/47"
Length: 320cm/126"
Wheel base: 210cm/83"
Ground clearance: 12cm/5"
Weight: around 60kg/130lbs (with two drivetrains)

Here are three different versions of my pedal car.
It's basically the same car body with different rear versions, which can be simply attached to the tail.

 

Basic car

 



 

The convertible

 

 

 

The Kamm tail

 

 

 

The pickup

 

 

 

There's still some work to do on the front, which has to be changed.

 

 

Kai

 

 

The monocoque in 3D CAD

Did I mention that I want to make the tandem fully faired?
For the first time a non stressed fairing attached to the frame, a further development could be a rigid, frameless monocoque.

To find the desired retro design I prefer, I have played around a bit with SketchUp.
Although I'm not a big fan of CAD, it's useful to see a planned design from different angles before the build starts.
I confess I'm not a skilled CAD designer, but hope to improve my abilities soon.

 Lenght: 320cm/126 inches

 Width: 120cm/48 inches

Height is 105cm, maybe I have to raise the roof a little bit



SketchUp is a rather simple program.
It's easy to use but has just a few tools.
For example the step at the bodys edges should be a 45 degree bevel, but I haven't found the necessary tool.
Furthermore I wanted the front and rear end of the body a bit narrower, but I wasn't able to alter the body of my pedal car that way.

The build will be done with 4mm gaboon plywood ( as the blog name suggests) and epoxy as a stitch&glue project.

By the way, here are the newest parts for the sociable:

Front wheels with 90mm SA drums and one rear wheel with Nuvinci N360

The second rear wheel is fitted with the Alfine11.

I can't decide wich hub is better for our needs, we have to find it out while riding :)

Kai

Tandem Videos

Here are two movies, which shows the maneuverability and speed capability of our tandem.

 

 

I'm still trying out the new action cam, hope to improve my skills in making short movies.

Surely a few more vids will follow the next weeks.

Kai