Building a KK Ace
6 CommentsMonday, 13 January 2014 | Hadi
The KK Ace was first kitted in the 1950's by Keil Kraft and has been a popular "stick and tissue" model ever since.
The Ace is an ideal candidate for beginners to traditional aero-modelling, but does require patience and basic aptitude with wood to achieve a model which flies. This is not a model to build in an afternoon!
Follow my progress in this ongoing build log as I work my way through the instructions to produce and hopefully fly the finished model, using one of our laser cut kits.
The KK Ace is a reasonably large model so you will need a build board that's at least 2 feet wide.
After pinning the plan out on the board, I covered the fuselage section with cling film to stop the glued wood from sticking to the paper plan.
The lower longeron has a diagonal joint half way along the fuselage - I found it best to glue the joint using cyano-acrylate (CA) off the plan to ensure a strong bond, before pinning it into place.
Once the first side of the fuse was built and set, I placed another sheet of clingfilm over the wood and built the second half of the fuse over the first to ensure a perfectly matched pair of fuse sides.
Once the fuse sides were done, I sanded them smooth.
Next up was to construct the main fuse formers.
We laser cut the former top rail but the sides and bottom rail have to be hand cut.
One tip here is to cut one side former as the plan and then use it as a template for the other side. This way you'll get identical sides and a better chance of a symmetrical model!
Luckily on the Ace, the undercarriage wire is a very simple bending job. The only potentially tricky task is to apply the forward rake to the struts once the basic shape has been bent up. Remember to leave plenty of wire for the axles - you can always trim off the excess once the wheels are securely attached.
The instructions suggest adding one main former to one side and the other to the other side - so that's what I did, trial fitting first to ensure perpendicular joints before fixing with CA.
Once the two fuse sides were joined, I cut the spacers from 3/8" square balsa strip.
A tip here: I find that if you cut balsa strip slightly oversize for the job in hand, you can then sand the ends on a piece of wet and dry held flat on the board. Doing this you not only get beautifully square ends, but you can also bring the length of the "stick" down incrementally until you have a perfect fit!
What is probably the hardest job of the whole build came next - namely sculpting the nose block from two pieces of 14" balsa sheet bonded together.
This was the first time I'd attempted this - usually our kits are supplied with balsa laminations to create a noseblock that's pretty much fully shaped and just needs sanding.
I'm quite pleased with the result but it took a long time to do...
Attaching the undercarriage to the fuse was the usual thread and CA job and went without a hitch except that I had attached the crucial spacer slightly too far back meaning the upright sections of u/c wire weren't flush to the uprights. Oh well, the tissue will hide it!
And here's the rear view:
Check out the next instalment soon and feel free to add your comments on the progress so far...