I did A-Level DT, so i am particularly interested in your project, good choice by the way. My project was to design a carrying system for a normal rucksack on a bike, it also turned out to be my design exam question (or nearly)
Anyway to the point.
I used a folding drinks bottle crate attached to plastic tube pushed into the ground. Unfortunately the tube was to flimsy, and the whole thing takes up too much space as I get the train to local races.
You need to bear in mind just how difficult collecting a bottle from a stand is, I can pick a bottle off the ground at ~10mph when not racing. When you are racing, this sort of coordination is vastly hindered. If you stop and collect the bottle expect to loose around 50m on your components.
The stand needs to be sturdy, and the bottles need to be held in place well, it is likely to get knocked by other people. Sometimes organisers put the feedzone on hardstanding, but commissaires might be lenient if you have to put your drinks somewhere else.
I suggest you do some testing/ design into the most sturdy fixment into the ground. A garden fork is good because it has four prongs that stick into the ground, because of the distance between the prongs the resistance you get from the ground in one direction is high (hence why its good for turning over large lumps of earth at a time). A better design would increase the width of each prong while keeping the cross section area/ width low. i.e. a section the looked like this +. But also bear in mind the problems of rocky soil. I worked as a geotechnical engineer for a while, hence my interest in the foundations!
From what i remember you have to do a testing phase for the project, the above would be quite a good test to set-up, there is also a wealth of literature referring to foundation design that you could use.
Last edited by mikeyg (26 February 2014 15:09)