Rudder Drilling – Part 1a

07-Jan-2014 12:09 ⋅ Leave a Comment ⋅

The last few days I have been researching how to drill and countersink the rudder trailing edge.  By hand measuring the AEX aluminum strip I determined the acute angle to be about 10-to-12 degrees.  If the common drilled hole through both sides is perpendicular to the chord, this means the countersinking bit will be about 6 degrees off the drilled line when removing material to accept the skin dimples. This angular difference does not seem like much, but we shall see how it goes.

I have also spent quite some time finalizing the bonding strap and static wick configurations.  Using #10 screws, nut plates, and a 3/8″ braided copper mesh should do the trick for effective electrical connectivity.  My intention is utilize the open area near the middle hinge for the bonding strap.  Parts were ordered and have arrived from Aircraft Spruce.

MISC LOGISTICS – continue to acquire painting supplies and work on the configuration of the shed for alodine/prime processes.  I have my eye on a 7.2CFM, 2HP air compressor, but need our finances to stabilize a bit before pulling the trigger.

Posted in: Section 07, Rudder ⋅ Tagged: ,

Rudder Drilling – Part 1

29-Dec-2013 20:03 ⋅ Leave a Comment ⋅

Eric helped match drill all the rudder skin holes common to the spar and stiffeners.  I do not understand the instructions drilling the trailing edge. In one step the plans call for drilling perpendicular to the chord of the rudder, later it talks about countersinking holes perpendicular to the trailing edge surface.  Right now these seem like contradictory instructions.  I will need to get some clarification before proceeding.

Posted in: Section 07, Rudder ⋅ Tagged: ,

Rudder Skins

28-Dec-2013 20:16 ⋅ Leave a Comment ⋅

The rudder skins were prepped and rigged ready for match drilling (Sections 7.6.3 – 7.6.5)

IMGP3662Today I used the soldering iron trick to cleanly peel away vinyl from the edges and rivet lines on the exterior side of the skins.  There is a big debate in the community about the utility of leaving the vinyl on (scratch resistance vs. corrosion potential), but I think it looks cool.  Besides the plane parts are currently stored in our climate controlled bonus room, plus I do not intend to spend decades waiting to process and corrosion treat these materials.

 

 

IMGP3665Removing the vinyl strips…

 

 

 

 

IMGP3667Final product.

 

 

 

 

IMGP3669Here the rudder trailing edge is being attached for final trimming to appropriate length.

 

 

 

 

IMGP3671and the whole nine yards clecoed together ready for match drilling.

Posted in: Section 07, Rudder

Rudder Framework

27-Dec-2013 17:16 ⋅ Leave a Comment ⋅

All the steps for 7.4 and 7.5 were completed today, along with 7.6.1 and 7.6.2. This means all the rudder framework parts (spar, horn, ribs, stiffeners) have been drilled, countersunk, and deburred ready for corrosion prep.  It took about 5 hours to get this done.

IMGP3642 The first steps involved countersinking nut plate fastener holes on the Rudder Horn.  This is a crucial part of the airplane steerage mechanism as the rudder control cables will attach here.  Countersinking this side with a micro-stop countersink cage was easy, the backside not so.

 

 

IMGP3643the back part of the horn piece is rounded, meaning the countersink cage cannot be aligned perpendicular to the surface and parallel to the hole.  As a result, hand countersinking was required.

 

 

 

IMGP3646Voila.  Using a hand crank attached to the #30 countersink bit, I was able to get the proper alignment.  It took a while longer to hand-bore out the metal, but actually I liked the control.  The appropriate flush rivet was continually used to check the depth, which in my opinion turned out quite nice.

 

 

 

IMGP3649Next was drill out the lower spar rib and corresponding flange part to match the attachment points to the horn.

 

 

 

 

IMGP3655aThe striker plates were also countersunk by hand.  These will eventually be flush riveted to the lower rudder spar.  They serve as the contact points for the rudder stops prepared in Section 6 for the vertical stabilizer.

 

 

 

IMGP3653Horn, striker plates, lower rib and spar clecoed together after match drilling and deburring.

 

 

 

 

IMGP3658Stiffeners attached to the rudder spar.

 

 

 

 

IMGP3659One rudder skin clecoed in place for stability.  Next steps will be debur the other skin and peel vinyl strips off the exterior surface along the rivet lines.

 

 

Posted in: Section 07, Rudder

Rudder Ribs

25-Dec-2013 17:26 ⋅ Leave a Comment ⋅

Finished separating the ribs parts with associated deburring from steps 7.2.1 and 7.2.2.  Also ordered inital round of attachment hardware for the bonding straps and static wicks to be used on the vertical stabilizer and rudder.

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MISC – Peter helped move the first dunk tank section out to the shed, plus added bracing to work surface legs. The premium buckets which will hold the alodine and brightener chemicals also came in yesterday.  These were relocated out to the shed this afternoon.

Posted in: Section 07, Rudder

VS Metalwork Complete

23-Dec-2013 19:00 ⋅ Leave a Comment ⋅

 

This week all the preparation metal work leading up to alodine processing has been completed. This means corrosion prep, priming, and final assembly with riveting remain, but at least all the fitting, match drilling, deburring, dimpling and countersinking operations are done.  From the build plans Sections 6-1 through 6-4.5 have been signed off.

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Posted in: Section 06, Vertical Stabilizer ⋅ Tagged: ,

VS Skins

23-Dec-2013 18:00 ⋅ Leave a Comment ⋅

The first use of the DRDT-2 dimpling device was on the vertical stabilizer skins. 

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A spare tablesaw base with 2×4″  mounts was adjusted so the height of the C-frame bottom was level with the top of my EAA-1000 workbenches.

 

 

 

IMGP3583Laying  a 5/8inch sheet of MDF on the bench top provides a seamless surface to the DRDT-2.  This picture shows the MDF will support the skin exactly level with the male die for the dimpling operation. 

 

 

 

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This setup allowed us to dimple with the skin resting on the bench top (saved me from building a special platform just for the DRDT-2 for this purpose).  The process went quickly and the results were excellent. When properly setup, the DRDT-2 will produce a uniform dimple every time.

 

 

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Posted in: Section 06, Vertical Stabilizer ⋅ Tagged: ,

Repair Rudder Stops

23-Dec-2013 17:58 ⋅ Leave a Comment ⋅

In Section 6 the rudder stops are supposed to be fitted and match drilled against the upper of the bottom hinge brackets.  I was about to post a picture of this activity when I noticed the lower bracket was showing in the picture.  As a result, I went back today to correct back to the appropriate configuration (upper of the two brackets).

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Posted in: Section 06, Vertical Stabilizer

Rudder Start

23-Dec-2013 17:52 ⋅ Leave a Comment ⋅

Started on the rudder section of the build plans today.  The initial effort involved separating stiffener and rib pieces with tin snips after marking carefully.  The usual deburring process then ensued.

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Posted in: Section 07, Rudder

Dunk Tank

23-Dec-2013 17:48 ⋅ Leave a Comment ⋅

The first section of the dunk tank for alodine and aluminum prep, DX503 and DX533 respectively, was completed today. It is make from three 8′ long 2×4 studs with a 1/4″ plywood bottom. This will be lined with 4-5mil plastic on each side, then filled with about 3 gallons of material. Drain holes at this end of the tanks will funnel material back into 5 gallon sealable buckets when each cycle is done.

The length of the tank is adjustable using 6″ 2×4 pieces. This 8′ section can be used for almost all empennage parts, the exceptions being the eleven foot spars for the horizontal stabilizer. For these another section about 5′ long will be made, then bolted to the end of this tank.  Two smaller tanks in this configuration will be easier to manipulate than on huge 12′ tank.  The backs of both tanks can also serve as painting surfaces when they are not in use otherwise.

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Posted in: Logistics