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Old Oct 20, 2009, 03:24 PM
Hot Dawg Glider Pilot
schrederman's Avatar
United States, TX, Weatherford
Joined Nov 2002
7,792 Posts
Owl,

I just go over the rib area from one side to the next and continue wrapping. I'll usually wrap a couple of bays and touch it with CA so it doesn't lose tension and has to be totally redone if I slip. I try to wrap in one piece from start to finish, but wrapping one bay at a time would work just as well. I just wick in some thin CA on the sides, and let the glue wick in the spar cap areas when I'm adding the sheeting. Remember that excess glue is just weight. As long as the bay is wrapped, and the tow is well bonded, I believe no weak spot would exist.

In this case, the spruce/balsa was used in the outboard panels just to help keep the cost down. The Journey will have full-span CF spars. Now if I can just get those ribs...

I didn't get to see Richard's model before it crashed. It sure was pretty in the pics.

Jack
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Old Oct 20, 2009, 04:44 PM
Registered User
Utah
Joined Aug 2005
153 Posts
Spruce vs. hard balsa

For what it's Worth,

On my Houston Hawk I weighed the tapered spruce outer panel spar caps intended for the upper spar caps.

I then cut the same spar caps for the lower surface from very very hard 1/8 balsa.

Using a balance beam gram scale the weights were within 2 grams. The hard balsa being lighter by 1 1/2-2 grams.

My conclusion use the spruce.
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Old Oct 20, 2009, 05:07 PM
Hot Dawg Glider Pilot
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United States, TX, Weatherford
Joined Nov 2002
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Good point... I never did that... Yep, use the spruce.
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Old Nov 01, 2009, 10:46 PM
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Albuquerque, NM
Joined Nov 2003
157 Posts
Thought I'd report on my Yardbird rebuild. Finished doing the center panel spar fishbone and have just now glued on bottom sheeting/trailing edge to the spar and rib tails. I've extended the spar by one rib bay on each side, so Jack might object to me calling it a Yardbird. I'd post a picture, but then you all will see how messy my garage workroom is.

Hope to have the center panel all sheeted up this week, then onto the mid panels. (I get to reuse my outer panels). And those spars are going to be made of out of spruce capped w/ carbon fiber strips. Want this next bird to last a little longer this time!!!
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Old Nov 02, 2009, 09:49 AM
Hot Dawg Glider Pilot
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United States, TX, Weatherford
Joined Nov 2002
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I guess you could call it the Yardbird +... I'm looking forward to seeing it. I'll be out for the next TD competition.

Jack
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Old Nov 02, 2009, 01:07 PM
agony sweetns the victory
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Any Flying Field Across America
Joined Jul 2005
3,515 Posts
Quote:
Originally Posted by schrederman View Post
He likes sailplanes, guitars, fishing, nice cars, and good-lookin' wimmen... what else is there?

Jack
Ya got the makin's of a good country western song there Jack
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Old Nov 02, 2009, 02:47 PM
Hot Dawg Glider Pilot
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United States, TX, Weatherford
Joined Nov 2002
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I think there has to be something in there about trains... but hey, I work for a railroad, so...
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Old Nov 30, 2009, 11:00 PM
LSF IV
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USA, TX, Corinth
Joined Jan 2009
91 Posts
Jack, my Yardbird and I completed our LSF level 3 slope flight of 2 hours this weekend. I busted a wing tip at the Houston LSS, but a little TLC and some carbon fiber got the bird flyin again.

Jimmymac
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Old Dec 01, 2009, 07:57 AM
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Albuquerque, NM
Joined Nov 2003
157 Posts
Yardbird rebuild progress report
All three panels are pretty much framed up. Almost ready to shape leading edges. Still have to attach the old tip panels.

Jack, is the Yardbird a 'RES Woody -legal' ship for the SWC? I use an Art Hobby fg fuse, but the tail feathers and wing are mostly wood. I'm hoping to get it done in time for that contest in February--haven't signed up, yet. If not, I'll have to fly my ancient Sapphire or Jade again.
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Old Dec 01, 2009, 08:42 AM
Hot Dawg Glider Pilot
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United States, TX, Weatherford
Joined Nov 2002
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Yes, it's legal. I flew mine last year. I was hoping to have the Journey ready for this year but still no ribs...
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Old Dec 26, 2009, 10:12 AM
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USA, FL, Winter Haven
Joined Nov 2004
121 Posts
Yardbird Broken Wings

RNSHAGAM: Did you have the double D boxes with the .007 carbon fiber top and bottom in your intermediate panels? Did you wrap the joiner in the intermediate panels? Just curious - I'm very near completion of mine and would rather rebuild the outer panels than crash the entire sailplane.
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Old Dec 27, 2009, 03:29 PM
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Albuquerque, NM
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dong727,
I used spruce for spars top and bottom, laminated with .014 cf on top and .007 carbon on the bottom. I also used tapered plywood doublers for the joiner box extending walls back two more rib bays from where the plans call for the end of the doubler--this is to avoid any stress risers like the one that took out the old wing. And of course, I wrapped the whole business with kevlar tow. Guess I'm not taking any chances again!!! If it breaks, its my own fault now...

Oh, and I should explain what I mean by tapered doublers. Fortunately, you asked just as I was about to cover my wing, so I was able to snap a picture for you--hope it explains it. Hope its not too late to make similar mods, if you can.
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Old Dec 28, 2009, 11:15 AM
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USA, FL, Winter Haven
Joined Nov 2004
121 Posts
Broken Wing

Richard: Thanks very much for the prompt response and photo! Your new wing looks truly bullet-proof. What I meant to ask was about your broken wing. Did it have the double-D section with the .007 carbon top and bottom as suggested in the Build Log? My wings are completed, covered and ready to fly. Meaningful mods are not an option at this point. If I want to change, I'll have to build whole new outer panels.
Regards, Don Grisham
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Old Dec 28, 2009, 04:10 PM
Registered User
USA, FL, Winter Haven
Joined Nov 2004
121 Posts
Hot Dog Jack - Your Thoughts

Jack: My Yardbird is completed and ready to fly. I'm a little concerned about the outer wing panels. They are constructed as per the plans with the additional double D shear webs and .007 carbon. I also wrapped the joiner boxes with Kevlar. Do you think my sailplane is safe to fly in its present condition if I do not do "gorilla" launches? Your thoughts? If anyone else reads this and is successfully flying without carbon in the main spar, please chime in and let me know.
Regards, Don Grisham
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Old Dec 28, 2009, 04:50 PM
Hot Dawg Glider Pilot
schrederman's Avatar
United States, TX, Weatherford
Joined Nov 2002
7,792 Posts
Don,

If you used HARD balsa in the outer spars, and I mean, the hardest, meanest stuff you can find, you should be OK for mild winch launches. If you didn't, I'd be careful.

Jack
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