THE DESIGN STAGES AJ Booker CATAPULLET THE DESIGN STAGES AJ Booker This presentation has an audio commentary: Play the presentation to hear it in order, or click on the individual slide icons for that slides info

DESIGN STAGES There were two main stages in developing both the CataPullet and the BASIC Catapult Hand sketches first CAD to produce final version In these days of whizzy computing graphics, a simple sketchbook of ANY type with ANY form of useable pen/pencil is best

These sketches were done in a burger bar in Derbsyhire! Beginnings CataPullet was actually Designed FIRST, BASIC version came later First sketches were trying to improve an existing catapult design, converting it into a more upright version These sketches were done in a burger bar in Derbsyhire!

Beginnings Initial Sketches of shapes and ideas These sketches used the idea of flat plates held up in the air high to increase the arm length and travel

Its A Chicken! Chicken idea came about from thinking of the legs as adjustable, to vary release angle I realised early on that making sure everything didn’t hit together was vital. The chicken shape had to fit round the practical aspects of the catapult

Its A Chicken With Legs? The base had to be stable There seemed to be conflicting requirements for the rubber band to be secure and the legs to be adjustable

Working out how to make both these things happen took the most time How Does It Work? Arm swings freely but legs lock in place... Working out how to make both these things happen took the most time

Erm... Whoops! Design works but shapes are.... I was concentrating so much on the placement of items that the overall shape took me by surprise when I reviewed it

One main shape, with feathers? Feathers and body evolve to provide ratchet and also rubber attachment point In designing, ideas worked at will often resolve into a workable solution...

Catch That Chicken? Ratchet catch proved problematic The ratchet design had to hold the body securely and be useable.. This took a lot of trial and error

CAD CAM CHKN CAD started Started with body, fitted bits round it... Adapted body to fit bits as well... Continuous process!

A4 Chicken Bucket Design tested by overlaying parts I wanted final design to be cut from a single piece of A4 plastic or plywood so body was shortened. There were 8 ‘versions’ in CAD to get the design right

3D Chicken Testing Hey look at this! This allowed me to check fit in 3D and also make some seriously impressive images for my client!

The BASIC Version? Simplifying CataPullet till I had blocks This was relatively simple as I had solved most of the problems developing CataPullet

BASIC Detail Making it all work right.. The placement of the ball holder proved tricky as it had to leave room for the ratchet mechanism

Pen To Mouse Time for CAD Quickly it became apparent I would have to do the rest of development in CAD to resolve the ratchet and hinge issues

One I Made Earlier CAD on BASIC version cannibalised I took the CataPullet version apart and tried to square it out, some parts needed shifting to work... This is NOT finished version

The BASIC version is a starter point, it works but looks simple.. 3D BASIC Not as impressive as a Chicken! The BASIC version is a starter point, it works but looks simple..

END Developed by www.ajbooker.co.uk For NELC.NET