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| Main Gear Bow and Nose Gear Strut (floor) |
cab
Ch 9: Talons for the Eagle
I'm not quite ready to start Ch 9 yet but my main gear bow and nose gear strut arrived from Featherlite so I had to share. Can't wait to get working on these.
cab
cab
Ch 7: Glassing the Sides (2 of 2)
Vrooom Vrooom...Check it out!! A major milestone reached...we can finally sit in the Cozy and make airplane noises. There is still a long way to go but it sure is nice to finally have something that's starting to be recognizable...at least to me.
Glassing the sides was fairly uneventful. It's a very short paragraph in the plans that took me about 9 hrs each side to accomplish. Thanks to my friend and co-worker Bryan who helped me with the starboard side. It only cut an hour off but having an extra set of hands sure made it easier.
I did have a little trouble on the port side so I'll offer a tip to help.
TIP: I wasn't too happy with the way the pilot side UND 3-ply top reinforcement came out. Glass threads kept peeling off the UND and some ended up in a rope-like clump creating a noticeable ridge in the glass. To avoid this on the other side I used some low stick tape (the blue painter stuff) to mark the edges of each reinforcement before I cut the glass. I marked a 3" width of glass, then an inch wide piece of tape; 4" width of glass, then another inch of tape, etc. If you measure it out correctly you can layout all three reinforcements right next to the 3rd ply of UND that covers the entire length of the side. (see pic) With the tape in place the threads will stay put.
Once taped, you can cut the strips apart down the center of the tape. Once glassed in place, simply fold the taped part up and run down the length with your electric scissors leaving a nice clean edge. Using this process, the starboard side came out much better. I'll be doing this with all my UND strips from now on.
AIR...Again!
After pulling off the peel-ply on the starboard side, I found that I had an inordinate amount of air in the layup from behind the front seat all the way back. It appeared from the grain it was in the first layer next to the foam. DRAT! I thought I had conquered this problem. The port side went great with almost no air at all. I guess I just couldn't see it.
The inspection criteria says that no more than 10% of any 6x6 section can have air. The pic to the left shows a sample 6x6 area. The trick is determining if you've reached that magic 10% coverage. Depending on interpretation, the 10% rule is meant for critical areas like wings, canard, etc that take stress. According the Marc Z from a forum email in 2006, you don't have to be as conservative outside of those areas. I'm trying to determine if I have a problem or not. I'm consulting with a fellow builder before I decide if anything needs repair and I'll update the post on my outcome..
Ch 7 Done! Now to start adding stuff to the fuselage...fun fun!
cab
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| Me and my co-pilot trying out the size of the fuselage |
Glassing the sides was fairly uneventful. It's a very short paragraph in the plans that took me about 9 hrs each side to accomplish. Thanks to my friend and co-worker Bryan who helped me with the starboard side. It only cut an hour off but having an extra set of hands sure made it easier.
I did have a little trouble on the port side so I'll offer a tip to help.
 |
| Left side: 23" wide 3rd ply for fuselage Right side: 3", 4", & 5" reinforcement strips |
Once taped, you can cut the strips apart down the center of the tape. Once glassed in place, simply fold the taped part up and run down the length with your electric scissors leaving a nice clean edge. Using this process, the starboard side came out much better. I'll be doing this with all my UND strips from now on.
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| A selected 6" x 6" area with air specks scattered throughout. |
After pulling off the peel-ply on the starboard side, I found that I had an inordinate amount of air in the layup from behind the front seat all the way back. It appeared from the grain it was in the first layer next to the foam. DRAT! I thought I had conquered this problem. The port side went great with almost no air at all. I guess I just couldn't see it.
The inspection criteria says that no more than 10% of any 6x6 section can have air. The pic to the left shows a sample 6x6 area. The trick is determining if you've reached that magic 10% coverage. Depending on interpretation, the 10% rule is meant for critical areas like wings, canard, etc that take stress. According the Marc Z from a forum email in 2006, you don't have to be as conservative outside of those areas. I'm trying to determine if I have a problem or not. I'm consulting with a fellow builder before I decide if anything needs repair and I'll update the post on my outcome..
Ch 7 Done! Now to start adding stuff to the fuselage...fun fun!
cab
Ch 7: Glassing the Sides (1 of 2)
Sorta like cooking chicken...only different...
It would be difficult and messy to glass large vertical surfaces like the sides so the plans have you build some A-Frame pivots to aid in putting the fuselage in a position that makes it easier to work on.
Cozy builders call this...The "Rotisserie."
The plans don't give you many specifics about how to do it but they do give you enough basics to figure out your own solution.
The plans suggest using the hole in F22 that would be used for the gear crank shaft but I don't know if I'll have one so I haven't drilled it.
They also suggest drilling a hole in the firewall but you would have to repair that.
For F22, I used clamps to hold my A-Frame between two boards. For the firewall, I used two small holes that I had already drilled to locate the control rods and I bolted a 2x4 to them. Then I put a hole in the 2x4 for a 5/16th pivot bolt.
You'll need to make the pivot points about 24" off the ground to be sure the fuselage clears the floor when turning. (UPDATE (3/29/13): You'll notice I made my A-Frames with a 45 degree angle. I suggest making them more like 30 degrees between them. At 45 degrees the feet are quite a bit wider than the fuselage and I keep tripping on them. Maybe I'm just clumsy :-).
It would be difficult and messy to glass large vertical surfaces like the sides so the plans have you build some A-Frame pivots to aid in putting the fuselage in a position that makes it easier to work on.
Cozy builders call this...The "Rotisserie."
The plans don't give you many specifics about how to do it but they do give you enough basics to figure out your own solution.
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| Firewall Attachment |
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| F22 Attachment |
They also suggest drilling a hole in the firewall but you would have to repair that.
For F22, I used clamps to hold my A-Frame between two boards. For the firewall, I used two small holes that I had already drilled to locate the control rods and I bolted a 2x4 to them. Then I put a hole in the 2x4 for a 5/16th pivot bolt.
You'll need to make the pivot points about 24" off the ground to be sure the fuselage clears the floor when turning. (UPDATE (3/29/13): You'll notice I made my A-Frames with a 45 degree angle. I suggest making them more like 30 degrees between them. At 45 degrees the feet are quite a bit wider than the fuselage and I keep tripping on them. Maybe I'm just clumsy :-).
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| Right side up |
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| Roll it around for glassing the sides or working on the inside |
TA DAAA!
The "Rotisserie" in Action
Time to glass the sides, cab
Ch 7: Contouring the Fuselage Top
She's back upright again and now it's time to get the sides ready to glass.
No...not the saw...
First I made room for where the canard will go by cutting out the the fuselage forward of the F28 bulkhead and across to the cutoff tabs on F22. Cutting on your fuselage is a little nerve racking...it just doesn't seem right. :-( I used 3 different saws for the process...my big crosscut saw, a mitre box saw, and a small drywall saw.
It was actually much easier than expected and it came out great. It will really look great when there's a canard mounted there!
Shape it up...
Next is the contouring of the top sides. Just like I did on the bottom, I built a sanding form for each of the templates used on the top. I started at the back with the D-D template then focused on the C-C template which is used from around the IP all the way to the seatback. Once the C-C work was near perfect, I moved up to B-B and then to A-A. I think doing it this way (back to front) helped me blend the curves along the sides pretty easy.
After getting A-A, B-B, and C-C blended well, I then went back to the aft section between the seatback and the firewall. I thought blending this section was going to be much harder than it was. It's a long distance and the two templates are very different. I first picked a point at the back where I wanted the shape to match the D-D template completely. The plans say just ahead of the spar cutout...I chose a point a few inches aft of where the doubler starts. Then I drew a line from the blue/white foam join line at the seatback to the D-D point I chose. This forms a bit of a long triangle on the side. Then I simply used my 22" aluminum Perm A Grit sander lengthwise to gently sand nice blended corner using that line as a guide for the blue/white foam join line. I think it looks great.
Onward, cab
No...not the saw...
First I made room for where the canard will go by cutting out the the fuselage forward of the F28 bulkhead and across to the cutoff tabs on F22. Cutting on your fuselage is a little nerve racking...it just doesn't seem right. :-( I used 3 different saws for the process...my big crosscut saw, a mitre box saw, and a small drywall saw.  |
| Ready for a canard now. Note the square top edges of the fuselage sides as compared to the pic below. |
It was actually much easier than expected and it came out great. It will really look great when there's a canard mounted there!
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| Sanding forms for the 3 templates |
Shape it up...
Next is the contouring of the top sides. Just like I did on the bottom, I built a sanding form for each of the templates used on the top. I started at the back with the D-D template then focused on the C-C template which is used from around the IP all the way to the seatback. Once the C-C work was near perfect, I moved up to B-B and then to A-A. I think doing it this way (back to front) helped me blend the curves along the sides pretty easy.
After getting A-A, B-B, and C-C blended well, I then went back to the aft section between the seatback and the firewall. I thought blending this section was going to be much harder than it was. It's a long distance and the two templates are very different. I first picked a point at the back where I wanted the shape to match the D-D template completely. The plans say just ahead of the spar cutout...I chose a point a few inches aft of where the doubler starts. Then I drew a line from the blue/white foam join line at the seatback to the D-D point I chose. This forms a bit of a long triangle on the side. Then I simply used my 22" aluminum Perm A Grit sander lengthwise to gently sand nice blended corner using that line as a guide for the blue/white foam join line. I think it looks great.
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| A gentle blended shape from the seatback to the firewall |
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| Port side complete...now rinse, wash, repeat on the starboard side |
Ch 7: Glassing the Fuselage Bottom
Here we go again...
This is another large layup. Don't believe the plans that say it should take you 3 hrs. Remember, Nat had built at least 2 other Aircraft before building the Cozy IV. Even with that, I find it hard to believe he did this in 3 hours. Plan on making it the day's activity and don't set yourself up to have to be somewhere at a certain time...you'll rush...and make mistakes.
A couple of thoughts...
- Make sure the shape and surfaces are what you want. If it's not right before you glass, it won't be right afterward either and you'll just have to add micro to fix it anyway. Glass is not a filler.
- Pre-cut the glass and mark which is which on the cloth. Also make a map to follow just to make sure you don't forget which piece goes where in the middle of your work.
- Use longer pot life epoxy so your not rushed. I use Aeropoxy so I used their 3665 hardener which has a 90 min pot life...worked great.
- Wet out only as much glass as you can reasonably work with at one time then move on to the next section.
Only 11.5 hrs later...done. I was very pleased with the results...only a few small dry spots found that were easily fixed. The slightly off colored piece of glass on the left front was from using the last\bit of some older hardner. It colors more and more rusty red with age but still works the same.
Onward, cab
This is another large layup. Don't believe the plans that say it should take you 3 hrs. Remember, Nat had built at least 2 other Aircraft before building the Cozy IV. Even with that, I find it hard to believe he did this in 3 hours. Plan on making it the day's activity and don't set yourself up to have to be somewhere at a certain time...you'll rush...and make mistakes.A couple of thoughts...
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| Layup Map |
- Pre-cut the glass and mark which is which on the cloth. Also make a map to follow just to make sure you don't forget which piece goes where in the middle of your work.
- Use longer pot life epoxy so your not rushed. I use Aeropoxy so I used their 3665 hardener which has a 90 min pot life...worked great.
- Wet out only as much glass as you can reasonably work with at one time then move on to the next section.
Only 11.5 hrs later...done. I was very pleased with the results...only a few small dry spots found that were easily fixed. The slightly off colored piece of glass on the left front was from using the last\bit of some older hardner. It colors more and more rusty red with age but still works the same.
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| Glassed Bottom. |
Ch 7: Bottom Antennas
About Antennae
Electronic navigation and communication require antennae. The great thing about composite, or plastic, airplanes as they are called, is that you can embed many of the antennae under the skin of the aircraft. Since ATC radar can see right through foam and fiberglass, it doesn't matter that the antennae aren't mounted on the exterior like they need to be for metal aircraft. The benefits are a nice sleek looking airplane with no unsightly antenna protrusions and less drag since there's nothing hanging out in the air stream to slow this bad boy down. It's certainly not much drag but you would be amazed at how all the small sources of drag can really add up.
Per the plans, I'm installing RST designed copper tape antennae except instead of using RG-58 coax, I'm using RG-400 throughout the entire aircraft. You can find several recommendations in the archives for it. RG-400 is similar 50 ohm coax that has replaced RG-58 as the standard for aircraft antenna feed lines It has a stranded center conductor and is double shielded which is needed for the transponder and GPS transmit lines...oh yea...and quite a bit more expensive. The best price I found was at B&C Specialty at $2.55/ft or $2.35/ft if you buy more than 50ft.
I'm installing the following systems that will have antennae "buried" into the structure.
- Dual radios - 1 antenna in each of the vertical winglets at the end of the wings
- Dual Navs - 1 antenna in the canard, 1 antenna in a wing
- Marker Beacon - 1 antenna on the fuselage bottom
- Glide Slope - 1 antenna on the fuselage bottom
- APRS - Automatic Position Reporting System used for flight tracking via the internet - 1 Ant in the wing
Other non-copper tape antenna that will be installed...
- Transponder - Installed in the nose
- GPS - probably in the nose
Fuselage Antennae
On the bottom of the fuselage, I'm installing the marker beacon (MB) and glide slope (GS) antenna. After determining where to install them, I oogered out the channels in the foam for the coax keeping in mind RSTs guidance on proximity and size of metal objects. You need to pay attention to where the nose gear will retract and the landing light if you're using the plans design...which I'm not. Then soldered the coax to the copper tape of appropriate length based on RSTs instructions. After everything is installed, I potted the solder joint and filled the channel with micro.
To the left is my antenna layout before final install. The marker beacon is on the right and glide slope in the center. I punched the coax through at a point just fwd and to the pilots side center of the instrument panel. Be sure avoid the wheel well area.
Note the oogered channel running diagonal back to the front of the IP...I changed the routing of the MB coax to keep the appropriate distance from the tip of the GS antenna and any metal. I'm not sure if I had to do this with feedlines but I figured I would play it safe. You can see the re-routed coax now comes toward the front more and then over to the punchdown.
TIPs: You'll need some tools. Based on a recommendations from an RV builder site, RST, and other internet locations, here are the tools I purchased. Coax stripper: I bought a Paladin 11255-LC CST and it worked great. BNC crimper: I purchased an Eclipse Lunar 300-054 crimper frame and the 300-038 die. For soldering supplies I got Kester 44 63/37 solder.
Now for the fun...time to glass the bottom. Onward. cab
Electronic navigation and communication require antennae. The great thing about composite, or plastic, airplanes as they are called, is that you can embed many of the antennae under the skin of the aircraft. Since ATC radar can see right through foam and fiberglass, it doesn't matter that the antennae aren't mounted on the exterior like they need to be for metal aircraft. The benefits are a nice sleek looking airplane with no unsightly antenna protrusions and less drag since there's nothing hanging out in the air stream to slow this bad boy down. It's certainly not much drag but you would be amazed at how all the small sources of drag can really add up.
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| RST Antenna Kit |
I'm installing the following systems that will have antennae "buried" into the structure.
- Dual radios - 1 antenna in each of the vertical winglets at the end of the wings
- Dual Navs - 1 antenna in the canard, 1 antenna in a wing
- Marker Beacon - 1 antenna on the fuselage bottom
- Glide Slope - 1 antenna on the fuselage bottom
- APRS - Automatic Position Reporting System used for flight tracking via the internet - 1 Ant in the wing
Other non-copper tape antenna that will be installed...
- Transponder - Installed in the nose
- GPS - probably in the nose
Fuselage Antennae
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| MB Solder Joint |
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| MB & GS Antennae trial installed just before permanent install and fill. |
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| GS Solder Joint |
Note the oogered channel running diagonal back to the front of the IP...I changed the routing of the MB coax to keep the appropriate distance from the tip of the GS antenna and any metal. I'm not sure if I had to do this with feedlines but I figured I would play it safe. You can see the re-routed coax now comes toward the front more and then over to the punchdown.
TIPs: You'll need some tools. Based on a recommendations from an RV builder site, RST, and other internet locations, here are the tools I purchased. Coax stripper: I bought a Paladin 11255-LC CST and it worked great. BNC crimper: I purchased an Eclipse Lunar 300-054 crimper frame and the 300-038 die. For soldering supplies I got Kester 44 63/37 solder.
Now for the fun...time to glass the bottom. Onward. cab
Ch 7: Prepping the Landing Brake
The landing brake was cut out during the building of the fuselage bottom...now it needs to be somewhat re-installed before the bottom gets glassed. The area around it get's routed out 1/16" below the surrounding area and the brake is tacked in place with 5 min epoxy.
I used a router tool I have for my Dremel to prep the area around the brake. This worked really well.
After the brake is tacked back in place and the surrounding area routed 1/16" down, layers of 1" wide duct tape, approximately 1/16" thick, is placed around the brake essentially forming a larger brake door surface. This is temporary as epoxy doesn't stick well to duct tape. It's hard to see now, but in chapter 9 the brake will be cut back out around the tape, the tape will be removed to make way for glass on the other side, and the whole thing will be hinged in place and the actuator installed. After that, the remaining area that was routed out (see pic below) will be filled with micro to form a nice seamless blended bottom across the landing brake.
(Deviation) Notice that I decided to extend the hinge all the way across the brake vs the plans shorter hinge. I'm hoping this will help eliminate any tendency for it to warp like some others builders have seen.
Since I mentioned the actuator, I plan to install a Firgelli electric actuator vs the manual plans version. This actuator has been used by several other builders, has a 4" throw, 150 lbs load, limit switches at each end, and a feedback potentiometer so I can wire it to my EFIS and know what position the landing brake is in at any time. More on that when I install it in Ch 9.
One more step before glassing the bottom...antennas! Onward, cab
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| Routing out the area around the landing brake |
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| The router tool for my Dremel made it very quick to carve out of the 1/16 depth of foam. |
(Deviation) Notice that I decided to extend the hinge all the way across the brake vs the plans shorter hinge. I'm hoping this will help eliminate any tendency for it to warp like some others builders have seen.
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| The landing brake ready for the bottom glassing. |
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Fergelli FA-PO-150-12-4 Actuator
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One more step before glassing the bottom...antennas! Onward, cab
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