Counter, no Contra rotating electric motor system challenge. (I hope I spelled it right ;)

[leaded50]

What is the scale of that airframe? Is it also a faom board build? I like the looks of that motor/ prop setup. Guessing it runs 2 ESC

Its a foamboard build yes. Length approx 950mm, wingspan 700mm. total weight with battery, el.retracts, eg. , 850 - 900g , Thrust on the contrasystem is 1420g on a 3s.
Can push voltage to 12.5 max recommended from seller( then get 1700g thrust).... they said motors aint for 4s.

(link to build: https://forum.flitetest.com/index.php?threads/payen-mitsubishi-pa400.64285/ )

 

[quorneng]

Vapepool
I too came across the MB 5 some 50 years ago and was highly impressed by its design features. At the time it well suited my requirements for a scale indoor electric round the pole control line as it had 'lots of prop' and a relatively short wing span.

Just 20" (510 mm) span but with a prop that is 1/3 of that span and 3 blade contra rotating too!
Long before the days of brushless motors it used a pair of geared 'slot car' motors to drive the contra rotating shafts.

It flew pretty well but with a basically hollow balsa body that acted like a sounding board the gear whine made it sound like more like a turbo prop than a Griffon.
After the war with no interest in piston engine fighters or desire to save such things for museums the one and only MB5 ended its days as a target on a gunnery range.
Unlike mine which I still have.

 

[Vapepool]

Vapepool
I too came across the MB 5 some 50 years ago and was highly impressed by its design features. At the time it well suited my requirements for a scale indoor electric round the pole control line as it had 'lots of prop' and a relatively short wing span.
View attachment 179675
Just 20" (510 mm) span but with a prop that is 1/3 of that span and 3 blade contra rotating too!
Long before the days of brushless motors it used a pair of geared 'slot car' motors to drive the contra rotating shafts.
View attachment 179676
It flew pretty well but with a basically hollow balsa body that acted like a sounding board the gear whine made it sound like more like a turbo prop than a Griffon.
After the war with no interest in piston engine fighters or desire to save such things for museums the one and only MB5 ended its days as a target on a gunnery range.
Unlike mine which I still have.

I bet that sounds fantastic.

 

[Vapepool]

I bet that sounds fantastic.

that is ingenious using the slot car motors and the geared shaft.....i actually have a few of those motors from my old slot car days.

 

[quorneng]

As it is getting on for 50 years old it is now definitely "retired" but a few years ago I did a video of a short ground test run just to confirm it still worked

 

[Vapepool]

Now I need to dig out my 3 view drawings and start making a build plan.