RacingSparrow Model Yachts - Fast Affordable & Fun Radio Control Yachting.

Frequently Asked Questions / Tips'n'Tricks

These are popular questions I get from around the world. If your question can't be found here email me and I may be able to help. Updated: 20June09

The Racing Sparrow forum is active and thriving and has a tonne of info in there, from building techniques, peoples sailing videos and more. The forum is in need of a prune but have a dig around to find answers. Some good general reading in there too.

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What is spray-bog/putty? Where do I buy it?

Firstly it's great stuff. It comes in spray can form, 300ml can. It sprays out a thick pink paint that dries quite fast. Very easy to sand back with fine grade sandpapers to a smooth finish. It fills and covers minor imperfections well and is recommended to get a professional finish. Once sanded back with 800wet'n'dry apply undercoat.

Repco(Auto chain in NZ)sell this item. Here's the store locations with phone numbers & opening hours.

In the UK the nearest equivelant is called 'Filler Primer' and Halfords (large motoring chain) Search for "filler primer". It's around £6 for a 300ml can.

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What is the Total weight of a RacingSparrow750?

The boat should weigh 2.0Kg sailing ready. 1.3Kg of that is the lead bulb.

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When and how do i remove the backbone?

The best time to remove the backbone is after you have done your fibreglass layer over the hull. I just cut it off with a craftknife. I use the wood left overs when making the keel jig.

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My lead bulb casting doesn't weigh 1.3Kg, is this a problem?

Aim to make your lead bulb between 1.2-1.3Kg. My latest boat has a 1.25kg-1.3Kg bulb on it. I've built it for wellington conditions, it can handle very high winds 30kts+ with the same sails. I'd say a 1kg bulb would be fine for a medium wind boat and lighter winds, it may struggle in the heavier stuff however. Most other model yacht designs have different rigs for different wind strengths. We simplified this by having a heavier bulb.

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What radio control kit do I need to buy?

Use the futaba basic 2channel, 2 stick controller set. (Futaba 2ER set. 29 Mhz) with add on sail arm. Widely available. Here's a link to a kitset for sale online in NZ.
Futaba Stick Radio - from RCNZ.com

The kitset comes with 1x handset transmitter, 1 x receiver for inside boat with aerial wire. 1 x battery holder for 4 AA's. 2 x 3003 servo motors. In addition to the kit you'll need to add the sail "swing arm" which replaces the default horn on the sail servo. Servo Yacht Horn - from RCNZ.com

If you're after a sail winch you can find one here: 7T sail winches - from RCNZ.com

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What are radio frequencies and which one should I use?

Radio control kits come with frequencies, all slightly different, this is how a group of model sailors can race each other and not have conflicting radio signals. It doesn't really matter at an early stage which frequency you choose, unless you intend sailing with other model yachties, then you want a frequency that is unique. The receiver and handset have inter-changable frequency crystals which are cheap and can be swapped out easily if required.

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Where do I source the aluminium materials from?

Ullrich Aluminium
Sales Centres all over NZ. - complete list with phone numbers and street addresses.

For the mast they stock 1 type of tube for the mast which is 7.93mm diammeter, 1.42mm wall. They also stock the other aluminium pieces you need.