Chapter 15 Firewall - cutting and fitting

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

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 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 that will be left on.   A few more holes need to be cut.   

Flight Testing

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 improve the accuracy of the flight tests.

Chapter 17 - Vance Atkinson's springboard pitch trim

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.

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

* Click the "Read More" link at the bottom to see all of the photos in this post.

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 inlet to a 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 cowl in position while the 5 BID inside layup cures.

Chapter 22 Electrical System - List

Electrical System List

PFD (Skyview HDX)

MFD (Skyview HDX)

Skyview Knob panel (Baro, Heading, Track)

Skyview AP panel

Skyview Com panel (controls Dynon Com radio)

ELT Panel (ACK)

Com/Intercom Panel (PS Engineering PDA360EX includes USB charging port)

Com Radios (Skyview Com & Avidyne Nav/Com & antennas)

Transponder (and antenna)

ADSB RX (and antenna)

ADSB Antennas (GPS & stick)

ARINC

ADAHRS (2020 ADSB compliant)

Skyview Network Hub

Magnetometer (old style compass eliminated)

AP Pitch Servo

AP Roll Servo

Pitch Trim Servo

Roll Trim Servo

VPX  (Electronic circuit breakers controlled through PFD)

SDS EFI/EII (Dual Hall effect sensors, coils, 3.5" panel, A/B ECU switch, LOP switch, throttle position, engine temp, MAP, AFR probe, fuel flow output to EFIS)

Master Relay (A&B)

Starter Relay

Ammeter shunts

Switches (on Instrument Panel)

Circuit Breakers (non-VPX protected circuits)

Starter button

Fuel Pump 1

Fuel Pump 2

Landing Brake actuator

Landing Gear

Com Jack - Pilot

Com PTT - Pilot

Com Jack - Copilot

Com PTT - Copilot

Com Jack- Pass Left

Com Jack - Pass Right

Heated seat pilot

Heated seat copilot

Heater/defrost blower
Joystick left (hat switch for trim, PTT, AP Disconnect)
Joystick right (hat switch for trim, PTT, AP Disconnect)
Lights - Interior
Lights - Position/Nav/Strobe lights
Lights - taxi
Lights - fuel gauges

EFIS module

CHT probes

EGT probes

Fuel Pressure (Fuel Flow is from SDS system)

MAP probe

Oil Temp probe

Oil Pressure probe

OAT probe

Pitot probe

Battery main

Battery aux (Skyview)

Fuel level sensors ( probes)

USB jacks

Cig lighter front/back

Autoextend module

Canopy warn

Gear warn

ELT (GPS connection, antenna, panel control)

Alternator Belt Drive 60 Amp 14.2 VDC Internal regulator and over voltage protection

Alternator Pad Drive 30 Amp 13.7 VDC Internal regulator and over voltage protection

Chapter 22 Electrical System

This chapter of my build is not "per plans".   An electronic breaker system and a modernized (glass) panel is being installed. 

System redundancy will include appropriate panel mounted circuit breakers for redundant fuel pump and ECU power.  One of the displays has its own battery.

Dynon Skyview HDX1000.  ADSB compliant with auto pilot.
Skyview Documentation
Skyview Planning
Vertical Power VP-X.
Plane Power 65 Amp belt driven alternator 14.2 VDC.
Plane Power 30 Amp Pad mount alternator 13.7 VDC.
ACK dual band ELT.
PS Engineering Audio Panel PDA 300 EX

Approximately 40 .lbs of Avionics 

Son of a blogger.....

Last year a bunch of photos in this blog turned into little empty boxes.   This was caused by dragging and dropping photos from other Internet sites (like Facebook).  These photos were actually links and  they can be expired by the original site.    I've uploaded a bunch of the photos that disappeared, but some are out of order and are not very well organized or captioned.   

Another issue encountered is that by creating a post with a large amount of photos, Blogger's pagination truncated older posts and they couldn't be seen unless "Older Posts" was clicked on.  Jump breaks were inserted to help remedy the ones I've found.   Also by default, Blogger's default number of posts to display is 7.

Recently, I found some other layout/format options that seem a little nicer, but would like to organize posts so they're better organized.   Clicking on the Chapter links above filters on the labels assigned to posts so hopefully that will help find specific posts.  Oddly, even though some posts are "labeled" for two different chapters (an example is Chapter 16),  not much comes up.  But if you click on Chapter 15, there's a post that has a label for chapter 16.

Update - Chapter 23 posts about the cowl seem to be exceeding limits.  I try adding photos in at the bottom but they show up at the top.   I put a page break in and noticed that when viewing, where the page break was inserted there is a small "Read more" link to see the rest of the post.  Maybe posting links to the photos would be better, but that didn't work well when the links to Facebook expired.

Chapter 17 Pitch and Roll Trim, Landing Brake and Center Console

This section is not per plans.

There are several options for elevator trim.  Most that have implemented electric trim use either the Atkinson or Strong trim systems.

There are a couple of plans for the Atkinson system.   The later one uses a rod that is about an inch longer than Vance's original.  

Getting the spring pressure and the stick travel so it feels right and having enough movement if the trim motor runs away has been a challenge that is still being worked on.

I used the mill to make some smaller springs that go inside the original springs to help provide more force at full trim down.

   I rethreaded the longer rod and Vance will test and see if it works when the weather is nice again. -Update - We're still not getting the right compression when allowing more travel. Update 5/4/2018 - the 30 .lb springs still don't allow enough travel.   I found a source with some 8" springs that will compress to 3". They're 3/4" in diameter and to avoid having to move the actuator mount, will require two parallel tubes. I'll try a POC today....Another update 5/18/2018- Vance said he'd probably announce his quick fix soon.   I'd like to come up with an improved design which would seem to need springs that are a larger diameter and take more than 3 inches to compress.   Or multiple tubes with a more complex interaction of components.

The elevator tube travels 1.6".   I used a scale and plotted the force to compress and stretch the springs that have the right force.   It takes about 30 .lbs to fully extend and about 16 .lbs to compress.   The original tube's length changes 1.7" from max compression to stretched.  The original actuator is about 24" long and has 3" stroke.

 A little research on compression springs reveals that springs should be selected so their load is about 45% of their full capacity.  I found a bag of 10 ea.  60 .lbs springs on Amazon for $18 that have 3.5" travel and should have them Wednesday.

Also, while testing, the motor became intermittent.  Some strained and broken wires were found at the motor. 

The wires on an older Motion Systems Actuator broke so needed repaired.   There's only six strands each in black and red OEM wires.   I replaced the old wire with high strand wire of the same gauge.  Some little U's made of .042 safety wire holds the brushes and springs in place.   The original wires were cut where they broke.  Insulation pulled off to make little pig tails that connect to the brush leads.  The new wire was twisted and soldered to the stubs that were left.

Some shrink tube and a wire tie should keep the wire breaking in a bad place.

I made a few springs that are wound the opposite direction so they will work properly inside the larger spring.   The first couple of springs didn't turn out perfectly, but I found if I set the mill to a right hand feed at 20 threads per inch using .050 music wire, it took about 7' of wire to make about a 5" spring.   The mini-lathe doesn't have enough torque to wind .080 wire, so I turned the chuck by hand.  The small springs didn't provide enough force.

My first tube had +/- 2" of travel with about 14 .lbs of force.   I rethreaded the inside rod so it was extending an inch less and put one of the smaller springs I made inside the larger spring to provide more force near the end of its travel.  

In order to increase the rod travel a little more than the original design, I cut about 1/4 shoulder on one plug and on the sliding bushing.

This is the cheap HF mini lathe.   I upgraded the tool post to a quick change model and quickly found out the tool holders were poor quality.  It's easy to spend hours learning how to use this.   It will wind .050 music wire to make a spring but .080 was to stiff so I had to turn the chuck by hand.   The arbors to make different sized springs were fun to make.

Chapter 22 - Electrical System - Instrument Panel and controls

I've made a list of all electrical components in a separate post.

Master / Main Alternator/Aux Alternator / Start switches (need to order)
Light switches (need to order)
Skyview glass panel PFD/MFD - Dynon  (on hand)
Skyview Knob panel (Baro, Alt, Heading knobs)
Skyview Com panel (controls Skyview radio)
Audio panel  ( PS Engineering PDA360EX includes 10 watt USB charging port)
Auto Pilot panel (Dynon - has the ability to adjust trim if needed).
ELT - ACK panel
SDS 3.5" panel.  2 switches (ECU A/B, LOP) 1 electronic mixture control (round potentiometer).
Vertical Power - integrated with Dynon.
Nose gear controls - position indicator LEDs.
Landing Brake actuator switch.
Fuel Selector in center console - Andair dual gang. (in progress)
Throttle Lever (need to make or order).  Mixture lever isn't needed with the SDS system.

Eyeball vents
Canopy warning

Joysticks:
Top hat switch for trim.
Auto Pilot disconnect.
Push to talk.

Chapter 23 Engine Installation - Electronic Ignition & Fuel Injection for SDS EM5

SDS EM-5 manuals are on this page:


http://www.sdsefi.com/program.html

I've run two lines from each tank up to a dual gang Andair valve.  The valve controls which tanks the fuel is pulled from and bypass fuel is returned to.

A more modern design would have been to put the pumps in the tanks like they do in automobiles.  This helps cool the motors and submerges the pump in the fuel to help improve efficiency.   A few downsides are there still needs to be a method to switch the bypass fuel into the desired tank.   Openings into the tanks for maintenance are going to add weight and also a likely place for leaks.

The lines in the tanks are positioned in the sumps.   The outlet is positioned near the front bottom of the sump where a drain sump is located.   The return is positioned under the screen with the end of the line pointing upwards.   This should help isolate air bubbles that might be in the system.   The recommended distance between the in/out lines in the tanks is 4".   My configuration is at 7".  Both lines return to the tank under the surface of the fuel to avoid building up static charges.  Another consideration is that cooler fuel should be drawn into the pump, so pushing the warm fuel where it can dissipate heat before returning to the pump and engine is desirable.