The 'Butterfly DLG' from Mick Page
Before the archetypal FF aeromodeller is allowed through the Pearly Gates, there are a few models that he has to have built to qualify for entry.
'Now is the time' , the Walrus said, to almost complete your task list and it came to pass that a Butterfly plan was acquired and work commenced to attempt to emulate one of, if not the most successful PMFC competition model of the past 35 years. Twenty hours later a Butterfly DLG emerged from the balsa dust and debris. The Master scrutineered my effort at the last Peakirk clubnight and apart from a few minor issues pronounced it mildly worthy.
I am not known for following a plan and it was ever so ..Some minor modifications and detail explanations follow.
The above errors gave me a heavy back end and a 55gm unbalanced model which needed 19gm !?***! of nose weight to get to a 40% CG ..74gm RTF and MP quotes 65gm. Moral is to use a decent DLG boom from Flitehook and try CA/ lightweight glass to attach stab.
Saturday March 1st sunshine beckoned and the Butterfly was glide tested on the local recreation ground. I had to shift the CG back to close to 50% and increase the decalage by a turn on the incidence screw to get a decent glide. Despite the right rudder offset the right glide was marginal. Throwing caution to the wind (well there wasn't any). I DL'd it into one of my best hooked launches. Model lawn darted into the ground ..minimal damage but viscous timer covered in mud and boom brackets broken. Following repair I will wait the wisdom of 'The Master' before attempting further shenanigans.
I now have only a Cloud Tramp to build to complete the mandatory aeromodelling set. Needless to say I am never ever going to build this and thus am very likely to live forever?