Wednesday, February 19, 2020

Windows

With the majority of the door work done I've moved on to installing windows.  I'm using the Silpruf method that is documented in great detail on YouTube by Zach Chase.  In this series of video's he demonstrates installing a top window in a Glastar Sportsman.  It runs a bit long but Zach does a great job of going through the entire process.

One item of note about the doors...  I finally got everything back together and found that the pilot door was slightly proud of the cabin top.  Odd, I was quite certain that it was level when I took the doors off for painting.  After a few minutes of scratching my head I realized that I had done all the leveling work without the struts installed.  Those struts put a lot of pressure on the inside of the door which is causing it to flex a little bit.  That means more work leveling this area again but fortunately its not a large area.

Window opening is sanded and small standoff's made of cured Silpruf are glued to the flange with black RTV.  These standoffs were then trimmed by hand with a razor blade to the exact height needed to hold the window off of the flange but remain flush with the cabin exterior surface.

Outside of window is taped and then back cut so that it covers only the top side of the window.

Inside of window is taped with three layers of tape.  First the inner blue tape to act as a nice buffer, the second 1/4" tape that comes up close to the line that marks the flange edge as marked from the inside of the airplane with the window in place.  Then a final layer of 1/4" tape that covers the first layer of 1/4" tape but stands about 1/16" closer to the enge.

You can see all three layers of tape in this close up picture.  You can also see where I lightly sanded the surface of the window that will have the Silpruf layer.

Outer edge with tape and paper protecting the fiberglass around the window.  Paint will not stick to anything that Silpruf touches.  I will admit that I needed more tape on the top side. I thought that would be enough but I found that during the install and clean up phase my gloved hand touched the unprotected fiberglass a time or two.  Fortunately my gloves were clean.

First layer of Silpruf applied.  This is just a thin layer to give a consistent look when viewed from the outside.  It also helps hide the standoffs which can show up in the final product if this layer is not applied.

Window installed, edges cleaned out of excess squeeze out, outer tape layer removed, and inner layer of 1/4" tape removed.  it has to sit like this for at least two days...maybe more because its a little cool in the garage.

Inside view of the window.  You can see where I peeled the last layer of 1/4" tape off.  This leaves a nice clean line of adhesive around the perimeter of the window.

Monday, February 10, 2020

Finishing up the doors and starting on windows

Finally the doors are about finished!  I've got a few tasks related to the doors yet to complete such as installing the 3rd latch block and the door closed indicators but for the most part I am done with them.  The painting turned out to be much harder than expected.  I should have expected more because I knew I wanted the inside of the doors to look good.  This is one area I will look at many times per flight so I didn't want to have to look at a blemish that I should have fixed.  Two different priming sessions, three paint sessions, and lots of sanding but at least I'm done...I think.


I didn't take any pictures with just the primer on but my last post had a few.  I ended up sanding most of that grey primer off in an attempt at filling all the pin holes.  I did a final sealing layer of Azko epoxy primer (the green stuff), lightly sanding with 320 grit, and then the first coat of paint.  This is after the first coat of paint.  The red blotches are spots where I didn't do a great job of filling the pin holes.  I had to come back with spot putty to fill those holes.
Final coat of paint applied.  Ready to install back on the fuselage...however I seem to have misplaced the shims and bolts that hold the pilot side door on.  I spent two days tearing the garage and many areas of the house apart and my best guess is that I must have mistakenly placed the bag of parts in the plastic box I took to Oregon with the engine last month.  Poo.  Now I have to make up some more shim's and size the bolts again.

This is the first time the windshield has been on the airplane so I had to take a picture.  I was measuring how far forward I had to paint the glare-shield.

This is the glare-shield painted.  Now all I have to do is install the windshield!

Rear windows trimmed and ready to glue in.  I am using the Silpruf method that is used on Glasair's.  Several RV-10 builders have used the method and it makes for a strong but professional looking install.  Van's method has you using weldon glue and then fiber-glassing over the windows.  The end result is lots of cracked fiberglass because the windows expand and contract at a different rate.


Saturday, January 18, 2020

Yep, more doors

I can finally see the light at the end of the tunnel with this darn doors.  Nothing hard about it but they sure are messy as you will see from the pics below.  These last couple of weeks have been very cold so my time in the garage has been short.  In addition to the tasks I took picture of below I also managed to finish riveting the top skin on the inside.  I forgot to do this when Travis was here so finished up the last 8 rivets.  I also epoxied in the two forward Naca ducts.

If you look at the hand hold (the hole) in the picture above you will notice that the instrument panel (the carbon fiber you see in the opening) blocks about half of the opening.  There is still room to fit your fingers in there but it looked kinda sloppy to me so I drilled the doublers out and fabricated a couple of new ones that move the grip further aft.  In the picture below you can see the new location.  

The hole is not quite as large as it was but its still 3/4" deep and actually has more room for your fingers than the original.  I suppose I could have modified the glare shield and moved it even further aft but I don't think its necessary.

Oh yea, I took the engine to and engine shop in Oregon last week so that they could install the prop governor drive gears that were left out by Avian.  I asked them to run the engine as well if they could.

I did some work on the panel as well.  The lower console is fitted and drilled to the upper panel.  I installed it in the airplane to make sure it all fits nicely.  Next up for this area is to drill the lower console to the tunnel screw locations.

With one side installed and the other off I took this picture to get some sort of idea of the angle and depth that is available in the lower console.  The aluminum square is marked in inch sections and it was 6" long.  It was clear that nothing with much depth would fit down there so I had to re-design the avionics in the panel.  More of that below.

As I mentioned above....we got a little snow this week.  2 full snow days and 2 that were iffy.

Back to the panel redesign.  On VAF there is a thread going on right now where Doug Reeves asked about having his autopilot controller mounted on the glare shield similar to the way commercial airplanes do.  Somebody designed a 3D printed housing that could be used for this purpose but unfortunately the design they used would not work for me.  So, I dusted off the Solidworks program, did a little designing of my own, and printed up this test housing.  It fits very nicely and will exactly as I had hoped it would.  I sent the design drawings off to Geoff at Aerosport to see if he would print the housing for me and possible list it for sale on his site so others with the Aerosport 310 panel might take advantage of the design.

An inside view of the housing.  Notice that the bottom of the housing actually hooks below the glare shield and the tapered part facing forward is there so I can drill a hole and run my wiring down into the avionics bay.

Ok, I saved the door work for last.  In this picture you probably wont see much unless you have built an RV-10 with these doors.  Those two top slots were actually openings where the hinged bolt to the door.  I posted something about this a while ago when I riveted nut plates to the hinges...well this is why.  The door seal needs a flat surface to sit against on the outer edge of this raised door portion.  Those hinges (and the door pin guides in the picture below) leave an air gap if you don't do something to seal them up.  In this picture you can see where I fiberglassed over the opening and then cleaned it up to look like it was stock.

This is the forward side of the door.  In those cavities the door pin guides get installed.

This is the aft side door pin cavities.

Monday, December 30, 2019

More Doors

The past few weeks have been dedicated to working on the door fit and the instrument panel.  I used my CNC to do some test cuts of the inserts for the instrument panel and found that there is a small error in the conversion from the Solidworks export DXF to the import process in Cambam (the GCode tool I use).  Turns out that everything I cut is just a bit over-sized.  So I took on the task of learning the Solidworks CAM solution.  It was a bit of a steep learning curve but I finally managed to get it working.  However....on my first test cut the controller board for my CNC failed.  I think it was in the USB connector but regardless it has become intermittent which is a problem.  Bottom line is I ordered some new parts for the CNC and will be making some upgrades to it soon.

Regarding the doors, I've been working on getting the seals to fit properly.  Once I felt they were about right I worked on the spacing between the doors and the cabin top.  Still lots of work to do but here is what I have so far.

This is the pilot side of the panel.  This is the insert that I cut that allowed me to discover the size difference in the DXF conversion process.  I had to do some significant edge sanding to get this one to fit properly.  I may have to do more since the paint will take up some room.  I'm considering having this anodized instead of painting but need to find a good local shop.

Passenger side door gap after inserting the foam spacer (seal), applying micro liberally on both sides of the foam, and then sanding the micro and foam spacer down to create an even transition.  In this picture the foam has not yet been removed.

Side view of same door as picture above.

In this picture the door on the right side of the photo still has the 1/8" rubber seal in place, the left side has been removed.  To open the door at this stage I had to use a razor knife to cut through the seal all the way around the door.  Then I could get the door open but had to remove the seal from both the door and the cabin top.  Both proved to be harder than I would have liked.


In this picture you can see the seam between the cabin top and the fuselage.  I sanded and then filled the small gap with micro/epoxy filler.

The door gap came out pretty nice by using some 1/8" rubber gasket material.  If I were going to do it again I don't think I would use the same stuff since it was a real bugger to remove.  The sticky side was up against the door and the plain rubber side was against the cabin top.  Turns out that epoxy loves that plain rubber and stuck like crazy.  I had to actually sand the gasket material off of the cabin side.  

Tuesday, December 10, 2019

Preping for last skin riveting

Much of my time recently has been focused on getting tasks complete that will allow me to rivet the forward top skin to the fuselage.  This skin is the last skin and major riveting job on the airplane!  I think I'm about there.

One task that is not shown below in pictures is some time I spent (on a nice sunny day) sanding and forming both doors for an 1/8" gap around the perimeter.  This gap will be filled with some 1/8" thick high density foam and then a layer of epoxy/micro will be added to both sides to make a nice consistent and even door to cabin top transition (after lots of sanding.)

I installed and torqued the rudder pedals.  I also fabricated and installed the brake lines.  I used PTFE -4 stainless braided hose and I replaced the plastic Tee with an aluminum one.  Because my master cylinders are behind the pedals it was a little harder to find a routing that would not put excessive stress on any part of a hose or impede movement of the rudder pedals.

This is a picture of the back side of the pedals.  You will notice that in the lower ports I used 90 degree fittings and the upper ports I used nipples with the 90 degree fitting on the hose.  No particular reason other than that I had the fittings available and I was hoping this would allow for more room for the hoses to pass each other during the swing.  I don't know that it made a difference but it didn't hurt anything either.

See this pile of hoses?  Seen them before?  Well this is the entire fuel system I fabricated several months ago.  Turns out I used standard rubber lined hose which normally is just fine but if I ever wanted to use fuel with alcohol in it there is a potential for degradation of these hoses.  So, I rebuilt all of my fuel system hoses using PTFE hose.  Not only is it better for the long run but it is also a bit smaller in diameter which turned out to be an advantage.

One of the steps required before I rivet this top skin on was cutting out holes for the vent fans.  Well, I decided to go with the bigger fans on the 10 so these holes are cut to fit a 120 mm fan.
 
The center support strut is now installed so I took this picture so I can contemplate wire routing to the overhead console.

I installed the top skin and the panel frame so that I could test fit the VPX/Fuse location. All is well but I couldn't resist taking a picture while its all installed.

One more picture just because I was happy with the days work.

I thought I would throw this one in there as well.  Here are a few of the parts/templates that I have printed using my 3D printer.  I have been amazed at how useful it has been.  Here are two 3D prints of the GSU25 ADHRS, one GEA24 EMS control unit, and a couple of templates that I used for drilling various holes.  The avionics templates were very handy in determining mounting locations as well as drilling holes for nut plates on the sub-panels.

There were a few days when I didn't want to work in the garage so I started working on the FlyLED lighting system.  I purchased "The Works" kit from Paul while at Oshkosh this year and just now got around to soldering the kit together.  I have to say that while I don't consider myself much of an electrician I REALLY enjoyed putting this kit together.  Getting a nice solder joint is just as satisfying as a nice line of well set rivets.

I had to cut some openings in my wing tips and trim the boards to fit the openings.  Here is the left wingtip with the boards cleco'd in place before I had started doing any soldering of lighting components.

Sunday, November 24, 2019

Interior Paint

The past couple of weeks have been packed with both small and large tasks that are in preparation for riveting the forward top skin on.  One of those tasks was painting the interior.  I don't really like painting on the interior because there just isn't a good way to orient the paint gun in a consistent manner.  So, it is what it is.  I am pretty happy with it for the most part but I haven't seen it out in the full light of day either....



A little masking and then some epoxy primer in areas I plan to paint.

Overhead console masked off and paintable areas primed.

Paint complete in the passenger and baggage areas.  Note that the areas not painted are going to be covered with interior panels.

Forward part of the fuselage interior painted.  no paint on the firewall for fire purposes.

Hard to see but this is the overhead area at the door openings.


Wednesday, November 6, 2019

Firewall work

Much of the past several work sessions has been work on the firewall.  I think I already mentioned it but I want to have as many nutplates and doublers installed as possible while I have access to both sides easily.

I used my CNC to cut out a battery box to mount on the firewall.  The RV-10 has its main battery in the tail but I wanted a second battery as a backup.  I made the battery box a little extra big so I could put insulation/padding around the perimeter to protect the battery from radiated heat.  

Test fitting many of the components with the engine mount on.

A couple of the doublers I am installing.  The top one is for the Air/Oil separator and the one down on the right is for the battery box.

This is a picture with all of the parts I have been working on circled in blue.  The red circles are tasks yet to be performed.  I'm not sure what I am going to do with the red circles...yet.
And the last item I am making mounting provisions for is the Fuel Pressure regulator.  This location should allow for an easy transition from the fuel block mounted on top of the engine case and the return fitting that penetrates the firewall just below the right heater valve.