Meet “Red”, the first production model Schools Science Trebuchet. Completed last night and delivered after range testing this morning.
“Red” is the unit designation and all machines are colour coded for parts indentification.
The science trebuchet breaks down for easy storage and transportation.
They feature retaining pin and R-clip fastenings with metal fittings for druability.
The machines are also fitted with a spring loaded self returning trigger for ease of operation and the 22AD variable angle adjustable release hook for easy tuning.
Testing indicates this machine is throwing around 40 meters with a 15kg counterweight and also very accurately. (Recomended maximum weight = 20kg’s.)
The Schools Science Trebuchet is based on the “Tiny” design available as a free download (downloads now approching 400). Or you can just pay me to build you one. This would be the opposite of “free”. Expensive… yet still cheaper than trying to build your own from the free plans then coming to the realisation that it aint as easy as it looks.
hittingmetalwithahammer.wordpress.com 
That is elegant/non-trivial work.