joining carbon fiber spars at the dihedral joints

Share your tips and information here

joining carbon fiber spars at the dihedral joints

Postby Geeze » Mon Mar 12, 2012 7:39 pm

[list][/list]
How do you do it? Where do you buy the spars and rib caps?

Thanks,
Geeze
 
Posts: 31
Joined: Sun Jan 10, 2010 2:34 pm
Location: Hamilton, Montana

Re: joining carbon fiber spars at the dihedral joints

Postby Steve Landy » Tue May 29, 2012 5:56 am

I'll add to the question: how do you make dihedral joints in wings with carbon fiber D boxes?
Steve Landy
 
Posts: 91
Joined: Sun Dec 14, 2008 11:21 am

Re: joining carbon fiber spars at the dihedral joints

Postby Robert Dunham II » Wed May 30, 2012 8:55 am

Go to <cstsales.com> for all carbon fiber items. Owned by Matt and Gail Gewain- they'll help you out.
Most planes I've seen with carbon d-boxes uses a thick rib (3/16" to 1/4") on the end of each wing panel. Panels are joined together by sanding dihedral in, ala HLG.
Robert Dunham II
 
Posts: 20
Joined: Sun May 27, 2007 5:12 pm
Location: Broken Arrow, OK

Re: joining carbon fiber spars at the dihedral joints

Postby Roger Morrell » Wed May 30, 2012 9:24 am

you can put a brace cut from carbon plate along the spar - CST sells the plate
and/or a carbon or kevelar "bandage" wrapped around the Dbox after the tip panel is glued on [using the thick rib technique mentioned above]

Roger
Roger Morrell
 
Posts: 145
Joined: Mon Jul 25, 2005 11:39 am
Location: Redondo Beach

Re: joining carbon fiber spars at the dihedral joints

Postby CHE » Mon Jul 09, 2012 8:06 am

What you need to do depends on where you fly I guess. If you fly at Lost Hills where your model is cushioned on landing by the dying breaths of unicorns then you don't need much more than the thick ribs. If you fly in places where wild animals literally rip your wing tips off and/or you fly on runways so hard as to defeat the, er, well I digress.

I use a brace from 2mm PCB material (glass fabric) which sits inside the spar flanges. I pack either side of the brace with balsa, sand to size and glue in with epoxy.

The TE I rienforce top and bottom with 2 x 1/2 tows of UD carbon, attached with cyano and sanded down to zero thickness at the ends - total length about 30mm either side of the joint.

The d-box I rienforce with two layers of 50gms glass cloth attached with cyano bit I've seen good results with UD carbon as well.

All these actions result in a very strong and stiff joint able to resist the effects of a rutting Haggis (but then you knew that, didn't you).

CHE
CHE
 
Posts: 170
Joined: Thu Jul 27, 2006 1:02 am

Re: joining carbon fiber spars at the dihedral joints

Postby Pete » Mon Jul 09, 2012 10:21 am

CHE,
You sound like you're all set to go flying in Texas.
No wild ruttin' Haggisses here but we got lots of other interesting critters.
Cheers!
"The best things in life are Free (Flight)"!
The proper number of models to have is...
one more!
Pete
 
Posts: 491
Joined: Wed Jul 13, 2005 5:21 am


Return to Construction Tips & Tricks

Who is online

Users browsing this forum: No registered users and 1 guest