Another project ! 1/4 scale Grunau Baby IIb

[Fred]

Thank you all !  :oops:

A bit of progress yesterday evening  

Put the aileron's frame in place. Frame is in 3mm plywood, slotted in place.





And I then glued the TE for the wing and the Aileron's TE...





And finally, I put the wing joiner tubes, made of 12mm diameter aluminium tube, for a 10mm wing joiner inside...
2 of them, a bit too much, but like that, I'm sure nothing will move !  



And you can see on this photo a small mistake... :oops:  I leave it to you to find ! Corrected now on the plan, must have felt asleep between 2 measurements !  :?:

Another mistake, not a huge one, but still ! When I checked the airbrakes, I remembered how they should go into the wing.. And I should have put the airbrakes and the mounting inside the box before gluing it to the wing !  

Ah well, I'll do that for the next wing, but I did a test yesterday, and you can still mount everything when everything is glued inside the wing, that just take more time to do...

Anyway, I did a test of the airbrakes, just to see them working...

The airbrakes parts :



Closed :



And open :



All good !    Spacers are made of 3mm plywood, and I used 2mm screws to fix everything. Axles are in 5mm carbone tubes, and the axle will them go through the airbrakes box in the wing and the airbrakes mounting plate... Not sure if it's clear, but a few photos of the system will clear the idea !  

Stay tuned !

[Alan_Perse]

Ah yes. I see the mistake. At rib No 3. Looks great though Fred. Keep up the good work     .

[joe]

keep it coming Fred!

[Alan_Perse]

I knew it was a Grunau Baby       , seriously I did     .

[Fred]

Alan, what were you thinking this glider was ? Honest !  

A bit of work tonight between 2 nappies, bottles and all the fuzz around, with the rudder...

The pieces :



And after 5 minutes and a bit of sanding...



I'll glue the TE tomorrow (10mm balsa)

[Alan_Perse]

Alan, what were you thinking this glider was ? Honest !  

I thought it was a glider made from glassfiber shit     . But seriously looking at the shape of the parts and the year it was made, it could only have been the Grunau Baby. But I would not have known if it was'nt for Marten Simons books.

[Fred]

Did not have enough free time yesterday to commit to gluing something (was going to start the elevator...), so instead, I put the fuselage together quickly to have a look (curious me ??)

Hop, no glue  





All looking good so far.
And I've put everything back in the box, I'll go back to the fuselage later, after I've made the second wing (that was more of an apetiser of what is coming next   )

[error404]

Great work Fred.  :clap:

[Fred]

Thanks Anthony !  

[Fred]

Still moving !  

Here is today's work, with the elevator.

All the parts :



Mostly 10mm Balsa and 2mm plywood.

As usual, everything is put on the plan. The elevator ribs are slided into each slots on the stab TE/LE, and glued... I have to admit that I used thin CA everywhere here... :oops:



Really easy...
A few adjustments are needed there and there for the ends of the ribs to fit tight...





And after... Well, not that long, you have a fix elevator !  



Now to the moving part !

Same as the fixed one, except this is not build on the plan, but "in the air". Same principle...







2 halves. They are then joined with a piece of 3mm plywood glued with epoxy.

Et voila !





A bit of sanding will then be required to smooth everything.

Happy, but the idea at the design process was to have a stab ready to be covered once glued and sanded... But because I want a all plywood finish, I will have to add 0.4mm on the elevator LE to apply the vanish on.
Can definitively be left as is if you go for a covered/painted finish.

So far, I roughly spend 5 hours on the project  

Tomorrow, back to the wings !

[Alan_Perse]

Looks great Fred     . Keep up the good work. You realy do build fast  :shock: . Just out of curiosity, what software do you use to design your wings etc, Compufoil, Profili 2?

[Fred]

Thanks Alan,

Sorry, forgot to answer your question  :oops:
For the wings, I use Tracfoil (http://fly.to/tracfoil), but the ribs webbing are made in Turbocad.

So, had an hour to spare this week end, time to go back to the Grunau Baby !
Work done on the fuselage, but this time, everything is glued !
Almost finished and ready for the servos to be installed before doing the sheeting in 0.8mm plywood.



All the formers are glued to the building template, just make sure that everything is square.
I started from the front to tail, gluing all the elements as I progressed (cockpit floor, servo tray...) to keep everything as straight as possible.
The strips are made of 5x5mm balsa.


This is the cabin template, made of 3mm plywood. Happy with that part, just the sheeting needed now !  



All straight !



The profile is the MS535.



Backbone is glued...



So as the bottom one (at this stage, I was able to move the fuselage around...)



Everything simply slot together  

And a few more photos...



Guides for the pushrod (5mm sullivan) are integrated to the formers for the elevator, rudder being a push/pull cable.



For once, I keep a log on the time spent, and so far, I have spent 7 and a half hours into this build  
So far, so good !

[Fred]

Not a lot done today...
The fixed rudder squeleton is now in place.
The 0.4mm plywood will then be rolled on it to make the final shape.

[Fred]

Servos and snake rod are in !  

[Fred]

Did a bit of work this week end on the Grunau, and did the second wing...
And with the really good weather this week end, that was time for the first setup of the machine in the garden !  

















 

Plan this week is to start the fuselage sheeting.. Should be relatively quick to do !

Not a huge amount of work left to be done now, a few bits and pieces...