Mayfly - by Peter Valentine

Here’s one for Pete
Retro helicopters
Pchristy
Posts: 413
Joined: 16 Feb 2018, 13:57
Location: South Devon, UK

Mayfly - by Peter Valentine

Post by Pchristy »

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!

Image
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!

Image
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.

Image

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!):

Image

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!

Image

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
bluejets
Posts: 316
Joined: 19 Jun 2019, 04:09

Re: Mayfly - by Peter Valentine

Post by bluejets »

Great stuff...love it......did you use the new ATtiny gyro..??
Pchristy
Posts: 413
Joined: 16 Feb 2018, 13:57
Location: South Devon, UK

Re: Mayfly - by Peter Valentine

Post by Pchristy »

No, the new ATTiny is in my JR Voyager-E awaiting Martin's next update. I used a small (and cheap!) GWS gyro that had been in my junk box for a while.

The GWS gyros are very basic, and a bit prone to drifting, but fine for a simple model like this!

--
Pete
bluejets
Posts: 316
Joined: 19 Jun 2019, 04:09

Re: Mayfly - by Peter Valentine

Post by bluejets »

Pchristy wrote: 10 Sep 2020, 09:06 I used a small (and cheap!) GWS gyro that had been in my junk box for a while.
Must have been a cousin to this one then...... :shock:
gws.jpg
https://www.ebay.com.au/itm/GWS-gyro-un ... .l4275.c10
Pchristy
Posts: 413
Joined: 16 Feb 2018, 13:57
Location: South Devon, UK

Re: Mayfly - by Peter Valentine

Post by Pchristy »

Yes, that's the gyro! I've got a few of them! Not terribly brilliant because of the neutral drift (not sure if its volts or temp causing it!), but adequate for small models.

I think the seller is being very optimistic with the price! :shock:
Phil_G wrote: 10 Sep 2020, 11:33 Well done Pete - You've rescued a piece of history there that would otherwise have been lost forever :D
Peter Valentine was a real innovator, way ahead of his time. Never met him but I remember reading his magazine articles over & over. Great stuff.
Phil
Phil: Its a shame you never met Peter Valentine, you would have got on well together! Decades ago he wanted to produce a flybar-less system for helicopters using gyros! The problem was that at the time, the gyros were all mechanical and the servos neither fast nor powerful!

Truly, a man ahead of his time, and a much missed friend!

--
Pete
Pchristy
Posts: 413
Joined: 16 Feb 2018, 13:57
Location: South Devon, UK

Re: Mayfly - by Peter Valentine

Post by Pchristy »

Ooops!

Following some further test hops, the model is currently grounded! The "experimental" tail rotor gearbox has turned out to be a dud, with the gears failing (melting!) in flight

Luckily I was able to get the model down without any further damage ( it wasn't very high!). I'll have to trawl through the collection of bits that PV left behind to see if I can cobble together a substitute!

I will get it flying again somehow!

--
Pete
Spike S
Posts: 181
Joined: 16 Feb 2018, 14:59
Location: Salisbury UK

Re: Mayfly - by Peter Valentine

Post by Spike S »

I was posted on exchange with the crabs back then. Somewhere, I have some super-8 film of the model heli meeting at RAF Odiham in 1976 (?) with footage of what I am sure is this Mayfly demonstrating very steady flight only feet in front of me. Will have to transfer it from 'wet' film to mpeg(?). Perhaps someone could then utube it for us.
Last edited by Spike S on 12 Sep 2020, 11:41, edited 1 time in total.
Spike S
(Tune for maximum smoke)
Tobe
Posts: 665
Joined: 16 Feb 2018, 06:19
Location: Varberg or Stockholm, Sweden

Re: Mayfly - by Peter Valentine

Post by Tobe »

I'm quite sure those tail gears are standard and should still be available but they might need some machining. Do you have any size like diameter length! Gear ratio 1:1? Let me see what I can find, if not I have junk boxes. Basically you are looking for "crossed helical gear" aka "45° Staggered Steel Gear"
A good info would also be what the cc are between the 2 shafts
I would guess they are in some alloy I.e. beryllium bronze which was considered self lubricating but...
I would keep the next well lubricated and if possible shielded from dust and dirt.
I remember from my Larks that this helped a lot to keep the tail gear working nicely lasting in time
Cheers Pete and be safe

Tobe
Cheers,

Tobe
Pchristy
Posts: 413
Joined: 16 Feb 2018, 13:57
Location: South Devon, UK

Re: Mayfly - by Peter Valentine

Post by Pchristy »

Spike: I was flying at that event! Peter Valentine was there, but with his tiny .049 powered Mayfly! You can see some footage of the Odiham event here:

I've since managed to do a transfer at higher quality - this one was done by pointing a camera at the projector screen - not ideal! I now have a proper 8mm telecine, and can do 8mm and Super-8 in reasonable quality!

Tobe: I think the problem was that both gears were some kind of plastic! One should have been metal, ideally!

I've had a trawl through the remaining bits that PV left behind, but haven't found anything compatible. I think the best bet is to use some Lark bits. The Mayfly experimental gearbox uses a lot of aluminium bits, and is quite heavy. The model is slightly tail heavy, as a result. I think I have sufficient bits to build a modified Lark gearbox which I can fit instead, and which should also be lighter.

It won't be a 5-minute job, though! I will still need to source some odd bits, but I'm sure its do-able!

I'm not giving up! Whilst it was flying, it was nicely stable! It deserves another go!

:)

--
Pete
Tobe
Posts: 665
Joined: 16 Feb 2018, 06:19
Location: Varberg or Stockholm, Sweden

Re: Mayfly - by Peter Valentine

Post by Tobe »

Gosh, amazing Pete, you brought back so many memories with this men and their fantastic flying machines. Often it was a matter to just follow/walk behind helicopter in any direction it took if you wanted to stay airborne.
Many helis had amazing fuselages and to save them from often the inevitable you had to build training ones but as often the mechanics were integrated that wasn't that simple either.
My Lark would only get airborne during windy days and if the temperature was below 20 degC so imagine how it was when I got my Heli Baby in which I had a Super Tigre .60 ST...this engine was such it has the size of a regular .40.
The Heli Baby is the only one of my early choppers together the Lark that I unfortunately didn't kept, but still have in perfect order the Super Heli Baby, the Heli Boy & the Heli Star before I went over to Falcon 505 of which I still have in bits and pieces at least 2 together with maybe not tons but 10's of kg of spare parts. I need to one day dive in those boxes and sort it out. If anyone need spare parts for the 505 let me know as there's a good chance but I'm short of canopies and I will get an excuse to reopen those boxes.
Cheers,

Tobe
Post Reply