Since last time I built the 2 seats.
I also purchased some grommet material from Aircraft Spruce and installed it in holes that wires and/or tubing go through. I want to make sure that I don’t have any chaffing of wires in the future.
I finish installing the firewall items and also attached the front wheel.
And then today I attached the engine. It was much easier than I anticipated and only took about 1/2 hour to do. It made it easy that I have a electric hoist in my shop.
For most of September and October not much work was done since I was still waiting for my quick build fuselage and wings to be delivered. Henry from Midwest Sky Sports delivered the mostly assembled fuselage and wings on 10/20. Most of the behind the panel electronics have been installed and Adam plans on coming over with the panel and finish the installation.
Since delivery I have assembled and mounted the main wheels.
I also painted the luggage area behind the seats.
Lately I’ve been mounting engine parts to the firewall. I’m almost done so hope to hang the engine before the end of the month.
I also have most of the rivet holes filled with epoxy and just need to sand them smooth.
I didn’t do much building in September since I’m still waiting for my quick build wings and fuselage to show up (hopefully soon). I’ve had plenty of time to do work so jumped ahead in the plans and started to work on my canopy. I did research into the sikaflex that is used to attach the canopy to the composite frame and it says that it is cured by the moisture in the air so I waited until this last week for the humidity to drop.
Talking to Henry at Midwest Sky Sports he recommended that I build a jig to hold the composite frame exactly square. So I screwed 4 wood brackets to my work table and then screwed the frame to the brackets making sure everything was level and square corner to corner. I elevated it so I could clamp the bottom of the frame while the sikaflex was curing.
I carefully taped the frame and plexiglass to keep the cleaner, primer and sikaflex off of the area not to be glued.
Here are some images of the plexiglass being dry fitted to the frame.
After I cleaned, primed and put sikaflex on the frame I lowered the canopy in place. I used some rubber tile spacers to maintain the correct thickness of sikaflex. Because of the expansion and contraction of plexiglass when it heats and cools you need to make sure that you have a thick enough layer of sikaflex between the composite frame and the plexiglass in order to handle the movement between them.
Per some recommendations from RV builders I didn’t use so much sikaflex to ooze out, but went back 24 hours later, took the tape and clamps off and then filled in any missing areas and used my finger to get a nice looking edge. I still have it clamped into place since it takes up to 3 days to fully cure.
Time: 1 hour
The sling construction guide calls for installing rivnuts to the elevator trim motor. But there is no way that you can drill that large of hole in the trim motor mounting holes without cracking the plastic. So I decided to go with some 6-32 nut plates, attached with flush mount rivets.
Time: 7.5 hours
The rudder was a little more challenging. The top of the trailing edge wasn’t straight initially with the clecos installed (see 1st picture). I took the clecos out and reformed the top rib a little to get it better.
Then the top fiberglass fairing had the wrong angle on the trailing edge. I trimmed it correctly with my angle grinder to get it to fit. I also used nut plates instead of rivnuts to mount the rudder strobe.
Turned out well in the end, but I’ll still need to use some superfill to fix the edge transition between the rudder skin and the top fiberglass fairing.
Time: 5.5 hours
Last week I received the replacement vertical stabilizer and rudder skins to replace the ones that were damaged in shipping. VS skin fit perfectly.
Time: 2 hours
As part of the work to be done the Sling manual calls for the rivet holes to be filled. I’m not sure why, other then for cosmetic reasons, but I am to the point where I’m waiting for my skins that were damaged in shipping to arrive so have time to fill the rivets. I found this post for builders of the RV12 on the same subject:
Modifying his technique slightly here are the tools that I used:
I mixed the superfil per directions and added some alcohol to thin it down. I went to the local farm & home store and got some 3mm syringes ($0.29 each) and 18gauge x 3/4″ needles ($0.39 each), grind the tip off of the needles. The syringe works great to fill each hole from the bottom. Here is how each rivet should look, the superfil should form a dome on top.
After about 24 hours the superfil will be dry and ready to sand flush. I used my dremel tool with a 240 grit sandpaper disk to sand the superfil flush with the rivet head, it also polished the rivet top but doesn’t remove any rivet material. It is surprising that the sanding disk lasts as long as it does… easily does over 100 rivets. I used a piece of stiff cardboard with a hole it in to put over each rivet that I was working on to protect the skin.
Here is the finished result: