Seeing In 3D

With my recent introduction to Google SketchUp I was keen to see my new improved design in 3D so set about creating it -

First making the seat top 400mm by 400mm. Then made the column half the size of my model (200mm diameter) with the thinner part of the column measuring 420mm. Working out the thickness of each layer so that the total hight is ergonomically correct at 450mm

Next I added in the five reduced sized cogs measuring 100mm diameter circle, so with two cogs totally 200mm with the column at 200mm the mechanism should actually sit directly underneath the 4000mm diameter square seat

Next I

added in the base/crochet design that worked well in my original wooden model. It is crucial that the height at which the cogs are suspended and the distance from the column is spot on and identical for all five cogs because if one is off it could jam, flawing the mechanism. Already I can see an improvement in the aesthetics, the proportions, angles and components sit really well together as much more refined piece

Next using the Arc tool in SketchUp I could easily show a rough idea of the five arms that are attached to the five cogs, that curve around the edges of the seat and up to surround the neck of the victim

I really like how my chair trap is looking as is becoming more than just a simply mechanism

New Look

Although time consuming making the full scale model proved very interesting and helpful, I can now see exactly where in my design the aesthetics are lacking. Straight away I can see the cogs are too big and also how they clearly extend further out than the seat, looking back at all the traps I researched they all have one thing in common - they keep the mechanism of the trap hidden and as discrete as possible as to not deter the victim, here is a sketch of an improved design -

As you can see from my annotations, I first halved the width of the central column because it doesn't need to be that big and also reduce weight. I also decreased the size of the cogs so that they 'look' right and so they don't extend outside the width of the seat (staying at 400mm by 400mm) as this is the standard dimensions for a seat

1 Column In An Aesthetically Wrong Pod

When I showed my adapted wooden model with the arms to my tutor, immediately Michelle saw the aesthetics were wrong. The aesthetics of a design is dealing with the nature of beauty, art, and taste, and with the creation and appreciation of beauty, basically it looked wrong - too mechanical. Michelle said there wasn't anything I could about the aesthetics looking at this small model, so the next step was to make a full scale model quickly, with the same proportions as my wooden model -

This is the column made out of 9 layers of hollow grey board discs, the five larger discs measuring 420mm in diameter and 45mm in height and the smaller discs in between measuring 320mm in diameter and 45mm in height, with the top disc at 420mm in diameter and 75mm in height. With a square seat on top measuring 500mm by 500mm and 35mm in height. The total height of the column and seat is 430mm and at the widest point 500mm, I tried to base these measurements on those of a standard school chair for ergonomic reasons

This is the finished full scale model and is blatantly obvious that its looks wrong - the aesthetics need to be improved, it is also interesting to see the scale I am looking at with my chair trap

Ganesha + An Arm...

Now I have a mechanism that is activated by someone sitting down on a suspended column and turning 5 cogs, I need to take this movement and come up with a way that the person is then trapped from this mechanism

It became blatantly obvious that arms should be attached to the cogs in such a way that when they rotate, the arms that are connected on the circumference of the round cogs will move with the rotation and move into a certain position that the user is trapped, confused? here are some sketches of what I mean -

The arms are simply an addition to the previous mechanism. The trap is set with the central column lifted, the cogs in their outward rotated position and arms lay out of the floor. Then as the column falls and cogs turn inwards the arms lift off the floor rotating at the same rate as the cogs. This mechanism will be designed so that then the column meets the floor, the cogs have rotated all they can and the arms are in their upright position all the way round the column with the 5 cogs and attached arms

I then added these arms to my wooden model, using simply foam board so that could quickly and easily see this advance in 3D -

Getting My Hands Dirty

Now I feel my mechanism design is getting somewhere I want to get into the workshop and start working with materials that I could potential use in the final piece. This is something that even the most expensive hi-tech software can't do, the physical making of the piece, something you can hold and tweak as you wish

I learnt a lot about realising this concept as a piece when making this wooden model. You can see from the two photos above how the movement of the column up and down causes the cogs to move inwards and outwards, it is movement that want to use to trap someone in the seat as they sit and push down the column. Also see how the cogs are suspended at a set height and distance from the column and can spin with ease on a metal rod, these are very similar to a Croquet hoops as they are pushed into holes in the base

Google Sketch(ing) It Up

When it comes to making a design sketch 3-Dimensional, a lot of designers don't have the appropriate resources and materials on hand and often more importantly the time to manufacture their piece. So software tailored to help you create a 3D computer model are very useful. A really good free downloaded software available is Google SketchUp

I thought I would give it a try and see if I can recreate my sketches of the central column with interlocking cogs, and take the design further 3-Dimensionally -

A huge advantage with using these modelling programs I can move around my design with ease, making it much easier to judge size, proportion, angles and scale compared to a flat 2D drawing. So it was easy for me to copy a cog that works with the column and rotate it to the angle I need to have them meet the circumference of the cylinder at the correct position

Development

Here are some preliminary sketches of how I could combine the central column of the corkscrew and the graphics piece by Gordon Young to design the basis for the mechanism that will grow and incorporate this Cylinder

I then started to think how the Cog component will sit and be sized is relation to the gaps in the column