We have power...and no smoke

 The past few weeks have been a blur of smaller projects.  One of those projects was getting the panel and avionics ready for first power up.  To reach this goal I had to finish tying up wire bundles, replace a connector or two,  and what feels like at least a hundred other tasks.  In the end I was successful in getting the system up and running.  I ran into three issues that I thought I would relate.  

First, the wiring diagram for the Carling Contura switches I am using is misleading.  If you look at the diagram without looking at the actual numbering scheme of the 8 terminals on the back of the switch you will wire it wrong.  I'm visual...I don't like comparing numbers to diagrams and if the diagram is wrong, so will my wiring be.  This was indeed the case, all 10 switches had to be rewired.  That took a day...or so.  

Once I finally got the master switch to work and provide power to the buss, the EFIS reported that the config module was missing.  So, back under the panel I went to pull the connector and see if I missed it.  Nope its there but I did find that two of the tiny pins that make the connection had backed out of their socket.  No problem, push them in and all is good again.

Then during the configuration phase the GNX375 was reporting that the transponder had failed.  Back under the panel (a little farther this time) and pull the entire back plate off of the radio tray only to find that I had used the pin numbers for the wrong connector when wiring up the RS232 connection to the ELT.  Fixed that, powered up, and the transponder was working properly.

Part of the prep for powering up included re-cutting all 4 instrument panel inserts.  I swear this must be the 5th time I have redone these panels.  This time I did it for three reasons.  First, I wanted to install a master warning light on the Pilot side panel.  Flying the G3X in the 9A I found that I sometimes missed the alert that came up.  I want to be sure a warning is very obvious to me so I added this indicator.  Second, OnlineMetals.com is now selling clear anodized aluminum plate.  It looks just like the brushed aluminum look that I really wanted.  So, I ordered some of that and I really like the way it turned out.  Finally, I had to replace the lower center console panel because the original plan was to put rheostats in to control the oil cooler shutter as well as the cowl flap position.  In reality the will only ever be open or closed so I replaced the rheostats with switches.

The seat belt brackets being fitted for the nutserts I installed in the frame of the seat.  I had to locate each nutsert by feel, punch a small hole to verify the location, and then cut a full size hole for the spacer that will go between the seat belt bracket (silver above) and the seat frame.

Spacers all fitted.

lower center console panel insert after re-cutting and labeling.

I also worked on the FAB including this fiberglass transition through the snorkel.

A balloon to hold the wet fiberglass cloth to the foam in the picture above this one.

New Pilot side panel insert. You can see I added both a Master Warn hole and label as well as an Alt Static hole and label.

Co-pilot side panel insert.  The only change here was moving the Passenger warning to this panel instead of the center panel.  The center panel will have an iPad mounted on it that will hide the warning.  Oh, I also changed to using #6 countersunk nutserts for the GDU mounting holes.  Much easier than trying to get the mounting frame that comes with the mounting kit to work.

New center panel.  No changes here except the new clear anodized aluminum.

These are the extra dry transfer labels I used on the new panels.  I tried using my CNC to do the engraving but found that the anodized surface left a very rough edge that I couldn't sand to smoothness without scuffing the surrounding anodized finish.  So I decided to use these dry rub decals and then coat them with a flat clear coat.  I really like the way they turned out.

Panel after installing my avionics and almost ready for first power up.

It works!

FInishing up the firewall forward wiring

The past few weeks have been mostly about firewall forward.  I managed to get the CHT sensors, EGT sensors, oil pressure sensor, oil temp sensor, manifold pressure sensor, both alternator amperage sensors, and the fuel pressure sensor all installed and wired up.  I also finished the firewall forward installation of my SDS Electronic Fuel Injection and Ignition system (EFII) installed.  

The throttle cable and the prop control cable are both installed and connected although I still have work to do on the prop lever in the throttle quadrant.  I plan on anodizing it black to match the throttle lever.  Speaking of prop governor cables, I had to modify my top cowl because the "notch" I cut into the shroud for the governor was interfering with the full motion of the cable arms.  Oh well...its only fiberglass work.

I did my first install of the exhaust system.  Well actually I only installed the down pipes from the cylinder flanges so far.  I needed to do that so I could drill and install the EGT sensors and associated wiring.  The #1 cylinder downpipe also has the O2 sensor bung welded on at about 12.5" down from the exhaust flange. 

I had to do more work on the top cowl as you will see below.  The #2 cylinder injector was standing a bit proud of the top of the baffles which means there is a significant possibility that the normal shaking of the engine will cause the injector fitting to come into contact with the top cowl.  To remedy that situation I have modified the top cowl by cutting out the honeycomb material on the inside as well as a little re-clocking of the 90 degree elbow on top of the injector mount.

The fuel system forward of the firewall is now complete as well.  I ordered some pressure tested, fire sleeved hoses from Tom at TSFlightlines to finish up the job.  I love Tom's work!

I'm sure there were a dozen other tasks that I forgot to mention in this post but maybe you will spot some of them in the pictures below.

Backup Master Solenoid, XC solenoid, ANL fuzes, and current sensors wired up.

Injectors plumbed and wired up.

Lots of scrap wire on the floor from all the FWF wiring work

This is the number 2 injector that I discussed above.  You can't really see it in the picture but there is only about 1/4" of space between the cowling and the injector fitting.

Odd looking picture but this is looking aft into the intake snorkel on the scoop.  I was measuring the location so that I can align the Filtered Air box.  It looks like it came out perfect!

Another hard picture to visualize but this is looking outboard from the spinner opening at the prop governor and its associated fiberglass work.  The top baffle plate for the governor is not installed so I can see what it looks like outboard.

Its all about cooling

One of my biggest concerns about flying this airplane for the first time is the engine cylinder head temperatures. Traditionally the first hours of an engines life are hot as the rings seat themselves. On the 9A I had piston oil squirters that helped keep the cylinder head temps down, but this engine does not have this option. My only option is to make sure I am making the best of the cooling that is available. That brings me to my last several weeks of work. Cooling mods. I used the baffle kit that comes from Van's and its a huge help, but its designed for a slightly different engine, and even the inter-cylinder baffles that come with the engine fit very poorly. Below are some of the steps I have taken to try to keep the air moving through the cooling fins on the cylinders and keep the cooling drag to a minimum.

The plans call for a series of slots cut into the lower scoop section of the cowling to aid in cooling air flow through the engine. This added air flow is necessary for time when heat load is high such as takeoff and climb phases of flight. They are not needed when in cruise and because these slots are always passing air they create a bit of drag. I decided to install these cowl flaps to eliminate the cooling drag when its not needed. The AntiSplat Aero cowl flaps I purchased are designed to be installed in the bottom of a cowl that has a honey comb core but the scoop area on the 10 cowl does not have honey comb in this area so I had to build up a mounting platform so that the installed flaps are flush on the outside. You will see a picture of the outside down below. To make this mounting platform I used my 3D printer to print up those two white forms you see sitting above the openings. One side was slid into the opening from the outside and the other was fit on the inside so that I would have a smooth flat surface mount.

Up close view of the mounting platform as I was testing fit.

Both flaps installed (no bolts) inside view.

Both flaps installed outside view (looking up at the bottom of the scoop where it overhangs my workbench.

I also formed the fiberglass duct around the top cowl inlet where the prop governor sits.  Still some cleanup work to be done here.

Oil door with hinge and latch cutouts complete.  I did have to fill those two miss-drilled holes on the hinge location and then re-drill the hole.  It took quite a bit of time to get this door to fit the opening properly.

This is the door after I got it all put together.  I did add a bit of carbon fiber plate to keep the door rigid.  This is simply a plate of carbon fiber that was left over from the instrument panel cut out adhered to the door with flox.  It really stiffened up the door.  I had originally used the honeycomb method that vans suggests but the latch I am using does not work well with that type of support.  I used carbon fiber on the 9A and it worked very well.

An outside view of the door after I had faired in the opening a bit.  I am going to have to to a little more sanding as there isn't enough edge distance to allow for paint.

Here you can see the wraps that I put on all cylinders.  The wrap is simply 9oz fiberglass impregnated with ultra black RTV.  These areas are locations where the baffles tend to leak a lot of air and any air not going through the cooling fins is just wasted cooling drag air.

Same as above but a view looking up at the bottom of the cylinders.  The Inter-cylinder baffles are not installed in this picture.

Really hard to see but this is the gap between the cylinders near the injector holes.  There is about a 1/4" gap between the cylinders so I filled it with RTV after putting a barrier of glass/RTV on the surface of the head fins to prevent the RTV from filling the cooling channels.

Aft side of #5 cylinder. 

These are the engine mount covers that I fabricated to prevent any cooling air flow from exiting via the holes in the rear baffles where the engine mounts protrude.  I had originally ordered these from Aerosport but after about 6 weeks I had to cancel that order (poor guys are just swamped) and make my own.  They are not as pretty as the Aerosport version but they will do the trick nicely.

A million little things

Wow has it really been since October that I last posted an update?  Well I haven't been completely idle these past several weeks but I will admit to going through one of those "less inspired" periods that I go through about once a year.  Hopefully this one is about over...

Anyway, as the title suggests there has been progress but its in the form of a bunch of little things.  Most of the time has been focused on the cowling and getting it properly fitted.  Here are a few of the things I've done since the last update:

• I beefed up the "flanges" that I created for both the upper cowl to lower cowl seam and the lower scoop seam.  Originally I used about 4-5 layers of regular 9oz fiberglass layers but the end result was less sturdy than I wanted.  I ended up laying down a layer of carbon fiber with a layer of 9oz glass over the top.  That took a bunch of time because I also had to re-drill the holes for the receptacles.
• I primed the two lower cowl halves so that I could rivet the receptacles on.
• I adjusted several fastener hole locations to get them to fit better.
• I installed the prop and spinner to test the gap and it was good for most of the circumference, but one of the bottom halves still needs work.
• I fabricated a bracket and installed the four remaining fastener receptacles on the firewall at the bottom where the lower cowling and the scoop seam meets the firewall.  I had purposely held off on that area until the scoop was close enough to completion that I could be assured that the lines would match.
• Cut the oil door opening and fit the oil door to that opening.  Hinge is drilled but still need to work on the latch.

In other news, I also installed the GNC255 tray into the radio stack and managed to get the backing plate installed.  There isn't a lot of hand space behind the panel in that area so it was a bit of a challenge.  This is pretty big since its the last of the avionics install tasks.

The baffling is primed and mostly installed now.  The only thing left is to tie in the bottom cylinder wraps, install the rubber seals, and install the engine mount covers.  That's actually what I am waiting for...I ordered the engine mount covers from Aerosport about a month ago and they still haven't shipped.  I guess Covid is sticking its nose into my business once again.

I also started working on the firewall forward wiring.  That includes moving the MAP sensors to the aft side of the firewall which required fabricating a mount on the sub panel.  Plenty of room but I do have to run the vacuum hoses through the firewall.  Should be easy enough to do.

Here are a few pictures from the past several weeks.  Much of the work was not photographed so I apologize for the lack...

Baffling installed after priming.

Ignition coils installed.

Oil door opening cut.

Seam flanges beefed up with a layer of carbon fiber and another layer of 9oz glass.

Here you can see where the receptacle holes were covered and had to be re-drilled.

Prop and spinner installed and cowling partially attached for fitting.  Good on the top and the left side but the lower right side needs some work.

Those two fasteners at the top of the photo that straddle the seam were installed after everything was fitted properly.

And finally, the cowl completely installed.  I still have several things to do such as the cowl flaps installation but its getting much closer to being done.

Baffling

 Actually I've been working on much more than the baffling but since the cowling and the baffling work together to keep the engine cool its a bit of a mixed bag of tricks.  I'm paying extra attention to the baffling because these tightly cowled RV's run hot and I don't want to spend time chasing cooling leaks after I start flying.

As I mentioned in a previous post I had planned to split the lower cowling in half to ease the installation/removal of this huge hunk of fiberglass.  This picture shows the "jig" I created with multiple strips of aluminum to hold the two halves in the exact position needed after I make the cut.  In this picture the cut has been made and as the picture below shows the 5 layers of glass that will become the flange that the fasters attach to.

This is the inside of the cowling with the glass flange laid up and epoxy curing.

Much of the baffle work began with edge deburring, hole cutting, and as indicated by this picture...modifications.  In this case two specific modifications are evident.  First is the little square "patch" you see in the middle of the picture.  This area of the lycoming cylinder has no fins for cooling.  That means if the baffling is flush against the cylinder no cooling air can pass in this area.  If you look at the cylinder picture below you will see what I mean.  My patch basically creates a small gap that will allow air flow past this area.  The second modification is a little harder to see.  On the far left side of the aluminum plate you will see a bracket with a bolt hole in it.  The baffle kit that comes from Van's is for a wide deck engine, my engine is a narrow deck.  They are similar but have a few differences such as the shape of the block and a few bolt holes.  In this case the inside edge of the baffle needed to be cut and reshaped to fit.  Along with that the bolt hole flange had to be fabricated to fit the new shape.

This is a picture of the inside of the same baffle piece.  Here you can see the small air gap that will allow air flow past the smooth portion of the cylinder wall...see below.

Here is the back side of the #5 cylinder.  You can easily see the small area where there are no cooling fins.

On the front side of the engine case there is another area that needed adjustment.  In this picture you can see the original baffle piece shape (it has the part number in blue ink on it) as well as the shape of the piece that I had to fabricate to match the shape of the engine case.

And here is the final product after cutting the improperly shaped baffle material off and attaching the correct shaped piece.  Much better fit.

I had to add this picture as well.  My good friend Ben has been helping me with a few tasks.  In this case he is back-riveting the stiffeners to the wing root top skin.  

I took this picture to help me fabricate a seal for the prop governor area of the baffles.  This is taken from inside of the ring gear opening looking outboard at the left side air inlet.  I need to fabricate a baffle plate that will seal the sides and top of the governor to the top cowl which can be seen at the top portion of the picture.

In this picture you can see the paper clips I am using to slowly trim the baffles down to fit within 3/8"-1/2" of the inside of the top cowling.  It took many iterations of install clips, install top cowling,  remove top cowling, measure, mark, and trim the baffling.

This little area took a LOT of time.  On the sides of the air inlet you will see some curved baffle pieces.  These have to be hand fabricated using paper templates and then aluminum bent to fit.  It took several tries before I was happy with the final product.  I also put one of these curved pieces on the inboard edge even though Van's plans do not call for it.  I may change that in the future but it seems like it prevented yet another possible air leak.

Finally, this is the left side air inlet with the prop governor issue I mentioned earlier.