The new axle is complete including the frame to mount it. I like the way the angle work and complete the stubby back end of the seatframe. The finish is not bad for an atmospheric layup either.

Layup consists of:
2x layers of blue cotton
2x layers of 6oz glass
4x layers of 9oz chopstrand glass

The reason for for the chopstrand mat is to provide the strength in flex to absorb bounds without reflex as rebound would break traction




Here are some shots of the stub-axle mounts. The big washer is just a spacer that sits on the machined bearing journal to allow me to snug everything appropriately.



I plan to do one for the race buggy on the vacuum table next. I'll cast some sidewalls to protect the wood from moisture too. The flex worked out well and I just have minimal sag with my weight in the buggy. Jumping on the back axle with the wheels on proved that it was both strong and did not bottom out on the ground which is a good sign.

Carbon illness

Another buggier wanting to get into freestyling. This builder has patternmaking skills in a composite boat building workshop though need the metal parts for the divinycell core carbon frame.

His frame consists of a semi-teardrop shape profile and the headset is a mating fit over it.


To keep weight down we considered 20mm thickwall tube for the stubs and front axle. You can also see the head set abgle had to be adjust to get the right lead angle on the fork since the down tube section of the carbon frame was to shallow.

Chasing the rainbow

Managed to find a replacement pressure cooker for the one I used to use for degassing resins and fillers. However still have not resolved the curing issues when adding pigments and I'm still chasing down a source for powder acrylic pigment.

The brown elastomers are the natural unpigmented colour. The grey ones are just dirty from living on the workbench for a few weeks. These were donated to Peter Lynn's Craig Hanson as test samples.



Soon as time permits I'll hook up the vacuum chamber and mill some new molds to improve ease of demolding.

Straight to plan B

Seeing as my buggy still has no rear end I've decided to go straight to finishing a springboard axle.


I wanted to make a composite anti-sway bar for the leading link so it seemed like a good time to dive in and finish that too. While it's curing I started making the stub axles and frame to hold it.

Damp and squishy

The original idea for a rear damper was to build an elastomer torsion suspension unit. The concept consists of two sections of square tubing, one inside the other, with an elastomer filling the corners providing resistance to torsion:


The original prototype worked well with only 30° of preload required for my weight. After several hours of work on the 'production' model I was disappointed to learn that the rubber inserts I used were too soft and getting 60° of travel for preload.


This won't be suitable and I'll have to consider finding an alternative rubber or filling them with urethane in future.

Cast off

Wayne Carkeeks' leading link fork design requires the use of 60 shore hardness elastomer donuts to support two short swingarms holding the front axle. These can be had from Mackay Rubber at about NZ$75 a unit which works out to NZ$150 per fork. I found a source for the 2 part casting urethane with a similar hardness. At around $100 for 1.5kg of urethane I can cast about 10 sets. Leaving me needing some time on the machinery to make some molds.



The first molds were solid blocks of aluminium(square mold on the right) milled out to the dimensions with caps and relief holes for overcast. The elastomers proved just hard enough to demold that this was not suitable though the first set came out very nice. For the next molds I went three part and made 4 in total so I can cast a set at a time. I used blue acrylic tint for the first set as used for colouring epoxy which worked well. Though the second set I used a grey tint provided by the supplier. These did not cure nicely and will need to be redone. I'll stick with acrylic tints I know too.

Leading link fork... hot off the welders bench

In staying with the through-tube design I decided to mix it up a little. Since I'm casting my own elastomers I don't mind integrating the stubs in my design. Smaller cheaper fasteners and less loose parts.

To give you an idea of size, fork is over 300mm or 1' wide and that is a 20mm bolt and 32mm through tubes. I've made another set of rocker arms for the axle mount. The first set did not finish as nice. I will use them on the race buggy leading link fork.

Next to weld on some bolt tabs for footpegs and stirrups.