I have been working on the project – maybe not as much as I like – I just haven’t been writing about it. Picking up from where I left off last time, I got in my Aircraft Spruce shipment, and got right to work on the oil door.
To start with, I located the door in the cutout and drilled a few holes around the perimeter; this allows me to cleco the door in place while I work on other fitting-related items. First up in that department was the hidden hinge. This is pretty straightforward; the measurements given for locating the hinge half on the cowl looked good, so I drilled and checked it in place.
The half for the door required a bit more work, though. It didn’t want to sit flush against the door itself; I suspect this is due to the cowl having a bit of a conical profile here, rather than a pure cylinder. Other builders I’ve read have used shims or flox to fill the gap; I instead decided to tweak the bends on the hinge itself to get a good flush fit. Basically, I needed to close up the sort of C-profile a bit on one end to pull the flange down. Then the entire flange needed to be bent a little to get a flush fit.
After numerous iterations of this bending, things were nice and flush and so I went ahead and drilled the hinge to the door as well:
Once this is riveted in place, there will be no visible hardware for the hinge at all:
The next logical course of action would have been to work on adding filler around the door to set the paint gap, but at some point I unilaterally decided I needed a break from fiberglass, so I decided to poke around at other firewall-forward things. This led me to revisiting the throttle and mixture cable routing. Specifically, I wanted to see if I could tweak this setup to help with my potential clearance issue between the mixture rm and the lower cowl. I really don’t want to have to mold a blister down there for clearance if I don’t have to.
To make a long story short, I determined that I could position the mixture arm further back, but not with the cable mounts as provided with the Showplaces cable bracket I bought. But all I really needed was to move the cable down and sideways a bit, and add a bit of angle. Normally I’d fabricate a bracket for something like this, but the bracketry here is 4130 steel instead of aluminum, which I imagine is related to this stuff being really close to hot exhaust pipes.
So I ended up dusting off some 20-year-old neurons, relearning how to do basic CAD modeling, and designing a slightly modified cable bracket, which I then ordered from SendCutSend. I’m pretty optimistic that this will help a lot with my cowl clearance issues:
From here, I guess I need to get over my anti-fiberglass feeling and get back to work on that oil door. I think that’s the last thing I really need to do before I can move on to the engine baffles – which is the task that started me on this whole cowl odyssey…