Tuesday, September 18, 2007

Allegro Lite Build Part 4

The fuse I got was very light and a little flimsy. To make sure I don't crack it on the first dork landing I decided to reinforce it with some carbon, especially around the wing seat. Some 12K carbon tow was laid underneath with some 200gsm carbon cloth laid on top.

Saturday, September 15, 2007

Allegro Lite Build Part 3

The Allegro requires a fair amount of pre-pregged carbon strips, none of which come with the short kit. I decided to make my own. The commercially available strips taper in thickness towards the tip panels which I didn't bother doing.

The uni-directional carbon material comes from AMT. The roll I got is 300mm wide. I cut this into four 75mm wide strips. Next you need to find a flat surface to work on. I scrounged two pieces of 40 mm thick bullet proof glass from a revamped bank that work perfect for this. Next step is to wax up a strip of mylar. Then cut the carbon material to slightly wider than you require. Mix up some epoxy and pour it on the carbon. I then used a hard roller to make ensure the carbon is fully saturated. Then lay on the next layer of carbon and repeat the rolling process. I had to lay four strips of carbon to get the desired thickness of ±0.7mm.
Once you're happy that the carbon has been fully impregnated by epoxy take some paper towel and blot up the excess epoxy by rolling with the hard roller again. This takes care of any unneccessary weight.
Only thing remaining is to lay another strip of waxed mylar on top and to place the other glass plate on top to ensure your strips come out perfectly flat. With the glass plates weighing easily 10kg each there is no need for extra weight on top of this "sandwich".
And the finished product...... Voila! Cutting the carbon into smaller strips is the next challenge.

Wednesday, September 12, 2007

Allegro Lite Build Part 2

I started out with marking out the hatch opening on the fuse and cutting it out. The fuse came with a seperate hatch cover which fits nice and flush with the fuse. I'll probably end up securing it with a spring loaded carbon rod which you epoxy to the hatch cover ala Xperience Pro style.

Tuesday, September 11, 2007

Allegro Lite Build Part 1

I bought this "short kit" ages ago and only recently got the itch to actually build it. I bought the kit from Eugene du Plessis who used to fly at VMG with Gert Nieuwoudt. The rib kit and boom come from Laser Art and the fuse is Eugene's own design.
I am quite a slow builder but I'll try and keep the blog updated with my progress. The Allegro is quite an intensive build. The Allegro (AL for short) is basically the 2m baby brother of the 3m Bubble Dancer, both planes designed by Mark Drela of the Supra fame. Look at the Charles Rivers site for more info.
For starters I am going to build the pure thermal plane but plan on building a second "E"-version fuselage specifically for F5J.