Category Archives: Random orbit 4 – Spindizzy

Steering

In June 2012 I took Spindizzy as a work in progress to a race meeting in Nottingham and it’s at events like this when you find out who your friends are.

The Sweetman clans saw how I was getting on and descended “en masse” to help out. They helped me fit a pair of rudders, pinched from RO3, some bike handlebars , routed the cable and generally moved the project on a great deal.

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This next photo shows the morse cable going inside the hull at the front to reappear at the back. Any guesses as to where the silver metal piece came from?

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Engine and Fan frame

0822c6ba7a7c14b34cd9f429b5060a2bRO3 was going to be a bit gnarly but for Spindizzy I didn’t want anything too fierce. In addition I also wanted an engine that would be easy to start and relatively trouble free. Nothing too close to the edge.

For those reasons I chose a Rotax 447 microlight engine. These engines have been around since God was a boy and are well used and understood. They are no longer in production but there are plenty about. the also have the advantage the because of a quirk in the UK racing regs they can be used in F3,my old stomping ground, F2, because they are between 250 and 500cc two stroke, F50 because they are weedy enough and FJ for the same reason.

It’s a twin cylinder two stroke making about 40BHP so it’s not going to set the world on fire but it’s good enough.

I had the engine frame made by Ken Rigley of K&M products near Newark. Ken has been doing Rotax frame for a long time and he just needed the diameter of the duct at the point furthest forward and the height of duct. He didn’t ask me what colour and I didn;t think there would be a choice. I was a bit surprised when it turned out red but as I was building a red craft anyway it didn’t seem to matter.

Hull, duct and planing surface

So, for this build I was going to need a hull and planing surface as before.

When I originally bought the moulds for the Outlaw I got a plug from which I pulled a mould. I still had this plug.

It is basically a top deck, a little heavier than I would like but perfectly servicable and good to go. It needed a lick of paint but that could wait.

85ffe21bfadbd70eecb52846a680a80aNext, a planing surface. As you know by now I have a mould and so I pulled a planing surface from that. The construction was just the same as Randomorbit 3’s planing surface.

So now we’re up and running.

I asked Les Bran of Bran Fibre to make me an 800mm duct and he duly obliged. I made a GRP box to fix it to the hull but didn’t take any photos of the process. Oh well.

Random Orbit 4 – Spindizzy

716aa4a3c46345cd7fbf08f91640a668Progress was slow on Random Orbit 3. This was a big build and was taking too long.

I decided a change was going to have to be made. My Son was fast approaching eleven and here in the UK junior racing starts at eleven.

I though RO3 was going to be a bit too powerful and gnarly for Jack and so I decided to shelve this build and start another, simpler, craft that we could both race.

Now, I am not one to waste a good name and so this one is Spindizzy.

As I now had the moulds and because I really liked the design, it made sense to go with another Outlaw.