Fokker DR 1 Triplane- make it fly. IT DID NOV !!!!!

[Frank v B]

This Fokker triplane found its way into my car when picking up Jim Spence's (Canuke) V-900 complete spare parts kit*.
Jim attempted to make it fly but had trouble and repaired it.  He would love to see it fly so here we go to improve the chances.

step 1- Make it nose-heavy.  WW1 planes are notoriously tail heavy because the nose is so short. Made two changes:
- install a larger motor- from 100 watts to 150 watts.  Note the blurry photo of the motors.  The old (gold) motor wires were starting to fry. 
- a long thin battery that fits into the motor mount.  I bought a long thin EVO 800mah, 3 cell at the last Kitchener Swap meet.
step 2- make the rudder operational.  Need all the help I can get to make it taxi and fly straight.
step 3- make the landing gear stronger.  It had ripped out.

Photos:
2846- shows the rudder cut from the fin, tri-stock added to the rudder's leading edge so it can turn and filler balsa in the fin to make the fin's trailing edge continuous.
   47- Tri stock sanded and trimmed, two hinges added and glued in place.
   48- the old 22mm motor on the left (100 watts) and the new (blue, 150 watts) 28mm motor on the right.  Note the fried wires on the old motor.  Too much draw.
   50- add a piece of plywood to the firewall to help with the newer, heavier motor.  Done so there is a flush front surface to hold the motor.
   51- the new battery.  Long and thin so it can slide behind the motor.
   52- the new battery in place.

Everything is now curing.  It is called getting ready for dinner.
Note: if some of these pictures look blurry to you.... you need another drink.

Frank

* that's what a paranoid person calls a second identical airplane to justify the expense.

[GuyOReilly]

@Frank v B , this is great building weather,  but you need not request it for the rest of us...   
Guy

[Frank v B]

Guy,

In Holland a rainy day like today is called "Summer".

Frank

[GuyOReilly]

Guy,

In Holland a rainy day like today is called "Summer".

Frank

Thank you for the clarification on weather terms in the "Old" country.     I wonder what @Andy Hoffer would say about a Saskatchewan-Day such as today.    What would they call it; not cold enough for winter, not dry enough to call it summer.... hummm     All I know is that it is the Start of the Building Season!   

[Andy Hoffer]

Guy,

In Holland a rainy day like today is called "Summer".

Frank

Thank you for the clarification on weather terms in the "Old" country.     I wonder what @Andy Hoffer would say about a Saskatchewan-Day such as today.    What would they call it; not cold enough for winter, not dry enough to call it summer.... hummm     All I know is that it is the Start of the Building Season!   

@GuyOReilly  and @Frank v B,

I would call it the harbinger of magnificent winter flying!   

Andy

[Frank v B]

Back to work

The cowl

Wanted to have a longer cowl so more of the motor would be covered.  The original one looked like a container stolen from a kitchen.  So I rattled through our kitchen and found two possibles but the Ikea bowl had sloped sides (correct diameter) and the Becel container was too large.

Decided to make my own.  Made two pieces of balsa the diameter of the firewall and 4 balsa stand-offs.
Will glue them together and report tomorrow.


Frank

[Frank v B]

Why wait until tomorrow?

Made a 5th stand-off and glued it together.  Once dry, I will sand a slope into it and cover the outside with 1/16" balsa.

Frank

[Gregor77]

Nice work Frank!

[Frank v B]

Thanks Greg, Mr. Triplane.

Covering the cowl

- cut two pieces of 1/16" balsa and soak it to make it curve without breaking.  Put the pieces on top of a wet shop cloth (blue).
- covered it with another wet shop cloth and let stand for about 5 minutes.
- glue the pieces with the centre joint at the top.
- clamp and let dry.

Note: the balsa skin was cut too big on purpose.  It is much easier to sand it flush after it cures than trying to line everything up before glueing it.

Frank

[GuyOReilly]

@Frank v B , I must say I am impressed!   
Looking great, and I will be using your wet method to do some balsa-bending soon.
Guy

[Gil.E]

@Frank v B
Now you really piqued my interest with this new exotic material (Balsa?) curving trick. I googled more about it and found this:
     

"One sided Moisture / Heat
If you take a sheet or strip of balsa and dampen one side you'll see that in a few seconds that the balsa starts to curve away from the dampened size. Conversely, if you apply a hot iron to the sheet of balsa, the balsa will curve towards the heated side. The reason why this occurs in both cases is due to a difference in moisture content in the balsa wood cells. The more moisture in the cell the more it expands.

In the damp application the damp side of the balsa expands causing the sheet to curve away. With the iron application the moisture is being driven out of the balsa cells on that side to contract and causing the balsa to curl in.

Chemicals
Sometimes you really need to get a piece of balsa around and things are already too thin for laminating practically - the solution can sometimes be to chemically adjust balsa to bend. Clouded Ammonia (water with ammonia in it) or Windex will make balsa especially flexible. The action by which this occurs is the breaking down of the balsa cell walls. Interestingly some people have reported that using vinegar also works, the key appears to be to soak the material in a non-neutral pH substance.

For clouded ammonia, use a 50/50 mix with water. CAUTION - use this mix in a well ventilated area. Ammonia can suffocate you. If you would rather not task the potential risk, consider using the long-soak method.

Long soak
If using chemicals such as ammonia or vinegar isn't your idea of a plesant experience, you can soak the balsa in hot/warm warm water for an hour or more (depending on the thickness). The heat is useful to accellerate the absorption of the water into the cell structure "

But no mention of the double sided sheet method. You might be on to something new here 
 

[Andy Hoffer]

Thanks Greg, Mr. Triplane.

Covering the cowl

- cut two pieces of 1/16" balsa and soak it to make it curve without breaking.  Put the pieces on top of a wet shop cloth (blue).
- covered it with another wet shop cloth and let stand for about 5 minutes.
- glue the pieces with the centre joint at the top.
- clamp and let dry.

Note: the balsa skin was cut too big on purpose.  It is much easier to sand it flush after it cures than trying to line everything up before glueing it.

Frank

OMG @Frank v B !

Three out of four photos IN FOCUS!!  It must be my eyes!

Andy

[Frank v B]

Gil,

Thanks for the research of the balsa bending methods.  I don't use chemicals.
I have used the bend the balsa by wetting the outside of the curve.  Problem is that I have had it split on the dry side so I started soaking both sides.
Shop towels have an amazing ability to retain water so I just use them to keep the moisture on the wood on both sides.  "Form follows function".

Sorry Andy about the three in-focus photos.  After another drink the fourth photo should be in focus.

Frank

[Frank v B]

Fitting the cowl.

Had to cut around the popsicle sticks of the firewall repair to make the cowl fit.  Sanded the front smooth but cleft a rim around the back so it would catch around the firewall/fuselage.

Will have to figure out a way to fasten it.  Will probably use magnets.

Frank

[Andy Hoffer]

Hi @Frank v B

I SO want to be there when you fly this in the house for Cynthia!

Andy