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Old Jul 18, 2012, 09:47 PM
Tossing planes into the snow
Canada, BC, Smithers
Joined Nov 2011
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Any of the above options will be an improvement, and well worth doing. My arrow shaft was also 14 grams, and was probably a little stiffer than a solid rod of equal weight.
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Old Jul 19, 2012, 12:37 AM
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Mexico
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Quote:
Originally Posted by Gore-Tex View Post
Well, according to the salesman the rod weighed 14 grams (I made him weigh it ). You think a hollow arrow shaft is lighter AND stronger? Hm, ok...



You mean glue the rod under the spar, on the belly of the plane, so the rod comes closest to the ground?
I was going to glue in a solid CF rod. I started to push it into the fuse, along the existing stiffener. But I didn't hit the resistance I was expecting so I just kept pushing it in until it poked into the servo bay. I cut it off at the skid, and GGed the end where it exited the fuse.

Works great so far.
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Old Jul 19, 2012, 01:29 AM
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Joined Dec 2006
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Quote:
Originally Posted by MrBlu View Post
I was going to glue in a solid CF rod. I started to push it into the fuse, along the existing stiffener. But I didn't hit the resistance I was expecting so I just kept pushing it in until it poked into the servo bay. I cut it off at the skid, and GGed the end where it exited the fuse.

Works great so far.
No glue along the length of the rod?
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Old Jul 19, 2012, 08:54 AM
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USA, CA, Pismo Beach
Joined Oct 2007
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Quote:
Originally Posted by MrBlu View Post
I was going to glue in a solid CF rod. I started to push it into the fuse, along the existing stiffener. But I didn't hit the resistance I was expecting so I just kept pushing it in until it poked into the servo bay. I cut it off at the skid, and GGed the end where it exited the fuse.

Works great so far.
Like gore-tex implies, this should be glued all along the length for maximum benefit. The easier it pushed in , the less benefit without adhesive.
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Old Jul 19, 2012, 09:41 AM
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Old Jul 19, 2012, 10:51 AM
Tossing planes into the snow
Canada, BC, Smithers
Joined Nov 2011
2,991 Posts
+1 Radio.Active, agreed on all points.
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Old Jul 19, 2012, 11:12 AM
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Joined Dec 2006
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Agreed. Looks like I'm missing a suitable rod then. Hm, would the CF strip method underneath be equally rigid with the GF spar left in? How wide would such a strip be?
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Old Jul 19, 2012, 11:40 AM
Tossing planes into the snow
Canada, BC, Smithers
Joined Nov 2011
2,991 Posts
Quote:
Originally Posted by Gore-Tex View Post
Agreed. Looks like I'm missing a suitable rod then. Hm, would the CF strip method underneath be equally rigid with the GF spar left in? How wide would such a strip be?
Anything you put on there will help. (the plane is nose heavy anyway). Even tape makes it fly better. I believe the hollow CF tube is the best choice because it not only stiffens the tail laterally and vertically, it also takes out some of the torsional twist.
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Old Jul 19, 2012, 06:27 PM
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United States, TX, Frisco
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Originally Posted by Radio.Active View Post
For a given material, and given weight, the maximum strength is achieved by a hollow cylinder ( the tube ), that is of larger diameter than the solid rod of the same weight. Think of it as the material in the center of the rod providing no resistance to bending or twisting. All the excess material near the center is useful for strength in tension and load bearing but that doesn't apply in this use on a tail boom.

Gluing only one end is not bad for the Radian but the other end and full length of the shaft will move as the tail twists or flexes as control surface act. So at a minimum glue the 2 ends. Gluing the whole length is unnecessary and adds some minor weight. Think in terms of a torsion bar on your car's suspension - fixed at both ends. But it is probably just easier to run a bead of Gorilla Glue the whole length, slap in the shaft and wrap the fuse in masking tape while it sets up.

Leaving the original fiberglass spar in place is then just added weight with no function.

CF arrow shafts are hugely less expensive than buying CF tubes at your LHS. I use Cabela's 6 arrows for $26 If you have an archery range near you, the CF tubes are free. CF arrows tend to break near the tip leaving 90% of the shaft in perfect condition for our hobby after you trim off the feathers and pull out the nock.
Any pics you could post of the process?
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Old Jul 19, 2012, 07:15 PM
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Old Jul 19, 2012, 08:52 PM
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Thanks RA. I just happen to be going to Cabelas this weekend to pick up my new waders. Looks like I'll be adding an arrow to the list.
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Old Jul 19, 2012, 08:57 PM
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Des Moines IA
Joined Dec 2005
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Originally Posted by Radio.Active View Post
Here is my whole Radian mod image dumpster

https://skydrive.live.com/?cid=DBDE7...65DDCB92%21672

Specifically for the CF arrow

https://skydrive.live.com/?cid=DBDE7...5DDCB92%211040
and

https://skydrive.live.com/?cid=DBDE7...5DDCB92%211021

Some images from earlier mods show 5 minute epoxy but I now use Gorilla Glue. Also, not shown, I now remove the tail skid and run the arrow from the servo bay hatch to the end of the tail. I also tend to use less and less GG now, just enough to hold the arrow in and rejoin the 2 foam halves were the fiber glass spar was removed. I used to like the GG to foam up around the sides of the arrow. Not now. You'll notice I'm using the extra foamy brown Gorilla poop instead of the white just because it is more readily available in larger sizes and common at HD and other building supply stores up here in my part of the Great White North. White is available at Micheal's but in small sizes and expensive even when they have 50% off coupons. I'm cheap.
Where did you purchase your blades and spinner?
Also what did you do to the wings as the 2 photos are diff.
Thanks
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Old Jul 19, 2012, 09:06 PM
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Old Jul 19, 2012, 09:23 PM
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Old Jul 19, 2012, 09:35 PM
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Des Moines IA
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Originally Posted by Radio.Active View Post
Here is what I used ... shows $CN

http://www.cabelas.com/product/Hunti...3Bcat103856580

or

http://www.cabelas.com/product/Hunti...3Bcat103856580



Both are 50mm, one is from HeadsUp and the other is from HK

http://www.headsuprc.com/servlet/the...Hub-for/Detail

order for the correct 4mm PKZ shaft

and

http://www.hobbyking.com/hobbyking/s..._adapters.html comes with 3 colletts including the 4mm
Thanks just ordered me one 10x6 and 11x6 blades and spinner are on there way.
I like buying from the greatest nation in the world so you know where I bought mine plus i have bought from them in the past.
Great company.
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