Christmas 2013 Build - KK Eaglet

After an enforced two month break from building models, I decided to celebrate Christmas by starting a new build. Why Christmas? Because, with a very supportive wife, I can!

The KK Eaglet is a model I've wanted to build for a long time. I already have it's larger brother and sister, the Competitor and Contester, so they'll make a nice trio. It's also a simple build and will serve well to get me back into modelling again.

A few ribs were cut before breakfast. I've cut them slightly fatter and slightly long at the back. The length will be cut by selective fitting when constructing the wing and an extra bit of meat on top of the rib will ensure a nice neat joint when sanding the trailing edge

Good on you, I hope you continue to enjoy it again.

Thumbs up for slight oversize component

Ooo goodie looking forward to this. I have to wait till after dinner to start mine boo hoo hehe. Merry Christmas to you and Mrs sephton xxx

Great to see someone else having a proper restful Christmas Day Ill enjoy your efforts

It's a copy of an original Eric. I photocopy the printwood, then transfer it to balsa by wiping the balsa with a tissue dampened in thinners. Then place the copy over the wood and rub it down with a dry tissue. The print should transfer, check it by keeping it in position on the wood and lifting each end in turn. If not, then I rub the back of the copy with the thinners damp tissue. Too much thinners just spreads the ink too much onto the wood, so it's important to use too little, then add a bit until you get transfer.

The resultant print is, of course, a mirror image of the original.

I didn't get much more done on Christmas day apart from showing the plan and parts to our guests, one of whom had built one over 50 years ago.... The wood used, by then way, is 6lb/cu ft 'C' or quarter grain.

I used to iron it on, but I found that I had to get the iron so hot it warped very thin light balsa. I colleague put me onto the thinners method and I've used it ever since. I'd forgotten about the iron on method K, thanks for the reminder.

Building continues on Boxing day. All the parts are now cut out and the building board prepared. I've left a lot of the parts oversize for selective fitting during the build and to have a bit of spare to work with when sanding to outlines. I've also dumped the front fuselage parts F1 and F5. The 6lb wood I've used for the 3/32" balsa parts would be too weak for such a highly stressed area so I'll make it up from two laminations of 3/32" sq of about 12lb/cu ft balsa instead. For a similar reason, part F4 will also need strengthening, probably by a 1/32" hard balsa doubler.

Hehehe I defo have the bug, am excited at just seeing all your parts cut out!!!!!!!
Daft question but is it weight of the wood that determines when you decide it isn't strong enough for certain areas?

There's no such thing as a 'daft' question Sarah, so ask away! In fact, I offered to do a thread on balsa a week or so ago, so apols for not getting round to it yet. Suffice to say here that the weight of the wood is roughly equivalent to the strength, and the weight of the finished model is inversely proportional to the performance. So it's always a compromise as to what weight/strength of wood to use. Light balsa is 4 - 6 lb/cu ft. Medium is about 10 - 12 il/cu ft and heavy, 15+ lb/cu ft. Most kits have wood of medium grade it's easier to work with than the light stuff. There is also the stiffness of the wood to consider. There are three accepted 'cuts', A grain (straight grain), B grain (random cut) and C grain (quarter cut). I'll explain it all in the balsa thread but for now, A grain is bendy, C grain is stiff and B grain is somewhere between the two. I used C grain for the ribs and formers for stiffness and A grain for the spars to make em bendy, i.e. they will bend rather than break under load. A grain is normally light in colour and the grain is stright and even over the sheet. C grain has a motled appearance and is often darker than A grain wood.

For out and out performance, the trick is to get the right grade and strength of wood so that the minimum size and weight of stock can be used.

The build continues.

I cut the longerons from a sheet of A grain 9lb/cu ft wood, then steamed them to a rough shape - be careful if you do this, STEAM IS HOT and it scalds!



One side was then fixed to the cling film covered plan using blocks of scrap 3/16" balsa (twice the thickness of the fuselage longerons). Parts for the second side are cut at the same time and left on the building board. Note the laminated replacements for F1 and F5. Note also that the longerons are left overlength and will be cut to size later after the fuselage is complete. Glue used is UhU Hart.

Beautiful curves

Time for a coffee and a break -

First image shows spars/longerons being cut from sheet. Note the black lines at one end to identify orientation and face surface of spar after cutting.




Second inage - fuselage upright production has commenced. I cut a piece for each side at the same time so that the two fuselage sides should eventually be identical.



FInal image shows fuselage side one complete with the parts for side two lying adjacent to their final positions. The 3/16" jigging blocks will allow side two to be built over side one - yes the two sides will stick together, but that's a characteristic I want and will use later.

..................the two sides will stick together, but that's a characteristic I want and will use later

I have to ask ............ why?

And stop biting your thumbnail !!!!!