[QUOTE=AvB;21154386]I like the switches Josh. They don't break!

Good Point!

I know there has been some talk about kevlar hinges, and some of you are now hollow moulding wings.so i have done this vid to show how I do the Aileron's and wipers.

cutting the Aileron's into a moulded wing. (22 min 40 sec)

That's why those burners go so fast Kev! Awesome vid And timely

Kevin that's awesome. Lots of usefull info in that vid

Now can you do one showing your layup and join?

Re cracking the hinge open... I have seen on some of the Euro sites they sand down to the Kevlar on the inside before they join the halves

Cheers Jeff

Thanks for posting the video on kevlar hinges Kevin. I'll have a good look at it tonight. I'm still smarting over my marathon effort to free up my first attempt (and possible the last!) at them on a four servo 2 mtr. wing. I must have spent 8 - 10 hours over multiple sessions trying to free them. The wing is now in commission, but the hinges are still not free at zero deflection. The hinges create a constant servo load to keep them neutral, which is not good.

Jim.

Jim, honestly if it's like that it's better to cut the hinges free and just hinge with Sikaflex. You'll have it done in no time and they'll work beautifully. I've had to do that a couple of times (including the recent heavy Scratcho where I used 3M 5200) and once they're done you forget about it.

Originally Posted by AvB

Jim, honestly if it's like that it's better to cut the hinges free and just hinge with Sikaflex. You'll have it done in no time and they'll work beautifully. I've had to do that a couple of times (including the recent heavy Scratcho where I used 3M 5200) and once they're done you forget about it.

Yes Andrew, the only reason that I have persevered with the kevlar ones is out of shear stubbornness! I will probably end up cutting mine off.
I can do silicone hinges really quick, no agony or fuss! I have just watched the first 9 minutes of Kevin's very good video demonstration and I have come to the conclusion that I must have wet out the kevlar far too thoroughly. I baked it first and then wet it out as well as I could. There is no other possible explanation to my problems with mine. I have 76 gsm glass cloth either side of the kevlar and I cut through both of them well and truly and still they are stiff to the point of loading the servos unduly. I could see the fuzzy kevlar each side indicating that I was beginning to go through the threads with my hours of scraping and sanding, before I painted the wings.

With all due respect and acknowledgement, I'll be using silicone hinges in the future.

Jim.

Awesome Kevin....
Great to people how easy it is...
In the video you say 4oz over Kevlar..?? You use 2oz.
Also note.... Don't have to use anything over Kevlar.
The Kevlar is the last part of the lay up. And I agree the tile cutter is the way to go.

Great work kev..

Tim

The lay-up on this wing was 2oz 4oz then the kevlar timber skin then 4oz.
I know it sounds like a light lay-up. but this lay-up has gone 200+mph.

Cool.... Different to the normal glass lay up..

.5mm vaneer is great. It makes a very strong skin , even with a light lay up you have trouble pressing or flexing the skin. This lay up is 150 to 180 all day..
Ezza did get to 229 before ( we think ) twist and flex blew a horn of a control surface and Ezza ploughed it in.. And @ around 1kg RTF...perfect for you Aussie conditions.

Tim

Kev puts a layer of glass inside his Kevlar hingeing.

Originally Posted by AvB

Kev puts a layer of glass inside his Kevlar hingeing.

Yes...

But it's not needed....it easier if you don't. That is what you break. So if you Finnish it short if the hinge line , you only break the Kevlar.
If you do have a layer there , it will make you controls stronger.
Glass is ok , but if you do run carbon across the line , then makes it very hard.

Kev just cuts from his template....and doesn't cut the inner piece shorter that's all.

Tim

Great video Kevin. Really good of you to take the time and make it.

Thanks Kev, always great to get another perspective on methods and techniques.
D.

Nice one Kev!