Tuesday, July 10, 2018

Arlington 2018 and ... more deburring

July means that its Arlington fly-in time.  I don't know what it is about this particular fly-in that I enjoy but I suppose its the flight and camping with friends.  The airshow this year was not as impressive as the past few years but it was still very good with some great pilots.  There was a new "act" this year in the form of a 60 drone "swarm" after dark.  I almost missed it (I fell asleep in the tent before dark) but Jeff woke Harry and me up and I'm glad he did.  The drones were amazing!  Highly recommended if you ever get a chance to see one of these performances.

I had somebody ask me the other day what I meant by "deburring".  Well since I just started working on the flaps I figured the timing was good to show you what I mean.  I always try to edge debur as the first step in any new assembly...it tends to save on bandages.

The weather this year was almost perfect.  The sunset in this picture was spectacular. 

Of course we had to send this selfie to a friend who "forgot" this was Arlington fly-in weekend.  The best part was he was still at work while we were here.  Sorry Martin! (not)

I thought the scene for the Friday airshow was very pretty so I took this picture.  Some ominous looking clouds in the background but they sure made for some great pictures.
Here is the pile of parts that need deburring for the flaps alone.  There are probably 50 different items here.  On this pile alone I probably spent 6-8 hours deburring.

This is what the edge of a rib looks like when it comes from Van's.  See all the rough edges and burr's?

Here is what it looks like after several minutes of filing and buffing.

Even the skins need to be deburred.  This one wasn't too bad.  Some of the skins are so sharp they cut fingers quite easily.

A little hard to get the focus right but you get the idea.

Tuesday, July 3, 2018

Ailerons structurally complete, on to rigging

I finished up the priming and riveting of the flaps this past week.  Nothing new in the pictures but I did remember to take a picture of the backing bar I use for the back-riveting of trailing edges.  This 1/2" x 1" x 48" stainless steel bar really makes the job much easier and quicker with less chance of warping along the trailing edge.

Update to the 9A oil cooler project.  Last weekend I was sitting at the run up area for an extended period of time on a moderately warm day with the engine running.  During that period the oil temperature got up to about 201 but as soon as we got some air moving over the cowling the temperature dropped to 185 and stayed there.  I am curios to see how this will change on a hot day with a long taxi like we see at Oshkosh.  I may have to go back to the larger inlet ring and restrict the outlet (already planned) when needed.  All that said 201 degrees is not bad,  the caution alert doesn't come on until 220 and the red line is 240 I think.

Now its on to rigging the aileron controls and then starting work on the flaps.

One of the ailerons as I was riveting the skins on.
Weighted down and almost ready for back riveting of the trailing edge.  Notice that I am using a continuous 1/2" stainless steel bar as a back rivet surface.  I purchased this a while ago for this purpose and it allows me to do all of the rivets without moving the aileron around.  Works very well.

"Acorns in a hole" as the Van's plans describe it.  This is the back side of the double flush rivets.  Because you are forcing the rivet into a hole it tends to bend the dimples a bit as you can see from the reflection of a few.

Almost perfectly straight!

Top side of the aileron.  Nicely set back rivets.

Monday, June 25, 2018

More Aileron work

Build time sure seems to be limited this time of year but I have been making a little progress on the ailerons.

I mentioned last week how effective the oil cooler is so this week I decided to neck the supply air from a 3.5" inlet down to a 3" inlet.  You can see below the blue inlet vs the white inlet.  I flew for over 5 hours on Saturday doing the Young Eagles flights and never once had an oil temperature get above about 190.  I could go on and on with these tests but I'm just delaying the work on the 10 so I think this is it for the inlet.  The outlet of the oil cooler is going to get a duct as well but that's a story for another post.  :-)

Left aileron cleco'd together for final drilling.

Right aileron cleco'd together for final drilling.

Saturday, June 9, 2018

Oil cooler duct clean up - 10 Ailerons

The past week or so I have been busy with travel (4 days in DC) and finishing up the new oil cooler inlet ducting.  The duct I had in place on my last post did not fit as nicely as I would have liked (I think I mentioned that) so I created another one and I think it turned out great.

I also finished filing, edge deburring, and other related prep tasks for the RV-10 ailerons.  Now I can start the assembly process.  I'm excited to get the wings completed so I can get to work on the fuselage.  I am debating whether or not I should do the wing tips now or later.  I am leaning toward doing it now so I can take the wings to the airport for storage.

First step was to design the duct using Solidworks.  

Here is the 3D printed ducting.  I also added a 3/4" aluminum ring to the inside of the duct to act as a stiffener where the hose clamp will hold the flexible hose to the duct.

Next step was to wrap a couple of layers of carbon fiber cloth around the duct and use some "poor mans vacuum bagging" (shrink wrap) to keep the cloth attached to the contours of the duct.  One note of caution if you ever try to use this method; put some peel ply over the carbon fiber before you start to wrap.  Without the peel ply the plastic tended to stick and not all of the excess epoxy was removed.
Here is the finished product after a little sanding and adding a final thin coat of epoxy.  Not bad.

And here is the inside of the same duct.  Notice that I put a little flox up under the aluminum ring to try to keep it in place.  Also, its a good picture of the new mounting brackets that I made out of aluminum angle.  I installed a couple of nut plates on each one so I could attach the duct to the top of the oil cooler.
Here is a side view of the duct after bolting to the oil cooler.

Front view so I can verify it won't interfere with the cowling.

Inside view of the duct after bolting to oil cooler. You can see a little bead of red RTV on the bottom edge of the duct.  This keeps all of the air going through the cooler.  

Ah yes...finally a 10 picture.  Here is the left aileron leading edge as I am in the process of drilling the holes in the stainless steel counterweight.  Its hard to see but the counter weight is the 1.3875" tube that you can see the end of where the copper cleco's are in the middle of the picture.

Sunday, May 27, 2018

The results are in!

Well, I put it all together and ran the heck out of the 9A this weekend and guess what... NO MORE OIL TEMPERATURE ISSUES!!!!  I am pretty excited about this.  I did a high power climb from sea level to 8000' this morning to test the new oil cooler and the hottest I could get it was 190.  If I had tried that same stunt 2 weeks ago my oil temps would have been well into the 200's. 

Very excited for two reasons, first I don't have to worry about oil temps any longer on hot days.  Second, I can now go back to work on the 10!  :-)

This is the oil cooler bolted in place.  The hoses are not yet attached because I was messing with the plastic elbows above.

Another shot of the oil cooler and shroud.

Oh yea, the 10 didn't go without a little love this week either...here are the 6 new cylinders for the engine...mmmm toys.....

On Saturday Jeff, Harry, Bob and I got a chance to fly to Mulino for lunch.  This is 3 of us staging outside of Harry's hangar.  we brought along a couple of new people (Jay and Danny) to give them a little RV time.
The remaining photo's on this page are courtesy of our passenger Jay.  :-)

I wonder when Jeff installed smoke?!?

Monday, May 21, 2018

A little 9 time

No work on the 10 this week other than ordering the cylinders and piston pins for the engine.  This week and probably the next week are dedicated to the 9A.  I mentioned working on the oil cooling system last week and this week I hope to finish that process up.  My 3D printer has been running non stop for over a week crunching out parts to me to test fit.  I think I'm about ready to lay some fiberglass and reinstall the baffles that I removed.  Here are a few pics of the process so far.

New Oil cooler sitting in the old mount location.  Notice that the support arms are about 2" too short.  

A little better picture of the oil cooler.

Not as much room under the cooler for an exit duct so I will have to rethink the heating air inlet again.
One of the 3D printed inlet ducts that I created as a test.  This one did not fit well so I have another one designed and on the printer that is a bit shorter and has a little different angle to the inlet ring.

Here is the new back baffle configuration.  Still a bit of work to do including a little primer and paint but this is a much better location for getting cool air for the oil cooler.

This is the outlet duct I created.  The bend on the corner was way too large so I had to redesign this one as well.  

Sunday, May 13, 2018

Las Vegas Baby

Yep, I spent a few days in Vegas this past week.  Thats nothing special until you learn that I flew my 9A down for the trip!  I rarely get to use my airplane for work related travel but at times like this its just plain fun.  No worries about what time the flight is, how long the line at security is, overhead baggage space, noisy kids/other...I could go on...

Since its been a couple of weeks since my last post I guess I have to say something about the 10 build so I will say this...I finished the bottom skins....finally.  I have prepped most of the aileron parts and its almost time to start some riveting.  No pictures of the ailerons this time since its just more of the same thing.

On a related note now that the temps are starting to rise I have to pay attention to the oil temperature on the 9A.  Well I am bound and determined to resolve that issue so I ordered a larger oil cooler (15 row).  I am also reworking the plenum to allow the cooling air to be taken from a higher/cooler point on the back baffle.  I will have pictures of that process later but I did post a picture or two of the current configuration.

This is one of the many pictures I took while riveting the bottom skins on to make sure I had properly set all rivets.

And here is the finished product.  The left wing bottom skin is riveted in place.

This is a picture of the 9A oil cooling solution.  You can see the duct that I 3D printed and will cover in fiberglass once I know its the correct dimensions.  On the upper left side of the picture you can see the 4" outlet that I clamp the 4" ducting to on the back baffle.  This is the outlet that I am moving.

Here is a picture of the inside of that same outlet.  The final location will be up and to the left.  I had to replace the entire baffle panel but you will see that soon.