Flyblog: my Hang Glider

tuning my litesport, bis

Thu, 10 Jun 2004 11:56:29 GMT

Checked out a few things last weekend.

Elastic had gone on stinger, bit of a fiddle to replace but easy in the end.
Checked the battens, all OK which shows that the original shape (bent) was very unlikely the first 20hours of flying (30 on it since then...). So it was delivered with rather dodgy battens shapes.
The VG rope (bottom part) was indeed twisted once around the lower cable retainer - hence the extra friction. Easy to sort out when you know what to do - easiest to pull off the bottom of the upright. At least with the normal uprights and FAST bar re-threading the rope is easy.

The glider now flies good and straight with no feeling of skewness... seems I've got completely through that phase now.

New A frame

Sun, 09 May 2004 18:42:46 GMT

Put on the standard A-frame today, finally arrived and went down to Parma to collect it from Franco. Looks nice, actually quite clean. Uprights much safer. I have also a new FAST speedbar, since the old one has the holes drilled slightly differently and cannot be used. Looks like I'll need to try and sell the whole ZOOM frame to someone.

Even though it's been of a bit of pricey exchange, it's the right thing to do. What I should have done all along - just gone for the FAST speedbar upgrade, which was quoted at 100 euros. This way round has cost me a lot more, even if I manage to sell the ZOOM frame to someone, I'll be more than 500 euros out of pocket. At least I have more chance of keeping my arms if I crash.

Took the opportunity to weigh the glider - just under 32kg, exactly like the manual says. In the bag it's 35kg (I'm amazed that the non-flying stuff weighs so much). I also completed the manufacturer's sticker, which was mostly blank (for example, date of manufacture of glider, date of test flight, etc...

2003, what sort of glider was my Litesport?

Tue, 30 Sep 2003 19:46:46 GMT

My Litesport is a classic, I'd say. But a few gripes.

I'm 99% sure it came cross tuned, that is a setup fault (outer wands differentially rotated) was tuned by setting it up wrongly (one sprog raised about a cm compared to the other). I had to learn to tune the glider to get rid of it. Thank Dennis Pagen for his articles in HG mag for the explanation. The manual wasn't much use. Tuning this glider is possible, but not for the faint hearted. It takes hours of fiddling.

The sail quality "could be better". The Laminar Pause sail (on my Easy) was a superb finish by comparison. There is no doubt this won't last as long. Plus in July I discovered a rip on the trailing edge root cover, created by bad stitching which had made too many perforations. Still to be repaired - doesn't seem structural, but it's not good.

The ZOOM frame is a bit OTT. It's strong - very strong - but at the same time delicate. The front and rear wires look as if they touch and rub the uprights, and the black anodising/coating comes off too easily, and so looks immediately tacky. The corner mounts are fiddly, since the pip pins seem to pull out the tubing/sleeve that holds the side wires in - a bit scary, you need to include that in your pre-flight check.

The bag is too big - too long, by 10cm at least, and too baggy. Makes it difficult to carry.

Apart from that, it is great. Especially in flight - superb. Take off easy with VG full off, then after I'm in the 1st thermal I pull VG on 1m, then I have just a hint of high siding. One handed in 3 or 4 up isn't uncommon. Go on glide, in smooth air just pull it on as much as you want and let it fly at trim. In thermals with VG on just 1m or so, trim is slow, once you are used to it that works great, the glider climbs with the best. VG is long, but easy to operate and doesn't look like sticking. Bar pressure is low, roll low and responsive too. I can fly three hours and not feel too tired, and I'm a not especially fit 40 year old. Big improvement over the Laminar Easy, but I guess any advanced glider should be the same in that respect, more or less.

Landing, of course if you get panicky could be a bit of a problem, it's potentially fast and responsive. But get it lined up, VG off and pull in and you'll drop OK. Then rounding-out comes quite early in general, and you'll need to just let it carry on going up, and flare will be quite soon, quite light, almost on auto I find. I've had four flights (out of 24) when the bar touched the ground, although two of those were bad ones (crashes, effectively) caused by unexpected conditions (exceptional ground effect, sudden cross wind). 20 landings in low or nil wind with the glider resting on my shoulders. Yes, I've got around 170 flights like that now, but even so. This is a great glider to land.

Conclusion: great value for money, a great club glider for someone who wants to save 2 or 3 kgs and 1500 EUR... I'm not sure I'd trade it today for either a Litespeed or any other flex wing. Suits me fine.

Tuning saga

Wed, 04 Jun 2003 20:03:54 GMT

I'm starting a collection of the links to all the posts mentioning tuning, just to keep it together. Once I get it sorted, I'll start to reflect on this whole saga...

Litesport 4 DHV test report finally...

Wed, 04 Jun 2003 12:26:55 GMT

And the result is - DHV 3. Take off and landing set at 2, but the rest of the in-flight stuff at 3.

Personally, I'm quite surprised, since the handling is very nice especially VG off. I guess that VG you could get into trouble if you are not aware of how the handling is transformed. But that's pretty obvious.

Double surface given as 87%, not 70% as I remember from somewhere (Dennis Pagen's review?).

Tuning, again

Mon, 02 Jun 2003 19:52:08 GMT

I seem to have finally sorted it. The glider was clearly not symmetric and I had what Dennis P. calls a "cross-tune", i.e. flies straight but isn't set up straight.

I got the tape measure out and measured all the wires, also to the trailing edge. All OK, but the tips still clearly differential by 2 to 4 cm. Decided the only way to sort out the trailing edge was set the left sprog higher, it was also visibily screwed in by a thread or two. Unscrewed it half a turn: better, not perfect. Unscrewed it another half turn: nearly spot on. Flies nicely, a bit more high siding required on the left turn, but that's where the inboard concentric gives a bit more anhedral.

Adjustments so far: right tip set to neutral from 10mm downward (more lift). Right sprog net movement maybe 1/4 or 1/2 turn down. Left sprog a whole turn up. Trailing edge is now near perfect, but I haven't checked the sprog height against the keel yet.

Probable next adjustment: set both inner concentrics up (more anhedral) and then the tips up (rotate concentric down), which should give fast response and a bit of high siding.

Tuning, continued

Sun, 01 Jun 2003 18:26:48 GMT

I figured that it still wasn't right. I had the feeling that the glider was cruising with the nose about 10 degs right of the true heading. Maybe more drag on the right wing. Who knows. And maybe it was me, but I couldn't thermal to the right on the 24th April.

Set the whole thing up in the garden. The Moyes manual is sensible, tells you what to check first, but doesn't tell you how to correct things if your glider is not symmetric.

Battens: nr 6 green over 1cm too flat in the middle. most of the outer battens too flat, but that's at least symmetric. Outer concentrics: set to zero, inner concentrics, +/- 10mm down (backward).

From the front: everything looks OK. But looking from the back, no sprogs in, clearly the right wing trailing edge too high. It was the batten symmatry check that was the worst - from the 3rd, the right wing sat higher.

So I set the right concentric to neutral, and lowered the right sprog half a turn. Seemed to have reduced the differential twist.

Result: flies even better - no apparent bias left or right, no nose pointing off-glide. But it's still not symmetric - I can see when It's parked that the left tip sits nearly on the ground, and the right one is up in the air. So the frame is not balanced. Yet. We'll get there.

Why was it delivered like this?

Sat, 10 May 2003 09:23:41 GMT

Nigel made a demo flight on the LiteSport (he likes it a lot) and noticed a small rip in the sail. Turns out it's made where the leading edge goes up against the keel/uprights when rigging on the A-frame: if you forget to put the padding in (which I do, regularly) before you close it up, then the rolling action of the leading edges around the keel seems to make the upright mount act like a knife. Very annoying. Solution: do as Icaro and others, make the padding integral to the upright fittings and leave it on the glider. The Moyes padding is a bit on the large size for that so I'll have to get the sewing machine out.

Tuned

Tue, 08 Apr 2003 17:59:12 GMT

Bit difficult to tell from last Saturday's flight, but my reseting of the tip wand socket and the sprog seemed to have pretty much cleared things up. It'll take a flight in good conditions to really tell, but certainly I had no major turns. So maybe the tip wand socket was strangely set up rotated by someone who perceived a turn.

The trailing edge is also now pretty symmetric, still maybe a slight rise on the right: the screw is six threads out compared to four on the other side, but I guess this is of no relevance since the engineering tolerance on the tensioning cable cannot be much better than a mm, and that is the aproximate difference. I need to do several long glides, however, to be really sure. I just didn't detect any turns in the last flight.

Tuning advice?

Mon, 31 Mar 2003 19:42:56 GMT

I had thought I had tuned out a slight left turn with the VG on. After fiddling a few times with the right outer sprog, it seemd more or less OK - maybe a touch too much, seemed to turn right slightly now. Rigging in the garden after replacing my bent upright, I pulled the VG on and sighted the trailing edge. Wow, that right sprog was lifting the edge over a cm. It was a disturbingly asymetric sight.

Next rigging, I check the tip wand socket. Left side, centred on the mid point mark. Right side, rotated backward (down) 1cm... so just the opposite of the sprog adjustment. Hmmm.

Email Moyes to ask if all of this makes sense. Few days later I get an email that "looks like I feel the need to tune my glider". Sure. I guess it's probably not realistic to expect much sense over the internet from halfway round the world (or 100km for that matter). So I've adjusted the tip wand socket back and rewound the sprog back in (lowered it) half a turn (it was 5/4ths). We'll see. I bet after I've finished with this the sprog will be back where I started and the tip wand socket balanced with the one on the left.

If so, why was it rotated back? Someone's perception of a spiralling right turn? No hint of that so far.

Mounting my eTrex on the aero base bar

Mon, 10 Mar 2003 19:52:07 GMT

For the record, a short description with photos of what I rigged up:

http://radio.weblogs.com/0108898/stories/2003/03/10/mountingMyEtrex.html

Getting that new aluminium on

Wed, 05 Mar 2003 20:09:48 GMT

Skiing's been taking priority for a while. But the season is now getting underway, so last weekend put the new uprights on.

Fiddly. The rear and front wires pass through slots onto the ZOOM fittings, held in with little pins that drop out easily. The wires can get snagged on the slot edges if you're not careful. Moreover, the uprights are left and right, so you need two spares... or cut an extra slot in the side for the rear wire (so the upright can go on both sides). Since I needed to fit two since my replacement and new spare were black, and Franco had sent me two from the same side :-| I drilled/filed the new slot through the existing one.

The old less bent upright straightened up OK, with me jumping gently on it... only a 1cm bend. Have to cut an extra slot in that one too, so it becomes an ambidextrous spare.

So far it has to be said that the ZOOM frame is nice but rather a lot of maintenance. Yes, it's probably low drag, but consider -ve points:

expensive (uprights ~100 EUR each)
front and back wires are sensitive where they pass through the slots on the uprights
you have to disconnect the cables to replace an upright, several small parts involved (although no tools)
they're heavier (I think)
you can't fit wheels
breaking your arms on the uprights in a crash seems a distinct possibility - they are tough

In retrospect, probably I would say go for the FAST bar but skip the ZOOM frame. (Although if I hadn't then I would probably also think I should have).

Anyway, if you break an upright with any frequency, then I wouldn't go for this. But if you want the cool hi-tech, low drag, etc, fine. There's a bit more work involved, and you have to do some maintenance and keep a good check on the frame and the cables.

Lost links

Mon, 27 Jan 2003 21:07:03 GMT

Looks like I got a whole load of links and stuff lost during a transfer. Here they are again:

My Laminar Easy review from 1999
Photos of my LiteSport
My LiteSport test flight, Sep 2002

Mon, 27 Jan 2003 20:25:43 GMT

FAST bar, ZOOM frame and wheels. Of course why would anyone put wheels on a FAST aerofoil bar with ZOOM coorner fittings? Well, so you would be less likely to break your arms, I suppose. And maybe for towing? I want to learn to tow, but not with no wheels.

So since Moyes informed me that the corner fittings are glued onto the FAST bar (as well as bolted, of course) I'll have to find another solution. Maybe the clip on ones, cut the centre out, find some way of making a bearing. SHould be able to get it to work. Hassle though. We'll see.