Engine Mount Initial Fit

I don't want the engine mount in place when I start putting things on the firewall, but while I'm waiting for that stuff to arrive, I figured I may as well get it fitted.  The bolt attachment points come with small holes pre-drilled, and the top steel brackets on the cockpit side of the firewall have the same size holes drilled.  Those are the only matching holes of the 6 required.  I put temporary bolts in the top to see what the rest of the mount looked like.

Well, it turns out I have a common issue.  This is a pretty big weldment, so it's not uncommon that no matter how good things look in the jig during welding, once the mount is removed it has a mind of its own.  When my top mounts are flush and the lower middle mounts set against the firewall, the two lower outside attachment points don't set flush.  I pulled the mount off and put a level across it to make sure it was the mount and not my firewall that was uneven.  Yep.  One side is about 1/16" off and the other side is 1/8" off.  I emailed Van's to see what they say, but I think the answer is just going to be to make some shims to fit the gaps.  I went ahead and ordered some 1/8" thick stainless steel bar, assuming I'll need to make shims.  This is the second time in a week that a lathe/mill would have come in handy!

Even though I can't finish the fitting until I have the shims made, I went ahead and drilled the top two holes to 3/8".  Regular drill bits worked, but I think I'd rather finish the final dimension with a reamer.  The drill bits kept catching as they went through the multiple different layers of material.  Since I have to wait for the steel bar anyway, I ordered a 3/8" reamer as well.  It still blows my mind that this is all that is required to support 250+ lbs of engine.

Pilot Control Stick

The tube of the weldment of the pilot control stick was warped or something, meaning the bushing that Van's sent wobbled in it and caused the stick to have a lot of slop.  Someone on VAF offered to machine a new bushing for me, so I sent them the measurements for a slightly larger diameter bushing. I bought a 0.38" reamer and opened up the weldment just enough to have a nice slip fit for the bushing.  I also had the bushing made slightly longer than the original, with the intent of putting a thin washer on one end to allow the weldment to snug up against the other control bracket weldment (taking out the slop along the length of the bolt).

This bushing made a huge difference and took out all of the slop.  After installing everything, the next step was to connect the lower control arm that ties the two sticks together.  This required about 100 slight adjustments to the pushrod bearings on either end to get the two sticks parallel to each other.

Once I was done, I took a step back to admire my work...and realized that the sticks really didn't look like they were the same length!  When I cut them to fit the grips, I cut the same amount off of each one (I think...).  Whether I made a mistake or the sticks weren't the same length to begin with, the bottom line was the pilot stick needed another 5/8" taken off.  I undid all of my fine work and pulled the stick back out, chopped the 5/8" off (after measuring a few dozen times) and reinstalled everything.

The roll trim uses a spring that connects to the stick weldments.  I put those in place when I bolted the control arm in place.  I aligned them to the arm on the trim servo, but won't actually connect them (with safety wire) until the aileron pushrods are in place and I can see the neutral position.

Pitot Install

I got the pitot installed, so now the left wing is done and buttoned up.

Attaching the wiring and tubing was easier said than done since getting through the access hole and then through the rib hole is pretty much a one hand endeavor. 

Left Wing Bottom Skin (5)

The left wing is all closed up, and I have the bruises on my arms to show for it!  The one thing I have remaining to do is put the pitot into the mast.  I'm not sure if that will be easy or not.  I have the aluminum tubes flared and all ready to plug the plastic tubes into, so it just depends if my measurements were right.

Besides the fiberglass tips, the one remaining big ticket item for the wings is to cut the leading edges for the landing lights.  I'll wait to do that until I get the wings out of the cradles - probably when I mount them to the fuselage for the initial fitting.

Left Wing Bottom Skin (4)

More of the same - I spent a few hours continuing my way down the left bottom skin today.  It's all the same as the right wing except for the addition of the pitot.

The pitot mast fits behind the spar flange and in between the skin and the supporting angle on the rib.  Because of the tight fit of the mast through the skin, it was a bit awkward getting it into place.  I couldn't just slide the mast into place because then it would be behind the support angle, and if I put it in the skin first and then lowered the skin into place, it sets on the wrong side of the flange.  I ended up partially sliding it into the skin, then bowing the skin out just enough so I could angle the bottom of the mast so it slid behind the flange.  It was enough of a bow that I got a little nervous about accidentally making it crease!  It worked out fine though.

Left Wing Bottom Skin (3)

Not much exciting to show for today's work.  I got about 3/4 of the top 5 rows of rivets done on the outboard bottom skin.  It went smoothly, minus the same frustration with the rivets around the aileron brackets.  There's just no riveting those without causing skin dings - at least with the tools I have.  It's annoying for me to have to see the dings, even though I know with some filler they will all disappear when I paint.  If I ever build again, I'm going to have to search for a long shank mushroom set to get into these tight spots.

Left Wing Bottom Skin (2)

I braved the 20 degree garage and finished up the inside bottom skin on the left wing.  I hung the other bottom skin, but the warm house beckoned.

Left Wing Bottom Skin

I finally got up the energy to reorganize the shop again so I could get back to riveting the wings.  I strapped up the inside skin of the left wing and started with the rear spar rivets.  It hasn't been that long since I did the right wing, but I was all thumbs with the riveting.  It took a while to get into the groove again.

Once I got down three or four rows, the riveting got a lot easier.  Just like on the right wing, I decided to put in plenty of dings by the flap outside bracket in order to give me more practice with filling before paint.  The inside rivets are just super close to the bracket, and the gun with the normal rivet set won't fit.  I tried multiple different approaches, but nothing really worked.  I had the same issue on the right wing.  I'm sure there is some specialty set I could buy.  Maybe next time.

I was able to get all of the riveting done down to the spar flange.

Control Stick Wiring

My stick grips from Pioneer arrived!  To save a few bucks, I went with their 3D printed version, which is about half the cost of their wooden grips.  I also think the printed version actually matches better with my interior than a wooden grip would as well, so win win.  Unfortunately, they messed up my order, but they've already responded to my email and are sending the right replacement parts.  I ordered the left grip with trim, flaps and autopilot disconnect buttons (and push to talk on the front trigger), but I asked for the copilot grip to be blank with no buttons.  I didn't wire the right side for any functions in the stick because I want that stick to be removable without the hassle of wires.  I also don't love the idea of a passenger accidentally hitting a flaps button or the trim switch with a book or something (there will be a PTT button on the panel should the passenger/copilot ever need it, and there will also be a flaps switch and autopilot on/off on the panel).  So they are sending me a blank switch plate to swap out for the one with all of the buttons.

I removed all of the wires from the right side grip.  The grip adds significant height to the stick, so the stick needed to be trimmed down.  How much was the question!  The grip goes on the stick 2 1/2 inches, but then sticks up like 3 or 3 1/2 inches from there.  I ultimately decided on trimming the stick by 3 1/2 inches.  It seemed like a lot, but I sat in the plane and that height felt about right.  The most important thing was ensuring the height wouldn't interfere with the panel.  I wanted the hand position to be as close to stock as possible.  Making it lower would add to the sensitivity of the controls, and any higher is just plain awkward to hold.  I probably won't know how I did until I actually fly, but from looking at pictures of other planes, I think it's well within the norm.  You can see in the picture that I removed the switch plate and buttons.  The PTT button is still on the front side, but it's pretty unnoticeable if you aren't looking for it.

I cut down the left side stick to the same height.  At first I was just going to use butt splice crimp connectors to connect the wiring to the wiring in the fuselage, but I decided to use a DSUB instead.  Since the grip is technically something I could want to replace at some point (unlikely, but it's possible), a DSUB would make doing that a non-issue.

The big question - did I match up all of the wires coming from the ACM to the correct pins at this connection?

Seat Hinges

Today I decided to knock out a simple task - get the seat backs put together.  It will come as no surprise that it ended up being anything but straight forward.  There wasn't anything difficult about what needed to be done, but for the life of me I couldn't figure out why things weren't fitting the same on each seat.  I still don't really know why.

The Classic Aero seats have an internal frame, but they don't have the bottom hinge or the upper support piece attached.

The upper part was easy enough to put on.  The hinge just had to be drilled to match the existing screws in the plastic bumper (designed to rest against the fuselage seat brace).

The bottom of the frame needs the hinge attached that pairs with a hinge half on the floor.  Supposedly all I needed to do was take a few measurements to center the seat, drill and rivet together.  I did that, only to discover the hinge they sent was cut wrong.  They sent two right side hinges (the hinges are asymmetrical), but I didn't catch it until I had already drilled one to match the left frame.  It's not really a big deal, other than making the end eye offset further towards the centerline than it should be (the hinge is still riveted to the frame so that the seat is centered though). That makes the hinge interfere with the heated seat power jacks I put in, so I cut off half of the inside eye so it would clear the jack. I could just grab some of my own hinge stock and redo this hinge correctly, but it hardly seems worth it given that the seat will rarely, if ever, be moved once it's set in the position I like.

The right side at least had the correct hinge, but I made the mistake of thinking the measurements to center the hinge on the floor would mean the seat was centered.  It should mean that, but with the hinge located where it should be, the seat back was shoved about a half inch to the outside and hit the rollbar bolts.

I still have no idea why the right seat is so far off.  All of the measurements of the floor hinges are identical to the left side. Technically all I have to do is slide the frame over the half inch and rivet it to the hinge in the location that centers the seat, but I'd really like to understand why it's different first.  I'll take a fresh look at it tomorrow.

I couldn't help but put a seat bottom in and try it on for size of course!  I started with the seat in the aft most hinge location, but that was way too far back.  I think either the middle or front hinge location will end up being the sweet spot for me.  I won't know for sure until I connect the rudder so I know where neutral is for the pedals though.  I think I'm really going to be glad I took the time to do the seat brace mod.  Being able to recline the copilot seat while setting the pilot seat in the normal upright position definitely makes the space feel much roomier.

Canopy Latch

I just got notice that my stick grips are on their way.  I also may have found someone who can machine a new bushing for the pilot stick, so hopefully before too long I'll have the sticks all finished up.  Until then, back to random tasks.  Since the seat back brace is now in, I can finally position the canopy latch cable.  I already had the nuts that secure the cable fairly close to where they needed to be, so it didn't take much to find the happy spot that allowed the right amount of movement on both ends of the cable.  I tightened the nuts down, then screwed on the cover plate for the left side.  It cleans up pretty nice!

The standoff for the left side is just a plate that I screwed to the seat brace.

Everything works really well.

I decided to go ahead and throw the panel back on since I need to figure out where to center the glass panels.  Once the sticks are in and I can put the seats in, I should be able to finalize the panel layout.

Control Sticks

The pilot side stick is one piece, but the copilot side has a two piece stick that allows it to be removed.  Van's has a service bulletin about the copilot stick recommending that it be bolted in place (after someone didn't attach the stick in place at all and had an accident during landing when the stick popped out).  I think that when Rose travels with me, she'll prefer no stick, so I really want to be able to remove it relatively easily.  That's also the reason I've decided not to put any functions on the copilot grip - I don't want the complication of having to have connections for wiring, and having to be able to secure the wires away from the control mechanics when the stick is out.  The stick is small enough that I can still just stow it in the plane when it's out, so grabbing and inserting it in an emergency is still possible.

Instead of using a bolt, I found a spring retainer pin (no sure what to call it) that is almost the exact size of the stick.  The spring looks like it could pop off easily, but it's very tight and actually requires significant effort to undo.

With the hole for the pin drilled through the stick, I mounted the base piece to the control column that ties the left and right stick together.

The left side stick connects to the control column the same way as the right, with the only exception that the stick doesn't come apart.  I attached it to the control column, but there was a decent amount of slop in the pitch motion (roll was fine).  The stick rotates around a bushing that slides between the ears of the control column.  The issue is that the sleeve that is welded to the stick and the bushing slides into is not a uniform size and allows the bushing to wobble a little.  Apparently this is a common issue - when the stick setup is welded, the hole is warped.  Van's runs a reamer through it, but in many cases that's not enough to fix the hole.  I looked on the forums and people say don't even bother calling Van's about it.  Van's says that all sticks are like that, so there's no reason to try swapping them with new parts.  Some builders say the slight slop in pitch isn't noticeable in flight, and others say it drives them nuts.  The slop on mine isn't awful, but I'd like to at least try to fix it.

The only real way for me to attempt to fix the slop is to ream the sleeve to a larger ID, then make a bushing that is slightly oversized from the existing one.  If I only had a metal lathe...

It may be easier to see what I'm talking about with a picture:  Not only does the bushing wobble in the stick mount's sleeve, but the bushing's ID is also a little bigger than it should be and allows the bolt to wobble inside it as well.  Add those two together and you get enough slop at the top of the stick to be noticeable.  

Top Skin & Misc Interior

I need a little break from wiring.  Not having at least the front portion of the rear top skin riveted on was holding up other tasks, so that's what I tackled this morning before my dogsitting duties started.  It's obviously been a while since I've done any riveting!  The first few rivets were ugly and had to be redone.  After that, the feel of it returned and the rest of the riveting went quickly.  I only did from the baggage bulkhead forward.  I can reach about halfway back inside the tailcone, but figured I might as well do it the easy way and wait for when I have help.

With the top skin riveted to the top fuselage longeron, I can finally put the seat back brace in, which then allows further work to be done.  I thought about leaving it out for a while still just to make crawling back into the tailcone easier for the final finishing touches, but if I use that logic, I'll never finish anything in the plane.  Making progress usually has some tradeoffs in terms of future convenience.

I put the brace into position and got all of the screws and nuts tightened up, but not without a bit of head scratching.  I have a ton of pictures from the initial assembly, but they don't show everything.  The assembly made sense at the time!  I had labeled all of the hardware and put it in baggies, but back then I figured I'd remember which screw went where I guess.  Since this was a modification (and I modified the modification), there really isn't anything to go off of.  I finally got it sorted out and jogged my memory though.  Lesson learned - you can never have too many pictures!

Of course, as seems to be the case almost 100% of the time, things that fit perfectly during initial assembly don't always fit perfectly later on.  I think it usually comes down to the order that parts are put together.  Especially with parts that are screwed together, there is enough slop in holes to make it pretty easy for everything to shift a little.  I wasn't planning on attaching the side panel of the flap motor housing, but I had to in order to get the rest of the parts to line up.  When I initially tightened the flap housing parts to the brace without the side panel, it was obvious the side panel wasn't going to fit.  I put the side panel on as my reference and then tightened everything up.  The other side panel is off, so I have open access to the flap motor still.  Just having the seat brace and the flap housing in place really changes the look and feel of the plane!

With the brace and flap housing in place, now I can move my way through a few other tasks that were somewhat contingent on them.  Even without the canopy in place, I can tweak the position of the canopy latch teleflex cable and get it set to the right length.  The seats from Classic Aero have integral seat frames and don't use the seat backs that I made, so with the seat brace in, now I can set them in place and attach the bottom hinges and rear adjustment angle to them.  Then, with that done, I can put the bottom cushions in place and make sure all is well for the control sticks.  Then the copilot control stick can be drilled (to attach the stick to the permanent portion of the central controls in a way that allows it to be secure but easily removed), and the controls can be finalized and put in place.  I did order the stick grips, so hopefully those arrive soon so I can wire up the pilot grip before putting the controls in place.