Mayfly - by Peter Valentine
Posted: 09 Sep 2020, 22:53
It was either late in 1973 or early in 1974 when I first stumbled across Peter Valentine and his "Mayfly" helicopter. Work had taken me to London from my home-town in Devon, and I'd joined the Watford Wayfarers Model Club. Shortly before leaving Devon, some of the model flyers in Plymouth had banded together and bought a job-lot of Schluter "Cobra" helicopters - not only the first successful model helicopter, but also the first to become commercially available.
The Cobra was (and still is!) HUGE! The fuselage alone is over 6 feet long! Expert wisdom at the time was that it would not be possible to build a model helicopter that was any smaller.
You can imagine my surprise on turning up at the flying field one day and finding some chap flying a tiny helicopter powered by an OS 10! And it flew extremely well!
Peter Valentine with the original Mayfly in 1974 (or maybe late 73!).
I knew Peter Valentine by reputation, having seen pictures of his futuristic "Firebird" fixed-wing designs in the magazines, but this was the first time I had met him.
We quickly became firm friends, and he told me that his earlier "Lark" design was being prepared for production by MicroMold, but that he was trying to make an even smaller machine, hence the Mayfly!
Peter was a great experimenter, and never made two helicopters the same! As well as the original Mayfly seen in the photo, he made a version with a 3-bladed head. Unfortunately, it proved to be too stable! It would sit there in the hover, and as soon as a control was applied, the rotor-head would counteract it! All that happened was the model would wobble a bit, and continue to sit there in a perfectly stable hover!
He also attempted an electric version. This is long before the days of brushless motors and LiPo batteries. The Mayfly-5 was his 15th design, and sadly never flew, the weight of the battery pack proving too much for the geared, brushed motor!
The original geared motor and speed controller from the Mayfly-5.
Sadly, Peter Valentine passed away some years ago, and I helped his family to clear his house. Whilst doing so, I stumbled across the Mayfly-5, and asked if I could keep it. The family readily agreed.
The Mayfly-5 sat in my attic for a number of years, but on a recent visit, my son asked if I was ever going to do anything with it! We dragged it out of its resting place, and had a look.
PV never built two models the same. There was always something different about each one. The Mayfly-5 has a very interesting tail-rotor gearbox (to put it mildly!):
Initially we tried just fitting a 3S LiPo, and seeing what would happen. The model was seriously over-powered with this setup, and was airborne at about 1/4 throttle! We reduced the pitch on the main blades and tried again. At this point, disaster nearly struck! The speed controlled couldn't handle the power and went short-circuit! The heli went to full throttle and the radio froze! Luckily, I hadn't fitted the canopy for these trials, and the model crashed into a nearby hedge! The magic smoke came out of the speed controller as I frantically tried to disconnect the battery!
By some miracle, aside for the burned out ESC, the model was undamaged! I did manage to find another ESC that a chap on another forum reckoned would handle a 3S LiPo, but I decided not to risk it, and go for a full brushless setup.
The first motor I tried nearly worked - it got light on the skids, but never got into a hover. From that trial I worked out that I needed a motor of around 350 watts, and 2200 to 2700 kV. Unfortunately, every motor of this size seems to be out-of-stock at present! Overlander, 4-Max and HK are all showing out of stock, and no due dates!
However, HK did show a 3000kV 615 watt motor, so I decided to give it a try. It turned up today, and I've spent most of the afternoon figuring out how to fit it!
I finally got it fitted around 5 o'clock this afternoon, and gave it a quick hop in the back garden:
Success! Its airborne at around 1/2 throttle! I can probably afford to reduce the pitch on the blades a little bit!
The tail-rotor trim is a bit out, but easily sorted. However, its very slow on the cyclic controls and will need the throws to the swashplate increasing quite a lot! Its also a little tail-heavy, so I might need to add some ballast to the front somewhere.
But it's FLYING! After all these years! Which just goes to show what a clever guy Peter Valentine really was!
--
Pete
The Cobra was (and still is!) HUGE! The fuselage alone is over 6 feet long! Expert wisdom at the time was that it would not be possible to build a model helicopter that was any smaller.
You can imagine my surprise on turning up at the flying field one day and finding some chap flying a tiny helicopter powered by an OS 10! And it flew extremely well!
Peter Valentine with the original Mayfly in 1974 (or maybe late 73!).
I knew Peter Valentine by reputation, having seen pictures of his futuristic "Firebird" fixed-wing designs in the magazines, but this was the first time I had met him.
We quickly became firm friends, and he told me that his earlier "Lark" design was being prepared for production by MicroMold, but that he was trying to make an even smaller machine, hence the Mayfly!
Peter was a great experimenter, and never made two helicopters the same! As well as the original Mayfly seen in the photo, he made a version with a 3-bladed head. Unfortunately, it proved to be too stable! It would sit there in the hover, and as soon as a control was applied, the rotor-head would counteract it! All that happened was the model would wobble a bit, and continue to sit there in a perfectly stable hover!
He also attempted an electric version. This is long before the days of brushless motors and LiPo batteries. The Mayfly-5 was his 15th design, and sadly never flew, the weight of the battery pack proving too much for the geared, brushed motor!
The original geared motor and speed controller from the Mayfly-5.
Sadly, Peter Valentine passed away some years ago, and I helped his family to clear his house. Whilst doing so, I stumbled across the Mayfly-5, and asked if I could keep it. The family readily agreed.
The Mayfly-5 sat in my attic for a number of years, but on a recent visit, my son asked if I was ever going to do anything with it! We dragged it out of its resting place, and had a look.
PV never built two models the same. There was always something different about each one. The Mayfly-5 has a very interesting tail-rotor gearbox (to put it mildly!):
Initially we tried just fitting a 3S LiPo, and seeing what would happen. The model was seriously over-powered with this setup, and was airborne at about 1/4 throttle! We reduced the pitch on the main blades and tried again. At this point, disaster nearly struck! The speed controlled couldn't handle the power and went short-circuit! The heli went to full throttle and the radio froze! Luckily, I hadn't fitted the canopy for these trials, and the model crashed into a nearby hedge! The magic smoke came out of the speed controller as I frantically tried to disconnect the battery!
By some miracle, aside for the burned out ESC, the model was undamaged! I did manage to find another ESC that a chap on another forum reckoned would handle a 3S LiPo, but I decided not to risk it, and go for a full brushless setup.
The first motor I tried nearly worked - it got light on the skids, but never got into a hover. From that trial I worked out that I needed a motor of around 350 watts, and 2200 to 2700 kV. Unfortunately, every motor of this size seems to be out-of-stock at present! Overlander, 4-Max and HK are all showing out of stock, and no due dates!
However, HK did show a 3000kV 615 watt motor, so I decided to give it a try. It turned up today, and I've spent most of the afternoon figuring out how to fit it!
I finally got it fitted around 5 o'clock this afternoon, and gave it a quick hop in the back garden:
Success! Its airborne at around 1/2 throttle! I can probably afford to reduce the pitch on the blades a little bit!
The tail-rotor trim is a bit out, but easily sorted. However, its very slow on the cyclic controls and will need the throws to the swashplate increasing quite a lot! Its also a little tail-heavy, so I might need to add some ballast to the front somewhere.
But it's FLYING! After all these years! Which just goes to show what a clever guy Peter Valentine really was!
--
Pete