Engine Installation - Part II

 While I was waiting / saving for the engine, I planned ahead on component mounting, firewall layout, etc.  The bad news is almost everything I planned had some kind of issue.  The ECU is not exception.

My original plan was to mount the ECU on the right hand side of the 'shelf', forward.  Well, the cannon plugs and wiring is to large to fit under the right side avionics tray.

Original plan

New plan

I turned the ECU 180 degrees, and moved it aft about 3".  This was easy, except the UL aux box is mounted under the shelf with captive fasteners on top.  Made a quick drill guide and done done.

The current top of mind issue is the firewall passthrough.  The wire bundle is ~0.85" across, but the connector is just shy of 2" in diameter.  So you need a 2" hole to get the connector through as the engine is prewired.

Talked to the US distributor, and a local gent that has a UL on a zenith.  Consensus is to make 2 C shaped pieces that interlock and cover the 3" hole, and leave 1" for the wires.

My last attempt at cutting stainless was poor, so I checked out SendCutSend.  I very quickly designed a part (using their standard parts catalog) that would do the job.

Minimum order is $29, so I ordered qty 14.  Each of these will be cut so they overlap.  Total of $32 USD including tax and shipping (to my US post box).  

Ordered Saturday, production started on Monday morning.  Looked like they were going to ship on Monday, but then their progress meter got stuck at 60%, and the estimated ship date went to 4 days later.  Guessing they are out of material or something like that.

Parts received.

I cut 2 disks into C's, and split the firewall passthrough in half and assembled the whole thing.

Works as intended.

Next steps:

1. Plan out engine wiring integration.  John Wood told me about this pretty good free / open source software called QElectroTech.  So far I am quite impressed.

2. Cowling.  Need to get this done before the weather turns cold.  Ideally I am waiting for the prop to arrive so line up the spinner.

3.  And a lot of everything else...

Engine Installation - Part I

 Very cool evening.  My son and I installed the UL520T on the airframe.  Took around an hour between freeing the engine from the crate, lifting it, and assembling all the mount hardware.

No major issues.  The only thing that needs some follow up is an oil line either to or from the sump is too close to the engine mount washer.  Will follow up with UL and find a solution.

The engine wiring looks pretty straight forward.  2 large cannon plug connectors to the ECU, and various fanouts for power, ground, coils, regulator, etc.  That will be a project for next week.

Next challenge is fitting and extending the cowl.  Hope to start on that next week.  Waiting for the prop.  Has been ready to ship since late June, and paid for since mid-July.  But I know the required spacing, so I should be able to start.

Instrument Panel - Part III (Wiring)

Now the wiring begins.... I both love and dread this part.  Love it because it makes things work, and dread because compromises will need to be made.

Step 1:  Electrical bus(ses).

Target is 3:

1. ACM - which includes avionics, lights, pitot heat, etc.  Everything that the ACM powers, which is everything but engine.

2.  Engine bus.  Stand alone bus for the engine, using breakers.

3.  Everything else bus.  This will be fuses, and for things that dont really matter - like seat heaters.  This will be the last priority.

The output of the two batteries goes to a central point, which is the current shunt.  This shunt will measure the total input / output to the batteries and will be inclusive of everything.  From the shunt, power goes 3 ways - to the ACM, Engine Bus, and to a fuse panel.

Fuel Pumps

The UL Power ECU has the provision to 'control' the fuel pump (or pumps) via a relay.  The ECU drives the coil on the relay (Fuel Pump Control Relay - FPCR), so it can turn the pumps on or off.  This is useful when on the ground working on things.  The system will pressurize, then the pumps shut off.

However, what if the relay fails?  So my fuel pumps switches have an 'auto' position (which goes through the relays) and 'force', which does not go through the FPCR.  Overkill?  maybe.

Everything else engine needs to wait until it arrives - hopefully in late May.

From a wiring perspective... 2 power feeds from each of the pump breakers.  1 feed goes directly to the switch, one goes to the FPCR.  The center position of the switches goes to the pumps.  The pump wiring is on a connector as the whole fuel pump tray is removable (kinda - have to take the header tank out first).

Header tank sensors.

Well this has been fun.  The sensors I bought from Radiant are cool, and I tested them very thoroughly with water to ensure they do what they should do.  But their connectors are, lets say, interesting.

The sensor is connected with a USB cable.  The head unit (of which I have 2) has the power connections.  Plus the cable lengths were way too long.  So I shorted everything up and put them both on one connector.

They are temporarily wired to power off a breaker to verify the wiring and connector.  Debating whether to power them from the ACM or a breaker or fuse.  Probably the ACM long term.

They flash red when liquid is not present.  Obviously the tank is empty, which is a good sign.

Radient recommends siliconing the LED's into the holes.  Not sure if I am going to do that, or make a mount.

 

ACM and Pre-Built Harnesses

I love the ACM.  I love the harnesses.  I have to figure out how to tame them.

To start, I plugged everything in.  No wires are tied in anywhere.  Just wanted to get the lay of the land (so to speak).  Holy crap, its a lot of wires and I am nowhere near done yet.

Dont judge me based on these pics.  Please.

The plan is to figure out where everything will go, then take it all apart and finish the trays and brackets, then reassemble for good. But I have to build the aircraft front, rear, and wing harnesses.  Everything is ordered to do that.

Main Power Distribution

OK - this is a mess.  But you have to start somewhere.  Again, the purpose was to figure out what goes where.

Two EarthX ETX900 batteries, two master relays with flyback diodes.  Each battery can be switched in or out.  This is all pseudo temporary, but it works.

The output of the two relays is bridged together, and the starter will come off here.  From the bridge point, goes to the main shunt with 6 gauge wire.  From there, goes to the ACM and engine bus.  The battery, aircraft frame, and engine all tied to a single firewall ground point.  Also a 10 gauge wire to the avionics bay ground bus.  This may need to increase to 8 gauge.

Engine Bus

As the ACM shies away from anything 'engine' related, I decided to have breakers for everything engine and fuel related.

10 gauge wire coming from the main current shunt on the hot side of the firewall.  It passes through a Hall effect sensor, so I will know (in theory) the current draw of everything engine / fuel related (but I won't know what is drawing what - just the total).

The Hall effect sensor is mount under the starboard avionics tray.  This may have to move simply for serviceability.  It will be very difficult to change - if not impossible.  On 2nd thought, if the MFD is removed there is a clear shot to it, but all of the wiring is not yet installed so that may change.  Time will tell.

Harnesses to build

- Aircraft front:  Comprises of prop controller, taxi lights (which will go to the wings - but that is a different story), cabin lights, panel fans, belly strobe, elevator trim.

- Autopilot servos:  These are pre-built from Advanced, need to be terminated on servo end.

- Sticks and flaps:  PTT, AP disconnect, IDENT, flip flops, Audio Panel switch, flap position potentiometer

- Wings (aka Aircraft Rear):  Pitot heat, landing / taxi lights, nav / strobes, fuel transfer pumps

- Engine sensors:  EGT, CHT, Fuel Pressure, CANBUS (to ECU, which has a large number of sensors), fuel tank sensors, etc.

The panel has taken a bit of a back seat due to waiting for a new panel from Glasair.  Should be here August 9th, then I have to recut it all over again.

Autopilot / Servo Wiring and Avionics Trays

 As part of my avionics package from Advanced, I purchased their pitch and roll servos.  All the servos come from the same manufacturer... also purchased the servo mounting tray from Glasair.

All of the brackets have been fit, fasteners drilled, and I added a few lightening holes in the tray itself.  While I was at it, I finished the left and right avionics trays that mount to the cage.  Lots of drilling and fitting nutplates.

All these were put through aluimiprep, alodyne, primed and painted.  The paint is PPG, and matches the grey of the cage.

Remote radio unit repositioned slightly due to cable length.

Everything dry fit.

Installed and wired.  I was SOOO careful to not mix up the wiring for the pitch and roll servos, and guess what - I cut them the wrong lengths.  So I de-pinned the connector and switched everything around.  

Left and right avionics trays are finished and nut plates installed.

The top picture is the left side tray (the IBBS is mounted under the tray). The next two pics are the right side tray.  I have not mounted the audio panel or Hall effect sensor yet... waiting for hardware.

I am going to need to raise the EMS and Audio Panel to clear nut plates underneath (they overlap each other slightly).

Handful of things to do before they are mounted - and actually will not be fully mounted until the firewall comes out.  2 holes need to be drilled in the forward tabs for the trays.

Next is the big tray that will hold the ACM, Skyview Network Hub, ECU, Boost Controller, Aux Box, and ADHRS.  I very quickly put it together to see if it was going to do what I wanted, with stuff I had in the shop.

Now that I think this is going to work, have gone back and finished drilling it, and making a few modifications, plus adding lightening holes.  Oh, and drilling for fasteners.... ugh.

After finishing, ready to mount.

Installed with most components present.

Lots of wiring still to do, but progress is definitely being made.

Engine and Engine Mount

The engine (UL 520T) has shipped from the factory.  Ordered March 20, was ready to ship in late June.  Also, prop is ready to ship as well once they receive the funds.  Big steps coming.

Engine mount received from Francois C.

Engine received on July 15!

Going to be a month or so before the engine is mounted.  Targeting mid August.

Originally I had the pre-filters and pumps on the cage, under the header in the cockpit.  The new UL pre filters are much larger, and reusable.  I had to relocate to the firewall.  Also, the coils and regulator are now mounted.

This new arrangement makes header tank situation much easier to deal with.  Just a single 1/2" line from the output of the header tank to the firewall.  The firewall bulkhead fitting had to be increased from -6 to -8 (3/8 to 1/2")

The above is the required UL power capacitor.  According to UL, this allows you to shut off the battery during flight.  Not sure I would want to do that.

Strakes

 The first builder that started the fuselage bonded the strakes on.  This involves bonding in the foam ribs, and the two halves of the strake, and then fitting the assembly to the fuselage.  My engine is inbound, so my goal is to finish up all of the messy / dusty stuff before it arrives if possible.

This picture is the strakes as they were when I bought the fuselage, but with a quick sand.

First layer of filler.  Just trying to fill the low spots.

Second later of filler.  Working on build the profile, plus the transition.

Third layer:  High build primer.  This way I can see what I have missed and refine the transition and any low spots.

Primer sanded...

2nd layer of high build

Multiple small imperfections still exist.  Putting this aside for now.  90 to 95% done.