Couple of hours in the shop today, continuing on fit up of the wing tip.
First up, I wanted to trim the wing tip a bit smoother. I marked the extent of the trimming out with masking tape and cut the line carefully with the Dremel tool, including some minor trimming at the trailing edge taper. Clamping it to the bench with wood screws and scraps of shim worked well. I put a container of clecos behind it to prop it up a bit:
I don't have some after pictures, but once trimmed back to the tape, I used some sandpaper to smooth everything out:
The plans ask for some standard L to be attached to the end of the spar tip and rear channel. I wasn't happy that would be wide enough to support the wing tip, so I made a custom wide L from some scrap 025 I had: Drilled the A3 pilot holes in the L:
Then I used finger clamps to hold it in place and back drilled through the spar tip, then upsized them to A4
The L's support the back of the wing tip.
The rear channel area is a bit tight and I mis-drilled the L at this location. It needs to sit more proud of the channel than shown below, so I made a new one (not shown). I also had to grind a bit off the tip of the rear channel so it could be inserted inside the wing tip far enough:
The wing tip now sits in the correct position. I was concerned that the nose skin would properly wrap around the nose of the wing tip, but everything measures up correct, so it should be good. I'm not final riveting the wing tip in place until the top skins, trailing edge and nose skins are complete.
I laid out the rivet line across the outboard lower skin and pilot drilled the holes to A3. I also roughly scribed a line across the inside of the upper outboard skin. This will need further trimming, but I've been fighting with it a bit when putting the wing tip in an out.
Knowing the outboard nose skin will fit correctly once it is wrapped around, I finished off the spar and nose rib rivets in this section:
I left the last outboard rib and spar rivets un-done in case I need to slip the outboard main lower skin out of place. These will get done once the wing tip is in final rivet:
The wing tip looks real nice in place now that both outoard skins a trimmed closer to what they will look kine. I still need to trim the trailing edge both lower and upper to match the wing tip. Before I drill the rivet holes for the wingtip, I want to back it somehow to prevent the pulled rivets from cracking the plastic. I was thinking some small flat washers on the tail side of the rivet, but I think instead I'll run a narrow strip of 016 aluminum along the inside and drill through the plastic and the strip as a backer. I also think this is a good spot to use a hand puller instead of a pneumatic gun:
I mentioned yesterday, I wasn't entirely happy with the grip length of an A5 rivet in this hole. I drilled out the A5 and will replace it with an A6 which has a longer grip length.
My testing of the 10 PSI pressure transducer that I ordered is going well, however I found the resolution of the 0 to 10 PSI sensor to be to large a range for what I need. I found some 0 to 1.5 PSI ones online last week at a "decent" price so I pulled the trigger and ordered a couple. I'm looking forward to testing them as I believe this will be the solution I'm looking for to measure fuel tank levels.
Next up, some final work on the lower surface of the right wing, including some cleaning of the aluminum. Then the wing gets flipped right side up for nose skin wrapping and trailing edge set up.
More to come this week.. Thanks for following along!
New here? Try starting at:
Husband, father and 911 dispatcher. Long time pilot with a licence that burns a hole in my pocket where my student loan money used to be. First time aircraft builder. Looking to fly my own airplane.