Trivia this week

Typical mags fire the top plugs on one side and bottom plugs on the other side.  I looked at one of the older Jeff Rose EI systems and it is wired this way.   The Fly EFII system specifies top plugs to one coil and bottom plugs to the other coil.     The ignition switch on traditional aircraft have Off/Left/Right/Both.   I'd noticed that some experimental/home built aircraft switches were labeled Top/Bottom.

The cylinder cooling fins have different depths on the left/right sides of the barrel.

Chapter 22 Electrical - SDS wire assignments - firewall connector pin assignments - wiring diagram

Pin assignments for firewall bulkhead connectors and other electrical wiring info.

Things I learned this week....

You can't cut stainless steel with an Oxy-Acetylene torch.  The metal pools and blobs fly when you hit it with Oxygen.   Oddly after discovering this, I found this video titled Dummy trying to cut stainless with a torch.

The Type - K yellow insulated lead thermocouple wire can't be soldered with rosin core solder.   It's made of nickel and chromium.   There's a new Type N wire.  http://www.thermometricscorp.com/thertypk.html

If you make a joke (regarding aviation) on social media, someone might complain to the FAA and they're obligated to investigate.  Recent account from YouTube "Just Plane Silly" channel story here:  https://youtu.be/P0Fs_RI4Hok 

Chapter 15 Firewall & 22 Electrical - EI/EFI, Dynon EMS, ACK ELT, Princeton Fuel module mounting

The Dynon EMS module and SDS EI/EFI modules need to be mounted on the cold  side of the firewall.   Mounting them on a removable shelf that is cut to still allow quick access and inspection of the engine mounting bolts and hard points should provide for easy maintenance and changes to be made in the future if needed.   

The ELT needs clearance for the antenna, and two small cables (DIN for GPS and remote panel).

The Dynon EMS module has an LED by the network connector (right side) that should probably be easily visible.
The CHT/EGT inputs are through the brown wires.  The additional inputs (oil temp, pressure, etc.) are through the multicolored wires (silver connector).   

The dual SDS controller has two relays that also need to be mounted.   There are 6 connectors on this module.

The rectangular hole for the bulkhead connectors and round hole for cabin heat are visible here.

A couple of removable plugs for leg bow inspection were made by using a 4.5" hole saw and cutting from scraps of left over strake material.  The foam will be microed.

BID covered strake foam shelf was bonded to the round covers with West 704 filler.

The Princeton modules will mount on the triangular space.

The orientation of the modules is limited by the available space.

Two Amphenol 37 pin connectors are mounted to a plate that covers a rectangular hole that is large enough for the D-connectors to pass through.   A nut plate is on the cold side of the firewall.   

Rotation was not limited by the clamp on the torque tube.

One of the few photos of the Dynon SV32 roll servo.   The ELT ground plane (copper foil tape) should be adequate.  West 407 filler was used to pot washers.

Access to the servo is through the opening under the heater duct hole.

Chapter 22 Electrical System - auxiliary sensors

Unused Dynon EMS ports can be used for additional data.
This would be handy for reading the delta air pressure and temp across the oil cooler, cylinders etc.


http://wiki.dynonavionics.com/Making_your_own_sensor_definitions
http://dynonavionics.com/cgi-bin/yabb2/YaBB.pl?num=1291258674/1#1
http://dynonavionics.com/cgi-bin/yabb2/YaBB.pl?num=1268164287

Chapter 15 Firewall - cutting and fitting

A deviation from plans is to use Stainless Steel rather than Aluminum.   

Edit/update - drilling to fast will heat up and dull drill bits.  Go slow and apply pressure for better results.

Made a template from cardboard.   Cleared off one of my 4x8 workbenches, placed scrap board to put underneath while drilling.  Borrowed a set of knock outs from a neighbor to make clean hole cuts.  The electric shear cuts wider sheets well but didn't work very well for trimming edges.  An angle grinder with a cut off wheel works pretty well for trimming the edges, but have to be careful not to heat the metal up to much.  The shavings from this are like little razors.  

Stainless can be hard to work with.   The hole saw grabbed and tore the metal a little here.   This hole was just for the knock out bolt.  Fortunately, the knock out cut this part out.

The sheet is clamped in place.   The cardboard helps align the knock out.

A uni-bit seemed to drill holes pretty well without tearing.  A sharpie marked the stop depth on the bit.

Still needing a little trimming, but is lining up pretty well.

Holes not cut yet that are needed are for the EMS system's D37 and D25 cables, alternator wiring, SDS EI/EFI, AFR probe wires, cabin heat, throttle, fuel source and fuel bypass return.

Stainless Steel parts from Cozy Girrrls.  Not all holes are drilled.  

Saw this technique either on an EAA video or another metal builder's site.

Cleco clamps hold the paper to the pulley so the holes can be marked with a sharpie.   Small dots mark where the cotter pin holes need to be.

  Keep the drill bit cool (I used water) and take your time.  These little holes each took about 10 minutes.   Black carbide drills work.   The drill press doesn't go slow enough and heats the bit up.

The sections covering the spar were added and fastened using rivets.   Some of the holes needed to be elongated slightly and edges trimmed in a few spots.   I put electrical tape on the inside edge of the holes for the vent lines to try to protect the aluminum from scratches when putting the firewall on and taking it off.    There is still a protective plastic sheet on the stainless steel.   A few more holes need to be cut.   

Flight Testing

Links to FAA Flight Testing Advisories:
https://www.faa.gov/news/safety_briefing/2014/media/SE_Topic_11_2014.pdf
https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2090-89A.pdf
https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_90-116.pdf

EAA Webinar on the Flight Test Manual:
http://www.eaavideo.org/detail/videos/homebuilding/video/5993410710001/webinar--introducing-the-eaa-flight-test-manual

Here's a link to Kevin Walsh's "Experimental Aircraft Flight Test Protocol":

http://www.cozybuilders.org/docs/Cozy-MKIV_Flight_Test_Protocol.pdf

I'll need to do some editing for mine, but it is really thoughtful of others to share with the group.
I've been reading this and will plan on using the data recording of the Skyview system to help reduce work load.   Also think I may ensure the Auto Pilot is working earlier in the protocol to help reduce work load and improve the accuracy of the flight tests.

Adding some notes here that will be incorporated:

Fuel Injection /Electronic Injection - Dual ECU Switch

When running dual ECU boards, this toggle switch activates relays which switch operation of the injectors from one ECU board to the other. In normal operation, one board is always firing the top spark plugs, the other fires the bottom plugs. The ECU select switch only switches the injector connection over to the other board. If one ECU board fails, you’ll lose one set of plugs but the engine should continue to run.

The recommended ECU checking procedure is to start the check on the backup ECU. At idle, Switch the ECU selector switch from Backup to Primary. If the engine continues to run, both ECUs are working. Now you can switch coil power off on the #1 coil pack. Switch that one back on and then switch off #2 coil pack power. If the engine continues to run, both coil packs are working.

Be sure to check that both coil power switches are back on prior to takeoff.

Chapter 17 - Vance Atkinson's springboard and electric pitch trim systems

Updated 12/25/2019

Vance's canard is unique and shows a universal joint that isn't on the plans Cozy IV.   Rather than a manual rod, an actuator with feedback will be installed.  I don't think I'll need the component that mounts on the wheel well if the actuator has enough force.  It seems its purpose was to reduce the travel distance of the T-handle and to bias the trim so pulling the handled would provide up trim rather than down.  Update - several of us with Cozy IV's have had to add more layers to make this type of spring a bit stiffer in order to have adequate pitch down force at cruise speed.  Vance flew my plane and said that it handled well.  The pitch force was not to stiff.

Vance later updated to an electric trim system, but a downside was if there was run away trim, needed to be disconnected to allow full elevator travel.   He accomplished this with a quick disconnect pin through the Heim joint.  We tried different springs to allow full travel if there was run away trim, but Vance did not care for the resulting stiffer/softer forces.

Here's a link to a photo of the plans to make a Davenport spring

Chapter 23 Engine Installation - prop, extension, Step 3 cowl

* Click the "Read More" link at the bottom (if it is there) to see all of the photos in this post.
Click on Chapter 23 above to see all of the Chapter 23 posts.

Catto 68" diameter 78" pitch prop with nickel leading edges and erosion tape.  

Freeflight Composites cowl.   Did multiple test fits and the line that was marked looked like it was going to be pretty close so I trimmed outside of that line.   To match the plans, the cowl needs a lip along the front edge, so I trimmed off where the CF meets the lip at the turtle back and similarly, trimmed the bottom cowl.    Then used hot glue and pop sickle sticks to hold the trimmed section on as a form for the inside lip.  In hindsight, I think a 2 to 3 inch wide 5 BID layup on this line before trimming might have resulted in less work.

The blocks had to be moved in order to apply the BID that lays up in front of the cosmetic piece.  This particular area of the cowl lips were a little proud and met the wrath of the belt sander.

Pop sickle sticks and hot glue worked pretty well and was easier to remove than Bondo.

To install the Camlocs, drill 1/2" hole where the cleco holes are.   Then drill 1/8" holes for the rivets to hold the receptacle.   The bottom hole here has a Camloc receptacle riveted in.   I used a small drill bit to bevel the holes for the rivets so the heads are flush.  I made a simple jig to locate and drill the holes for the receptacles.

3 BID curing while the trailing edge is shimmed up to help correct a tendency to sag.

A layer of duct tape is on the bottom of the turtle back/spar lip.  Flox was applied and peel ply over that.  Nut plates were installed on the cowl and screws are holding the cowl in place for the flox to harden.   While the flox is still green, it's sliced with a box cutter along the seam.  Then after the flox cures a little more, the screws are removed and light pops with my hand broke the flox loose along the cut seam.

Article comparing NACA duct vs scoop

The plans construction method for the cowl lip is to attach foam blocks to the inlet and carve the foam to this shape.   I opted to use a 1x2 piece of PVC foam and a belt sander.   

The cowl wasn't made to accomodate the scoop for the NACA inlet.  The lip has to come down and inch.   I cut the cowl back 7" to help make a ramp for the scoop that won't be to draggy.  

Prepping the foam lip to be glassed in.

Small fairing blocks on the bottom cowl ramp.

Two identically shaped blocks will help keep the boat tail cowl in position while the 5 BID inside layup cures.