Half way through 2011 I was fortunate enough to be asked to compile the Instruction Manual for the Composite Arf 2.6m Edge 540. Great!!! I think…. have you ever written a manual? Let me tell you it takes a whole bunch of work, but hey, I do like the looks of the new Edge and my building table is empty….so why not!
I won’t go through the whole build process, you can read that in the manual! What I generally would like to cover is what I thought of the model, and how the project turned out. Overall I was very pleased with the end result, the model flew better than I expected and the DA120 pulled it around like a rag doll! But as always there were a few items that bothered me a little, and some that I just had to live with.
When building a new model I generally don’t use a lot of the supplied hardware, I may be a little anal in this department but honestly some of the hardware supplied nowadays is pretty lack lustre. Comp Arf is not a lot different in this department than any other manufacturer, while the supplied hardware is good enough to do the job, but that’s about it! There is certainly no bling in the hardware supplied. Mostly I changed the 3mm threaded rod for Secraft turnbuckles and all the bolts to stainless items. There are a few things you don’t get in the hardware pack; Fuel tank, wheels, tailwheel, spinner etc, but that’s fine at least I can pick the items I want!
The Edge has huge ailerons and there is only one servo allocation per wing. Personally I would prefer to have the option of 2 servos per aileron, but it wasn’t the end of the world, you just need to be careful with your servo selection and how you set them up mechanically. I chose Futaba BLS152’s (30.5kgs) with 1.25” Secraft alloy arms. I was hesitant to use longer arms, and felt the servo needed the best possible advantage. The ailerons are pretty effective with this set up and the roll rate was pretty brisk!
One of the major gripes I had was it was near on impossible to get the C of G required, and everything needed to go up the front of the model. In the end I added 250 grams of lead to the front of the model. Let me say I hate adding ballast to a model, and it did irk me to do it. But looking back at it, 250 grams is the weight difference between a DA100 and a DA120!! That’s right, the DA120 is 250 grams lighter!!! So looking at it, I could get the model to balance if I used the heavier (and less powerful) DA100, or I could use the lighter and more powerful DA120, add 250 grams of ballast and still come in at the same weight!! No brainer really!
The Edge flew extremely well, and surprised me how well it flew precision IMAC. It locked in beautifully, not like any other Edge I had flown. Sitting back looking at the model, you will notice that it has a long tail moment (the distance from stabs to wing). You couldn’t get the wing any further forward, which also explains why the C of G is difficult to obtain. It also helps explain why the model fly precision so well, a longer tail moment really helps to lock the model in and takes away the quick pitch response you get with short coupled models.
So the conclusion for me was the Edge 540 is a cracker of a model, forget the fact that you may need to add some ballast. I’d rather have the model fly beautifully with some added lead, than be pitchy and only slightly lighter! While I’d rather there was an option for 2 aileron servos, it’s no big deal, just pick good quality powerful servos and be careful with the mechanical set up. Add your own hardware, bling it up a little, a model as nice as this deserves some bling anyway!! In the end you will have a really cool looking and great flying model, and like all Comp Arf’s….you won’t need to iron it!! Happy Days!