Posted by jb92563 on Monday, November 14, 2011 @ 05:13 PM:
While upgrading to webber gear and making sure the everything was working well after the install, I noticed something about the landing gear doors.
Some folks have mentioned the their gear doors are not closing properly when retracted.
I noticed the same thing on mine and took a carefull look at what was hapeening with the gear door springs.
Apparently on mine the spring wires that go under the washer were straight and tended to bind and not close the doors properly.
The solution was to curve the spring so that it does not bind during its full range of motion.
Look at how I curved the spring with some pliers in the picture below.
Now the gear doors close perfectly and do not bind at all.
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Posted by Bob Grimstead on Thursday, November 24, 2011 @ 06:23 AM:
That's very interesting Ray, but I don't think those springs or their attachments are standard.
They're certainly not like that on either of my Fourniers.
Yours, Bob
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Posted by jb92563 on Monday, November 28, 2011 @ 11:19 AM:
A previous owner must have changed out the originals.
That might account for why mine were binding.
In any case, they don't now, since I curved the spring where it passes under the bolt/washer arrangement.
I'd be interested to see what the originals do look like if anyone cares to snap a pic when convenient.
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Posted by SteveBeaver on Monday, November 28, 2011 @ 11:41 AM:
Try this:
http://sbeaver.com/cgi-bin/fournier/cutecast.pl?forum=11&thread=310
Posted by jb92563 on Monday, November 28, 2011 @ 12:06 PM:
Hmmmm....that is exactly what my springs looked like before I bent them curved.
Perhaps the bolt/washer arrangement was different than what I have.
What was happening was that when the gear doors would close the straight part of the spring would get to an angle where the straight part would bind between the bolt/washer and the metal of the door. The spring wire would flex through this binding but the friction of that would stick the doors a bit and they would not smoothly close or even hang up during ground testing.
This would be ultimately due to the spring coil location not being exactly center of the door hinge and the resulting offset of geometry.
Probably the air pressure while in flight would help the doors close but since it was an easy fix, and I remember some folks halving trouble with positive closing in flight, I decided to remove the cause of the binding.
Now the doors slam shut quite nicely on the ground and should do equally well or better in the air.
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Posted by SteveBeaver on Monday, November 28, 2011 @ 01:13 PM:
Your bolt/washer go through a trapezoidal brace riveted to the gear door. Now imagine in the center of the short side (near the washer in your picture) of the trapezoid there is a small hole 3/16" from the edge. Through that hole is threaded a small wire loop perhaps 3/8" in diameter. Something like a miniature keyring. The long straight leg of the closing spring passes through that ring too, and so pulls the door closed.
Steve
Posted by SteveBeaver on Monday, November 28, 2011 @ 01:16 PM:
I found one in the basement!
Looks like I put the pretend spring through from the wrong side (the hinge being on the right) but you get the idea I'm sure.
Posted by jb92563 on Monday, November 28, 2011 @ 01:58 PM:
Is that what comes on the RF4D from the factory?
It is a simple, elegant design that will not bind...must be a Fournier creation!
Thanks for digging that up. If I have any more trouble I'll correct it with this design.
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Posted by SteveBeaver on Monday, November 28, 2011 @ 02:18 PM:
All three RF4s at our airport have this system, so I assume so.
Posted by eugenio on Monday, November 28, 2011 @ 04:00 PM:
Yes, it is and it works fine. If you need some new spring ask Collin, he might have some.
Eugenio
