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Flywheel Replaced – 5 hrs

June 28, 2014 Leave a comment

Saturday June 28, 2014

I installed the new flywheel this morning and got the prop re-installed. Here is a shot of the safety wire installed on the crush plate.

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And here it is with the spinner re-installed. Everything is now back to the way it was before the kickback.

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Here is another view of the starter and the new ring gear. I tested the starter to make sure it was still operating fine.

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As a check, I performed another “pull thru” test described by the Emagair installation manual to see if the timing was still set at top dead center (TDC). As a reminder, in this test the spark plugs are out but grounded to the engine and the prop is rotated by hand while observing the spark timing relative to the timing marks. However, this time I watched very carefully as the TDC mark slowly approached the hole in the starter. To my surprise the #1 spark plug fired about 1.5 teeth (about 3.5 degrees) ahead of TDC. I repeated this several times with the same results except the two P-Mags would sometimes fire at different times by as much as half a tooth (1.2 degrees) in spite of being set exactly the same. At this point I was thinking the P-Mags were just set advanced by 1.5 teeth and this was the probable cause of the kickback.

I decided to reset the timing to 1 tooth after TDC which is about 2.4 degrees retarded. So I rotated the prop to 1 tooth after the TDC timing mark and followed the P-Mag instructions to re-time them. After doing so, I performed the pull-thru test again and found that the #1 spark plug fired ½ tooth before TDC. What? There is that same 1.5 tooth offset advanced from the set point again.

So then I rotated the prop to 2.5 teeth after the TDC timing mark and retimed the P-Mags. This time I found that the #1 spark plug fired 1 tooth after TDC. Again, there is that 1.5 tooth offset.

I haven’t found anything in the P-Mag documentation about an offset between the set point and the spark during the “pull thru” test. Maybe this is an intentional timing offset to account for latency in the P-Mag electronics, or maybe there is a problem with my P-Mags. I don’t know. I plan to call Emagair on Monday to find out if this is normal or if it indicates a problem with the P-Mags. I was just not ready to try another restart today and risk damaging another ring gear until I can explain this behavior.

Here is another shot just to remind me how close she is to flying.

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Categories: Last 10 Percent

First Start and Weight and Balance – 17 hrs

June 22, 2014 Leave a comment

Sunday June 23, 2014

This post covers all the events of the last three days. On Friday I took a vacation day from work and went out to the airport to prep the aircraft for the first start. First I needed to pre-oil the engine and verify that it was developing good oil pressure (>25 psi). I removed the dessicant plugs and caps on the spark plugs on the spark plug holes and, following Lycoming’s recommendations I cranked the engine with the starter to watch for the oil pressure to rise. The first attempt at about 10 seconds showed nothing. A second attempt of 10 seconds again showed no pressure. The third time I cranked for more than 10 seconds and the pressure started to rise, reaching 39 psi before stabilizing. I let the starter cool a while and cranked it again and saw the pressure rise as before. OK, the engine is pre-oiled and I can have confidence that oil pressure will come up on start up.

Next I did an ignition check. This is simply connecting the spark plugs to the wires and grounding the bodies to the engine so you can see the spark. Then I turned the prop slowly by hand with the ignition turned on and verified that the spark plugs fired at the right time. All looked as it should be.

I installed the lower plugs in the engines and put the dessicant plugs back in the top holes. The rest of the time I was there was spent preparing for the engine start and weight and balance including installing the spinner and gear leg fairings and checking the settings in the Skyview setup.

On Saturday morning I had several friends and some family members turn out for the engine start attempt. Before everyone arrived I removed the dessicant plugs and pre-oiled the engine again since Lycoming says to do it within 3 hours of the first start. Then I installed the top spark plugs.

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I had two spotters, one on each side to watch for engine leaks or other trouble. I also had a friend armed with a fire extinguisher, just in case. Everything seemed to be ready. I had the instructions from Airflow Performance on how to do a cold start in hand. On the first try the engine fired after one or two turns and rev’ed up to about 1500 rpm then died. The same thing happened on the second attempt. Each time it ran 3 or 4 seconds then stopped. I was juggling the throttle to try to get it to idle but it would stop each time. Looking back I suspect it was the purge valve being at idle cut-off that was the problem. The engine would fire on the prime charge I added each time then die for lack of fuel flow. However, not realizing this at the time I tried several more attempts and on the sixth try I heard a clack and the prop stuttered. Immediately I stopped and one of my spotters took a look at the ring gear and found this.

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There was a kickback that took out six teeth. I’m not sure why or how this happened. For one thing, the Skytec NL starter has a shear pin that is supposed to shear to protect the ring gear. I don’t know why it didn’t shear. The starter looks fine and the pin does not seem to be sheared, although I did not try to crank it again. So this attempt to start the engine ended in disappointment and a damaged ring gear that I will have to figure out how to repair. I will call Aero Sport Power tomorrow to get their advice.

After that disappointment I finished installing everything on the airplane for weight and balance. Dave Prizio was scheduled to come by at 1:30 with his calibrated scales so I did not have time to mourn. Here is a shot of the airplane with everything on. This is the first time everything has been in flight condition (except the ring gear) at the same time. I also drained all the fuel out of the tanks.

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The weighing of the airplane only took a few minutes. We got it leveled up on the scales and the empty weights were 283 lbs on the nose gear, 415 on the right main, and 419 on the left main for a total of 1117 lbs. My c.g. calculations are all done on a spreadsheet and when I plugged the weights in later I was happy to find that I will be able to carry my wife and about 90 lbs of baggage and stay in c.g. range from take-off with full fuel to landing with no fuel. That is only 10 lbs less than the maximum allowed by Vans so I am happy considering  I have a very light prop which tends to push the c.g. aft and limit baggage. I guess that 20 lb crush plate on the prop was a good thing.

Today I went back to the airport and removed the cowling, crush plate, prop and flywheel. This is how forlorn the airplane looked after pulling the flywheel. I don’t know how yet but I have to get the ring gear replaced.  I’ll report more on the flywheel saga when I find out more.

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Categories: Last 10 Percent

Engine Prep for First Start – 2 hrs

June 15, 2014 Leave a comment

Sunday June 15, 2014

The picture below doesn’t tell much about what I did today but I snapped it as I was wrapping up so I posted it. To prepare for the first engine start I removed the engine sump plug and drained out all the preservative oil that has been keeping the engine in good order for the last year and a half plus. I removed the caps on the lower spark plug holes and turned the prop to push out the excess oil in the cylinders and then cleaned up all the drippings. I installed a Saf-Air quick-drain valve in place of the sump plug to make future oil changes easier and less messy.

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Then I added three quarts of mineral oil to the engine and waited a few minutes to let the oil settle, then checked the level on the dipstick. It measured 1.5 inch from end. This is what Aero Sport Power calls the 2 quart line. Then I added two more quarts of oil and after a few minutes of settling I checked the level on the dipstick again. It measured 4.0 inch from end.  This is the four quart line and this process is called calibrating the dip stick. I stopped there for today because I had an appointment for a Father’s Day call from my daughter so I will put in two more quarts next time to mark the six quart line. From that I will extrapolate to the eight quart line because I plan to start the engine with six quarts. No point filling the crankcase to the max capacity just to perform first start.

 

Categories: Last 10 Percent

Fuel Pump Test – 8 hrs

June 14, 2014 Leave a comment

Saturday June 14, 2014

The main goal today was performing a fuel flow test. This is to make sure the fuel pump can deliver at least 25% more fuel flow than is required at max power, that is, 18.125 gal/hr. Before getting to that today I installed aileron stops to reduce the up/down travel a bit. The stops are nylon spacers that are .60 inch diameter and 3/8 long and go on the aileron pushrod brackets to limit the up travel on each side. Access to these spacers is limited by the aileron and flap and to get to the nuts that hold them in I made a custom wrench from .040 4130 steel sheet. You can see one of the nylon spacers in this photo along with the custom wrench.

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The next shot is the wrench installed on the retaining nut. You can see how narrow the slot it so the thin wrench is just the ticket. To get access to the bolt head I had to disconnect the flap pushrod and allow the flap to hang straight down. Once I did that the installation of the spacer and tightening the nut was pretty easy.

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I also installed a tie mount for the strobe wires on the rudder and adjusted the right flap angle to match the aileron in trail. And I  re-installed the engine breather tube because I had removed that at the recommendation of Dave Prizio to trim a bit off the length and increase the gap to the exhaust. After all that and a few more small details I pulled the airplane out of the hangar so the fuel truck could come by and put 3 gallons into each tank. Here is a photo with the sun beating down on her. She looks like a real airplane now – not a collection of parts.

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First thing I looked for was leaks at all the fuel line fittings from the wings through the fuselage and the firewall forward. To my amazement I found none! I expected to find at least one weeping fitting. Since this is the first time I had fuel in the tanks and they have been sitting around for a looong time, I wanted to flush the dust out of them so I put an AN fitting in place of the sump valves and flushed the gas through to a 5 gallon container as seen below. I strained the gas back into the tanks through a Mr. Funnel filter which catches anything that should not be in there including water.

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After flushing, I put the sump valves back in and put the fuel back into the tanks minus a small amount with tiny specks of dust I found in the Mr. Funnel. Then I disconnected the fuel hose that comes out of the firewall and into the mechanical fuel pump and directed that into a 1 gallon container. With the help of Denise, we turned the mechanical fuel pump on and 90% filled the one gallon container in 1 minute. That is about 54 gallons per hour – well above the 18.125 gallons per hour minimum required. Then I reconnected that hose and disconnected the hose going into the servo (after the mechanical fuel pump) and saw the same 54 gallons per hour from the other fuel tank. I think I have enough fuel pump capacity. Then I reconnected that hose and tested the flow through the purge valve back to the right fuel tank. I saw 5 gal/hr on the Dynon with wide open throttle and full rich mixture. That is right in the range expected. This now paves the way for the engine first start which I hope to perform next weekend.

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Here is a shot of Denise and her sister helping out. It’s good to have helpers.

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Categories: Last 10 Percent

More Final Assembly – 7 hrs

June 7, 2014 Leave a comment

Saturday June 7, 2104

Denise and I made the trip to the airport today to do more final assembly work to get ready for the first engine start and the airworthiness inspection. First I installed some safety wire on the prop bolts, and a starter bolt. The prop bolts can be seen below.

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I also connected the left aileron pushrod to the control stick. The left aileron was a little out of trail so I adjusted the rod end in the fuselage to bring into alignment. I also installed the flaps and adjusted the control rods to align them int the stowed position. All control surfaces are now installed and connected. I powered up the panel and did a functional test of the flaps and the angles of the three down positions. The angles were about 14, 25, and 43 degrees so I will need to adjust the angles in the Skyview setup a tad to get 10, 20, and 40 degrees, which seems to be the most common.

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I took this next photo so the FAA inspector can see how the flap hinge pins are retained because you can’t see this after the control rod is connected.

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I also did some other minor tasks today including installing the aft wing spar cotter pins, and cotter pins on the rudder cables at the rudder horns. I also had an appointment with Dave Prizio to inspect my firewall forward setup in preparation for the first engine start. Dave wrote an excellent article in Kitplanes magazine a year or so ago on the firewall forward and preparing for first engine start and since he is my Tech Counselor who better to look over my engine to make sure I have not missed something before I crank it up. He found a couple of nylon lock nuts that I forgot to swap out with all-metal style lock nuts and he recommended I trim back the breather tube to allow a little more room for engine motion. I started working on those items today and will finish them up next weekend.

Categories: Last 10 Percent

Wings Completely On – 4 hrs

June 1, 2014 Leave a comment

Sunday June 1, 2014

This morning I left early for the airport and, with the help of my friend Scott, I finished installing the remaining four bolts on the left wing front spar. That means I drilled the rivets that held the COMM antenna double in place to get the bolts in. After the four bolts were installed and the nuts torqued we re-riveted the doubler plate back onto the bottom skin. We also installed the right wing tip and tested all the lights; Nav/Pos, strobe, and landing. All circuits are working fine.

I had to use all the tricks I have ever heard about to get those bolts in. I tapped them with a hammer but there is very little room in there to swing it. The rivet gun with a flush set worked best because it taps the bolts in in small steps. The bottom nuts on the forward side were a bear. Warning: if you drive the bolts in too far, too soon, you won’t be able to get the nuts on. The nuts have to be started when there is only about 2-3 threads showing on the forward side. Otherwise, the landing gear weldment is in the way. I don’t know what you would do in that case. I wish I had an air-drive ratchet. That would have saved time and back aches. I could only make one or two clicks of my manual ratchet with each swing. To draw those nuts in and tighten the bolts took at least 15 minutes each.

I also installed the bolt for the rear spar on the left wing. Wings are completely on now.

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Categories: Last 10 Percent