Saturday, October 20 2007 @ 08:28 PM EDT Contributed by: Kevin Horton Views: 1419
The biggest accomplishment this week was putting on the registration marks. As usual, it took about three times as long as expected, as I had to clean off some oversprayed primer where the fuselage skins overlapped. The inside of the skins are completely primed, but I also applied primer on the outer surface of the skins where another skin riveted on top.
Originally, I planned to keep the aircraft in the garage until none of the remaining tasks could be done in the garage, but that plan has changed. I need to submit a picture of the assembled aircraft with registration marks as part of the application for the Certificate of Registration. I understand that it can take many weeks to get the C of R back from Transport Canada, so I want to get the application in as soon as possible. Now that the registration marks are on, I want to get the aircraft moved to a hangar as soon as possible.
I need to find a flat bed trailer for the move to the hangar. I thought I had a line on a suitable one, but I looked at it on Friday, and the bed is too narrow. I could probably just get the aircraft on it, but the wheels would be on the very edges of the bed, and that makes it too easy to have a disaster.
Sunday, October 14 2007 @ 07:01 PM EDT Contributed by: Kevin Horton Views: 1335
A while ago I realized that I should have put a doubler on the inside of the skin where the COM 1 antenna mounted. I removed the nutplates, fabricated a doubler, and alodined it, using an Alodine 1132 pen (Alodine is a type of passive conversion coating to prevent corrosion on aluminum). Today Terry helped me dimple the holes on the skin and rivet the doubler in place.
I also laid up the fibreglas for the plenum chamber transition on the left side of the cowling. I also studied the 12" registration marks, and figured out exactly where they need to go on the rear fuselage, so that they do not end up on top of one of the rear fuselage static ports. And, Terry did a bunch of work on the upholstery for the fabric covered cockpit side panels.
Sunday, October 07 2007 @ 02:53 PM EDT Contributed by: Kevin Horton Views: 999
This week I did a tiny bit of wiring clean up ahead of the firewall, then bit the bullet and took a closer look at the Hall Effect current sensor. A Hall Effect current sensor is a loop that goes around a conductor, allow the current flowing in the conductor to be measured without physically putting a current sensor in the circuit. I purchased such a sensor from Grand Rapids Technologies to measure the current produced by the main alternator. The current sensor has three long wires attached to it, and I connected those wires to the engine monitor when I did its wiring, being careful to cut them to a length that allowed putting the current sensor loop where I intended to run the alternator cable. But, I later discovered a major interference problem with the planned alternator cable routing, and I moved it to the other side of the engine, without thinking about the impact on the current sensor.
A few months ago I realized that the current sensor was still hanging forlornly from its wires, and the alternator cable was now way over on the other side of the engine. Big depression :( It seemed obvious that the current sensor wires were too short to reach the alternator cable. I was convinced I was going to have to splice the three wires, and I wasn't sure whether that would affect its accuracy or not.
Mid week, I did what I should have done when I first discovered the "problem" - I actually grabbed the Hall Effect sensor, and pulled it over towards the alternator cable. Much to my surprise, I discovered that I actually had just enough length on the wires to get the current sensor around the alternator cable where it made a bit of a loop at its current limiter. That was a very nice surprise. I was very, very happy. I managed to secure the wire on some existing screws, and all I have left to do is find a good way to hold the current sensor in place.
Sunday, September 23 2007 @ 08:34 PM EDT Contributed by: Kevin Horton Views: 1240
This week I took care of a few minor items, including a small gouge on the prop blade root. I had put this tiny gouge in the blade root when fitting the spinner. It wasn't completely clear whether the gouge actually went into the aluminum, or was only in the paint, but I could risk ignoring it. The prop blade root is under a lot of stress, and the imbalance resulting from a blade failure would almost certainly cause the engine mount to fail, with the resulting aft CG leading to a fatal crash. I used very, very fine sand paper to blend out the gouge over a long distance, then used an Alodine 1132 pen to put an anti-corrosion coating on the aluminum. Today I sprayed the area with Tempo epoxy prop blade paint. The resulting repair is pretty much undetectable.
This week I also did most of the work to fabricate a doubler for the belly mounted COM antenna. Although these antennae typically require an internal doubler to ensure no cracks develop in the skin, for some stupid reason I forgot to install one. I had to remove the antenna, drill out the platenuts, and fabricate an 0.032" doubler. Sometime this week I need to get Terry to help me dimple the holes in the fuselage where the doubler will mount, then we can rivet it in place.
Today I pulled off the vinyl tape around the windscreen fairing and took a closer look at the seam filler around the edges. I'm not completely satisfied with it, but it looks better than I thought. I'll do a bit of touch up to fill in a few small low spots to smooth it out a bit.
Sunday, September 16 2007 @ 06:44 PM EDT Contributed by: Kevin Horton Views: 1098
I was a bit demotivated after last weekend's windscreen disaster, so I didn't get much work done this week. Yesterday I redid the worst parts of the seam filler around that fairing, and finished the parts that I had not yet started. It went much better. The trick was to do it in small sections, so I could pull off the tape on the windscreen before the seam filler had skinned over. I will have a bit of touchup work to do once the new filler fully cures, but I am now confident that I can end up with at least a minimally acceptable transition from windscreen to fairing.
I screwed up trimming the piece of rubber inner tube that does the transition from the cowling to plenum chamber, so I had to make it again, for the fourth time. Grrr.
Sunday, September 09 2007 @ 09:04 PM EDT Contributed by: Kevin Horton Views: 1081
I'm pretty frustrated right now. Today did not go well.
On Friday I purchased some auto body seam sealer to use to fair in the edges of the windscreen fairing. Today I attacked that job, and it didn't turn out well at all. I had put some vinyl tape on the outer surface of the windscreen fairing and on the windscreen where I wanted the edge of the bead of sealer to be. When I put the sealer in place I tried to keep it just on the area I wanted, but some of it spilled over onto the vinyl tape on the windscreen. When I was done, I pulled the vinyl tape off, but the sealer had already started to skin over, and pulling the tape off left a very ragged edge in many places. I was really freaked out, as I had this ugly disaster on the windscreen, and I didn't even want to think about having to buy a new one, and redo all that work.
I took a deep breath, and looked closer. The left side (which was done first), was completely ugly. The right side, was much better, as I was much more practiced with the seam sealer, and had much less sealer on the vinyl tape. I decided to see if kerosene, one of the very few solvents that is safe to use on plexiglas, would soften the sealer. I was greatly relieved to see that it slowly dissolved the sealer. It took quite a bit of time, but I was able to remove the bulk of the sealer on the left side. I'll give the remaining sealer a few days to set up, then I'll have to try again.
Sunday, August 05 2007 @ 03:41 PM EDT Contributed by: Kevin Horton Views: 1263
Many, many months ago I started working on some fibreglas pieces to transition from the cowling air inlets to the plenum chamber mounted on the engine. The fibreglas pieces will connect to some rubber, which will connect to the plenum chamber. Hopefully this will provide a relatively air-tight connection, while allowing for relative movement between the cowling and plenum. At the moment, I consider this concept a big experiment. I've had to modify the original idea a bit, but I haven't run into anything that suggests the concept won't work. I'll post full details and photos once I have finished the fabrication, and confirmed the concept works.
Another parts order arrived, so I was able to finish several other small To Do items. I found a few more items to add to the list, so the net progress this week was about two items, with the list now sitting at 23 items.
I put the front seat back in temporarily, as I need to sit in the cockpit to evaluate several possible mounting locations for the Dynon HS34 expansion module. Once I decide where to mount it, I may fabricate the wiring harnesses to facilitate a planned later purchase of an expansion module and a second D-10A EFIS. The second EFIS would go directly below the current EFIS, and would normally be used as an EHSI, replacing the CDI that is currently in that location. The HS34 is needed to allow the EFIS to display deviations from the Garmin GNS 430.
Tuesday, July 31 2007 @ 06:13 PM EDT Contributed by: Kevin Horton Views: 3378
A few days ago, I started the installation of a canopy lock.
Yesterday I finished fabricating the canopy lock, and drilled and clecoed it in place. I bent the arm that attaches to the lock cylinder, to increase the clearance to the canopy frame, move the arm end inboard, and put it at 90 degrees to the canopy sill.
I wasn't sure at first whether I should rivet the lock striker plate in place, or use #8 screws. I let that question stew overnight, and decided to use the screws. That will allow me to remove it when the aircraft is painted, and it let me use the bottom end of a screw for an Adel clamp that secures the static line, which runs underneath the canopy sill. I needed to secure the lien in that area, to ensure that it couldn't chafe against the screws (or rivets) that attached the lock striker plate.
Sunday, July 29 2007 @ 08:03 PM EDT Contributed by: Kevin Horton Views: 1917
I was on vacation last week. I split my time between working on the RV-8, doing some computer programming, and just enjoying the fine summer weather. I added a few new items to the To Do List, but managed to complete enough items to get it down to about 25 items left.
I made new serial data cables for the engine monitor and Garmin GNS 430, as the similar cable for the Dynon EFIS had proved fragile. The new connectors were a royal pain in the you know what to solder the wires too, but the new cables should be much more durable, and easier to repair if needed.
I spent quite a bit of time polishing out scratches in the canopy. I used the Canopy Scratch Kit that Van's sells - it works quite well. I only needed to use that kit on selected areas. I used some 3M marine Plexiglas cleaner and polisher to clean up the rest of the canopy.
After the canopy was all clean and polished, Terry helped me get it back on the aircraft. A local RV builder reported that he managed to break the #8 screw that attached the canopy latch to the latch shaft. My canopy latch is fairly stiff to lock in place, so I was afraid that perhaps the same failure could happen to me. I removed the #8 screw, and drilled, tapped and countersunk the latch assembly to use a #10 screw, which is a lot stronger.
Yesterday I spent quite a bit of time pondering how to make a canopy lock using a spare key set, the same as the one for the forward baggage door lock. Obviously a canopy lock won't stop a serious thief, as he would just break the Plexiglas. But it should stop a casual thief from grabbing a headset, etc while the aircraft is at an airshow. I've got a bit more work to do to finish this off, then I'll post a description and pictures of the rest of the lock system.