48" span Cessna L-19 Bird Dog- Let's make some balsa dust!

[Frank v B]

Have not built anything in a week.  Sorted through my plan selection and picked 4 potential ones....then I got a phone call from a friend asking whether I could build this kit.  Are you kidding me!  I believe!! There is a higher power.

- 48" span
- ailerons, no flaps but...let me get into it.
- 200-250 watt power system.

The photo shows the separated parts in the box and the left-over flashing outside the box.
Instructions, plans.

I hear screaming from my workshop.  100 spare servos, 20 spare motors and 25 ESC's going "Pick me!"

Frank

[GuyOReilly]

Just in case you would need inspiration for the colour scheme.   
Also, I know a guy who flew that plane. 
Guy

[Frank v B]

Guy,

Done!*

F.

* I have yellow and blue covering.... and I don't want you to have a tantrum at the field if we show up with another colour scheme.

[Frank v B]

Sub assemblies.

Good thing I always build against a metal ruler when joining pieces that have to be straight.  That is the front part of one fuselage side.
The knife point shows a gap at the top of about 1/32 of an inch.  The fit is good but the alignment is off.

F.

ps: now I know why the owner got frustrated.  This kit was designed for scratch building, then it was optimized for laser cutting a few years later.  The joints do not show up on the plans.
I suspect the instructions were written by the guy who was probably fired from Balsa USA and wrote their old instructions.  (from my post on Rob's Sopwith "I have only built one balsa USA kit and that was in about 1990.   It was a box of balsa and a type-written one page instruction sheet that essentially said:
"Thank you for buying our kit.  Put all the balsa pieces together properly, add the covering, add engine, radio and fuel.  Happy flying"  )

[octagon]

Frank, are you building it for him or for yourself. I love Guy's colour scheme. Great colour to see in winter or summer.

[Frank v B]

Rob,

re: your question "Frank, are you building it for him or for yourself."

The answer is YES.

We will see what it looks like when it is finished and then maiden it.  Then ownership will be decided. 


Frank

ps: this non answer is for self preservation.  If I say "I am building it for someone else".... no issue at home.  If it is for me it will beg for the "fine, which plane are you getting rid of?"  That's modelling's equivalent of "which one your children do you like best?"  Let sleeping dogs lie.

[Frank v B]

Death by 1000 clamps.

There were two of each of the two main formers (at the leading edge and trailing edge of the wing) so I decided to laminate them.  The plan only shows one of each.  The extra one will only add strength where most fuses break.  Also laminated the two identical nose block pieces.

The clamps are the Dollarama tomato clamps and are great for this kind of work. Two sizes.  All these green clamps were $2.50 plus tax.

I am using Lepage's Express fast drying wood glue.  There are many clamps because the moisture in the glue will affect it while it dries.  I do not want it to curl overnight.

Note the two pins in the nose block lamination.  The two pins are to stop the wood from sliding while drying.

Frank

ps: I cannot use CA.  My wife is allergic to it.  I don't want to test that theory in case the allergy is not just CA but all model airplanes.

[msatin]

I don't think I ever seen Frank happier! 

[Frank v B]

Yep for happier.

Happiest would be this project and Spring!

F

[Frank v B]

-Fuse sides received the tri-stock and 1/4" square longerons.  Will let it cure overnight.
- formers have been prepped to accept the 1/4" square balsa longerons

F.

[Frank v B]

Adding the formers.

When a fuselage pinches in at the nose and the tail, I set the middle cabin formers first to make everything square.  Added the 3 cabin formers to one side and let it cure.  In most planes the formers at the leading edge and trailing edge of the wing are 90 degrees to the fuse sides.  I glue these first then let them cure.

step 1- prep one fuse side with formers.  In this case I let the first former cure in the 90 degree position so the rest would follow suit automatically. (photo 13)
step 2- add the middle formers 90 degrees to the fuse side (see triangle) and let the glue cure. Photo 15
step 3- add the second fuse side.... to be done tomorrow.

Do not add any other formers nearer the nose or the tail or you will get a banana shaped fuselage.  Since the fuselage pinches in, none of these will be 90 degrees to the fuse side.

This kit has interlocking formers and wing plate so these all have to be glued to lock together.  They all have to be done at the same time.  Clamps are so they can cure overnight without working loose.

F.

[Frank v B]

Second fuse side installed.
No other formers yet until this dries.  When the other formers are inserted it is critical it be done on a center line so it is straight.
This will happen tomorrow.

Frank

[bweaver]

Your photos depicting the construction techniques are great for information to those who are looking for guidance in matters of construction.

[Frank v B]

Thanks Bruce.

Pulling the tail end of the fuse together.
Challenge: to make the fuse as straight as possible.
Approach:
1) Draw a datum line on your building board.  I used a black magic marker. See pen pointing to datum line in photo 24
2) mark the bottom centres of each of the 3 main formers.  See photo 24. The fuse is inverted. The forward of 3 formers had a gap in the bottom.  The green tape is to mark the center line of the former.
3) pin fuse on the board so the center lines of the 3 formers are on the black datum line.
4) trim the back end of the fuse so the sides can be squeezed together.  I marked it visually  (black line on the balsa), then cut it.  Final sanding is easy.  Pull an emery board (2 sided with sandpaper) between the squeezed side and move back and forth.  Photo 26.  It automatically sands both sides at the correct angle. Photo 27
5) Glue and clamp the back end together and make sure the joint is directly over the datum line. Photos 28 and 29.

Let dry and cure overnight.

Frank

[Frank v B]

The rear deck.

They want you to build the back up with a 1/2" x1/2" square balsa on the rear deck and then add a 1/8 " rear deck. Then sand the corners round.

Two tricks:
- Note the magic marker line on each side in photo 31.  This will be covered up by the back deck but it will appear if I sand too much.  This is my sanding stop line.
- the rear deck has a break in it.  Did not want to do it in two pieces so I scored the bottom with a hobby knife, then filed in an angle with a triangle file.  See photo 31 as well.  The score line is to the left of the triangle file.  The wood has been filed. I carefully bent it, put glue in the file line and pinned the deck in place.  Photo 32

Note: top deck grain runs lengthwise.  Fuselage bottom sheeting will have the grain running cross-wise.

There is nothing on the plan indicating the shape of the dashboard.  I used scrap 3/16 balsa and glued it in place.  It is larger than it needs to be.  Will contour it when it is dry. Photo 33.

Frank