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Post by thevon on Feb 5, 2008 13:56:31 GMT 10
Those photos of that slope, later in that thread, look unbelievable! I think if we could get Sean or Ezza onto that slope with a fully ballasted Reaper they'd be doing 150+ too! BYYEEUUUWWWteeefful ridge. But the ice on the ground! Those guys were really rugged up!
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Post by sean on Feb 18, 2008 13:54:45 GMT 10
I had a great fly yesterday, first day I've had in months where it felt like DS was really working the way it should. I flew at a site I've only flown once before up here near Maleny. It's a pretty gnarly spot with a very turbulent backside, like a washing machine really, I was hoping it'd be a bit better. I tried DSing a number of lines in the area but they were all rough and you could see there was lots of wind on the back. It was a funny day, I was flying my foamies really carelessly so carnage was inevitable - I was DSing the Skua in one spot witha nice bowl-shaped backside with a really strong shear layer. But the back was rough and there are powerlines close behind/above the DS zone so I was flying the bottom turn stupidly low to stay under the lines and get under the turbulence as much as I could. There was a satisfying Barrumph sound each time it crossed the shear but it was so rough I couldn't hold togther consistent laps. Coming towards me on one pass with the Skua I went too low and hit a barbed wire fence at maybe 70! I thought - that's it, it'll be nearly cut in two - but to my astonishment there was no damage! Just a tiny scratch near the tip! So I kept at it, and hit the fence a second time with no damage, and then clipped it another time, but it stayed in the air... The wire in the fence was very loose so I think the energy of the crash was being dissipated. Then I threw out the Reaper, with no ballast, and it immediately started ripping, within 3 laps I reckon it was doing about 100 but then about two laps later in it went - it was really turbulent and the bottom turn was very low. It sort of got sucked down and disappeared from view behind the hill - then I heard a gut-wrenching crunch and saw this yellow nose (minus wings and tail) appear from out of nowhere and sail 10 metres through the air! It was pretty funny actually, the most spectacular foamy crash I've had. The wings are fine, not a scratch and the fuse departed from the wing quite cleanly. Only prob is the tail boom and fin are broken in a messy way - I'll try CAing the boom together and wrap some carbon around it, but if that doesn't work I'll dig the boom out of the fuse and put a new one in. There was no way I was going to try the Bird in conditions like this, so I drove over to Bald Knob to try my luck. It was raining pretty hard in Maleny earlier in the day so I found I was the only one there. Amazingly the wind was almost east with just a touch of south in it (it seemed SE-SSE at the other spot), so I started DSing at the top gate. It was working OK, but the Skua copped more punishment getting stuck in the top of a tree, took a while to get it down. At this stage I'm thinking - should I throw the Bird out? With so many crashes with the foamies I had begun to think my flying on the day was not up to scratch. But I chucked out the Bird anyway and it was like chalk and cheese, it was immediately going very fast and cleanly cutting through the turbulence doing effortless laps fairly high and back from the hill. Only a few days ago I finally got around to balancing the wings after the repair job I did on one of the wings - they were out by quite a bit but it flew with no aileron correction on the front so I didn't bother balancing. It required about 20g in the outer servo bay of the light wing to balance. Interestingly yesterday while DSing it was tracking so much more smoothly then before I can't help but think this has made a difference. The way it carved big smooth effortless circles was quite beautiful. DSing a fair way back from the hill it's hard to know what speed it was doing but it looked quick to my eye, I'd say 120s give or take 10, it actually seemed faster than that but you tend to overestimate speeds when there isn't a radar around . At these speeds it seemed to get on step and DS much smoother than when it's going slower, and interestingly it seemed quieter than usual. With no radar around I wasn't trying for max speed, just letting it cruise around while keeping it well off the ground. Like the spot I'd been at earlier, there was a really pronounced shear layer so it felt like proper DS. After half an hour maybe I flew onto the front for a breather, but when I tried DSing after that I just couldn't get the speed up again. That hill is a mystery, I don't know why it was working so well when I first threw the Bird out, the wind was not the ideal direction and not particularly strong, and I regularly fly there in very similar conditions working much harder to maintain 70 or so. When it stopped working later in the day I couldn't really see what had changed - perhaps the wind had dropped a tiny bit but back home Seabreeze showed the wind at Maroochydore got stronger as the afternoon progressed . It was a good day, only problem is I can feel the early signs of an impending mouldie addiction. Sean. Reaper Carnage:
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Post by skyboyken on Feb 18, 2008 17:32:15 GMT 10
Sounds like you had a good day despite the damage - good stuff.
It sure makes me glad I've done the same as you and put all the electrics in the wing of my Reaper! BTW Sean I won't be flying this Thurs, I'll still be building.
You don't necessarily have to use carbon to fix carbon. If you can get the fin out you can cut fibreglass cloth into a 20mm tape and wrap the join, overlapping 50% on each wrap. Then if you want to get really clever slip a piece of heat-shrink over the whole thing and shrink it! Once it's dry cut off the shrink wrap and it should be stiff and neat.
About the Bird Sean, how do you feel about its DS handling qualities now that you've had more time with it? I get the message you're really happy with its level of performance, I guess I'm asking whether it's fun to fly or hard work but rewarding. Bottom line, if you had written it off yesterday what would you replace it with?
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Post by sean on Feb 18, 2008 18:02:33 GMT 10
Hi Ken,
I was very happy with it's perfomance yesterday, it was very easy and predictable, and most important fun. In the past it's been a bit tricky to DS in rough conditions getting knocked this way and that - I'm hoping I've cracked it by balancing the wings but before I can get back to you with a definitive answer I'll need to DS it a few times. Aside from balancing the wings, extending the antenna up the V-tail has pretty much eliminated my glitch problems. I think on the first few days I DSed it I was getting lots of glitches, but at the time i thought it was being knocked around by turbulence cause they always happened on the same part of the DS lap- when it was coming straight at me.
Also, yesterday it felt like it "got on step" and became more stable, at slower speeds it seems like more work, the tail doesn't stabilise yaw distrubances as effectively.
If I were to buy a replacement in a similar price-range, I don't know. An X tail and larger span would be high on the list. Another Carbon Bird with a custom X or T tail would be awesome as the only thing about the Bird's handling that I don't like is yaw stability.
The double-glass Opus would be a good buy, only a little more expensive and from what I read good for similar outright speeds - but being bigger and heavier I suspect on an average day it'd be faster, just a hunch though. A double-glass t-tail Opus would be nice but not sure if they make them. It's amazing how much bigger the Opus looks too, and the span is only 40cm more.
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Post by skyboyken on Feb 18, 2008 21:33:18 GMT 10
Thanks Sean!
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Post by sean on Feb 19, 2008 16:10:26 GMT 10
The Reaper's fixed... I didn't feel like spending much time on it so thought I'd use the quickest method I could come up with.... I found that the tip of one of the spare golf club shafts that I have was a perfect fit inside the broken section of the Reaper's boom. So I cut the old fin away and soaked the broken boom sections in hot water to get rid of all the dirt. I cut about 4 inches off the tip of the spare golf shaft and CA'ed it into the broken section, then slipped the two broken sections together and liberally applied more CA. Boom fixed! I thought it was the dodgey way to do the repair but it's really strong, as strong as before I reckon. With a sand, some electrical tape over the broken area and the fin glued in you can hardly tell it was ever broken. I've gooped the fuse back onto the wing and am waiting for it to dry. Job done! Took about an hour all up. Oh yeah, with a bit of extra weight in the tail I'll need to rebalance before flying but that won't take long. It's amazing how well the wing survived the impact, it's literally unmarked, not even a wrinkle .
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Post by ezza on Feb 19, 2008 20:24:10 GMT 10
Nice and simple fix Sean.
I was thinking the same with your wooden fuse. You could just slip a whole new shaft right over the top like a sheath. Just need to line up the tapers. It adds a fair bit of weight but with ds'ing that is all the better. ;D
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Post by sean on Feb 20, 2008 20:19:34 GMT 10
Andrew and I went to Bald Knob today hoping for some big speeds as strong southerlies were forecast. But, there was almost no wind! Most of the day the wind was under 10kt, maybe 5kt for long periods. It did come up briefy and we got some OK speeds considering the light wind. The wind picked up a tad and I had the Bird getting around at 80mph or so, then the wind picked up again and I reckon it was sitting on around 100 - doesn't sound much but still looks pretty quick when it's in close. Unfortunately Andrew was off retrieving his Reaper after it failed to stay up on the front in the light wind, so no radar verification on that.
Then the wind completely died out, we were wondering what to do, whether to go home or try somewhere else when Chris Callow showed up complete with the sexiest glider I've ever seen - an Erwin DS. Chris is a multiple World F3D Champ and the Erwin is an exotic carbon DSer so we were expecting quite a show, and we got it!
Chris was flying that thing really aggressively, banging super-hard turns inches of the ground narrowly missing the many trees that are scattered around, it was very spectacular. Basically he was flying that thing like most would fly a combat wing except it was about 3 times faster. The wind was really dead at this stage but the Erwin was still getting around in the 70s/80s, but because he was flying so low, and so close to the trees it looked much faster. In the same wind my Bird was doing 60s and 70s, - it was nice to see the much smaller Bird wasn't too far off the pace especially considering my higher more conservative line.
The calm wind was a disappointment, but it was good to see such a talented pilot do his thing.
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Post by atmosteve on Feb 20, 2008 21:17:10 GMT 10
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Post by thevon on Feb 21, 2008 12:20:14 GMT 10
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Post by skyboyken on Feb 21, 2008 17:45:46 GMT 10
How was the Erwin for lateral stability when DS'ing? Did it want to track straight or shake its tail?
It looks sensational BTW!
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Post by sean on Feb 22, 2008 18:15:01 GMT 10
Hi Ken, It tracked nicely, but then the conditions were very smooth, you'd have to see it in turbulence to know.
To my eye the tail area and moment look fairly large compared to the size of the wings. Also, the v-angle of the tail is less than usual so there'd be a bit more side area than a typical v-tail.
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Post by thevon on Feb 29, 2008 17:41:22 GMT 10
Sean went down to Byron Bay last night to visit Ezza and score some DSing in the strong SSE which was due to hit down there today. I called up Ezza before and got this report (Sean's on the way home).
The wind wasn't ideal as it started S and went SSW, resulting in some pretty bad rolling turbulence. The perfect direction there is SSE. The wind strength was 20 kts to 34 kt gusts. So there was some good power but some dangerous turbulence too.
Sean got 144 with the Reaper. But it started to flip over dramatically in turns ... initially at around 140, then at slower speeds. Very concerning as it for example did 1.5 barrel rolls coming out of the bottom turn! Sean showed his amazing flying skills keeping it all together when others would have lost track of which way was up! One time he did a big loop over the backside and another time shot back up the lip inverted, and on the last time he was lucky to land it back near himself (which is over the back).
On inspection they found that it had the same problem that Ezza's Reaper did ... the ballast was hammering its way out the end of the tube and ramming into the EPP, allowing the other slugs to slide back and forth. Planks are so sensitive.
He got 167 with the Carbon Bird. It probably did better but many laps weren't in line with the gun. Ezza said it handled beautifully. At one point some rain came over and Sean kept DS'ing and the Bird went totally silent! The water on the surface must have damped the usual whistling/ shrieking of the hollow molded wing. It was freaky having it cruising past at 140 with barely a whisper.
Ezza put the Opus up too, and got into the mid-190's but the wind had gone rolly-polly and the plane was getting bounced around, so he didn't keep it up for long. Sean was nervous watching it, apparently.
That's all I got! Sean will no doubt expand more later.
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Post by sean on Mar 1, 2008 0:18:21 GMT 10
Just wrote a pretty long post, accidentally pressed the wrong button and lost it all! So I'll keep it relatively brief this time!
Amazing day! That site is VERY intimidating, like nowhere I've flown before! With no decent landing zone, 30kt + of gusty wind, a fair walk to and from the DS zone with a fairly narrow window through which to see your plane, thick bush all around, and a crazily powerful rotor it takes some commitment to throw off, even with a foamy! Today was a major learning experience - much bigger DS conditions than I'm used to made me feel like a complete DS newb. My Bird was definitely capable of more speed but by the time I started to feel comfortable I was losing concentration, which is when mistakes happen, so I decided to call it a day and bring the plane back in one piece. Most of the time I was flying my thumbs were shakey and hands sweaty - the site seems to have that effect! But all in all I was happy with my new PB, it's a respectable jump up from my previous best and the Bird lives to fight another day.
When Ezza flew the Opus the conditions weren't as good as when i was flying the Bird, I'm absolutely sure he would have cracked 200 no worries at all at that time, but he didn't feel it was a 250+ day so didn't risk it. His flying is just so confident now, great to watch. The turbulence was bad when he was flying and even the tank that is the Opus was getting badly knocked around which is why I felt nervous watching. You could hear how strong the turbulence was every time it crossed the shear layer - it didn't sound like a quick punch through a clean shear - the closest thing I can think to describe it is distant rolling thunder...
Really bizarre how the Bird went almost completely quiet in the light rain, the water must have an effect on the airflow. It was only a brief shower and landing is a 10 min job so we kept at it.
Previously when flying here Ezza had landed his Opus on the beach below but today we were able to hover in both the Opus and Bird, plonking them down on top of some thick bushes around on the frontside, but getting to the landing zone was hard work in itself - it required walking qround 50M through a tunnel of trees, running between openings in the canopy to keep the planes in sight. With crow on both our planes had their noses down about 30 or 40 degrees, gently descending with no groundspeed yet getting tossed around quite a bit by the crazy wind. With practice a hand catch would be possible but the bumpy conditions would make it a challenge.
Shame the Reaper played up - within a few laps it broke my previous PB. It would occasionally do these crazy rolls and full aileron couldn't keep it level. On one occasion it disappeared from view, I pulled up which was all I could think to do, and very fortunately it reappeared. At first we thought it was freak turbulence so pressed on, but later Ezza's dad noticed it was happening when the speed got up around 140 so we figured there was a structural problem and brought it in. Upon inspection we found the ballast could slide several inches left and right in its tube, would have had something to do with the two nasty crashes it'd had in the last few weeks. The ballast couldn't move before the flight but the end cap on the ballast tube must have been just ready to go. At least this explained the uncontrollable rolling! I guess the lead occasionaly slid across to one side so when pulling the top or bottom turn the severe imbalance produced a very strong roll, too strong to keep in check with aileron. Yet another lesson learned!
Lots of fun!
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Post by laanguy on Mar 1, 2008 20:15:01 GMT 10
Great job Sean. Thats an amazing effort considering how long you have been Dsing. Past my PB already and officially this makes you second fastest Aussie.
Well done.
Andrew
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