Sunday, October 26, 2014

90% done and 90% to go

I've seen the title statement a few times while reading other builders blogs and I am really getting a feel for what it means!  This week I have been busy with the inlet ducts fiberglass work and during those times when I am waiting for epoxy to set up I work on other smaller projects on my To-Do list.  So, here you go... a few of the projects for the week.

I finally got around to fitting the oil cooler inlet to the firewall.  You can see the valve I am using to control air to the cooler during the cooler months.  I decided to try something new here...I am using a push-pull servo mounted to the bracket and controlled by a rheostat on the panel.  I powered this up after getting it all mounted and it seems to work rather nicely.

Here is the same view of the oil cooler inlet duct with the valve open.

So I was working on getting the slider tracks bolted down with countersunk screws (pictures later) and found that I had somehow managed to crimp my static air line under one of the nuts.  Well, I ended up replacing the entire run of tubing.  Good thing I used braided hose for my brake lines, it left me with some extra tubing for this task.  :-)

Speaking of using countersunk screws to bolt the slider track down.  Here they are.  The canopy is off which is why you see the roller assembly but no canopy.  The reason for using countersunk screws instead of the round head screws called out for in the plans is to allow me to finish the tip up mod which has a piece that runs just above the bottom of the track.  Round head screws would sit too high to allow the roller assembly to pass.

Ok this is kind of funny.  Remember last week when I mentioned lending a bunch of rivets out to a friend who is building a 12?  Well it turns out that I was ready to install the side caps seen in this picture but I didn't have the rivets!  I laughed about it but I have so many tasks that waiting on this one was not a big deal.  In this picture you can see another modification that I made besides the eyeball light.  Just below and to the right of the eyeball light there are two new holes with nut-plates riveted to the back of the cap.  These two holes will allow me to bolt a Ram ball mount here.  The idea is that I can put anything here....say like a drink holder.  ;-)
Here is the problem of the weekend...I finished the shape of the new inlet ducts and after temporarily setting them in place I decided to check the fit with both cowling halves installed.  Yep you guessed didn't fit.  So, after a few choice words I took my obligatory two steps back and came up with a solution to the problem.  In this picture you can see the amount of space I had to work with.  My finger is wedged between the cowling and the top of the baffles where the inlet currently sits.

Time for some surgery on both inlets.  It turns out that the original inlet duct would work if I used some of the new parts that I fabricated for the other inlet.  Here I have started the process of integrating the two parts for the right side inlet.

And here is the left side.  I had to really chop this one down.  Here I am starting the process of putting it all back together.  Ok I'm back to almost where I was when the weekend started.

Sunday, October 19, 2014

Not much to show but some fun news

This week I feel like I haven't got much done on the airplane this week, at least not a lot visual.  I had a couple of evening events this week that cut into build time.  However I did finally schedule my transition training with Mike Seager in Oregon for the middle of next month.  I'm excited about getting some left seat time in an RV.

One more exciting thing happened this week, I finally got my registration from the FAA.  It look a long time because of course I goofed up the serial number....not sure how but I did.  Its getting exciting!

I also finally made up my mind and started work on the plenum.  Rather than band-aide the whole thing together I decided to do it right.  This starts with cutting the plenum and salvaging those pieces I think I can.  Then I fabricate two new inlets that actually fit the baffles.  I plan to make the inlets semi permanent mounted so all I have to remove is the "lid" to get to the top of the engine.  I think that will make the access easier and therefor more likely I will "pop the top" to do occasional inspections beyond the annual inspection.  So, step one is complete...I have hacked the plenum up.  I am now forming the new inlets.  That involves using Styrofoam board sections laminated together and a rough file.  You can see the pictures below to see what it looked like.  Next I lay several layers of fiberglass and carbon fiber over the mold.  That's about as far as I have progressed this weekend.  I still have a few more layers of glass to put on the mold but its coming along now.

Here is how we sit as of Sunday evening.
I saw these fuel tank vent fairings on a vendor site and decided they looked cool so I bought a couple.  This is one that I loosely fit to see how it would look.  I need somebody in the airplane to help me tighten them down.

Same website had these fuel tank drain fairings.

And finally, the reason I was at said website....I needed some rudder pedal extensions.  These will help me keep my feet off the brakes.

Ok, so here is the decision I made....I cut the Sam James plenum into pretty much just a lid (as you can see in the next picture).  These are the inlets that didn't line up properly and would not seal on the back side.

Here you can see the center baffle piece I fabricated.  Its not fully trimmed yet but that will come after I finish the inlets.

In this picture you can see the both the old inlet and the new Styrofoam form that I am laying fiberglass on to fabricate the new inlet.  Notice the big difference in air flow area.

Here is the new left side air inlet.  As I mentioned earlier I still have a few layers of fiberglass to apply but you can see already how much better it fits.

And here is the right side inlet.  I have to add a flange to the top of this inlet or to the plenum, not sure which I am going to do yet.  Probably the inlet.

While I was waiting for the inlets to dry I went ahead and put another coat of micro on the canopy skirt and then promptly sanded it down.  This side is pretty close to being done but the other side still needs a little work.

Friday, October 10, 2014

Time to take a break

I am so frustrated with this plenum that I have decided to move on.  I'm going to break something or say something I shouldn't so its best to just start working on something enjoyable while I ponder my next steps on the plenum.  As it stands right now my options are to jury-rig it to make it work until I get some time to make a new one (that fits) or just bite the bullet and design my own now.  Its sad that I paid $460 for piece of fiberglass that I can't use.  I guess the bright side of the whole issue is I learned a lot about plenums in the past week!

So moving on I decided it was time to work on the oil cooler ducting....

First step was to pull the oil cooler off the firewall so I could do the fiberglass layup directly on the cooler.  Here you see the cooler with a Styrofoam mold that I formed using sheets of Styrofoam board hot glued together and then molded with a saw and sandpaper into the shape I wanted.

Another picture of the mold from the other side.

Next I laid up a couple of layers of fiberglass tape followed by a layer of carbon fiber for stiffness.  The carbon fiber cloth was a very heavy weave so it frayed all over the place.  for the piece that goes on the back of the baffles I will attempt to use my vacuum bagging process.

Here it is after I chipped the foam out of it, smoothed the outside with micro/epoxy and then sprayed a coat of high build primer on it.  I still have some build-up around the flange where it got a bit thin but its looking pretty good so far.
While I wait for the first part to dry I started working on the baffle part.  I forgot to take a picture of it after I had formed the mold but its similar to the first piece except this one has a flat flange that will bolt to the aft baffles.  You will see it once I get it trimmed.  My vacuum pump was putting out a lot of oil vapor or smoke so I only let it run for a couple of hours.  I hope that was enough to let the epoxy set up hard enough to hold shape.  We will see in 12 hours what it looks like....

Oh, I also started fitting the induction system to the lower cowl.  Well as is par for the course the past week or so, it didn't fit.  I few iterations of trimming and I got it to fit length wise.  However, Will sells two version of the backing plate, one that is normal and one with an angle in it that is suppose to work well for cold air induction systems like mine.  Well, turns out my air inlet is almost perfectly aligned with the fuel servo inlet so I need a different backing plate.  See the picture below.

See that beveled shadow?  It shouldn't be there.

Even after trimming about an inch off the end I am just barely fitting.  I still need to trim at least another quarter inch off the end unless the new backing plate gives me the room I need, which it might.

Here is the view from the outside looking down the air inlet.  You can see the fuel servo back there (blue tape covering the air inlet) and its pretty close to perfectly aligned.
I finished sanding the windshield fairing and shot a coat of primer to check the actual condition.  Turns out it was pretty good and only a little more sanding was required to smooth it up a bit more.

And after the last coat of primer I removed the masking and plastic and here it is!  Its not perfect but I am very happy with how it has turned out.  Now I need to finish up the canopy skirt and I will have met my goal for the summer of finishing the plexi work.

Monday, October 6, 2014

Foiled by poor quality

I am going to vent a little here so please stand back....

So you remember several months ago I showed you a picture of the nice new plenum I had purchased from Sam James?  I re-posted the picture below that shows the plenum in all its glory sitting on the fuselage of the airplane.  Well this weekend I decided it was time to get the plenum fitted to the baffles.  I figured that the quality and attention to detail that went into the cowling should be true for the plenum as well, right?  Well let me tell you that it is not even in the same class.  The plenum does not even come close to being usable as it is.  So, I have read in a couple of other builder blogs about how others had the same issues but I (incorrectly) assumed that the product would improve with time (as the cowling has).  Wrong.  I have rarely seen such poor quality in an aviation related product.  It is not even remotely of the same quality and workmanship that the cowling and induction system are.  Will James (North Shop) makes the cowling and induction system and I have commented a couple of times in the past about how much I enjoyed working with him.   He has been extremely helpful and his products are top notch quality.  Sam James (South Shop), maker of the plenum, is very experienced, knowledgeable and a joy to listen to during his composite forums at Oshkosh.  So I expected a lot from his products.  Let me show you in pictures what I dealt with all weekend long.

Ok, so here is the plenum (orange piece sitting on the engine) as I begin the fitting process.  The only thing I have done to the plenum at this point is spend way too much time grinding down rough edges, seams and places where excess fiberglass strands had protruded.  This is where my "quality of product" concerns started.

Here the plenum is after I had made my first cut to get it to fit.  Note that I chose to make this cut because the form of the plenum did not fit my engine block (the one it was designed for).

Here you see the beginning of the metal baffle section that I decided to fabricate on the front of the engine.  I can form this a little better and then use red RTV on the back side to eliminate any air gaps.  Remember I said earlier that since this is an air cooled engine I need all of the available air to be used in cooling the engine, not escaping through holes where it does nothing but create drag.

Here you can see where I had to cut the left aft edge of the plenum off.  It did not fit...not even close.  I will have to fiberglass a new recess cover and since my oil cooler will get its cooling air from this section of baffle I need to make some other modifications to it.

Ok, yet another round of cutting on the plenum here.  As you can see I have pretty much removed the entire front center section.

Here are a few of the pieces I had to cut off the plenum.

Another good example of the quality of product I am talking about.  See that nice groove down the middle of this piece?  Well this is a seam where two pieces were joined together.  You can see the layers of glass on the back side to make the part strong but on the front it was only partially filled with what I assume is gel-coat.  You can see the darker orange where the thickness of the stuff is very deep.  That said if you look at the groove you will see there was a huge void under the top layer of gel-coat.  I found several areas with voids like this.  Some air will always get trapped in a fiberglass layup but wouldn't you think that these should be filled with micro or better yet flox?

I'm not sure what to think of this.  See that dark reddish spot?  Well, its a pool of the epoxy or gel-coat.

Ok, final picture in my rant post....  This is my way of forming a lip that will seal against my forward baffle material.  This grey stuff is clay that I am molding and will lay some fiberglass over to form the lip.

Friday, October 3, 2014

Oil Door

I decided to do a single post on my oil door installation.  There are several days worth of pictures here but this should show the process.
First step was to cut a hole in the cowling for the door.  If you look at the picture above you can see both a white circle and an area of the cowling where the surface looks different.  That different surface area is where Will did not put in the honeycomb support structure when he molded the cowling.  It allows me to cut a hole and not have a bunch of honeycomb pockets to fill.  So, using that white circle I measured a 5" x 5" opening and then proceeded to cut it out with my dremel cutting wheel.  For the door Will was nice enough to include a separate piece of molded fiberglass that was about a foot square and was molded to match the contours of the cowling in this area.  This picture was actually taken after I had cut the hole and door and added the flange underneath.

Next up we lay up the "flange" that the door will sit on on the under side of the cowling.  I used 3 layers of glass and overlapped the edge of the hole by about 3/4" of an inch.  Eventually, after the layup had hardened, I went in with my Dremel sanding drum and trimmed that back to a quarter of an inch.

After trimming this is what the opening in the cowling looks like.  The door is sitting to the right of the opening.  I did come back and add a very thin layer of micro slurry to the lip to smooth it out.  I have to be careful not to build it up to the point where the door will sit proud of the cowling once its painted.

Next I added a layer of 9oz carbon fiber fabric to the back of the door to stiffen it up a bit more.  I have read accounts of the door popping open in flight due to the door flexing under the pressure of the air inside the cowling.  This single layer of carbon fiber really stiffened up the door.

Next I used some flox and the door hinge to create a level "pad" for the hinge to mount to on the under side of the cowling.  I used clear packing tape all over the hinge to make sure the epoxy mix did not attach itself to my hinge.

Hinge is drilled and cleco'd to the door and the cowling.  The latch is drilled and cleco'd to the door and if you look close you can see a small notch where I will be installing a small steel striker plate for the latch.

Another view of the door all cleco'd together

And the under side of the door with the steel striker latch cleco'd on and the door closed.  Now I have to wait until I paint the inside of the cowling before I rivet this all together.