Baby Flea

Here is my next project, proof that you can build a quarter scale model and still not exceed 1 meter span

It is Henri Mignet's HM16, also known as the Pou Bébé, or Baby Flea.

Max.

Is that not the same as Ian's Berty Basset

No, Ian's Pou is a HM14, the type most people will recognize as the Flying Flea. In fact, Mignet designed, built and flew many variants of the Flea, but the HM14 is the one that grabbed the imagination of the homebuilding enthousiasts at that period. Unfortunately, it is also remembered as the Flea that had some fatal flaws, which eventually led to a ban of the type.

This HM16 is a smaller version of only 4 meter span. Henri Mignet was of small stature, and it was said that the Baby Flea could only be flown by himself with some degree of safety.

Max.

Some computer generated "artist's impressions":

This looks an ideal subject for a free pull-out plan.

Watching with interest.

MZ, that looks interesting I'm very fond of some of the old home built designs. What sort of power plant are you thinking of using. Keep the updates coming I'll be watching this one.

The thought crossed my mind

JVR, for now I have allowed space for a HK NTM 35-42, which is capable of 450W at 3s. I am running this motor in my 1250mm span Tiger Moth, turning a 10x5 Master Airscrew at 1000Kv. Ample power, but I may change it to another type which can be accommodated more easily with the dummy engine I have planned.

Here is a picture showing how I designed the frame, mostly from light (poplar) ply:

Max.

Fascinating subject. I'll have to get around to building one -along with the 100s of others on the list ! There is a free-flight plan for a 31" 0.8cc Flea which was a freebie with the Oct.1969 Aeromodeller , designed by Rene Stamm. APS Code BC. There was also a free pull - out 17 1/4 " Ebenezer Flea for .01 - .02 power by J.M.Fullarton in the Dec.1965 AM. A 1/5th 53 1/2 HM18 for .25 power. a Bob Wright design Superplan with the 1992 Radio Modeller. A sport - scale 66' for .30 -.40 in the Nov.81 RCM by Randy Whistley and an Abbott - Baynes 77" .60 power, by Alan Smith in the Mar. 91 Flying Models. Maybe you could use this info as X -ref. for your build. Hope you post a flying video .

My, you either have a fantastic memory or a good archive index . I built the Randy Wisely one when it was published in the 80's. Flew it for a while with mixed success, then took it halfway around the world to NZ, only to crash it on the first flight there. It is still "under repair" .
My current design is actually based on the RBCkits Pou du Ciel, scaled up a few notches. I designed that one too, and flew it successfully for a while. Check out the RCGroups thread on that.

Max.

Fantastic memory ? Noooooo ! Just a folder of Flea plans and assorted info. I've collected over the years. Keep us posted with your build progress. I would gladly donate all this to any would - be Flea builder. My wish list far exceeds my life expectancy !!!

Hello Maz Z

Looking at those computer generated pictures made me think of the asp 160 flat twin that is calling out for this style of aircraft for it to be fitted into, would it be feasible to scale it up for that size of engine what sort of size would it end up at, or just stick with a 91 fs if the 160 twin is to big.

I wouldn't be surprised if Ian Redshaw built one, Max. He's got a bit of a 'thing' for Fleas (aircraft, not insects!). He had a tiny one a few years ago long before he built his 1/2 scale one. He used to bring bits of Bertie Basset to our winter evening indoor sessions to show us his progress. For a 1/2 scale model, it was surprisingly small. He's an annoyingly superb builder and pilot He's also my go-to test pilot if I have a model I'm a bit unsure about.

Has this Flea got the same, often fatal, design flaw of it bigger sister?  ie that pulling up increased the the speed of the airflow over the top of the tail plane (because of the slot effect) and caused it to dive. 

Geoff

Edited By Geoff Sleath on 08/08/2015 13:28:48

Probably yes Geoff, although I did not read that anywhere. Mignet never published any plans for this type, so there were not many made. But my smaller version (about 700 span) did not display such misbehaviour, so I am hopeful...

@J V R : I have no idea about engine sizes v.s. plane size in that range, but the Flea designs usually have a very low wingloading. The Randy Wrisley (not Wisely ) HM14 I built many years ago was 2 meter+ span was only powered by a .25 twostroke, so your .90 or 1.6 may even be sufficient to get a half scale version airborne, who knows..

By the way, scaling up a CAD design is not as simple as many think. You have to consider standard sheet wood thickness, and construction details that are appropriate for a smaller design may not be so for a scaled up version.

Max.

Okay, after several years lying dormant in my computer I woke the project up again, and finished the re-design of the larger version in the last couple of weeks (told you scaling up is not that simple...). I send the parts file off to my favourite kit cutter and they arrived this afternoon. So let the build start (when my building shed cools down sufficiently, temperatures here in The Netherlands are soaring over the next few days. No different from the UK I guess).

Max.

Edited By Max Z on 29/06/2018 16:44:09

And I thought my 1/4 TK4 is small No need to take the wings apart for transport in the car!

Good luck with this model,

Timo

Glad to see you've resurrected this project. I look forward to witnessing your progress and may even build one myself if it can be electrically powered.

I visited Old Warden less than 2 weeks ago as I was in the area and saw the Flea there. Unfortunately it's strung up in the air in one of the hangars and difficult to examine closely. I think it has a Scott engine, which further entices me having used a 1932 TT Replica as my main means of transport back in the 1960s. Of course its current location is as high as it's going to get as actually flying it is illegal in the UK because of the number of accidents they suffered.

Geoff

Some pictures to give you an impression of  the build sofar. The one with the flat top is the actual status, I need to place it upside down to add the bottom planking first. The other ones show a mockup of the front top cowling.

Max.

Edited By Max Z on 01/07/2018 14:09:08

Frame for the top cowling fitted permanently. Frame of the forward hatch completed (to slide the battery in and out). Wing struts fitted temporarily, I will take these off again and complete the planking of the cowling first, as it will be quite awkward to finish that with the struts in place.

I also had a stab at making the landing gear, I am waiting until I have the ordered correctly sized wheels (87 mm diameter Dave Brown lite wheels) to finish it.

Max.

Edited By Max Z on 03/07/2018 14:55:18

Nice and tidy job indeed!

Will you reinforce the rear strut somehow?

I am not sure what you mean by that, the struts remain as they are now, but I am adding a small block on either side under the "deck", to give the rear strut more glueing surface.

Max.