OK guys (and girls) here we go!
First a bit of background. I rarely build kits, I have a pile of RC ones that sit there, and over the top of them I'll happily scratch build whatever I want. Up to now all my control line models have been scratch built from someone elses plans, or worse, my own. I noticed recently that my local hobby shop has SIG kits in stock. The running joke at the LHC is that they never have anything I want, but after seeing a few Kobras and smith miniplanes (another kit I'll probably never build), I got all hot under the collar, and started enquiring about what else they could get.
As it turns out they were happy to get me a chippy, one of my life-long loves. Seeing as they could get it in, I jumped in, maybe a touch prematurely
I'm planning to build this ala Dave Fitzgeralds modifications, and maybe a few others to shave some weight out of it. As it stands the wing will lose it's asymmetry and I've stretched the span out an extra inch each side. The wing will move forward a little and the tail will be stretched as far as I can on the supplied fuselage sides. I don't plan to use the heavy wood for the tailplane, and instead will go for a 1/8" ribbed core and 1/16" sheeting over that. Should look the same but weigh less. I still haven't decided as to whether I'll do the same for the flaps. I may do if I have a rush of blood to the head. I've got a 4" bellcrank that will find it's way inside, of course it will be fitted with a weight box and adjustable leadouts. If I can get my head around it, it'll probably also have an adjustable elevator horn. After much discussion on the engine a trip to said hobby shop will probably procure me a nice new 46LA to power it.
I read everything I could find on the chip and found that with some modifications it could be a pretty good stunt model. I gingerly opened the box and was greeted by a pile of printed sheet balsa, some sticks, a nice canopy, and some heavy ABS parts.
I then do what I usually do, which is put the plan up on the workshop wall, have a cup of coffee, and stare at it, until I know exactly how it goes together. I don't lay plans down unless they're under my glass worktop, and in this instance there's really no point as the rib spacing and spar positions aren't the same.
I read the instructions and sniffed at the method of construction of the wing for a starter.
The plans call for laying down the trailing edge sheet and building the wing off that. I'm not to keen on this method for tapered wings. while you may end up with a flat side, I always worry I'll build two sides with the same washout, making a nice propeller shaped wing!
I thought about building using rods, but eventually caved in, and built a sacrificial jig using rock hard 3/8" stock I had lying around. Centrelines are marked on the blocks, and the fronts are set up to accept the diamond leading edge, and the TE is notched for the 1/4" SQ TE.
Using a long straightedge I set up the TE in the right position, and using the root and tip ribs, set the LE to be in the right spot. After that, I fed in the lower mainspar, and fitted the rest of the ribs. Each one was slightly too long or just a little short, so some 'micro fitting' was called for. eventually I had the ribs all in with a few CA tacks, and checked it for straightness.
As each rib was pulled out, I made a quick tracing, just in case I need to do some repairs, and the root and tip ribs will be used for cutting the fuselage and tip blocks later.
A few asides, meet Catty, he's a fixture in most of my recent build threads (on other forums) and he's usually hovering around or looking at an area of importance. Keep an eye out for him! Another thing to note is my trusty new scales from hobbyking. A paltry 9.90 to ensure you know what weighs what.
Some pics of yesterday's work.
Topic: Sig Super Chipmunk build (Read 27309 times)
