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Old Oct 30, 2012, 05:24 PM
Tossing planes into the snow
Canada, BC, Smithers
Joined Nov 2011
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Is there anyone who has successfully replaced the shaft of the stock motor? I have a slightly bent shaft on the Radian after the last ski hill incident. I can still fly it but there is some vibration, and with the prop removed, it can be seen that the shaft is bent when it is spinning.

I have a Corsair that uses the same motor except the shaft is reversed so it can be mounted in the usual way in front of the firewall. That motor started making funny sounds a few months ago. so I figured I would take it apart to see if the problem could be solved. With a lot of work I was eventually able to loosen the 2 allan screws on one end, but the third one on the other end will not budge. If I could get it apart, I might be able to figure out what is making the noise, and if not, it would at least work in the Radian with the shaft reversed.
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Old Oct 30, 2012, 05:26 PM
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The stock fuse stiffener isn't stiff enough. So, while replacing it (I'm looking at getting and using a CF tube since I need to order a wing spar anyway) wouldn't it make sense to "pull" the fuse into position so the decalage is zero while glueing in the stiffener rather than dealing with decalage and fuse stiffening as seperate issues? Seems both could be dealt with in the same operation.
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Old Oct 30, 2012, 05:42 PM
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Quote:
Originally Posted by Jovanx View Post
Is there anyone who has successfully replaced the shaft of the stock motor?
Might look at http://www.horizonhobby.com/webapp/w...pe=productgrid The shaft has 4 set screw flats you don't see in the pic and is 1 29/32" long.
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Old Oct 30, 2012, 05:55 PM
Tossing planes into the snow
Canada, BC, Smithers
Joined Nov 2011
3,147 Posts
Quote:
Originally Posted by t.edwards View Post
The stock fuse stiffener isn't stiff enough. So, while replacing it (I'm looking at getting and using a CF tube since I need to order a wing spar anyway) wouldn't it make sense to "pull" the fuse into position so the decalage is zero while glueing in the stiffener rather than dealing with decalage and fuse stiffening as seperate issues? Seems both could be dealt with in the same operation.
The Radian 480BL and the Park 480 are two different motors. I will have a closer look and thank you for the link.

Yes the stock stiffener is definitely not stiff enough, and yes you can pull the fuse to wherever angle you want while installing a better stiffener. They can both be dealt with at the same time. It is just a matter of fine-tuning the slot before gluing the arrow shaft into place. If you make the slot an even depth all the way along, and tape the ends while the glue is drying, it will reduce the decalage.

In my case, the decalage was already good, so I made the slot deeper in the middle than the ends and ended up not changing the decalage by very much.

Here is something to keep in mind...the existing fuselage keel can be replaced with an arrow shaft without a weight gain, and the arrow shaft has a thin wall and is very light. The wing spar should be replaced with something stiffer, such as a standard CF tube that has a thicker wall. If this doesn't make sense, I could upload a picture that will show the difference in the wall thicknesses.
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Old Oct 30, 2012, 06:13 PM
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Quote:
Originally Posted by Jovanx View Post
Here is something to keep in mind...the existing fuselage keel can be replaced with an arrow shaft without a weight gain, and the arrow shaft has a thin wall and is very light. The wing spar should be replaced with something stiffer, such as a standard CF tube that has a thicker wall. If this doesn't make sense, I could upload a picture that will show the difference in the wall thicknesses.
It looks like the "common" .375" OD CF tubes are .290" ID or ~.040" wall. What's the OD and wall thickness on an arrow shaft? I hadn't decided on a dia. for the fuse stiffener, or if round or box or two pieces of flat seemed better.

The fuse stiffness really seems pretty good until you get back to the thin section just before the tail surfaces

I also have a piece of .028" wall .375" OD 4130 chrome moly tube for a really stiff wing par should ballast be desirable.
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Old Oct 30, 2012, 06:30 PM
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Old Oct 30, 2012, 06:46 PM
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United Kingdom, England, Windermere
Joined Oct 2010
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When you remove the original FG spar, cut about 8" off and glue it in the slot above the wing saddle, stiffens it up a treat..

Chris..
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Old Oct 30, 2012, 06:49 PM
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Originally Posted by Radio.Active View Post
horizonal stabilizer
Is your horizontal stab just balsa and monokote or light ply or fiberglassed and monokote? I really don't like the stock horiz stab/elev.
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Old Oct 30, 2012, 06:54 PM
Tossing planes into the snow
Canada, BC, Smithers
Joined Nov 2011
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Originally Posted by Kickstart View Post
When you remove the original FG spar, cut about 8" off and glue it in the slot above the wing saddle, stiffens it up a treat..
Chris..
I was thinking about shoving a 3mm CF rod in there as a skewer. There is something about that spot that looks weak, although I have not had a problem yet. Are there people who have had a failure in that location?
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Old Oct 30, 2012, 08:53 PM
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Old Oct 30, 2012, 09:11 PM
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Des Moines IA
Joined Dec 2005
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Would these blades work on the stock spinner?
http://www.bphobbies.com/view.asp?id...03&pid=W898906
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Old Oct 31, 2012, 04:14 PM
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United Kingdom, England, Windermere
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Originally Posted by Jovanx View Post
I was thinking about shoving a 3mm CF rod in there as a skewer. There is something about that spot that looks weak, although I have not had a problem yet. Are there people who have had a failure in that location?
I always thought it looked weak and it was one of the places that broke when i crashed once.. it was easy to insert as they hadn't even put any glue in on my Radian.... I think it can only help and since I had a spar sat there it seamed stupid not too..

Chris..
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Old Nov 11, 2012, 05:59 PM
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United Kingdom, England, Windermere
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Originally Posted by Gohmer View Post
I fly mine with a lighter motor that lets me have a 3.25" CG without adding weight to the tail. No need to hack up the tail section.
which motor do you use..?
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Old Nov 12, 2012, 02:39 PM
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Old Nov 12, 2012, 05:45 PM
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Owatonna MN 55060
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Originally Posted by kickstart View Post
which motor do you use..?
axi 2212/20
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