Couple of short sessions deburring bulkheads yesterday and today. Nothing much to report.
Deburring
Spent time tonight deburring the next couple of bulkheads. Not much to show, just scotch brite and sections of shiny aluminum. Hoping to have the next few bulkheads ready to prime this weekend.
Riveted aft bulkheads
Yesterday I worked on riveting the aft three bulkheads. Each of them are made up of several parts, including doublers.
I tried a few techniques to clamp parts, and to support the rivet squeezer. my first two rivets were perfect, but in the wrong holes! I got distracted for a minute, pulled out the wrong cleco, and set a rivet in the wrong hole. I set a second one before I suddenly realized my mistake. Fortunately I was able to drill and remove both without any damage.
I found it easiest to clamp the parts to the bench, with some carpet as padding, then hold the squeezer the two hands to set the rivets.
Today I was able to finish the job, the aft three bulkheads are ready to install now.
Drilled and Primed Bulkheads
Today I spent a couple of hours drilling and dimpling the aft bulkheads, and then a couple more hours priming several parts.
I used the drill block to match drill several holes from one of the bulkheads into the Vertical Stabilizer, the block was a huge help to ensure these were perpendicular to the bulkhead web. I was happy with how they turned out. Three of the holes will get final drilled to #12 and will take bolts that hold the vertical stabilizer to the fuselage. Any error in the hole orientation will effect the aerodynamics of the VS.
I needed to dimple the flanges of two bulkheads, but due to the angle of the flange, there is no way to get a female die on the inboard side of the flange. I have a spare squeezer yoke, so I cut off the end with a hacksaw, then ground it down to a small cross section. With the modified yoke, I was able to squeeze the dimples.
In the evening I primed several parts for the aft bulkheads. The new hi-flow connectors made a significant difference. I used less paint, and the finish was much better. The paint atomized into much finer particles, covering the parts more evenly. The compressor was working harder, and I had to wait for it to catch up a few times.
It’s hard to tell from the photos, but the finish is significantly improved.
Air Hoses and Drill block
After a few days in Texas, I spent time tonight getting ready to drill some critical holes, and to prime some parts.
I picked up a drill block from Brown Tools and practiced using it on some scrap. Pretty straight forward, and makes it very easy to be perpendicular to the surface when drilling holes. This block is for #30, #40, #21 and #10 drill bits.
I also swapped out my air hose connectors, replacing them with hi-flow fittings. I ordered all of these from Amazon. You can really see the difference in diameter of the connectors when comparing them to the standard connectors. I also replaced my air filter with a smaller in-line filter, and removed a few unnecessary fillings. The idea is to increase air flow through the paint gun, and to maintain pressure when the trigger is pulled. More air flow should result in a better paint finish. Hopefully will test this out tomorrow.
Finally, I got my VS down and clecoed the bulkhead that will be match drilled. This is all set for drilling tomorrow.
Bulkhead work
Today I final drilled a few holes in the aft bulkheads.
Most of the holes were #30, but a couple were 1/4 inch, which I did on the drill press. Then I took the pieces apart and deburred the drilled holes.
Bulkhead work
I skipped ahead a little, as I’m waiting on a drill block to help with some of the drilling where alignment is critical. I worked on the F-01410 bulkhead; deburred, stepped-drilled a systems hole, fluted and dimpled the F-01410 bulkhead. Then I straightened and final drilled the 1/4 in holes in the F-01410C, then clecoed it ready for final drilling.
Then I clecoed the F-01411 Bulkhead ready for final drilling.
These two bulkheads will hold the horizontal stabilizer onto the fuselage, so there is a lot of reinforcing here.
Deburring bulkheads
I put in a couple of hours tonight deburring parts. Not much to report. It’s a straightforward process, but can be a bit slow going, especially where there are corners. I almost finished deburring the aft three bulkheads, but started falling alseep, so calling it for today. Of course most of these parts will need final drilling and then more deburring, but that is a relatively quick process.
Rudder Stop Countersinking
My 3/8 countersink arrived today, so I in stalled it in my modified cage and calibrated it on some scrap. Using the bench press, I countersunk the 8 holes in these two stops.
I’m really happy with how these turned out.
Deburring
I spent a couple of hours today deburring parts for the aft two bulkheads. I also finished shaping the rudder stops.
Deburring was straightforward, except for the flanges at the bottom on the bulkhead, where there is a very small gap. I picked up some Emory cloth to squeeze in between the tighter spots, otherwise I used files and edge deburring tools. I still need to final drill some of the holes, but I’m waiting on a drill block that will help ensure the holes are exactly perpendicular, since some of them receive fine-tolerance bolts that hold the vertical stabilizer.
Finishing the rudder stops involved some more filing. I clamped my vixen file to the bench and this helped ensure a straight edge.
I also modified a countersink cage to allow me to countersink the rudder stops. There is very little clearance between the flange and the hole. Also on-order is a 3/8 inch countersink bit to allow enough clearance (typically they are 1/2 inch).