Fuselage

[Brock]

There must be some technical term for the short pieces of filler rod that become shorter than a welder cares to use/hold.  I'm call'n them Filler Nubs.  Anyone have a better term?  The reason I'm thinking of Nubs is that I've got a small collection of them which means I've been be getting some welding done ;-)

Today I finished off the landing gear brackets.  These brackets were a learning opportunity.  They get mounted on each side of a 5/8ths inch tube but are specked to be 3/4" appart.  The solution is to statigically bend them which takes expirence which takes practice.  So now that I've practiced I'll be ready for the next build, no going back on this one.

[Chuck in Indiana]

When you build your next one  you can keep from bending by making a bracket that doubles as a seat belt mount.

[Brock]

Can anyone tell me why these 3/8 bushingings are welded to the side, of the 4" Stabilizer Connectors, and not through the center like their counter parts on the fuslage?

[jrbirdman47]

I just figured it was because the horizontal stab connector tube thru-bolts had no need to be centered on the axis of the tubes, and welding them to the side was easier than drilling and welding in the center. Although, truth be told, for the application I doubt that either really must be centered. The distance the attaching bolts would be off center if the bushings were welded to the side of the fuselage tube is likely negligible. (I compare the rigid attachment set up to the trim jack screw assembly used by the Piper rag wings. In that case it was way easier to offset the jack screw assembly reference the connector tube) But that's just me......

[Kamcoman77]

Just a little heads up for anyone who hasn't made the connectors. Use 7/8" x 0.058" for the H. Stab TE and 3/4" x 0.058" for the LE instead of 0.062". Your 3/4" H.stab TE & 5/8" LE will slide right in (no reaming). Also use 0.058" wall for your elevator horn tubing unless you are making a folding tail.

[Brock]

A little progress.  Today I finished the stabilizer connecting tubes as well as the mount point on the fuselage.  Learnt a few things along the way.  First ah-ha was don't drill the connecting tubes through the stabs until they are mounted on the airframe.  Reason is that mounting them on the airframe first makes sure the bolts will just slide right in.  I was close enough but had to drill through to releave a bit of alignment.  Second, the length of the airframe 3/8x1/4 bushings is shown as 1.5" but it does not show how much to leave on top or bottom.  After some figuring it looks like having the minimum (or less) so that elevator travel will not contact the frame.  Making the bushings short will allow them to be adjusted with aluminum washers (lighter than 4130) and ensure the shortest possible bolt (again weight).

All in all I'm quite happy with the results.  Sighting down from the firewall to the tail reveals a very straight verticle and level horizontal (off maybee 0.4 deg  Measured with a calibrated eyeball).  It could have turned out much worse.  You can see in the first pic that I drilled the connector tube through for the bushing, then after welding I milled them down to the weld.  Just now, I can see why one would want to weld the bushing on the side.  It makes for a lower profile mount as the weld is on the side of the bushing and not on the end.  Oh-well, I'll likely cut down the bushings in the fuse anyway for minimum stand off from the frame.

[Chuck in Indiana]

You can easily square up the tail with the brace wires, FWIW, I made the tabs out of 4130. Nice shop, and nice job. Attaboy..

[Brock]

Today was spent cutting and drilling elevator hinges.  Most of the time spent went into thinking and head scratching.

Question: Does the Aluminum need to be treated before mounting the 4130 hinges?  Along the same lines, does the Aluminum need treating before fabric?

[Kamcoman77]

Aluminum tubes need cleaning with alcohol or acetone before hinges or fabric. I guess you could give them a light scuffing with red Scotchbrite pad if they look extra dirty. I used JB-weld under my hinges for a little extra security, even though I used full circle hinges installed during empennage build.

[Brock]

Yesterday I managed to mount the last hinge.  Welded a 3/8 x 3/16" x 1/2" tube to station 5.  A bit tricky to weld as it needed a bit of space from the rudder tube.  Needs some clean up but seems it will be solid enough.  The excess JB-weld covers old rivet holes as the tail feathers I received had the gussests extended to meet each other not leaving room for the hinges. 

[Brock]

Aluminum tubes need cleaning with alcohol... full circle hinges installed during empennage build.

I see you used 3 sets of hinges instead of the plans two on your vertical fin.  So then you would use four sets on your rudder eh?  Would you do it that way again?

Flu-Flu has just two sets of half-hinges on the vertical and one tripple on the rudder/station-5

[Kamcoman77]

I used three sets of hinges on all my empennage, except the rudder. I did use four on the rudder.

[Brock]

Seems I've been away from this project for months.  Today I finally got back to work.  Actually part of the delay was analysis paralysis.  Since I used such a large axle (20mm) I started with a 7/8ths inch tube with the center drilled out to 5/8ths inch.  I was looking for cleaner solution, though possibly heavier.  The axle is all one peice and strong enought to never need replacing.  You can see a slightly different manner of welding on the tabs, just seems slightly cleaner.  The tabs are .090" which I had extra of.