Claus...Duetto updates!

Claus Maikis,

Just noticed your post on glow-plugs.

Awhile back I was exchanging mail with Andy Sweetland about a Duetto he was building with your latest mods to the airfoil and other things.

I lost his mails in a computer snafu.

Could you say a few things about bringing the Duetto and Boogie-Woogis up to current speed as you see it?

...I have plans for both...love the biplanes!!!

Andy...hows the Duetto coming...!

Thanks,

Hello Pete,
let me first say a few general things about my bipes. DUETTO was intended as a fully competitive airplane, to be used in competition. It ought to fly as well as a biplane possibly can, and I wanted to find out how good a biplane I can design. Oh, it did quite well, I even won a few contests. But of course it had its limitations ( especially in very hot weather the DUETTO seemed to have not enough lift , the last corner of the triangle or hourglass were exciting, to say the least ).
The BOOGIE is a pure fun airplane with only that nostalgic look as a design goal. It can hardly do a square.
Another flyer wanted to build the DUETTO, but I recommended several changes to the design ( these are the changes I told Andy, as far as I remembered ).
Use a 60 engine instead of a 46
Increase wing span by about 5” , tail span by 2”
Increase airfoil thickness by 10% ( from 27 to 30 mm )
Increase flap chord by 3/8 “
Lengthen rear fuselage by at least 1”
Lengthen fuselage nose by about ½ “ ( to compensate for heavier engine )
Increase dimension of wing gap ( top wing higher )
This new design flew VERY well. When I watched it from outside I didn’t notice any difference to a monoplane ( well - this was not a world top class flyer ). But of course this was no longer a DUETTO ( see attachment TWINI ).
If I would ever build a biplane again I would use the dimensions as given here. Install the interplane struts as near to the wing tips as aesthetics will allow. Biplanes have short wings which makes them not very stable around the longitudinal axis.
I hope this information can help you a little.
Regards, claus

You may find more interest in bipes here than you think. I would like to get a set of plans, who do I contact?

Bob

The plan is available from Nexus http://www.nexusonline.com

The price is 9 pounds 50 p inc VAT. We don't pay VAT when we buy from the UK.

Hi Pete,

I've just seen your post.

Now that the F2B Working Group exercise is finished (as far as I'm concerned), the "Duetto" is coming out of the cupboard again (i.e. the straight answer to your question is that it hasn't progressed at all since we were last in contact in May!!).

What Claus has written is (of course) absolutely correct, but as I see that you've lost my original E-mails on this subject I've just sent them to you (direct) again.

If anyone else is interested in the details then I'll happily send them their own copies of the above E-mails (I guess that a bipe stunter is a bit too "out of the ordinary" to be of interest to many on this Forum to make it worth while posting here).

But one thing I'd to add to what Claus has written which may be of general interest to many - for my "modified Duetto" I've chosen ST .51 power, not .60. I read in a UK model mag just last week that C/L ST .51's are now available again, from Tigre Engines, 13 Smith Street, Watford WD1 8AA, England; at a cost of approx 75 UK pounds (usual disclaimers).

Wow, that is one nice-looking bipe! I have to admit to having a soft spot in my heart (and probably head) for biplanes - they just look really cool to me! Maybe I'll think about building one someday, but it'll definitely be a while (got to improve my skills first...

Tim

Claus: What is your span? I know that it was increased 5", but from what? Thanks. Currell

hello Currell,
the answer " 5 inches more" was given to Pete because he has the plans.
The span of the original DUETTO was 112 cm ( 43,6" ).
The span of TWINI is 125 cm ( 48,7" ).
Another subject: yes the Super Tigre 51 ( which was a very good stunt engine ) is available again - from China. But nobody knows whether it's just the RC engine with a venturi, or the control line stunt version ( which had another timing for the ports ).
Regards, claus

Claus and Andy,

I lost track of this thread..was out of town for a few days.

Thanks for the response...I really enjoy the biplanes...will do another one eventually...( I should post my Sterling 'Flying Fool' pictures...decayed silk and all !! )...

Hope a few folks will get fired up for something new after seeing the gorgeous Duetto in clear and red silk...?

If you have input on your bipes, submit please as I think it very refreshing...maybe for more than just me.

Thanks again for your replies, (I lost all my old e-mails from Andy in a ipo switch.)