C

chris mitchell

Well Known Member
Patron
Lots of questions today!

We have now got the aileron for the right wing bolted in postion -made easy with the temporary assembly pins from Averys to get all the various spacers and washers in place. I then installed the W818 pushrod which was the subject of my last post; with the aileron locked centrally and using the handy little W730 widget to position the bellcrank, there is about 13/32nds of the rod end screwed into end fitting which I guess is just about enough to make me feel that it will be secure. There is a lot more room there for adjustment than I had anticipated and had I realised I might have cut the rods a bit longer than the specification - anyone got any comments on that? Is this a common finding?

I've been looking at the aileron control stop, whihc suddenly makes an appearance on drawing 13A. As Iunderstand it, it is riveted to the outboard side of the W413 hinge bracket and limits upward deflection when it bears on teh leading edge of the A407 aileron bracket? THe "down" limit is prvided by the "up" limit on the other aileron? Have I got that right? There is no specification for how far the stop projects out from W413 - enough to impinge squarely on A407 and no more? I don't understand the instruction about the rivet heads. Could someone explain please?

Finally, I offered the flap into position and looked to get the trailing edges of flap and aileron aligned, both along the TE and in the same vertical (when on the finished aircraft) plane. It will be very tight on the edge distance for the flap hinge if I push the TE of the flap out to the same level as that of the aileron. I was going to draw a line on the flap hinge marking the minimum edge distance there and see how it looked but again I 'd be glad of any comments or helpful suggestions.

I'll try and post some pictures later to show what I mean.

Meantime, back to the shop for some more measuring and thinking, but no drilling or cutting. Many thanks for help.

Chris

RV8QB
Empennage completed, wings in progress.
 
I just finished hanging my flaps so I can tell you what I did.
First, I made sure the ailerons were clamped in neutral using the method decribed in the plans. Then I riveted the flap bracket to the bottom skin with about 4 rivets or so. (Dan's method ) Clamping the flap hinge to the skin/bracket was a breeze and aligned up perfectly with no edge distance issues. I used a piece of 1/4" pine I had laying around to get my gap between the flaps and ailerons, and it all came out pretty as you please.
 
Re: the edge distance on the flap hinge ... I have the same issue; I had to order additional hinge from Van's, I believe it is the AN257-P4 (instead of the P3 supplied). This has a wider attach strip but the same eye spacing and will fit the hinge that is already on the flap, allowing for the edge distance when the flap is aft enough to match up with the aileron.
Don't know about a source in GB ... I bet the shipping for a 6' piece of the hinge from Van's would be killer! It was 25$ here in the USA... I added a bunch of spare angle, etc to fill the container. Maybe you could have it sent with another builder's kit or parts...

T.
 
TShort said:
... I bet the shipping for a 6' piece of the hinge from Van's would be killer! It was 25$ here in the USA... I added a bunch of spare angle, etc to fill the container. Maybe you could have it sent with another builder's kit or parts...

T.
Click to expand...

The flap hinge was the one piece of my kit that I had to re-order - same issue - needed more edge distance to get the trailing edges to line up, and had to go with the "P4"....I wasn't looking forward to the shipping, and was expecting an expensive mailing tube. I was shocked when a 16" x 16" square box showed up...sure enough, the Van's shipping guys know just the radius they can bend the hinge material and not have it kink! I bet the shipping wouldn't be too bad....

Paul
 
Thanks guys thats all helpful. As suggested by Matthew, I put a few rivets in to hold the flap brace to the skin to steady it all up, squeezed them a bit flat so as to minimise interference with the hinge. (I'm sure I read about this somewhere but can't find it now). With the brace and skin held steady I found the discrepancy at the trailing edge I could easily get down to 1/16 or a smidge less without pushing the edge distance. I wondered about the P4 but I worry that it would be less rigid with just hinge supporting the flap rather than the skin/flap brace/hinge combo - as at least two of you have done it so it must be ok.
Shipping can be a big issue so I'm interested to hear that it goes in a 16" box - we have to pay 17.5% tax not only on the part but also on the shipping, so a cheap part can soon become pretty expensive!

Chris :D
 
Chris, You may want to try this alternate aileron stop method. I found it on someone elses site. look at drawing 13A at section A-A. I replaced the A-711 spacer with larger dia. Aluminum spacers that i turned on my lathe. my left side one was .483" dia and .362 long. the right side was .477" dia and .376 long. Yours will vary as mine did. I installed the aileron per instructions and used a digital level to set the proper up travel of the aileron. Then measured the remaining space between the 3-14A bolt shank and the W-413-ppl inboard hinge bkt. This will tell you what dia. to make your spacers. I think this is a simple elegant solution that will work fine. I may have to fine tune after I install the wings and controls. I cannot see that we would be slamming the ailerons hard to the stops when flying so it will remain to be seen how it works out. Tony

PS I also had to order a -4 hinge to get proper edge distance for the flap hinge.
 
Why different length aileron push rod tubes

Just completed cutting and assembling my W-816 push rod tubes and started wondering why there are two different lengths: 69 3/16 and 72 11/16. Which one goes on the left and which on the right?
 
Bud-

If you look at DWG-15A, the 72 11/16" measurement is between the eyes of the rod end bearing. The 69 3/16" measurement is the length of the pushrod made out of the AT6-035x1.125 rod. Both pushrods are the same length.

 
Wow what a dumb question

I make my living as an engineer designing and building scramjets for a major aerospace company. I really blew print reading on this one. Luckily I can still cut the tube to 69 3/16.
 
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