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Old 04-15-2011, 08:57 AM
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Solomoriah Solomoriah is offline
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Default Semroc Hawk: I suck at gliders

So I got a Hawk as a bonus on an order last year, and despite my poor results with gliders, I built it anyway. Wednesday I flew it for the first time, and it nose dived. So... what do I do to fix that?
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Old 04-15-2011, 09:32 AM
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Quote:
Originally Posted by Solomoriah
So I got a Hawk as a bonus on an order last year, and despite my poor results with gliders, I built it anyway. Wednesday I flew it for the first time, and it nose dived. So... what do I do to fix that?
Nose dived in boost or in glide?

If glide, add some weight to the tail.
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Old 04-15-2011, 09:32 AM
Scott6060842 Scott6060842 is offline
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Add weight to the tail? I'm assuming that you trimmed it out before flight.

My understanding is that the Semroc Hawk performs best when built without sanding sealers, paint, or primers that weigh it down.

I finished mine using permanent markers.
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Old 04-15-2011, 09:50 AM
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sandman sandman is offline
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Quote:
Originally Posted by Solomoriah
So I got a Hawk as a bonus on an order last year, and despite my poor results with gliders, I built it anyway. Wednesday I flew it for the first time, and it nose dived. So... what do I do to fix that?


OK, now listen carefully.

This is from years of trimming stick and tissue rubber band airplanes.

When making adjustment for glide make one and only one change per trial!

I cannot stress this enough. Otherwise it will just be another lesson in frustration.

Add or subtract weight, do several test tosses to see what it does remembering what you just adjusted.

If that does not work go back to the original setting, if you added weight take it off.

Then try one more adjustment either ellevon, rudder, weight whatever but ONLY ONE change!

If that doesn't work go back to the previous sett.

After a while you will get the hang of it but you have to keep going back to your original setting almost every time.
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Old 04-15-2011, 11:30 AM
AstronMike AstronMike is offline
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Sandman's trimming info mirrors my own, and some of you on here *KNOW* how that can be!

What I'd suggest for such a small glider is to use an 'easy' trimming weight, most likely a small paper clip. From the sound of your post, just place this over the tail, preferably on the underside of the rudder. Test toss....multiple times. If the bird is now stalling, move the small clip to a point more forward. Test again.

You should likely 'hit' what looks like a good trim point soon enough. Im also assuming that you *DO* have some decalage in the stab, right? If not, and it is a 0-0 config, then you may have unmitigated h*ll trying to 'lock in' a valid trim. If you seem to be stuck between stall and dive with only the slightest weight shift, then you are in this boat.

One 'hack fix' for such a deal is to add VERY SMALL elevon tabs to the stab, one on each size. Just use tape, fold it over itself, leaving no more than 1/8" extending beyond the aft edge of the stab. Bend these up slightly, and toss. You may find you need that small paper clip now as NOSE weight, and this is actually preferred. IN no case should you have to bend the 'elevonettes' up much at all, or youll throw off the boost for sure.

Now, if you really want to build a no frills cannot miss glider, please dig up my SkyDart LV plans and info on this Forum. Slap one of these together and you will wonder where stuff like this has been for so long.....
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Old 04-15-2011, 11:48 AM
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Totally agree with the advice from Sandman.
ONLY make one change at a time...otherwise you will never know which change made the difference.
Gliders are not THAT hard...you just have to be patient with them and always trim before first flight.
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Old 04-15-2011, 03:43 PM
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Quote:
Originally Posted by Scott6060842
Add weight to the tail? I'm assuming that you trimmed it out before flight.

That would be a bad assumption.

Seriously, I suck at gliders. The last two I built, both of which are now lost, I killed hours trying in vain to trim... probably because, despite the best of explanations, I really don't understand what I'm doing.

Up I do good. Parachutes I do good. Gliders I suck at.

Quote:
Originally Posted by Scott6060842
My understanding is that the Semroc Hawk performs best when built without sanding sealers, paint, or primers that weigh it down.

I finished mine using permanent markers.

I took that to heart with my Tinee... and I don't have it anymore. Not that it glided... it nosedived, actually, right into a beanfield.

Quote:
Originally Posted by sandman
When making adjustment for glide make one and only one change per trial!

I cannot stress this enough. Otherwise it will just be another lesson in frustration.

Gah. STILL a lesson in frustration. As I mentioned, I spent a lot of time trying to trim two other gliders. Admittedly, one was a Sparrow, which I'm told is hard to trim. Paradoxically, it actually sort of glided, though not well, and was lost on its second flight.

Quote:
Originally Posted by AstronMike
Now, if you really want to build a no frills cannot miss glider, please dig up my SkyDart LV plans and info on this Forum. Slap one of these together and you will wonder where stuff like this has been for so long.....

Hmm. I might just have to do that.
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Old 04-16-2011, 07:34 AM
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GuyNoir GuyNoir is offline
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Here's a spot with some clear tips / hints:

http://www.gryffinaero.com/models/f...ps/hlgtips.html

Or look at stuff for catapult gliders like the attached PDF.
Attached Files
File Type: pdf catapult.pdf (14.2 KB, 300 views)
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Old 04-16-2011, 11:16 AM
nvrocketeer nvrocketeer is offline
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Sounds like the motor failed to eject.
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Old 04-16-2011, 01:35 PM
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Solomoriah Solomoriah is offline
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Nah, I saw it eject, and it was absent when the rocket was on the ground.

Guy, I printed out that web page, but I haven't had time to read it over yet. Thanks!
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