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Old Oct 14, 2012, 09:40 AM
Gravity? No, the Earth sucks
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United States, IA, Des Moines
Joined Apr 2011
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sorry for the pics- but it is windy and rainy so i got to do something-lol
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Old Oct 14, 2012, 09:43 AM
buyer of the farm
United States, FL, DeLand
Joined Mar 2009
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Here's the infamous "Radian on a winch" photo that aeajr posted a year or so ago. Yes, the Radian can take it!


It lived and flew fine later.
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Old Oct 14, 2012, 10:08 AM
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United Kingdom, England, Windermere
Joined Oct 2010
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Had my Radian nearly 18mnths now, 2 months ago now a spinner let go on me for the second time...took the firewall off and bend the motorshaft.. so I decided it was time for a new fuse since it was starting to look a bit rough round the edges..
So, new fuse, new firewall, spinner, prop, motor, did all the recommended mods, bought an 850 3s battery for her.. I was well chuffed, she flew so well, a lot better than before, catching thermals and keeping in them was a lot easier, until today... the spinner let go again taking the firewall clean off the front of the plane, i'm extremely unhappy, third time it's done this and I've been really careful with the prop and spinner, no hard landings, no accidentally catching a spinning prop on anything..
third time i've lost control of the aircraft... now i'm left with a pile of bits, broken fuse, broken firewall, broken spinner...all less than 2months old, it's not like i'd flown it much, the weather has been awful these past few months only been out a few times..and worst of all no money to repair it, not sure if i want too..not sure if i can trust it anymore..

sorry for the moan...
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Old Oct 14, 2012, 10:20 AM
Proud member of LISF and ESL
LI, New York, USA
Joined Mar 2003
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When you put a stiffer rod in the wing AND you take it into a highly stressful wing manauver, like that winch launch, you have the potential for a stress point developing at the end of the rod. The foam flexes more than the rod and that can produce a rip in the foam.

In the winch launch photo, the wing rod and the foam flex together so there is no stress riser at the end of the rod. The flex of the wing actually relieves stress to help keep the wing within its strength paramaters. If it were rigid it would be taking more stress till it exceeded its breaking point and then would snap.

For those who have experience with winches, that was a EXTREMELY gentle winch launch. The taps were light and far apart.
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Old Oct 14, 2012, 10:35 AM
Tossing planes into the snow
Canada, BC, Smithers
Joined Nov 2011
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Quote:
Originally Posted by aeajr View Post
When you put a stiffer rod in the wing AND you take it into a highly stressful wing manauver, like that winch launch, you have the potential for a stress point developing at the end of the rod. The foam flexes more than the rod and that can produce a rip in the foam.
That is true for sure, and is why I will probably put some tape on the underside of the wings just for peace of mind. I like the way it looks and flies with the stiffer rod, but it definitely concentrates the stress into a smaller area. Thanks for the awesome picture.
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Old Oct 14, 2012, 01:34 PM
buyer of the farm
United States, FL, DeLand
Joined Mar 2009
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Quote:
Originally Posted by aeajr View Post
In the winch launch photo, the wing rod and the foam flex together so there is no stress riser at the end of the rod. The flex of the wing actually relieves stress to help keep the wing within its strength paramaters. If it were rigid it would be taking more stress till it exceeded its breaking point and then would snap.

For those who have experience with winches, that was a EXTREMELY gentle winch launch. The taps were light and far apart.
That was just an undeniable demonstration of the amazing engineering job on the wings. You can't tell where the rods end and the foam begins because there is a single curve from root to tip. Great engineering by Parkzone. I assure everyone that is no accident.
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Old Oct 14, 2012, 01:37 PM
buyer of the farm
United States, FL, DeLand
Joined Mar 2009
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Quote:
Originally Posted by Kickstart View Post
Had my Radian nearly 18mnths now, 2 months ago now a spinner let go on me for the second time...took the firewall off and bend the motorshaft.. so I decided it was time for a new fuse since it was starting to look a bit rough round the edges..
So, new fuse, new firewall, spinner, prop, motor, did all the recommended mods, bought an 850 3s battery for her.. I was well chuffed, she flew so well, a lot better than before, catching thermals and keeping in them was a lot easier, until today... the spinner let go again taking the firewall clean off the front of the plane, i'm extremely unhappy, third time it's done this and I've been really careful with the prop and spinner, no hard landings, no accidentally catching a spinning prop on anything..
third time i've lost control of the aircraft... now i'm left with a pile of bits, broken fuse, broken firewall, broken spinner...all less than 2months old, it's not like i'd flown it much, the weather has been awful these past few months only been out a few times..and worst of all no money to repair it, not sure if i want too..not sure if i can trust it anymore..

sorry for the moan...
Kickstart, you're having spinner problems I haven't heard of before. Anybody else able to confirm similar malfunctions? What could be causing this?
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Old Oct 14, 2012, 01:41 PM
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NorCal
Joined Dec 2009
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Kickstart, are the spinners breaking at the prop pin? Sounds like you have just a stock motor and prop.
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Old Oct 14, 2012, 03:24 PM
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United Kingdom, England, Windermere
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Originally Posted by Raften View Post
Kickstart, are the spinners breaking at the prop pin? Sounds like you have just a stock motor and prop.
Yes, they're breaking at the prop pin, I was reluctant to upgrade to another spinner because of the weight penalty but looks like i'll have to now, this is my third one and it's so destructive when it lets go but more important is the loss of control.. I just wish the manufacturer would adress this problem..
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Old Oct 14, 2012, 03:34 PM
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NorCal
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Quote:
Originally Posted by Kickstart View Post
Yes, they're breaking at the prop pin, I was reluctant to upgrade to another spinner because of the weight penalty but looks like i'll have to now, this is my third one and it's so destructive when it lets go but more important is the loss of control.. I just wish the manufacturer would adress this problem..
When are the failures happening, application of full throttle? I have had a loud bang two times when the props were folded back and I gave it full throttle but never had a failure. Anyone know if there is a way to program a soft start. I just bring the power on slowly these days.
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Old Oct 14, 2012, 03:38 PM
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..usually just after I open her up.. I know what you mean about the bang if you just hit the throttle, I always try to bring it up slowly..not sure about programming a soft start..might be the answer..
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Old Oct 14, 2012, 04:10 PM
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NorCal
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Originally Posted by Kickstart View Post
..usually just after I open her up.. I know what you mean about the bang if you just hit the throttle, I always try to bring it up slowly..not sure about programming a soft start..might be the answer..
Thank you for confirming the bang, one friend tried to tell me I was hearing things. I haven't been able to fly due to health but did take apart my newest radian and check and mod and paint. I'll look at the pin hole walls after every session.
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Old Oct 14, 2012, 04:15 PM
Tossing planes into the snow
Canada, BC, Smithers
Joined Nov 2011
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Originally Posted by Kickstart View Post
..usually just after I open her up.. I know what you mean about the bang if you just hit the throttle, I always try to bring it up slowly..not sure about programming a soft start..might be the answer..
That is indeed disturbing. Here is how to set it for a soft startup (1 second instead of .25 second). I just did it to mine so I know these instructions will work.

1 turn on radio and set throttle to full
2 plug in battery and there will be 2 sets of fast ring tones
3 move stick to center
4 now it cycles through the various menus, wait for a sequence of 5 beeps
which is the startup rate menu
5 move stick to full and there will be one beep, a pause, then 2 beeps
6 after the double beep, move the stick back to center
7 there will be a fast hi-lo-hi-lo sound, then disconnect battery.

It is also possible to get a 5 second gradual startup by changing it from airplane mode to helicopter mode. Haven't tried that yet, but it might be the best option. I also changed it from a hard to medium brake, and that definitely helps with the smoothness of the motor starting/stopping.
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Old Oct 14, 2012, 04:18 PM
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United Kingdom, England, Windermere
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thats good info Jovanx, i'll do that when I get her back together..where did you find that info..?
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Old Oct 14, 2012, 04:31 PM
Tossing planes into the snow
Canada, BC, Smithers
Joined Nov 2011
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Originally Posted by Kickstart View Post
thats good info Jovanx, i'll do that when I get her back together..where did you find that info..?
It is from a little printed cheat-sheet that came with the Radian. It also comes with the Radian Pro and the Corsair which use the same ESC. In the case of the Corsair, the programming instructions are also printed in the manual. If you don't have the folded-up cheat sheet, it should be available on line, or I could scan it for you. Good luck with putting it back together.
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