A possible very old glider conversion

A very, very long time ago (about 60 years!) I hand a hand in building one of these, a Mercury Marauder, notable for its unusual 'diamond' fuselage orientation.

With no suitable location, or real knowledge of how to fly it, it was only ever 'test' glided.
After some 30 years sitting in various lofts I set about using the wing, with a new 'conventional' fuselage, into a 2 channel RC glider but this was using big heavy 25 mHz kit!
With the weight of the RC the wing was not really strong enough to bungee launch so with ailerons added it was intended to slope, which it did just once but not very successfully.
It has sat in the loft ever since - I think it is still there!
Given only the wing of the original Marauder remains, and it is significantly modified anyway, I am tempted to restore it to its 'slope' configuration but as a powered glider.
Using modern micro gear the wing should be adequately strong as even with motor power it would weigh little more than the 11 oz (with nose weight) of the original glider.

Depending on what is actually left this thread may not go very far!

This sounds like a interesting project, I think "The Vintage model company" do a kit of that?

Quite correct Eric 27 mHz.
After 30 years in the loft this is what the glider now looks like.

The wing was extended to a full 72" from the Marauder's original 65".
Note the all flying tail plane set 1/3 of the way up the fin!
As was common for A2 gliders of the period it uses a heavily under cambered wing section.

Hmmm! There is rather a lot of work required to get it back to any sort of flying condition.!

That "could be" lovely, personally I would build a new original fuselage for it but that's just me...

I have actually downloaded a free set of plans for the Marauder and I probably still have the original somewhere too.
The issue with re building it in its original pure glider form is I don't really have anywhere to fly it, particularly as true 'free flight'.

The alternative is to restore it in its current 'RC' form but with power so it could be flown in my 'tree lined' field to prove to myself that the original conversion (including its all flying tail plane!) was aerodynamically sound.

Spent a couple of hours removing the extremely brittle tissue from the wing.

Despite it age the balsa, and the joints, are in surprisingly good condition.

As the rest of the air frame at 30 years old is only half the age of the wing it should be OK!

Nice project, be fun to rebuild it and aero tow it! that would float around lovely.

Klippy
You may well be right about lateral stability as the fin is pretty small and was set in front of the tail plane to allow it to tip up with a D/T.
The other problem from memory was the 'built up' nose which meant any firm 'arrival' required it to be rebuilt.

My reason for removing the polyhedral was simple to reduce the natural stability a bit as the ailerons were going to be rather small. Really just cut out from the substantial solid trailing edge of the wing tip section.

Despite the lightening holes in the trailing edge it still required almost 1/4 oz out on the other tip to balance the wing.
The joys of 'kit' wood even back in 1958!

All the tissue stripped off.

In this state it weighs 197 g (6.95 oz).
Covered in doped light weight tissue, a motor and all the electrics 400 g (14 oz) looks possible which would give a wing loading of 4.2 oz/sqft.

Nice! really looking forward to see how this progress.

Before much (any?) covering goes on the electrics have to go in.
First the motor with its printed mount.

Initially a fixed prop as it is simpler and lighter.
Light and carefully stream lined the mount allows cooling air to pass through the motor.

With an 8x6 it draws 9.5 A giving a modest 65 Watts on an 1800 mAh 2s which should give a good 10 minutes at WOT.
Elevator and rudder servos next.

Nice work! maybe we should create a vintage glider converted to rc section!

It looks like the motor, prop, ESC, 4 servos and the rx are going to weigh 60 g. The battery another 90 so provided the tissue and dope doesn't come in at more than 50 g my 400 g target looks possible.
I was going to order a 'stab' Rx but given its free flight heritage 'stab' should not really be necessary and I already have this 6 ch DSMX 'micro' Rx.

The rudder servo will use pull/pull lines although the elevator will use a light weight snake so both servos will be on the CofG.

The first test of the pull/pull rudder set up.

Still waiting for the snake to arrive from HK.
I can at least cover the tail planes with the tissue I got from Webbies yesterday.