LAUREN:'Today's Dengineer is 12-year-old Will, from Cambridge.'
WILL:I need help from the Dengineers because I love rugby and I want to play for England one day.
SEGE:So Will, you want the outside of this den to be in the shape of a rugby ball?
WILL:Yeah.
SEGE:Right, that is a very tricky shape of course.
LAUREN:'Sege has designed the den to look like an actual rugby ball. 'The windows will look like stitches on a vintage style ball 'with a door for access at the back. 'The interior is a rugby pitch with seating areas 'and goalpost cupboards at either end. 'There'll also be a TV and whiteboard for Will and his mates 'to watch games and discuss tactics.'
JOE:'The den is really coming on 'but how exactly has Sege made something this shape this big? 'Will's massive rugby ball needed to use some clever engineering.
JOE:'It's a very impressive structure and I just wondered' how you go about making something like that.
SEGE:Well Joe, dead easy. OK, what we do is we get some big sheets of plywood and we cut them out into little circles rather like this model here.
JOE:So you sort of make a skeleton of a ball?
SEGE:Exactly that.
JOE:Then where do you go from there?
SEGE:Well what you have to do then is you have to cover it over with thin strips of wood. What I've done is I've demonstrated that by using tape. So now you can see that once the tape's over there, you now have a shape developing.
JOE:It's a basis of like that wall then.
SEGE:Exactly.
JOE:OK.
SEGE:What this shows now is that we have the basis for the fibreglass.
JOE:What is fibreglass?
SEGE:Well I've got a bit here. Fibreglass is actually woven plastic–
JOE:Right.
SEGE:and it's woven with glass fibres going in all different directions to give it strength, you see.
LAUREN:'Sege has layered the wooden structure 'with large sheets of fibreglass and used resin to glue it down.'
JOE:'The fibreglass and resin bond together like a huge plaster cast 'to make the den, waterproof, strong but also light in weight.'
LAUREN:'And the fibreglass is also very flexible 'which means it's perfect for boats, waterslides 'and even a rugby ball den.'
JOE:'Right, time for a Sege demo.'
SEGE:It's as simple as this. Now this is my favourite bit. Then what we do is we take the brush and we just stick it all down.
JOE:Amazing, and then you cover the whole thing just like that?
SEGE:And you cover the whole thing. There we got can you see it all start to stick?
JOE:Got ya.
SEGE:OK?
JOE:I'm surprised that something that flimsy is actually strong enough to make it that hard.
SEGE:That's what makes fibreglass so good. Now I'll show you one that I've already made and you'll see exactly how strong that is.
JOE:Look it's like a cocoon.
SEGE:Isn't that fantastic? You actually bang that hard look.
JOE:Yeah. Aaaah.
SEGE:You can't-- It hurts doesn't it?
JOE:Yeah I regret that.
SEGE:And that's the beauty about fibreglass.
Presenters Lauren Layfield and Joe Tracini and The Dengineers team help rugby fan Will from Cambridge transform his den into a giant rugby ball.
They investigate how you create the oval shape for something as big as a den; using plywood to create the skeleton of the ball, and covering the structure in wood and fibreglass.
They describe the unique properties of fiberglass that allow it to be waterproof, strong and flexible; perfect for creating a rugby-ball-shaped den.
Teacher Notes
This could be used to introduce the process of design, and as a prompt for class discussion and learning in areas such as initial research, designing and making a structure. They could investigate the different properties of fibreglass. What are the advantages of using this material?
Curriculum Notes
This clip will be relevant for teaching Design and Technology at KS2 in England, Wales, and Northern Ireland and 1st and 2nd level in Scotland.
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