[TBrum]

My winter project has been started today - I have never built a 35% before, so decided to take on this little project so that I'm ready for it's maiden in early Spring 2008.

Below is a link to the Aerotech website for all the specs on this great looking plane... I haven't decided the colour scheme yet, but I'll focus on the build first.
http://www.aerotech-rcmodels.com/Pro...k54/yak54.html

I have a DA100 with KS cans for this plane, but will also work at lightening up this build wherever possible (particularily in the tail) and may consider a DA85 or a 3W85xi on a single can, since they engines have incredible power (debatably more than a DA100!!!)

I bought this kit on RCC - there are a few parts missing, but the seller is working at getting replacements for me. My initial thoughts of the kit are:
* all the balsa sheeting has been squared by Aerotech - should be easy to sheet the cores!!
* the instructions are terrible, but the drawings are awesome
* except for the missing pieces, everything was damage free!

Here are a few pictures of the kit... huge cowl, lots of lumber and a ton of cores (wing cores not shown)

[TBrum]

In deciding where to start first, I thought I'd get all the balsa sheeting completed on all cores first off, including the wings for the following reasons:

1) Looking ahead in the construction, about 1/2 way through construction of the fuse, the wing sockets need to be completed, which requires finished wings to execute.

2) I wanted to experiment with a few options of sheeting the cores - in fears of messing up the wing cores, I wanted to start sheeting a less critical core.

This plane has the following cores (9 in total):
* Main wings (2 huge cores)
* Elevator / stab (1 core)
* Rudder (1 cores)
* Turtledeck
* Fuse top-front section - right behind the cowl
* Fuse bottom - landing gear area - completes the round fuse shape in the bottom
* Fuse bottom - mid section
* Fuse bottom - tail section

[TBrum]

Step #1 - Sheeting the fuse bottom core (mid section)

The most common method of core sheeting I've heard of so far is to:
1) tape all balsa sheets together (in this case 1/16" sheeting)
2) flip the taped sheeting over and open up the joint (tape acts as a hinge) and apply glue (CA, Elmer's wood glue, etc).
3) allow to dry - light sand
4) apply Elmer's ProBond PolyEurathane glue (now called Ultimate glue at Home Depot), spread out very, very thin with a spreader.
5) dampen core with damp cloth
6) mate the damp core to balsa sheeting that has a thin layer of ProBond
7) place the core/sheeting back into the countermold and put lots of weight on the panel (Ie: 100+ lbs) to ensure the sheeting is tight against the core (this glue expands as it cures, so lots of weight is required)

As per the picture, I glued the sheeting together with Super Phatic glue from Ontario Adhesives - this is like Elmer's wood glue, only it dries in about 15 minutes - an awesome product!!.

I then followed the above steps using ProBond, ensuring that I kept the ProBond very, very thin to prevent as much expansion as possible.

After about 8 hours, I took all the weight off and voila... 1 completed core!!

[TBrum]

Step #2 - A different approach to sheeting (IMO - an awesome, much faster, equally strong method)!!

On my next core, I glued the sheeting together with thick CA (it's a bit faster than Super Phatic glue, equally stong, but doesn't sand as well)

I them tried something new... Ontario Adhesives sells a product called AeroBond (about $10.64/150ml bottle - I will need 2-3 bottles for all the sheeting on this plane) - I was so impressed with it, that I posted a separate thread on this product on RCC... see the link!

https://www.rccanada.ca/bb/viewtopic.php?t=37402

Now this is the way to sheet cores - very fast to do, no mess, no expansion and equal strength!! Aerobond is a contact cement, so you just brush on the adhesive to both sides, let dry for 15 minutes and press together!!.....

[TBrum]

Thanks to Aerobond and Ontario Adhesives, I got all the Fuselage Cores sheeted within about 2 hours!!!

As per the picture, from left to right....

* Upper Turtledeck - 1/16" sheeting (Aerobond and SuperPhatic from Ontario Adhesives)
* Lower Fuse - mid section - 1/16" sheeting (SuperPhatic and ProBond PolyEurathane glue)
* Lower Fuse - tail section - 1/16" sheeting (Aerobond and SuperPhatic from Ontario Adhesives)
* Lower Fuse - landing gear area - 1/16" sheeting (Aerobond and thick CA)
* Upper Fuse - front - 3/32" sheeting (Aerobond and SuperPhatic from Ontario Adhesives)

[TBrum]

Onto the main wing... I'm going go as far as sheeting the left wing and then repeat the process again for the right!

The wing cores come with a hole hotwired out for the wing tube. There is also a removeable foam block at the end of the hole for a 1/4" thick plywood tube support plate

The first picture shows the wing tube in the core....

In the second picture, I took my dremel and routed out a ring, 1/8" deep in the support plate so that the wing tube interlocks for more strength.

In the 3rd picture, the support plate is test fitted in place along with the wing tube. I have also cut out 3 holes in the core along the wing tube hole... this is where I will inject the ProBond into as I permanently slide in the wing tube (you push in and rotate the tube as you pour in ProBond so that the whole tube get's coated well for a secure bond!!)

[TBrum]

Next step was to contour the support block to the shape of the wing so that the sheeting will bond well to this area (don't worry.. I didn't take the first picture while the band saw was running!!)

The second picture shows the wing tube area ready for probond!!! I trimmed the foam block behind the tube support plate with my wife's electric bread knife (that's reminds me - I've got to put it back in the cupboard quickly!!) The foam block needs to be put in this void so as to prevent the expanding ProBond from separating the tube and support plate.

[TBrum]

Next, I flipped the wing over and marked out the aileron cut line and where the servo bays would go and where the servo lead tunnel would need to go... all of this was as per the drawing. The kit comes with the laser cut balsa servo bay sides and basswood servo mount plates.

Picture #2 shows a little wire cutter I rigged up with my sodder gun (it's just 1/16" copper rod that is bent to shape). I taped a metal ruler to the foam core as a guide for my sodder gun hot wire... it worked flawlessly!!

Not Shown - as my last step of the day, I glued in the servo bays and wing tube and tube support using probond... it's back in the countermold right now curing... tomorrow I'll see how it turned out and will snap some pictures.

If all goes well, a light sanding of the core and I can get this wing sheeted tomorrow using AeroBond!!

[bigguy]

Very nice.Keep the pics coming. I am very interested in this thread.

[always flying]

I've just subscribed!..


keep the pics comming! these build threads as detailed as this one or alot of work! "GOOD ON YOU TBRUM" You will soon have yourself a finnished product that will be your new pride & joy!..Who said hard work never pays off!!

mannyh