Bright Sparks (2)

The ‘go’ department was a 550 can motor, persuaded into life by a 7-cell pack of 1 Ah SAFT NiCads. These were of the popular Sub-C size. With modern NiMHs you can get the same or better capacity in AAA cells! If I thought about it, I would have said that SAFT was one of those anonymous continental acronyms for the name of the manufacturers. It wasn’t until much later, in the ‘90s, when I  started going to Germany for the big Dortmund shows, that I realised that SAFT is the German for JUICE

Power from this mighty pack was summoned to the motor by a simple V3 microswitch operated by a servo. I completed the model on the Friday preceding one of the first dedicated electric flight meetings, at Pressed Steel Fisher, Oxford. Test flights on the Saturday morning were successful, except for an attack by a notorious resident crow, which managed to pierce both upper and lower surfaces of the Solarfi lmed wing with his beak, while it into our club competition rules – to allow a re-flight if an attack took place, some on video).

best electric rc planes for beginnersRepairs completed, I headed the next day to Oxford, where I had a pleasant day’s flying, exploring the envelope of the model’s aerobatics, as the Voltaire. After an enjoyable day out, I left fairly early and wended my Two days later, I was surprised to
receive a small parcel – a trophy tankard from the Oxford do, which I hadn’t realised I had won. Apparently the High Tension had  impressed them quite a bit, and garnered me the first of many trophies for electric flight.

SAVA-SHAFT!

At the Oxford do, there were a couple of traders selling electric flight accessories. Alan Fry, of Importeknik, was showing a prop-saver device. This had a small hub, to which the propeller was bolted, with six pins sticking out radially around the hub. Another, similarly adorned, hub was fitted to the shaft, with a locating spigot to centralise things. The two hubs were connected flexibly by rubber bands, ‘cat’s-cradled’ between the twelve pins. In the event of a prang, the propeller part could ‘teeter’ sideways and minimise bending loads on the prop and shaft. I bought one, and it can just be seen on the High Tension in the photo nearby.

My (dream) day job at the time was as a professional inventor for a major oil company. The mindset encouraged me to look at all technical items to see if there was room for improvement, or, in this case, simplifi cation. I rapidly reached the conclusion that the prop-saver device was unnecessarily complicated, and looked to see how it might be simplified. My solution, later branded the Sava-shaft, was a simple hub clamped to the motor shaft by two long screws, and with a spigot at the front to fi t the propeller bore. With the propeller mounted on the spigot, a couple of small rubber bands were wrapped around the long screws to secure the prop. This design has just three parts instead of the 16 of the original device! The Sava-shaft proved successful and popular, and was made in all sizes up to one to fit a 1 kW Astro .90 motor for my friend, the ‘Kilowatt Kid’.

Bright Sparks (3)

South American Annual Killifish (2)

The phenomenon of diapause also occurs in some plants and mammals. Some seeds need to be exposed to the cold before they  germinate, while kangaroos and wallabies have the ability to pause the development of embryos until such times as food becomes plentiful again. Diapause and the built-in delay of not all eggs hatching upon … Continue reading

Bright Sparks (1)

Electric Flight BC (Before Chinery) Whilst I can rightfully claim to have influenced the development of electric flight in the UK, the  term ‘pioneer’ sometimes applied to me rather overstates the case. I humbly offer my side of the story! The earliest record of a successful electric flight in the UK was Col. Taplin’s flight … Continue reading

Why Not Consider A Brackish Aquarium? (2)

None of these  fish is difficult to look after and they will thrive on the range of foods stocked by aquarist stores. As with all aquarium  fish, it is important to feed them two or three times daily rather than just providing one large meal. Housing The corrosive effects of salt means that … Continue reading

Allergic Rhinitis (Hayfever)

Allergic rhinitis – or hayfever – is defined as an allergy that affects the nose. However, the nose isn’t the only part of the body affected by allergic rhinitis. You may also have problems with your eyes, sinuses, throat and ears. There are two types of allergic rhinitis defined by their cause: Seasonal allergic rhinitis – when you experience … Continue reading