The horizontal stabilizer (HS) build steps describe relatively simple assemblies of the front and rear spars, to the point where they need to be primed if a builder chooses to do so. It would be a pain to prime just these spar assemblies on their own – such a small job – so I decided to go ahead and prepare them, and prime the entire vertical stabilizer, rudder, and HS spar assemblies in one preparation and painting session.
I pulled the necessary parts, and completed the rear spar assembly today through to the point where it is ready to be primed. That leaves the front HS spar assembly, which is a bit more work but doesn’t look too bad.
Spent most of the past week recovering from a run-in with a surgeon. Glad I slept through it all.
Finished dimpling the rudder components. Now, the standard Van’s plans don’t call for electrical bonding between control surfaces and the air-frame, and don’t include any facility for static wicks. For a VFR platform, this may be OK. For an IFR platform, this may or may not be OK, it’s easy enough to find anecdotal evidence for either case on the various forums, so this topic is a bit like priming. It’s not hard to add the facility to bolt on static wicks while building the rudder. It’s messy to add static wicks after assembly if they have not been allowed for at this stage. There’s a placement document floating around – here – that describes recommended static wick positions for the RV-10.
I didn’t like the approach described by some builders, of drilling extra rivet holes in the rudder skin and countersinking those holes, using the combined thickness of the skin and stiffener to achieve adequate countersinking depth. The only extra “holes” I wanted to put in the skin are those for the wick mounting bolts, so I used existing skin rivet positions for one of the elastic anchor mounting holes, and made up a doubler so that the “other” anchor mounting hole could be an internal rivet between the rudder stiffener and the doubler. The doubler is countersunk as required. The elastic anchor nuts are cadmium plated and can’t be countersunk – that would expose raw steel across the surface of the underlying dimpled alclad. Each mount uses one MS21080-3 single lug elastic anchor and one MS21078-3 two lug elastic anchor. There’s not much room for the aft most anchor, and the bolt that is used to retain the wick will have to be carefully sized and perhaps trimmed so as to not protrude beyond the anchor (to the extent that it contacts the opposing surface).
The wick mounts are on the left side of the rudder. Although the doubler adds a fair bit of stiffness, that’s going to happen anyway since the static wick mount is completely solid/stiff. After match drilling, countersinking etc. the components were assembled onto the rudder skin and a 3.5mm drill was used to drill down through the skin, using a pair of “fitting” anchors as the drill guide. Then the holes were carefully enlarged from the outside of the skin using a tapered hand reamer. Once a sample MS35206-261 machine screw would just fit through the holes, I disassembled everything and used the hand reamer to slightly enlarge the holes in the skin to a good clearance fit, and enlarge the internal holes in the stiffener/doubler combination to be slightly larger than those in the skin. After deburring everything, the entire assembly fitted together well and the skin holes were perfect.
During assembly, I’ll use a small amount of pro seal between each internal surface around the wick mounting holes, to prevent any water ingress. If there is no wick mounted, each hole will still require a screw, so that the screw end into the elastic part of the anchor provides a weather seal.
The final step in preparation of the rudder components was to countersink the trailing edge wedge. With a little set up time it was easy to bore consistent countersinks using the drill press. It’s tedious because there are a lot of holes. I completed all of one side and just started on the other side but elected to leave the rest for another day because I looked up at the clock and it was almost beer o’clock.
While cleaning up, I had a container to label. I’ve been slowly putting common rivets from the various kits into containers, and I noticed the following interesting bag of rivets. Missed this one when I did the empennage inventory … Van’s did get something wrong after all.
Match drilled the assembled rudder. I also match drilled a 50×50 mm piece of Aluminium angle to the trailing edge, to use later on during rudder assembly. I’m planning to use the technique described here to set the trailing edge. After match drilling, I disassembled the rudder and deburred both skins. That leaves skeleton debur, R-1006 countersink, and dimpling.
Deburring rudder skin after it has been match drilled
Finished deburring rudder components. Assembled and match drilled the rudder skeleton. Deburred the skins. I cleco’d the skins together along the trailing edge, and used a vixen file to debur both skins at once so that the trailing edge of the skins stayed identical. I then cleco’d the skins onto the skeleton, ready for match drilling.
I’ve started preparing the rudder parts. I may get the rudder to a point where the parts are ready to prime, and do the rudder and vertical stabilizer in the same preparation and paint session. The following set of parts is the result of ten hours of cutting, filing and de-burring over the past two days. Still a few parts (covered in blue plastic) to go.
Dimpled the VS skin, and underlying structures. Countersunk the VS rear spar where called for. Vertical Stabilizer parts are now all ready for priming.
Finished the wing kit inventory. All parts present, Vans are now 2 for 2. The fuselage kit will have to remain in its box for a week or two while the shed extension gets finished, at which time I can move the vehicle and some other things out of the aircraft manufacturing space”.
The large shelf I built is filling up with parts. The wing skins are safely tucked away underneath what you can see in the photo.
Freight costs are a big deal for builders in Australia. I’m worse off than most because after goods clear customs in Australia and are available for pick-up, my crates then have to do another sea crossing down to Tasmania. Other issues to lose sleep about include importation charges and the vagary of international exchange rates.
Combining multiple items into a single shipment is one way of reducing total cost. Between this, and being dead certain the local currency was going to de-value across the year, I ordered the (slow build) wing and fuse kits about five months ago. Today, after being loaded and unloaded from two ships and at least four trucks, the crates showed up.
One of the wing kit crates had an accident during its travels, the bottom plywood was split open by about half an inch, and some pieces of the crate had been left behind somewhere. Perhaps floating in the Pacific. I opened it up and was relieved to find no damage to the skins. I got most of the wing parts inventoried before calling it a day.
