Lippisch P13a

You can buy offset outlet bends for wc

BB
I looked at them but in my case not only did the pipe have to offset side ways to the rear but upwards as well. Only one with a flexible section could do that.
Top view showing the rear offset.
 
Side view showing the vertical offset.
 
It works well enough. Just have to hope the flexible bit lasts!

Anyway it has allowed a bit more progress with the Lippisch.
The full duct glued in place in the half shell and the RH formers added on top.
 
Note the the three magnet wires leading back from the EDF. Exactly where the ESC will go will depend of the battery position and I have no idea where that will be! 

It could fly using just two elevon servos but I think it might be wise to add a working rudder and a gyro rx too! 

The new toilet toilet is fully operational so on to the next task erecting my daughters new timber pergola - in the middle of winter!

Started skinning the other half of the P13a's fuselage.
 
It does rather show just how much space there is inside and there will be quite a bit more inside that huge broad fin!
I may have to actually build and attach the outer wing panels to get an idea of where the battery will need to go.
At the moment the heavy EDF in the nose makes the light Depron structure feel very nose heavy.​​​​

The new toilet toilet is fully operational - - bet that's a relief! 

Still slowly going forward
The 'fuselage' completely skinned.
 
The exhaust slot showing the dummy side pieces to create the scale size.
 
It is quite light. With the EDF and 1500mAh 3s included it totals 240g.
Hopefully not too much over 300g when complete.   
 

I have built the fin but not fixed on yet.
 
I will make a hatch once I have worked out where battery has to go!
To call it a 'fin' is a bit of a stretch. It is hugely thick!
 
Lippisch may have been a renowned aerodynamicist but what was he thinking when he sketched the P13 out. To make matters worse it was intended to be supersonic.   

Completed the basic part of the RH wing.
 
It is a little more aerodynamic than the fin but not by much! 
About its only saving graces is it weighs just 14.6 g.
The LH wing is currently under construction.

Although there appears to be little progress I have been working on it as my serious cough and cold has allowed. Not that it effects my DIY directly but the cough has resulted in a serious lack  of 'proper' sleep.
Anyway the wings are now complete..
 
Just a bit larger than that 'printed' Lippisch at 660 mm span rather than 600. I have not been able to find out the weight of the printed one but I suspect it is quite a bit heavier.
The elevons and rudder are currently "under construction". With the three servos suitably positioned' I should finally be able to 'set' the battery location.

The Lippisch had a substantial belly landing skid which will make a hand hold for launch. There is precious little else to hold!   

Not much visible progress to show.
 
The elevons fitted and their servos installed.
The Lemon Stab rx in its Depron 'box'.
 
Just a push fit so easily removeable. Past experience has shown it takes quite a bit of fiddling to get the right combination of what goes where and what needs to be reversed either on the stab itself or the tx before everything works and reacts in the direction it is supposed to.
A rudder is next as soon as the servo arrives from China.

Whilst I am reasonably confident it will have the power to fly however the closer it gets to being complete the less confidence I have that it will be controllable. Just about all the aerodynamic surfaces are about the opposite of what I would expect to work well. 

The only reason I even went ahead with the Lippisch is my Handley Page  HP 115 which has nearly as ridiculous proportions yet it ended up flying remarkably well.
 
However its wing section is more realistic and with basically a similar weight and power it does have virtually twice the wing area. .
I fear the Lippisch will be a step too far.  

Having selected the "delta" dip switch on the rx but as i feared setting up the elevons to show both correct control sense and the correct stab reaction did take some fiddling. Not only had the L & R elevon servos had to swap the plug positions on the rx but they also had to be reversed on the tx and on the rx dip switches before it all worked correctly.

It does not surprise me there are many forum entries where beginners get stuck not realising just how many possible setting combinations there are with 'stab' elevons.
Still the rudder, its servo and the nose skid to add but so far it weighs 346 g including the battery.  Say 370 g ready to go.

My confidence that the Lippisch will be controllable has not improved! 
 

My feelings entirely, I had similar problems with the Seagull, and I wasn't fitting a stab!

A bit more progress,
The fin/cockpit is glued on.
 
Although in more or less the right place for the cockpit the hatch is a bit over size to make fitting the battery a bit easier,
The battery box.
 
With a complete nose to tail duct the battery was always going to be mounted over the duct. It is slightly off set to the right to counter the weight of ESC mounted on the left.
The battery position fore and aft is a guess and puts the CofG a bit further forward than I originally imagined but I guess I can live with a bit nose heavy given its questionable aerodynamics.  

 

For no real reason other than it was sunny an 'outside' picture.
 
Given its experimental nature it will be painted white (it is after all white Depron) with black details in such a way that it will be hopefully easy to tell which way up it is!
I hope I will be a bit more successful than this guy!

 

Audibly very windy - hopeless conditions for a featherweight model!
I note he didn't actually say what it weighted in at - no indication if he checked the controls were working in the correct orientation - or even if he could fly anything!
Several of those 'launches' - what we could see of them - were fully stalled as soon as he let go!
edit
That vid was four years ago -
Here's a different model he was flying a few weeks ago - that's all over the place as well!

The DTFB Puri. . I have seen worse (and done worse) Maiden flights. It looked very sensitive to control surface movements. Better use of adhesive would have helped as explained