Received this reply in relation to an ongoing saga (I thought it was over) involving the KMP Stuka. Without going into too much detail, apparently everyone who fits a more powerful engine into their models is a "wanker customer".

The question here is thus: Is upgrading to a more powerful engine a common practice or do we just do it for the pleasure?

"Mark,

I don't mean to sound rude, but I feel I've just gotta say this. Firstly, I do understand you are upset that you lost a new plane due to structural fault... BUT

I have three friend's who work in one of QLD's largest hobby store and they call people like you "wanker customers". You buy a 91-120 size plane, over-engineer it, it crashes and you blame everyone else but yourself.

It's designed for a 120 engine and that's all. You stated that it's ok that you used a 150 because you were spinning a smaller 3 blade prop; frankly you're an idiot. Do you even know why a 150 can throw a 3 blader? It's because it's got more torque and more torque means a LOT more stress on the airframe. Two types of engines will cause structural failure, an unbalanced high-revving engine and a engine with lots of torque, and you used one of those.

I'm not saying you didn't have a factory fault, but I am saying your choice of non-spec'd modification would have definitely aided any possible fault. So stop complaining and just be happy that you are very lucky that you got a refund. All you are doing is making a jackass of yourself.


PS: before you go commenting back like you know what you are talking about, I have a BAE (Bachelor of Aeronautical Engineering) majoring in structural engineering."


http://www.rcuniverse.com/forum/m_56...tm.htm#6547828

wow Mr. BAE is sure proud of himself..throws some pretty strong language around.....
At first he admits there was a structural failure..then blames a bigger engine for the fault....without looking over the debris He's only guessing that the bigger engine caused the failure..yes it might have..then again...perhaps there was some fault with the material, which he admits is a possibility.....
hmm being a Yank, I'm not sure what a wanker is.....so I'll ask the educated Mr. BAE does it look like what you see in the mirror?

Hey those BAE guys are alright, They use to get us coffee and doughnuts while the real work was getting done.

Guys,
I could let you know what a wanker is but I might get into trouble....the word tosser comes to mind, slapping the monkey. I am sure his three friends who run the hobby business in Queensland would be mighty pleased to know he has let everyone know what they think of their customers. What an excellent endorsement of their ethics in relation to customer service. I certainly will not be buying anything from any Brisbane Hobby business.


Regards
Mark

The question here is thus: Is upgrading to a more powerful engine a common practice or do we just do it for the pleasure?

You can do whatever you wish to in this hobby. The pilot never dies, no matter what the designer/engineer/builder does. That said............

There are a number of reasons to use a more powerful engine. All of them are basically intuitive.

Any time you do it, however, you should consider beforehand whether or not there will be excess weight added to the nose. Consider it, and if so, either solve the problem while building or be prepared to have a sluggish or possibly less safe flying model. When the CG moves too far forward the elevator is simply unable to deal with that. Matter of fact, when the CG moves forward at all, the elevator becomes less and less effective the farther the move. What some interpret as "more stable" is actually the elevator losing effectiveness.