Post by thevon on Mar 17, 2008 21:08:20 GMT 10
I know I'm a bit weird but I’ve never liked the way the Reaper boom is so breakable.
I have to say that despite many enormous thump-ins, some over 100mph, it actually took me quite a while to break it. But on a recent DS trip I got 3 minutes flying before a lazy flop-in falling out of messy air snapped the golf club shaft.
This close-up shows the bit of coreflute I jammed into the shaft on the slope, and with that and a bit of CA I got quite a bit more flying before snapping it again!
I've always thought when I broke it I'd try a beefed up version of the setup I have on the Bat, which uses a 5.5mm carbon tube as a boom and it slides into a piece of coreflute which is double-side taped onto the plane, so it can detach (or rip the coreflute) in a crash.
The first thing was to get the angle grinder and cut the fuse back to expose enough wing.
I made the new fin out of 3mm balsa, a bit taller and a bit thinner than the original.
Then covered it in the 80mm laminating film. I’m strongly plugging this stuff for fins, and elevons. It’s amazingly good. I don’t like the way it’s clear (ie I’d like a solid Profilm colour) but it’s just so smooth, light, tough and easy to do that I won’t use anything else now.
I actually stuffed this up a bit … should have done the overlapping side first, so it’s a bit rough
Then used the verniers to help get the slot to exactly the right width … you can use them as a knife guide.
This system hasn’t given me any problems on the Bat at 110 mph even in bad shear, so it’s pretty decent. But the Bat fin pushes right up to the TE, so there’s almost no free length to bend. Whereas the Reaper has a long boom. This may be the undoing of my whole plan, because it may flex way too much.
To improve things I chose to use 6mm solid fibreglass rod for the long piece, as it’s going to get doinked and although flexier, the F/G doesn't shatter like carbon. Then I’ve slid a carbon tube as an outer sleeve around it, to span between the TE and the fin. In a big doink, the carbon tube might split but that’s OK, easily replaced.
The only problem was that the “solid” rod that the kite shop sold me turned out to be hollow when you cut the end off. So it’s probably flexier than I want, but I pressed on. This next photo, due to the contrast, isn’t very clear but you can see the outer carbon sheath.
Here’s how it looks from the bottom, pushed into the coreflute. No attempt to pretty it up till I’ve test flown it!
Top:
The whole thing:
I’m not sure this will work … wait and see when it flies. It will definitely have a lot more give than the standard fin but whether it makes it un-DS-able is yet to be determined! I'll soon find out! I’m hoping that it’s ugly but functional (rather than ugly and DYSfunctional like its owner).
I have to say that despite many enormous thump-ins, some over 100mph, it actually took me quite a while to break it. But on a recent DS trip I got 3 minutes flying before a lazy flop-in falling out of messy air snapped the golf club shaft.
This close-up shows the bit of coreflute I jammed into the shaft on the slope, and with that and a bit of CA I got quite a bit more flying before snapping it again!
I've always thought when I broke it I'd try a beefed up version of the setup I have on the Bat, which uses a 5.5mm carbon tube as a boom and it slides into a piece of coreflute which is double-side taped onto the plane, so it can detach (or rip the coreflute) in a crash.
The first thing was to get the angle grinder and cut the fuse back to expose enough wing.
I made the new fin out of 3mm balsa, a bit taller and a bit thinner than the original.
Then covered it in the 80mm laminating film. I’m strongly plugging this stuff for fins, and elevons. It’s amazingly good. I don’t like the way it’s clear (ie I’d like a solid Profilm colour) but it’s just so smooth, light, tough and easy to do that I won’t use anything else now.
I actually stuffed this up a bit … should have done the overlapping side first, so it’s a bit rough
Then used the verniers to help get the slot to exactly the right width … you can use them as a knife guide.
This system hasn’t given me any problems on the Bat at 110 mph even in bad shear, so it’s pretty decent. But the Bat fin pushes right up to the TE, so there’s almost no free length to bend. Whereas the Reaper has a long boom. This may be the undoing of my whole plan, because it may flex way too much.
To improve things I chose to use 6mm solid fibreglass rod for the long piece, as it’s going to get doinked and although flexier, the F/G doesn't shatter like carbon. Then I’ve slid a carbon tube as an outer sleeve around it, to span between the TE and the fin. In a big doink, the carbon tube might split but that’s OK, easily replaced.
The only problem was that the “solid” rod that the kite shop sold me turned out to be hollow when you cut the end off. So it’s probably flexier than I want, but I pressed on. This next photo, due to the contrast, isn’t very clear but you can see the outer carbon sheath.
Here’s how it looks from the bottom, pushed into the coreflute. No attempt to pretty it up till I’ve test flown it!
Top:
The whole thing:
I’m not sure this will work … wait and see when it flies. It will definitely have a lot more give than the standard fin but whether it makes it un-DS-able is yet to be determined! I'll soon find out! I’m hoping that it’s ugly but functional (rather than ugly and DYSfunctional like its owner).
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).