Body shell fitting and harness check.

Managed to squeeze a morning's work during 1/2 term holiday in which I trimmed the body shell to slot over the roll bar. It will be bolted to the aluminium strips that run along each side of the chassis with 6 screws, 3 each side.

Ugly slots to fit over the roll-bar triangulation will ultimately be
covered by a helmet fairing, although I doubt this will be in place
by the first race!!

Roll bar top clearance looks good for at least 50 mm.

Sure is snug in there!! Probably a little less so for intended
students instead of tubby me!!! harness fits really well and has tons of adjustment.

Still to complete....Battery hatch hinge+catch, drivers headrest, helmet fairing, wiring......the list goes on....

Some cool CAD and virtual wind tunnel testing for POWER

Before the year 9 team began the build of Plume Power, some fairly intensive CAD sessions (it took 7 versions to get it right) resulted in a comprehensive set of plans for the team to follow:

Pro Desktop assembly (including driver!)

Plywood chassis tub bodywork over the top is to
be Correx thin corrugated plastic.

Looking pretty like the CAD drawing!!

carefully dimensioned 2D set of plans.

After about an hour and a half in the virtual wind tunnel. This is free software from Autodesk (Flow Design)

Nice smooth flow lines....

Not much turbulence to the rear.

The final analysis with the wind speed set at 13 metres per second (30 mph) gave a Coefficient of drag of 0.28 and a drag force of 6.749 Newtons.

Not sure if this is good, bad, indifferent or even useful until I consult our resident Physicist, Mr. Raymond.........sure is interesting and cool though!!!!

OK!! by comparison here is a wheels-out car I designed a while back (fairly comparable
to the yr 10-11 Projectile. Its test results are a CofD of 0.46 and a drag force of 12.37 Newtons
That's quite a bit of difference......the year 10's and 11's may have some competition with Power!!

Not long now!

So, with 2 weeks to go before our first race of the season at Goodwood (on 8th June), work on Projectile continues at an ever more frantic pace!

This week, saw the drivers 5 point harness get mounted, a seat back fabricated, the nosecone attached and a drive-train guard made and fitted.

Not the most comfortable, but we might ask Miss French
to help upholster the seat back with some padding and
some CNC embroidery!!

Chain and sprockets safely inside the box and away from fingers
(and the drivers head!!)

Just the body shell to fit and the wiring to do now!

Meanwhile the yr 9 team welcome a new team member and continue to work steadily fitting the rear axle mounts...

Welcome to our new yr 9 team member Alex Lee Ranson....there he is in the car, lets all point!

Axle mount 'triangles' have been boarded over an bonded on
with waterproof PVA. Now to drill them and bolt on the back axle!

Beautiful TIG welding and some 3D printing!!!

The front and rear roll bars for Projectile have come back from Marcus our friendly TIG welder and they are fantastic!!

Cleaned up a treat with some wire wool!

Lovely welding!!!

Rear triangulation anchor to chassis floor.

Front roll bar in situ.

In case you were wondering the rear roll bar is actually reclaimed climbing bars from when the school gym was refitted!!!

In the meanwhile, Mr. Raymond got busy with our 3D printer, printing out a NACA duct which hopefiully provide a low drag airflow over the motor.

Halfway through...

The finished Duct

The wooden battery box with its bathroom bolt locks is now done.....

Easy and neat!

And this evening the year 9's made some excellent progress on the rear axle mounting brackets for their car Plume Power....

difficult to see, but carefully made triangulated
brackets will be bonded to the chassis tub. The axle brackets will bolt through.

A decision was made to locate the batteries inside the cabin, under the seat....

nicely hidden and still able to easily house a 6' driver!

Only 3 weeks to go before our first race, so the pressure is well and truly on to finish Projectile in time (thankfully Power is not racing until September...)

Roll bar mock up and more year 9 progress on Plume Power!

Our 2 year 11's Reece and Nathan, have been hard at work fabricating the complicated aluminium roll bar. This has involved some bending and careful notching of 32mm tubing (which I salvaged from the old climbing bars that were changed in the gym some years ago!)

Unequal triangulation is to allow enough room for
the motor to adjust back and forth on its hinge mount

Arrows in permanent pen are alignment marks for the welder

Here you can see how well the tubes are fitted together
this should help when they are TIG welded!

The plan is to re-tape the roll-cage together on a board, using the alignment marks. and then hand the whole jolly lot to our tame TIG welder, so we can just bolt it in when we get it back.

Meanwhile...

Tash and Hannah have started coating the foam nosecone
in silicon sealant, this makes it waterproof and shiny!

And this evening, the year 9's have been very busy with the build of Plume Power....

Gluing and nailing in triangular bracing to reduce flexing in
the stepped in nose section.

Alex starts to frame around the top of the chassis walls

Crikey, it's starting to look like a car!!!