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Oct 17, 2007, 11:23 PM
Yes, ALL your money...
winchdoc's Avatar
Quote:
Originally Posted by mccomposites
... as long as the trailing edge slop is tight...
You are correct, Sir!
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Oct 17, 2007, 11:41 PM
Registered User

Tips for root rib/sub rib/joiner tube assembly


On the Vector,
I agree with Jay, I like to cut out the foam everwhere, slots for the joiner tubes and the root and sub ribs, When everything is lined up glue the joiner tubes to the ribs with thin foam safe CYA, the ribs to the foam with med foam safe CYA. Then fill the cavities with epoxy/cabosil/chopped cotton/micro, not real dry but thick enough so it will sand ok. Carefull with the sanding block so not to get the top of the tube filler too flat. Fill any low/flat spots with spackle, doublers for the carbon skin, done. Be sure to brush some extra epoxy all over the root ribs, sub ribs, and slurry/spackle, that helps the skin bond and hold better, for more durabilty/strength.

I also like to make the slot in the foam about 1/4" longer than the end of the joiner tubes, and fill that with slurry too, helps with the stress riser at the end of the tube, sice the compressive and tensile strength on the slurry is better than the foam core. If round holes are bored through the foam, the stress riser will be more on the sub rib, probably never fail in the air, but it will probably be more likely to rip out the sub rib in a crash landing.
I have used this method on unlimited size slope racers like the Apex 1 and 2, Vindicators, the "bagged wing" 2M Extreme's, Vector1 and Vector2, plenty good for frontside flight.

This side of a full contact shear web/spar it works fine, but its not as light as the rounds holes in the foam for joiner tubes.

Hope this helps

Brian
Oct 18, 2007, 12:09 AM
Eagle Butte User
PDX Slope Pilot's Avatar
That was helpful. Great info being shared. Thanks Brian!

Vic
Oct 18, 2007, 12:30 AM
Registered User
Hey Hutch,
To cut smiles I made a jig for my drill press.
It has a rod the size of the wing rod sticking up and then I clamp that to the table on the drill press. I set it up so the rod is the right distance from the reamer bit. Then just turn on the DP, lower it down until it punctures the fuse and swing the fuse back and forth on the rod and you get perfect(most of the time) SMILES....

TIM
Oct 18, 2007, 07:53 AM
Knowledge increases life's FOV
Sled Driver's Avatar
Thread OP
Quote:
Originally Posted by PDX Slope Pilot
If I understand you correctly, with the Xica, you basically are just using a root rib e.g no sub rib, setting your joiner tube up with microballoons and epoxy then bagging it all at the same time?
Wish that I could fill the cavities and bag the skins on at the same time. Unfortunately, you have to fill the cavity, let it cure, sand it out, and then bag the skins on. It is the prep' to do everything right makes bagging strong wings that will last take so long to build. Fortunately, not all wings have to be that strong to last, e.g., Shrike, Pica, and conventional 60" slope wings without joiners, do not require the additional work to last.
Oct 18, 2007, 08:09 AM
Embrace the suck
nauga's Avatar
Quote:
Originally Posted by A6INTRUDER
To cut smiles I made a jig for my drill press.
(sound of hand smacking forehead)

Great idea!

Nauga,
who says "OW"
Oct 18, 2007, 09:19 AM
Yes, ALL your money...
winchdoc's Avatar

cutting smiles


I drilled a few holes in my Dremel router base to match various size pivot rods.
get the distance from bit to hole correct, and then I put the pivot rod thru the appropriate hole and use the right size bit to swing the arc. Consistant smile cuts every time. Mostly I use it for all-moving stab smile arcs.

WinchDoc

"nothin' left to do but smile, smile, smile..."
Oct 18, 2007, 10:42 AM
Registered User

Great ideas guys, please keep them coming


Thanks a lot for all the ideas here
I spend to much time on RCG's, and to be perfectly honest I rarely see anything I can learn much from, with 20 yrs around gliders especially the skilled builders and designers I ahve learned from, "been there done that" almost everytime, but this thread is actually very interesting, educational, and fun. There is a pretty good size group, of pretty savy twisty wing home builder guys in the PNW, 2008 should be very interesting, I plan to have a couple Vector2's for the 6 pack. Something about the twisty wings and the PNW, ever since I have lived in Oregon I have wanted a Vector or Xica for Eagle Butte and Peterson Butte, must be the good landing zones and Ken Stuhrs legacy, the hard working builders here, and the fact that they are fun, and the wings are so simple

On the tubes in the stabs, I have used sub ribs, but not required, the weight is better used on skin doublers for the obvious reasons.

I will try not to ramble too much

Brian
Oct 18, 2007, 08:30 PM
Eagle Butte User
PDX Slope Pilot's Avatar
I will be excited to have my Vector2 up and flying by the 6 pack if not earlier. I agree it's refreshing to read the useful content in this thread, so keep on Brian....

Doc, do you have a photo of the mechanism you use to make your smile cuts? I'd like to make the same or borrow A6INTRUDER's jig. Not quite sure I follow how you do it.
Oct 18, 2007, 09:18 PM
Twisted and Confused
flyonline's Avatar
A bit OT here, but also related to the thread on slowing down wings. Does anyone have any braking system in their TW's? If they're slippery and carnagable then some braking system would be a big help, especially for tight LZ's. Pop up blade airbrakes are one idea as it would easy to negate any pitching moment and increase drag.

Steve
hoping to become a TW afficianado one day
Oct 18, 2007, 10:01 PM
Yes, ALL your money...
winchdoc's Avatar
Quote:
Originally Posted by flyonline
A bit OT here, but also related to the thread on slowing down wings. Does anyone have any braking system in their TW's? If they're slippery and carnagable then some braking system would be a big help, especially for tight LZ's. Pop up blade airbrakes are one idea as it would easy to negate any pitching moment and increase drag.

Steve
hoping to become a TW afficianado one day

Here ya go...

https://www.rcgroups.com/forums/show...down+wingerons
Oct 19, 2007, 09:20 PM
Twisted and Confused
flyonline's Avatar
Thanks for the link, answered most of my q's

Steve
Oct 20, 2007, 12:52 PM
Knowledge increases life's FOV
Sled Driver's Avatar
Thread OP
Installed the stab joiners last night...
Oct 20, 2007, 08:08 PM
Detail Freak
target's Avatar
Jay-

Thanks for posting your process.

Two questions for you:

1. Is the outer layer of balsa on the stab just so that you have something to sand to match whatever minor angle(s) are on the vertical?

2. I have a Xica with the stock 66" span E374 wings. I want to bag up the SD-7003 2 meter wings I have. Will I need to increase the area of the stock stabs, or do you think that there is enough reserve stability to use the stockers. The plane is setup as a Pitcheron right now; I may change back to full flying stab and wingeron as we have previously discussed.

I welcome your opinion.

Thanks,
Target
Oct 20, 2007, 09:34 PM
Knowledge increases life's FOV
Sled Driver's Avatar
Thread OP
Quote:
Originally Posted by target
Two questions for you:

1. Is the outer layer of balsa on the stab just so that you have something to sand to match whatever minor angle(s) are on the vertical?

2. I have a Xica with the stock 66" span E374 wings. I want to bag up the SD-7003 2 meter wings I have. Will I need to increase the area of the stock stabs, or do you think that there is enough reserve stability to use the stockers. The plane is setup as a Pitcheron right now; I may change back to full flying stab and wingeron as we have previously discussed.
The balsa root rib does trim more neatly than just foam when sanding the root to match to the fin. The laminate also attaches much better to end grain balsa than foam, by a factor of 15 or better. So, the balsa ties the top and bottom skins together much better than the foam does. This does help transfer loads from the joiners to the skin, but it really helps keep the trailing edge from breaking, cracking, or buckling when the stab gets whacked on the leading edge. Effectively, the end grain balsa helps hold the laminate in place so that the laminate can take more load. Does that make sense?

The stock stabs on the Xica should be fine for your 2 meter wing.


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