to build a LAPIDAR 1940's flyingwing - Page 2 - RC Groups
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Jul 21, 2006, 02:08 PM
Fantasy Scratch Builder
HanW's Avatar


Hallo Robbin Andrew.

Thats sad to hear this.
you are not there only one.
I also the firts time,
The CG op the picture is correct.
I have control that by mine modell.
Hi Han, also where is the CG, I guess that it is 75% from the LE at the fuselarge position
Corect CG Chord is by fuselarge 97cm.!!!!!!!!
CG 40 cm from LE.!!!!!!!!
+- 40 %!!!!!!!!

ps Make youre batteries in the nose.

Greats Han.
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Jul 23, 2006, 06:44 AM
Registered User


HI, the latest is that I have lenghtend the nose almost as it should have been, but I call it a FRENCH nose now and added 12ozs lead underneath! instead of the 3 1/2ozs.
Mind you with the large wing area it doesn't seem to have make any difference. The CG is well forward now so I expect it will be under control, cheers Robin
P.S. its just started raining so can't test it today.
Last edited by robin andrew; Jul 23, 2006 at 12:20 PM.
Jul 27, 2006, 01:50 PM
Registered User

6ft lapidar

HI, just been to try flying again after a delay caused by very hot weather.
Had 7 take-off attempts but it did not get airbourne properly.
The first started with 12 ozs of lead under the nose to give a 40% CG.
Gradualy I took off more lead until it looked good because it sped along the ground about 1" off the runway but with full up elevons it did not climb.
This repeated for several more attempts until the lead was down to 5ozs when suddenly it tore off and up into 3 thirty foot loops and landed upside down on the runway (during which it prop hung for a few seconds!)
So I guess the CG lies about half way between at 8ozs lead under the nose
at 50%. After rethinking about it, I suspect I need more washout in the tips to get a 'Rotate' automaticly instead of having to haul it off with full up elevons. Sadly, Robin Andrew
Last edited by robin andrew; Jul 28, 2006 at 04:45 AM.
Jul 27, 2006, 05:25 PM
Fantasy Scratch Builder
HanW's Avatar


I think you make the same mistake as I did.

1) The CG must 40%!!

2) The nose must 7 Up!!!
You do not that, Its an formule 1 Car.

3) And I missing the elevaters.
I try this week takeoff whit de elerons as elevaters.
He dit not takeoff!!!!(its an wing off een F1Car)

4) Wy did he not takeoff.
The elerons pust the end of the wingtips to the ground.
It didnt lift of the nose.
I did see when he fly's and I give up whit de elerons de wingtips push down. The nose did not up.

5) You must build elevaters in the wing(flaps)

6) where are de the batteries now.

Don't forget... I have 3.6 kilo gram in the nose (60X2400 sanyo) (60x 60gram)
It loke likes muts bud it is true!!!!

So this was it for today.

Robin Andrew succes!!!!!!
Let me now.....

Jul 28, 2006, 03:33 PM
Fantasy Scratch Builder
HanW's Avatar

mail from Robin Andrew.

Hellow Han,    thankyou for your advice on getting the 'lapidar' to take-off.  Can I ask a question;  If I fit flaps to the centre section in front of the propeller, are they set downwards for takeoff, cheers Robin Andrew
The rudder must Up. pict redcolour.!!!!!!
The outside ruder neutraal yellow!!!!

Cheers Han.
Aug 09, 2006, 05:14 AM
Fantasy Scratch Builder
HanW's Avatar

little problem.

Hoi Robbin Andrew.

I have an problem sinds sunday.
I have made an hard landing.

greats Han.
Aug 12, 2006, 03:59 PM
Fantasy Scratch Builder
HanW's Avatar


Hoi Robbin.

He is almost raddy to fly.
Some little thinks.

Greats Han.
Aug 13, 2006, 01:46 AM
Registered User
willin's Avatar
Oh! My! How has this one escaped me? What a beautiful unique ship this is. What a shame it is so difficult to trim so as to fly.

I like the camparative description (analogy) to the formule 1 Cars.

The work I have seen here is truly fine. Also a fine repair job of the damaged plane.

I will watch this thread more closely.

Aug 14, 2006, 12:59 PM
Fantasy Scratch Builder
HanW's Avatar

lapidar ready for take off!!

Hoi Robbin Andrew.

The Lapidar is Ready.
He can fly!!!!!!
Here some picts.

How was the meeting sunday.

Aug 14, 2006, 02:55 PM
Registered User


Hi Han, yes I can see the nose up attitude of 7 degrees well in thoes pictures.
WE couldn't hold the fly-in as it was rained off!! So it will give me chance to lenghten the nose leg, cheers Robin
PS thanks for the lovely shots of your large model.
Aug 14, 2006, 03:28 PM
Fantasy Scratch Builder
HanW's Avatar

Tanks for de complements.

I have weigt my model.
12,5 kilo.!!!!

Succes with the nose.

Aug 21, 2006, 08:45 AM
Fantasy Scratch Builder
HanW's Avatar

nose wheel lapidar.

Hoi Robin.

I found an sheet of nose wheel.
Thats scratsbuilding.

Aug 21, 2006, 11:10 AM
Registered User


Hi Han, thanks for the latest on the nose wheel. Just after I sent you a messarge that I couldn't think how to lengthen it, I suddenly thought it out. So I have added on a longer strut and now the nose now sits up at an angle about 7 degrees.
I've now built the front trouser fairing longer to make it fit the new shape and I'm charging up for tomorrow. Our weather has been wet and windy lately but I'll give it a test tomorrow if it's fine at the runway, cheers Robin Andrew.
Aug 21, 2006, 05:50 PM
Fantasy Scratch Builder
HanW's Avatar
Here is the weather the same.
Good luk tomorrow.
I hope he wil fly.

Aug 22, 2006, 03:43 PM
Registered User


HI Han, its not good news. I did 6 take-off's with the longer nose wheel and hooray, the model now lifts off the runway about 6" but when I release the up elevator on the tip panels it nose dives back onto the runway. After the 5th test I cut in some 10" long fixed trailing edge panels at both wingtips and tilted them up; this gives some more fixed reflex. Low and behold, it makes it much better at keeping 18" just above the runway but i didn't climb out. On the last test, all people watching and I put our heads together and because it still dives back onto the runway, decided to reduce the nose weight to 1/2 and it took off and went into the usual 2 twenty foot loops and prop hanging but crashed nose first onto the runway.
There is structeral damage to the wing and one tip 'waggler' fell off but I think it is repairable. I now convinced that I don't have sufficient FIXED reflex built into the wing, therefore it is unstable, cheers Robin

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