Plugged trim tab tubes, profiled additional T25′s
The open tubing ends were plugged with a t-88 epoxy and micro-balloon slurry. I profiled the counterbalance retaining ribs to fit the tubing and other rib in preparation for welding.
Trim Tabs, Counterbalance Prep
I finished cleaning up the areas on the elevator around the trim tab cutouts to get everything flush and smooth. I also got the hinges working and removed the primer around the counterbalance area to prep for welding in the additional T25 retaining ribs.
Trim Tab Cutouts
This evening I worked on grinding the cut tubing areas flush on the trim tab cutouts. I also worked on removing welding scale from within the trim tab hinges.
Prepped parts for welding, Welded additional fairleads, Rudder fabric attachment
Today I prepared tubing for welding by using my die grinder and scotchbrite roloc wheels to remove the Avipro paint and primer. In some smaller areas I had to use a small detail wheel on a dremel tool. Today I successfully added fairleads at STA E and a fabric attach channel on the lower rudder hinge. The fairleads were added to prevent the rudder cables from rubbing on the back seat as covered in a previous post. The channel I added to the rudder is to provide a place to attach the fabric on the bottom of the rudder since there is a hinge there and not much stationary area to glue to. The rudder fabric channel was bent from .032 4130 and the fairleads are .058 x 7/8 tubing (3/4 long).
Bent T25 ribs and Rudder fabric attach channel
I bent up 2 additional T25 ribs that I intend to weld in place to help retain the counterweight. I don't like the idea of screwing through the structure per the instructions so this is an alternative shown in the scratch builder guides. I also bent up a channel to be welded between the rudder horn and the lowermost tube to provide a fabric attachment location. .032 4130 was used.
Determined best location for additional fairleads at STA E
I ran into a small problem with the rudder cables at station E. There is no fairlead at this location on my kit and as a result the cables rub on the seat frame. Bob had them removed some time back to make room to access the seat belt/float bushing at that location. There are really 2 solutions for this. I chose not to adhere a rub block to the seat frame because the cables are really far out of the corner and it will make my cable guards quite large and eat up flat floor space. I chose instead to add a fairlead near sta. E. I spent most of the evening determining a location that would eliminate the rub, put the cables into the corner, and stay out of the way of that seat belt bushing.
Welding Practice
I got my tinman rig in the mail this week and managed to get it put together today. I spent quite a bit of time practicing with the torch as I wanted to get the hang of running beads with it. I also experimented with different tip sizes and heat settings on different thicknesses of material. I took a semester of welding class at my local community college, but they taught tractor welding (not aircraft welding) so it took quite a bit of time for me to get the hang of it. I bought a variety pack of 4130 from onlinemetals.com which contains 5 thicknesses .025-.050. I welded these into an open box and got it to hold water. I then practiced running several beads across each face. The it's really hard to run a bead across middle of an .025 face, I probably need a #0 tip for that, but the welds on the plane will be in locations that will always require a #1 tip or higher. THe last bit of practice involved welding tabs onto tube, cutting slots in tubes and filling the gap, and welding tubes together.
My welds are to the point where they're airworthy but sometimes not all that pretty. I can manage fairly nice looking welds on .040 thickness and higher. o32 is getting there, it's hard to make them look good across a face, but in a cluster with a nice wide fillet it's not as hard.
Welding practice occurred over a period of a week. Although I expanded on a skill and prepared me for work ahead, this effort did not add to the plane so I'm not logging the hours to the project.
Airventure 2010
No building progress over the past two weeks. Stacey and I attended Airventure to get ideas for the project and meet up with other builders. There were not many Bearhawk's at OSH this year. Bob brought his Patrol and competed at the New Holstein super cub contest. Ray Gabriel was the only other Bearhawk on the show line. Mark's Bearhawk was doing demo rides and the Ron Burleigh BH was at the booth as usual. We attended the dinner and most of the people there I had never talked to and don't really participate on the online group.
Overall we had a good show and got a few ideas for our project. The highlight of the weekend was the New Holstein pig roast. Super Cub guys are crazy... It's a requirement.
3 Month Progress Update
I've been forgetting to take pictures of the project, and when I do, the editing and posting process has fallen to the back burner. Here's a look at the fuselage. You can see I still have a little trimming to do on the floor inspection panel.
Hours Worked
| 7 days: | |
| 30 days: | |
| 365 days: | 14.5 |
| Total Project: | 182 |
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