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Post by ezza on Sept 16, 2007 23:48:47 GMT 10
Yep, the Reaper's awesome, never even hinted at dropping a wing despite many full stick turns both fast and slow. It will do the "hyperstall" thing if you hold full back and let her slow down but that's a good thing as far as I'm concerned because it means there's no traditional stall drop, the plane remains completely controllable at all times. One thing that takes some getting used to is if you trim in some up to gain height it can end up sinking instead, it flies more efficently with a fair bit of speed and will actually climb better that way. That Banana sounds good, I'd like to get me a composite but thanks to DS I'm too busy playing around with foamies now , need to learn to read DS conditions a bit better before I start throwing composites into the dark side. My next build will be an own design 48" plank so I've got an every-day all-rounder in my fleet . Hi Sean, Yeah, too much uptrim just kills a plank. They like nose down and fast. The banana is dad's plane so I will probably never 'really' get to ds it, but I have tried a couple of conservative laps and it accelerated rather quickly. I could see things getting flexi on the second or third lap so that was it, straight back out to the front. Have to say it is absolutely sweet on the frontside...just a little hard to see when it is going away or straight at yourself. The fuse and wing are so thin.
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Post by sean on Sept 17, 2007 11:04:08 GMT 10
I was looking at the glass mini-blade last night. With the two piece wing I could get one quite cheaply (makes shipping costs reasonable) but I'm not totally convinced. Looking at video of one being DSed at about 100-120 the wings were flexing badly in the top turn ;(. Anything with a one piece wing is a big jump in price thanks to shipping.
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Post by thevon on Sept 17, 2007 13:24:43 GMT 10
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Post by sean on Sept 18, 2007 19:17:07 GMT 10
Got to see Andrew's Bat today, man that thing is stiff! Those flat spars are the way to go! Unfortunately didn't get to see it fly...
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gas
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Post by gas on Sept 18, 2007 19:51:32 GMT 10
this build is very inspiring and is great for anyone building any type of foamy, there is enouph graphite in that thing to call it a composite or a flying crowbar, i will try the same trailing spar setup on my next jw60
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Post by thevon on Sept 20, 2007 21:35:42 GMT 10
Wow, awesome, that's all I can say! Got the opportunity to put the new Bat in its element today in the strong NW at Bald Knob. Initially it took off and soared up in the lift. Man, it was fast. But tended to get blown about a bit and when it hit the big lift it tended to over-pitch up so Sean reckoned CG too far back, so I put a bit more lead in the nose and it flew better. Mucked around with the rates and the dual rates and it was amazingly good.
Sean dived it over the back to see how it DS'ed it and we were surprised that it really got chucked around with the turbulence . It wobbled and yawed and jumped about (but still DS'ed pretty quick!). So we brought it in and made a few more alterations. 1) put even more weight in the nose (so basically I ended up putting back in all that nose lead that I hacked off at Shorncliffe last weekend!). 2) Putting a much bigger fin on the back; one from the Drongo, and 3) taping a lump of lead on the belly, just in front of the CG.
Throwing it out again it still soared nicely but tracked much more cleanly. Still flying inverted with very little down trim. Cracking nice roll rate and looping with ease. So I handed it over to Sean to "maiden" it for DS, and in no time it was slicing fast loops around the eastern side, looking very similar to his own Bat! He said that it felt excellent, and had a "solid" feel to it. I suspect that's thanks to the rock-solid HS5475 digital servos hooked up to the mid-elevon region, and the overall rigidity of the wing.
I thought that the speed of the thing was going to freak me out but when I took over and started DSing I found exactly what others say ... a good plane makes DSing easier! The Bat just does it really well. Even at high speed you still feel like you're in control. I spent quite a while at it and was getting some decent speed, and keeping it mostly on line.
So after a couple of hours I felt like things couldn't get much better and called it a day, knowing I'd made some progress and that the Bat was even better than I'd hoped. Plus, I went home without any damage to the planes ... always a bonus!
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Post by thevon on Oct 18, 2007 8:45:58 GMT 10
An update on the flat ribbon spars. The Bat has been performing exceptionally well and the ribbon spars have withstood lots of DS prangs, nose-ins, cartwheels etc with no dramas at all. Very impressive. But the other day I was flying in a new spot and there were cows with calves in the paddock. I was pretty tired and probably should have packed up to go home but it's always "try one more spot!". Anyway I got pretty worried because this big cow with horns was getting a bit agressive and coming towards me bellowing etc. Did a dive in, Bat is carving around the backside, noticed the cow getting stroppy and I was trying to watch her (hard when you're flying), and flew the Bat straight into a very solid tree. Crack. Most embarrassing. Turned out the cow had a calf sitting in the long grass just in front of where I was flying, so no wonder she was carrying on! Anyway, the crash was the sort of thing that would have written off a composite plane for good. Quite sickening. But the damage to the Bat is really pretty minimal. It must have really flexed the wing across the centre because it snapped 3 of the 4 ribbon spars that cross the centreline. When I cut the covering off them to fix them I found they've snapped quite cleanly. It was really easy to patch them. I cut right thru the break and lifted the spar for a coupla cm either side. It was stuck pretty well to the 77 glue which I still reckon is doing a good job. Then I ran a strip of sandpaper under them, then put a new short piece of spar under the break, overlapping about 2cm either side. Then squirted lots of CA glue in between the old and new, and pressed down. It all got reassuringly hot! Hey presto, good join. To have withstood such a crash with such little damage is great. I suspect the spars cracking may have "absorbed"some of the shock. I thoroughly recommend this method. But don't forget I also have a 5mm hollow round spar running thru the centre of each wing. However next time, I'd like to try using thicker ribbons - maybe 1mm thick. I again have to seriously recommend the Bat, modified this way. I think a lot of people are building more exotic and difficult models but the Bat is easy to get and easy to modify, and cheap and it flies insanely well. Very exciting to fly. Fast and aerobatic on the frontside and DS's excellently.
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Post by st on Oct 18, 2007 9:36:04 GMT 10
............. To have withstood such a crash with such little damage is great. I suspect the spars cracking may have "absorbed"some of the shock. I thoroughly recommend this method. But don't forget I also have a 5mm hollow round spar running thru the centre of each wing. However next time, I'd like to try using thicker ribbons - maybe 1mm thick. I again have to seriously recommend the Bat, modified this way. I think a lot of people are building more exotic and difficult models but the Bat is easy to get and easy to modify, and cheap and it flies insanely well. Very exciting to fly. Fast and aerobatic on the frontside and DS's excellently. Nice quick repair andrew. In your sort of setup, ie. a mixture of stiff (spars) and flexible (foam), the stiff components will take almost all the loads/stress/shock. How do you know if the hollow spar is OK? When I started reading your story, I was thinking "what a whimp"! ;D Especially for a vet! I've never come across a cow to be scared of, unless it is a very wild one contained in a small area (cattle yard or something). Some bulls yeah, but a cow? Lucky there was a calf close to you or I'd still call you a whimp ;D
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Post by sean on Oct 18, 2007 11:19:36 GMT 10
He he, I was there too and the cow was acting quite aggressive towards us. Never have I seen a cow be anything but completely placid before! I think our flying had scared off her calf...
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Post by thevon on Oct 18, 2007 14:08:43 GMT 10
Simon, I just grab the wing and try to bend it like a banana! You can see where a spar is broken as it will crease at that point. The main spars were fine but they don't bridge the centre so in the crash the thin ribbon spars took the centre bending load and deflected under the load ... but it was a good result really.
I agree about being a whimp with the cow - I was a bit ashamed at my fear! I was getting a bit of a knot in my stomach, trying to DS and scare the cow back at the same time! DS is pretty mentally exhausting and I think I had gone past the "too tired" point!
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Post by ding on Oct 18, 2007 19:42:56 GMT 10
Simon, I just grab the wing and try to bend it like a banana! You can see where a spar is broken as it will crease at that point. The main spars were fine but they don't bridge the centre so in the crash the thin ribbon spars took the centre bending load and deflected under the load ... but it was a good result really. I agree about being a whimp with the cow - I was a bit ashamed at my fear! I was getting a bit of a knot in my stomach, trying to DS and scare the cow back at the same time! DS is pretty mentally exhausting and I think I had gone past the "too tired" point! Did the top or the bottom (in relation to load) break. Or was it impossible to tell?
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Post by thevon on Oct 19, 2007 10:02:44 GMT 10
The wing didn't break, but the 2 top ribbon spars broke and one of the bottom ones. No damage to the EPP.
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Post by st on Oct 19, 2007 10:10:12 GMT 10
Andrew, I think Ding was trying to work out whether the busted spars brokle in compression or tension. My guess would be compression - pushed into the foam/buckled & broke. If so the extra bit under the break should help stop that happenning again.
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Post by ding on Oct 19, 2007 19:27:32 GMT 10
Andrew, I think Ding was trying to work out whether the busted spars brokle in compression or tension. My guess would be compression - pushed into the foam/buckled & broke. If so the extra bit under the break should help stop that happenning again. Exactly... that was what I was trying to work out. I would have thought compression too. I can't imagine them snapping under tension. I reckon it would have happened under compression and then popped back into place just leaving the break with no evidence
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Post by thevon on Oct 19, 2007 22:00:57 GMT 10
Ah, yes, I understand - yes, each of the broken spars was broken like a crease, but the break was still held by strands, if you know what I mean. Lkke breaking a green stick - it snaps but the fibres are still holding the 2 pieces together. I had to cut thru the break to open it up. Therefore it looked like flexing under compression. I think a break under tension would have torn it up differently.
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