More subpanel

Today, I finished up the weather seal that goes around the perimeter of the subpanel. This thing really was a chore to make, and I'm glad it is done:

The funny part about making planes is that you really make them about 3 times. First you roughly assemble them, then drill parts into them, take them apart and clean out the holes you just drilled, paint/prime the parts, and finally rivet the whole thing back together. So, I spent the rest of the evening deburring and prepping the parts for paint. Here's the subpanel taken apart:

Subpanel work

In Omaha last week for work, so no progress on the plane.

Not much to show for today's work, just some weather stripping for the subpanel and some more parts. 

Fabricated the F-644-L and F-644-R parts. They arrived as a solid channel so I cut them up with a scroll saw (I still don't have a bandsaw) to make the individual pieces. I deviated from the plans here and make them 2 1/8 inches vs. the 2 inches called out by the plans. If it doesn't fit I figured I can always trim it to the original size. 

The next part was the weather stripping piece. Again, I deviated from the plans and made this a continuous part. The plans want you to break this up into a left, center, and right part - but since it's supporting a rubber weatherstrip I figured it should just be one continuous piece. Of course, this one part took FOREVER with only a drill and a couple of files. This started out as an aluminum extrusion, and you cut out the flanges so it can fit the curvature of the panel. Normally I wouldn't go against the plans but in this case since it keeps water off of the avionics it was a nice change. I think it worked out OK

 

Cleanup, interior mockup, FAB mounting plate

Had the day off work so swung over to avery tools in Fort Worth to pick up some bulkhead penetrations for the engine firewall. Didn't get around to installing them because the black box for the engine monitor doesn't have a home yet and I want to optimize the installation to make the wiring easy.

Finally cleaned up (vacuumed and "dusted") the plane. It was looking pretty rough; haven't been doing a good job with housekeeping and FME. So got that wrapped up and re-taped the open ends of hoses and such for components that are not completely installed. This actually took a fair amount of time.

I can scratch the FAB mounting plate of the list (hopefully!). The as-purchased design from vans has the cutout for the throttle body servo in the middle of the plate that mounts the FAB to the throttle body. This would be great, except the mixture arm would bump into the cowl because the throttle body does not sit in the middle of the engine - it's offset. So anyway, to combat this, I shifted the FAB plate over 1 inch. Worked great for clearance, but the bolts that secure the plate to the servo ran into the filter. Bah. I compromised and shifted it 0.75 inches over and that gives enough clearance to both the mixture arm and filter, success! 

It looks loose here, that's because I didn't tighten all the bolts (the nutplates shouldn't be repeated exercised because they're a friction fit). 

Baggage floors and firewall

Nothing very exciting, but a long 3+ hour job of fixing the gasket issue on cylinder #4 (it was upside down!) and drilling out a few rivets connecting the subpanel to the fusealage/firewall and the floorboards. Why does it take so long? Well, to get to the floorboards it's pretty tight - I had to lay down in the tailcone basically. On top of that, I saved all the "hard" rivets for today. They are in tight corners where a normal drill would not fit - thankfully the angle drill saved me.

A few pics:

Rocker cover gaskets

Replaced the cork gaskets on the rocker arm covers with some silicon gaskets. These are supposedly more robust and since they are resistant to high temperatures they will last longer and you can tighten them up if they start leaking. Sounds good. Old vs new - left vs right.

This was obviously pretty easy, but noticed that cylinder #4 is different and the gaskets are not centered and don't seem to fit the cover. Doh.
You can see that the gasket sags. This gasket was the same size as the other ones, what worries me is that it looks like the cylinder is different than the other three. Hopefully though, it's just a fluke and that gasket is screwed up. 

On another note, I started drilling out some rivets in the upper gussets that connect the subpanel. My new angle drill is a new favorite. It cuts through aluminum and rivets like butter - plus it can get into really tight areas where my regular dewalt never could. I'll need to do some more drilling to completely remove it, but got a good start. 

Subpanel fabrication

Drilling out the old subpanel will be a challenge because of the close fit of some of the rivets to adjacent parts. An angle drill should help a bit here, so one is on the way from the yard store. Quick shipping and a nice USA drill for a decent price. Hope it works out.

In the meantime, fabrication of the replacement subpanel kicked off. Unfortunately, I forgot to order a part so I'll have to contact vans and have them ship it. But, here's the progress so far.

Certainly is starting out better than the part that's in there now. Hope I can finish this up without making too many mistakes. Making a few minor changes here - the weather seal design from the factor has you split it into 3 pieces (corresponding to each panel); but I'm going to make it continuous. Hopefully this will keep water out as some tip up canopies have this problem. 

Also, if at all possible, I'm going to mount, wire, and fit my avionics on the bench then rivet everything permanently. Hopefully that will make it easier than trying to install them in the plane (lying on your back). 

Mixture linkage solved!

After trying lots of different locations, I figured out how to make the mixture arm travel full length and without binding. I'm glad to have that done.

Basically, I shifted the ram air box 1 inch over toward the co-pilot side. The allowed the mixture arm, in the down position, to fully travel from the rich setpoint and idle-cutoff setpoint without binding or catching on anything. I'll need to tweak it a little bit because the air filter hits the heads of the bolts from the fuel servo, but that's an easy fix.

You can see that it fits nicely in this mockup. I'm going to order new cables and bracket plate, but this looks good for now.

Here is the top plate for the forward air box.

 You can see what I'm talking about, shifting it over 1 inch makes the cutout off center, but now everything lines up better anyway. It's like it was meant to go there strangely enough.

 Since the top to the forward airbox  has to be remade anyway, I'm going to make it from steel instead of aluminum. Evidently the aluminum will crack over time. So, why not make it steel and forget about it? I was really glad to have this solved - one step closer to getting the engine done.

House distractions

The bathroom lights have been flickering for the last month or so. Always a comforting sign. It didn't appear to be anything on the load end (the devices that use power), so I narrowed it down to the line/supply end (where the power gets distributed.)

The previous owners did everything on the cheap, and this included the breakers. I'm not sure what brand they are, but not one I had ever heard of. The thing is, about 6 months ago I had to replace a couple breakers that were shorting out, causing my internet to randomly drop off. That was hard to find and I should have wholesale replaced all the old breakers then.

You can see why the lights were flickering:

I'm lucky this didn't do something worse. Fortunately, it's an easy fix to swap it out. Went with the gold standard Square D breakers.

Here pretty soon I'll be replacing the whole electrical panel. Always something....

Baggage floorboards

I got the idea from another builder to make the baggage floors removable. Keeping the antenna cables as short as possible is desirable, so the transponder will go under here since it can be remote mounted. It shouldn't affect the weight and balance of the plane too much (only 3 pounds) and will de-clutter the usually cramped instrument panel. Of course, that meant drilling up a shitload of rivets.

Got through most of the hollow pull rivets, but ran into trouble on the solid ones because the size of the drill motor is large enough I can't get a good angle to drill straight-on. Looks like I'll need to buy another tool - an angle drill or attachment - to get those out.

You may have noticed the delay in posting - had a nice ski trip to Colorado and went to Breck, Copper, Vail, and Keystone. Good skiing and nice to see old friends. I was doing some "tree skiing" and thought this was cool. Not bad for a camera built into a phone.