Empennage

Page Index
-Elevator Const.
-Elevator Hinging
-Elevator Trim Tabs
-Rudder Const.
-Stabilizer Const.

This page was updated on 03/04/2010
*New stuff!* 9/10/05- Welded in the trim tab ribs. New pictures. The following parts are done: elevators, trim tabs, stabilizers, vertical stabilizer spar, Smooth Landings, Capt Al Click on the images to enlarge them. Supersize the image by clicking on the sizing icon that appears when you hold the mouse in the lower right corner of the picture.
Rudder Construction	Return to top
7/15/05- To build the rudder, I first drew it out on my fuselage table back on May 16, drawing the centerlines for the spar and ribs. Using the dimensions on the plans for the 3/8" trailing edge (T.E.), I drove in nails at the T.E. measurements and then made the curve with 1/16" welding rod. Finally, I drew the T.E. line along the welding rod.
7/15/05- Bending the T.E. was fairly easy. In the lower left hand corner of this photo you can see that I u-bolted my 1/2" Hickey bender to the table. I drew marks every 1" on the T.E. and did a slight bend every 1", checking the curve with the line drawn on the table after every bend. The T.E. came out with the nice smooth, graceful curve that the Skybolt is noted for. After using my 7/8" alignment block to set the jig blocks for the spar, I then used my 3/4" alignment block and screwed down 12 more jig blocks to hold the ribs square to the spar.
7/15/05- I have to admit that I bought the ribs from Steen Aerolab since I don't have a sheet metal brake. The ribs came cut and numbered for each position in all the tail surfaces. Well worth the money. Since the ribs are only .035", I notched them with my tin snips which was easy and worked out great. Sure saved a lot of grinding and filing, although there was still some filing to get a perfect fit. You can see the fit here is plenty good enough for a TIG weld.
7/15/05- Here the ribs are all tacked in place. I tacked the top and bottom of the leading edge too, and then heated the top of the spar and tapered it down to the T.E.
7/15/05- The rudder is 90% finish-welded. All I have to do now is weld on the trim tab plate and the rudder horn (and the hinges of course).
Elevator Construction	Return to top
7/16/05- I drew out the elevator spar, ribs, and trailing edge (TE) on the table so that I could start bending the 3/8" TE. Here I am going slow with the Hickey bender bolted to my table. I did a slight bend every 1/2".
7/17/05- Finished up both elevator TE's and got ready to taper the 7/8" spar down to 3/8". I wasn't satisfied with the taper of the top of the rudder spar since it looked kind of beat up with hammer marks so I decided to use 2- 1/4" steel plates to protect the elevator spar from the hammer.
7/17/05- After heating and beating the elevator spar sandwiched between the 2 plates, I got a much nicer result with the taper.
7/17/05- Here is 1 set of elevator and trim tab ribs from Steen Aerolab. They sure save a lot of work.
7/17/05- Seven hours later, 1 elevator is finally mocked up. I still have to cut & notch the ribs, screw down the rib jig blocks, tack weld it together, cut out the trim tab, and find some MS20001P2 hinges. Then do it all over again for the 2nd elevator. Is this fun or what?
7/18/05- This morning I finished notching and fitting the ribs to the first elevator half. Did all the notching with the snips.
7/20/05- Tack welded all the ribs and trailing edge to on the first elevator. The second elevator is underneath. I'll notch all the ribs tomorrow.
7/21/05- This is the elevator spar tapering down to the 3/8" trailing edge.
7/21/05- This picture gives a little better view of the spar taper that I achieved by sandwiching the spar between 2- 1/4" steel plates and heating and hammering.
7/21/05- Both elevator halves are now tacked. Of course I still have to cut out the trim tabs, weld in the trim tab ribs and mount the hinges.
Stabilizer Construction	Return to top
7/24/05- Bent the leading edge of the first stabilizer. That 7/8" x .049 tubing takes a lot more muscle to shape than the 3/8" trailing edge on the elevator. I just used my 3/4" Hickey bender bolted to my bench top to do the bending. It was no problem.
7/24/05- Using the same 1/4" steel plates to sandwich the tubing, I tapered the last 4" of the leading edge with my trusty ball pein hammer.
7/25/05- The ribs are all notched and ready to be tacked.
7/25/05- One side of the stab is tacked with my handy #9 TIG torch. I love that torch.
7/25/05- That's me tacking the opposite side of the the stab.
7/25/05- This is how the tip of the stab looks before it is welded to the elevator and cut.
7/25/05- I notched the 30 degree end rib so that it would cover the end of the spar.
7/25/05- This is a top view of the outboard end of the stab spar and the way the end rib is notched so that it covers the end of the spar.
7/25/05- This is another view of the end of the stab spar.
7/25/05- The stab is now all tack welded.
7/25/05- Finishing up the last weld on the stabilizer.
7/26/05- Started the day bending the .875 x .049 leading edge tubing for the 2nd half of the horizontal stabilizer. Being careful to keep the tubing level, I make a slight bend every half inch. It's a 2 hour workout bending this big tubing. Patience!
7/26/05- By the end of the day I have a 2nd stabilizer! Now onto welding on the elevator hinges, welding the tip to the elevator, adding the last rib and cutting the counterbalance free.
7/27/05- To make the hinges for the elevators and rudder, I first cut some 5/16" wood spacers on my table saw. The spacers hold the 3/8"x.065 tubing exactly in the middle of the 1"x.058 tubing. I then tacked the ends and middle before welding the entire length of tubing on both sides. After my 1/4" and 7/8" reamers are delivered from Enco and I ream the tubes, I'll saw the 1" tubing lengthwise down the middle and then slice the 2 halves into the 3/4" and 1/2" sections of the hinges. While I wait, I'm going to build some other parts.
7/29/05- Yesterday I cut out the patterns to 5 different control horns and the stick boot. Today I cut the steel on the band saw, filed, and then polished the edges of the pieces. I use file folder stock for my patterns.
Elevator Hinging	Return to top
8/10/05- For the last 10 days I've been working on welding the elevator counterbalance tips and hinging them. I have 1 elevator hinged, this is the second one. Here I have finished fitting the tip rib and am getting ready to weld it in.
8/10/05- After welding the tip of the stab to the tip of the elevator, I welded the tip rib in place and cut the counterbalance loose from the stab. It's now part of the elevator. My trusty sawsall came in handy.
8/10/05- I am using the stock hinges detailed in the plans. This is a trial fit of the 3 piece hinge.
8/11/05- After I cut some more hinges in my chop saw, I cleaned them up with my 4" hand grinder. Chop saws leave a lot of flashing on the edges of the cut which you have to file or grind off.
8/11/05- This is the tip of the elevator with the hinge and rod being fitted.
8/11/05- Since there are so many 1/4" holes, like the hinge holes, I spent a little extra and bought a carbide tipped 1/4" reamer instead of a cheap one.
8/11/05- Using the 1/4" rod meant for the brake pedal attachments, I lined up all 3 hinges at one time. You can see the rod in this picture. Using the rod enables perfect hinge alignment and no binding. In fact when I turn the elevator/stab on end, the hinge pins slide right out! As soon as I tack these hinges, both elevator/stabs will be hinged.
Elevator Trim Tabs	Return to top
9/4/05- It was raining all day today so it was a good time to tackle the elevator trim tabs. I measured and cut the hinge ribs and the MS20001p-2 structural hinge to length. I marked off the spacing for the #8 nutplates at 1-1/4".
9/4/05- I cut 6 .040" shims and taped them to the hinge and the rib with double sided tape. Then I drilled 1/16" pilot holes through the hinge and the ribs. The shims simulate the layers of fabric and paint that will go under the hinge and allow the trim tab to end up properly positioned.
9/4/05- After a lot of drilling and countersinking, all the nutplates are installed with 3/32 countersunk blind rivets.
9/4/05- Here are the drills, countersink cutter, screws, rivets and nutplates that I used. Since they aren't specified in the plans, they are: AT 455 countersink 100 degree cutter, AT484 pilot, AT441 Microstop countersink, AN525-832R7 washer head screws, CCR244SS-3-02 flush head steel rivets, MS20605S3-2 nutplates.
9/4/05- In this end view of the trim tab ribs and the hinge, you can see the .040" shim to account for the thickness of the fabric and paint. If you don't do this, the trim tab will stick out the back of the elevator by .080" and won't be flush with the horizontal surface of the elevator when you do the final assembly.
9/4/05- The ribs are ready to be tack welded.
9/10/05- This is the second set of ribs and hinge for the right trim tab.
9/10/05- Use double-sided tape to stick the .040 shims in place and hold the hinge to the ribs while you drill the #20 holes for the washer head screws. It's pretty easy to do all the holes and countersinking on the drill press. There's just a lot of them.
9/10/05- I think that it's probably a lot easier to set up the hinges and get them shimmed and drilled properly before welding the ribs in place. All that's left to do here is fit the trim tab end and center ribs and tack everything in place. I had to squeeze the trim tab ribs quite a bit thinner to make them match the elevator ribs.