Water Rocket Costing
Water Bottle: I used a 1.5L water bottle costing £1.75, I chose the bottom as it was a smooth cylinder shape with no obscurities so its aerodynamically streamlined.
Nose cone: I used the cup part of a plastic wine glass as the nose cone and cut off the base as I found it fitted the bottle well and was itself a smooth design, which is important to the stability of the rocket and is aerodynamically efficient, it can also hold weights in the nose which helps with balance and stability while in the air, the plastic wine glass set cost £2.00 with 4 in the pack.
Bungs: I was able to find some wine corks that I was able to adapt to work as a bung for the rocket, I driller holes and trimmed down the cork so it will fit in the bottle top without it catching, as I already had the cork, I didn’t need to buy them but I would estimate that it would cost £0.75p each.
Valve: The valve I used was originally used for tubeless tyres on mountain and road bikes, I thought this would be a logical thing to use as I had spares and is designed to work with most pumps, I figured it will be perfect for holding pressure in the bottle without leaking as its designed to keep pressure in with rubber seals. The valves themselves are quite expensive at £5-£6 each.
Platform: I used wooden plates for the base as it is sturdy and also economically friendly as it is made from recyclable materials, I cut a circular hole in the middle of the plate so the pump can fit without causing disruptions to the rocket itself as it made it unbalanced at the base. The paper plates came in a pack of 100 with packs of wooden cutlery as well costing £30, these were purchased and used for another matter but a single plate would cost £0.10p
Rocket Legs: The rocket legs was made from Wooden forks from the same package as the platform, I altered the forks design to create 2 prongs for stability, I used 3 forks as legs and picked the forks as they are light, thin, economically friendly and strong, wooden forks from places like fish and chip shops can be used as legs as an alternative, for costing, the forks came in the same package as the platform for the rocket, and would cost £0.15p-£0.20p each.
Tape: For tape I used Duct tape as it is light, cheap and is very useful to hold the rocket parts together, it holds the nose cone to the rocket and cardboard extension to the bottle. The cost of the tape would be £3.75 per 50m roll.
Release mechanism: The release mechanism I used was a Allen key that was used to hold the cork in place and hold pressure, I drilled a hole through the lid of the bottle and the cork to create a hole for a pin mechanism that would be able to be pulled out to release the rocket, I connected some string to the end of the Allen key so I can pull the pin from a safe distance, the cost of this is low as I used scrap parts and pieces from around the house, the Allen key can be swapped out for any other material if it fits and is appropriate.
Extension material: I extended the rocket length by 6 Inches so I could be able to make the rocket level, it also made it so I can add reinforcements to the base of my rocket legs, I used some cardboard from a package but other materials can be used, ideally something that can get wet, costings for this will be low at £0.10p worth of materials.
Labour
-50-hour individual.
-labour rate = £6.50.
-Labour = £325
Materials
-Duct tape = £3.50.
-1, 1.5L water bottle=£1.75
-2 sheets of card = £0 due to recycled.
– Cork/Bung = £0 due to recycled.
– Bicycle pump = £10
– Tubeless bike valve=£5 each
– Microbits = supplied by University.
Total cost = £351.75