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Author Topic: Wood stiffness  (Read 1951 times)

Offline Russell Shaffer

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Wood stiffness
« on: September 20, 2006, 04:50:07 PM »
Will two pieces of 1/4 balsa laminated be stiffer or stronger than one 1/2 piece, assuming the same grade of balsa for both choices?  Thinking of a Flite Streak.
Russell Shaffer
Klamath Falls, Oregon
Just North of the California border

Offline Ralph Wenzel (d)

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Re: Wood stiffness
« Reply #1 on: September 20, 2006, 06:32:18 PM »
Will two pieces of 1/4 balsa laminated be stiffer or stronger than one 1/2 piece, assuming the same grade of balsa for both choices?  Thinking of a Flite Streak.

They will be considerably stiffer and less warp-prone, too, as long as they are laminated on a flat surface. And while you're at it, stick in a layer of .4 oz. fiberglass cloth and make it stronger, too, for a very minimal weight gain.
(Too many irons; not enough fire)

Ralph Wenzel
AMA 495785 League City, TX

Offline Steve Helmick

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Re: Wood stiffness
« Reply #2 on: September 20, 2006, 10:37:09 PM »
Don't laminate them with any kind of white glue or aliphatic. I'd suggest epoxy or a urethane glue like Gorilla Glue. There are several brands...see your Lowe's, etc.

One thing, tho...for a Flite Streak, the fuselage is 7/16" thick, not 1/2". Many folks are building up profile fuselages, some using 1/64" plywood as the side skins. Good stuff!  ~^ Steve
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In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline W.D. Roland

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Re: Wood stiffness
« Reply #3 on: September 22, 2006, 11:34:41 AM »
what Ralph said

Steve--why not  white glue or aliphatic resin?
 that would have been my choice with the aliphatic being number 1

David
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Offline Bob Reeves

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Re: Wood stiffness
« Reply #4 on: September 22, 2006, 11:57:22 AM »
what Ralph said

Steve--why not  white glue or aliphatic resin?
 that would have been my choice with the aliphatic being number 1

David

Not Steve but can answer the question.. Two reasons.. 1. it won't dry, not enough air gets to it in the center. 2. it's water based and will cause warps.

Offline W.D. Roland

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Re: Wood stiffness
« Reply #5 on: September 22, 2006, 12:58:24 PM »
hi Bob---never had that problem with alphatic resins.
 if its problem can always coat 2 parts let dry and use heat to activate bond--dont remember what the method is called--fantastic for planking and monokote iron--
i think his joint will only be 1/4 in wide?

David
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Offline Russell Shaffer

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Re: Wood stiffness
« Reply #6 on: September 22, 2006, 03:34:52 PM »
Joint will be 3 inches wide.  I'm going to glue two 1/4 sheets to make 1/2.  As per the plans I have.  I think I'll also go with the glass reinforcement as suggested.  For my flying, stronger is better.
Russell Shaffer
Klamath Falls, Oregon
Just North of the California border

Offline john e. holliday

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Re: Wood stiffness
« Reply #7 on: September 22, 2006, 03:42:19 PM »
You can forget the fiber glas if you use the new poly-urethane(gorilla) glue.  Pancaked the Primary Force in Topeka Ks at the memorial day contest.  Fuse is still in one peice. Later,  DOC Holliday
John E. "DOC" Holliday
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Offline W.D. Roland

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Re: Wood stiffness
« Reply #8 on: September 22, 2006, 04:08:09 PM »
Russel

kinda confused on what you want to do

thought you wanted to make a flight streak l.e.

rereading i see you want a fuselage

on flight streaks in combat we didnt often break rear of fuse.

we used 12in long doublers(5ply)
a triangle peice of 1/4in ply at wing l.e. to motor mount
elevator moved in line with wing--mainly so it wouldnt come off in crash-also flew better
cut down rudder
no flaps
new tips
was good slow combat in pre mongoose days and survived straight ins usualy!

pic of superstreak here 

 David
« Last Edit: September 22, 2006, 08:51:07 PM by Robert Storick »
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Offline Russell Shaffer

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Re: Wood stiffness
« Reply #9 on: September 22, 2006, 08:20:22 PM »
I'm convinced - won't use the glass in the middle.
Russell Shaffer
Klamath Falls, Oregon
Just North of the California border


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