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Aileron Idler Linkage Bracket
Posted: Mon Oct 22, 2012 12:56 pm
by dougm
The other conversation on this prompted me to email Jeff Shoemake and get his comments on the subject. In short, the bracket
IS supposed to be there.
Below is my email and his response:
dougm wrote:
Hi Jeff,
I have another question for you. A topic came up on the forum recently
regarding a bracket on the aileron linkage. The bracket in question is an
angled brace that runs from the aileron idler to the spar. It does not
appear anywhere on the plans, but it IS included in the pictures on your CD.
The question is: Is this supposed to be on the plans or is it just
something that someone added on their own? IF it IS supposed to be on the
plans, then what diameter & thickness should the tubing be? and what sized
bolt should be used to anchor it to the spar? I have attached a copy of the
picture with an arrow pointing to the brace. Could you please clarify this
for us? Should we be including this part in our builds?
Thanks,
Doug
Hey Doug,
The bracket is supposed to be there. Thanks for pointing out that it is not
shown on the plans.
Billy and I decided to put the bracket in when we were developing the push
pull linkage on his plane. I cannot say for a complete engineering
certainty that it is needed, but it cannot hurt (except adding weight).
The bracket is made from 1/2" x .035" tubing. The tubing is flattened on
each end and bent to match the angle it makes with the spar. The end that
attaches to the bolt of the idler is of course 1/4" and simple slips over
the bolt. The end that attaches to the spar has uses a 3/16" bolt thru the
spar. The length is not critical.
I hope this helps.
Jeff
Re: Aileron Idler Linkage Bracket
Posted: Mon Oct 22, 2012 3:31 pm
by RSouthard
Thank you Doug for checking with Jeff and posting his response.
I have been pondering on how to add the support now that the leading edge plywood has been completed. I've talked with John Hanson about this too and he had a good idea of a fix. Cut a small as possible slot into the bottom of the leading edge plywood , just large enough to slip in a washer and nut using a box wrench, that have been mated using JB Weld then tighten from the other side.
During assembly I sealed the D section with System's Three Clear Coat so I figured this might work. Make a internal 1/16" plywood patch to epoxy in place inside to cover the slot from the inside and then after it has cured make another 1/16" patch to fit perfectly to fill the gap. After the T-88 cures, sand and reseal the plywood in that area.
Any other ideas to add to this or Scott's idea?
By the way too, John and Jeff left the support out too because it was not on their plans sheet either. He said that they have had no issues to date related to that support not being installed.
Re: Aileron Idler Linkage Bracket
Posted: Mon Oct 22, 2012 6:13 pm
by dougm
I would be tempted to do something like Scott's idea and go in through the leading edge nose. I would be a bit unsure of patching the plywood and getting a nice smooth finish afterwards... I suppose it could work though. If you go in through the leading edge nose then you have more wood to work with to blend in the patch... maybe you could bevel the left & right side of the hole kind of like a funnel to give you more surface to glue to.
Whatever way you go I would want to make the hole large enough to be able to fish out the nut & washer if you happen to drop them inside.
Re: Aileron Idler Linkage Bracket
Posted: Tue Oct 23, 2012 2:50 pm
by mtaylor
Just a quick note to say that a magnet dragged along the outer surface of the leading edge skin will work to pull dropped nuts or washers to the opening and retrieved. This also works well when checking for and cleaning out the belly of the fuselage of washers, nuts, bolts, snips of safety wire, etc. Slide the magnet along the belly till something is "snagged" by the magnet, then slide it to an inspection hole to retrieve.
Re: Aileron Idler Linkage Bracket
Posted: Tue Oct 23, 2012 3:33 pm
by splischke
I made the brackets last night but I need to blast and prime them before installing. This gives me time to decide whether to go through the front bull-nose or through the bottom skin. I don't see either method more advantageous over the other. Just don't forget this bracket and you won't be in the same boat as Ron and I
Re: Aileron Idler Linkage Bracket
Posted: Tue Oct 23, 2012 6:06 pm
by MarkM
Thank you, thank you, THANK YOU, gentlemen, for researching this and clearing it up for me, and for us all. My thoughts are that I was leaning toward putting this brace in anyway. From an engineering standpoint (caution: I'm NOT), the biggest concern is not the compression tube being strong enough, but rather sideways (bending) loads being applied to the tube back-and-forth, hundreds of times every flight, eventually causing fatigue in that thin wall tube, which is hiding inside a fabric-covered wing and hard to inspect. In a typical homebuilt (which doesn't fly much) this probably won't be a problem... but why take the chance? We're talking about less than $5 worth of tubing, maybe couple hour's work, and a couple of ounces of weight. For that, why not?
Thanks also for starting the new thread, Doug. I'll keep in mind when naming any new threads I post to stick to the subject; it makes it easier for others to search later. Of course this also underscores the importance of this forum, where we clear up confusion and address plans omissions and boo-boos. When in doubt about something, ask!
Mark Matelski
HC-077
N429MM
Re: Aileron Idler Linkage Bracket
Posted: Wed Oct 24, 2012 3:43 pm
by PoconoJohn
Where's the other end of the bracket? I can't see what it's connected to. Thanks!
Re: Aileron Idler Linkage Bracket
Posted: Wed Oct 24, 2012 9:43 pm
by splischke
I finished installing the overlooked idler brace. It was easy to do. I bored a 7/8" hole through the nose piece with a forstner bit. This diameter is just large enough to accept the washer. I had no trouble installing and tightening the nut with a 1/4" socket and extension.
Doug, you mentioned the length of the idler brace is not that important. It isn't but just be sure it goes past the false rib to allow space for the large AN washer.
PoconoJohn, the other end of the bracket is attached to the compression tube at the idler pivot bolt hole.
-Scott
Re: Aileron Idler Linkage Bracket
Posted: Wed Oct 24, 2012 10:29 pm
by RSouthard
Dang this hurts...
I'm having a hard time bringing my self to take the plunge and do this..Thank you Scott for posting your pictures. Good job!!!
I moved this bottom wing to the hanger over the weekend to make room for building the ailerons..
Re: Aileron Idler Linkage Bracket
Posted: Thu Oct 25, 2012 5:38 am
by JBMoore
Ahhhh, homebuilders using the 'ole noodle... good work all!
Jeff Moore