Monday, April 24, 2023

SDS EM5 O2 controller

 The SDS programmer hadn't been showing the correct AFR since replacing the controller with the AEM controller and sensor.  I found that the white wire (AFR output) that connects to the SDS ECU had slipped inside the solder sleeve when I heated it, so was not making electrical contact.   After using a new solder sleeve, the programmer now reads 18 with the engine off.  I changed the VPX settings so that the AFR is powered on when the Alt Field switch is turned on.  The AFR controller takes a few seconds to run diagnostics.  It doesn't have a remote status indicator like the 14Point7 did.

I found a small crease in the baffling near #3 cylinder so used a leather punch and lacing tape to get the seal to lay down better.

Reviewing the EFIS data, after making lower cowl ramp changes, the cylinders coldest to hottest are now 1,2,3,4. With a 20-30 degree delta depending on air speed and power setting.   Previously, 1 and 4 were the coolest, 3 was the hottest with up to a 40 degree delta.   If #1 could be brought up a little and #4 down, the delta temp would be great.

Today I'll attempt to use my cheap new laptop to get some log data out of the SDS ECU to dial the map in better.  Based on fuel flow, it looks like with the mixture knob centered, about 10% more fuel is needed during take off to obtain max power.  



Sunday, April 23, 2023

Pitch trim stiffened

The weather is crappy, not going anywhere any time soon so pulled the canard off to access the paddle board pitch spring that's riveted to the elevator torque tube.

 The pitch trim is okay at 160-ish KTAS but at WOT going 180+, the stick needed my help to stay in level flight otherwise it would climb.    I added two plies of full length UNI and a little 1" BID at the actuator end to keep the spring's UNI from splitting and cracking.

I'll work on some other items while the epoxy cures.


----update ---  The AP can hold altitude at WOT now.   The pitch stick is noticeably stiffer, but I think the only other option than stiffening the spring would be to change the canard incidence.   



Sunday, April 2, 2023

2023 CI squawk progress

 Brake bleeding - complete.

AFR Sensor - changed - verified operation.

Placards & document holders - better adhesive - complete.

Antiskid for foot area - complete

PH6 -> 6XT conversion?   1.25" versus 1.50" pistons, new aluminum block spacer, inner shoe.

Ordered from McMaster-CARR:

BUNA N o-rings:

Pistons: 2-215 (1.25")   

Park Brake: 

2-006

2-010

3-904


SDS Service Bulletins checked:  http://sdsefi.com/aircraft.html


Saturday, April 1, 2023

Condition Inspection 2023

 The first annual condition inspection has been relatively uneventful.   There were a couple problematic items that need addressed:

The canopy 10/32 screws for the front two latches had been abused and were loose as a result of overtightening the canopy latch when I closed a Sharpie in it once.   Some 10/32 Helicoils were installed to repair the threads.

The Dynabeads for balancing the tires would occasionally stick inside the valve stem when checking tire pressure so I installed special filtering valve stems on the main wheel's tubes.   The front tube's stem was to short for the longer valves.  

The left brake pedal  (Matcomfg Triple Pucks) had been getting softer.  Attempts to bleed using a pneumatic bleeder weren't successful and am suspecting the vacuum bleeder is malfunctioning now.  I replaced the pads even though they weren't down to the wear indicators yet.  The bleeder screws were replaced with ones that have O rings in them ($25 ea.) so air won't leak around the threads when vacuum bleeding.  The lines between the reservoir are the smaller Nylaflow and the capillary action isn't letting the bubbles travel up the tube very well.  I'm still working on this.  The thinner walled Nylaflow (1000 psi) is easier to see bubbles through.  I removed the Matco parking brake as it showed that it was starting to leak a little.

The SDS O2 EM5 O2 sensor was not reading correctly.  I purchased a cheap controller and sensor so I could bench test sensors.   The original O2 sensor was reading correctly on the bench after shooting it with carb cleaner.  I'll swap the sensor out, test the current one and this will help determine if the 14point7 O2 controller is bad.  I also reconfigured the VPX to turn on the O2 power when the Alternator Field is turned on.  Instructions for when to power on the O2 sensor seem to conflict, and the reason for this is there is ceramic in the sensor.  If it is hot and water hits it, it can fracture.  One idea is that the engine/exhaust needs to be hot so condensation will not get on the sensor.  But if the sensor isn't hot, carbon will build up on it.   Realistically, I only need the sensor working enough to get a few engine runs to plot the current AFR and tweak it as necessary.  I know from looking at fuel flow, that when going wide open throttle, the mixture knob needs turned rich 10% for max power.   By adjusting the map, manual adjustment of the mixture knob won't be necessary.   By looking at EFIS data and using fuel flow to compute horsepower, the mixture setting was making a difference of about 20 horsepower or more.  The base map was made by Barry from an interpolation of the 360 and 390 engine maps.  Since this 370 engine has 9.6:1 pistons and Superior Cold Air sump, is not surprising it needs more fuel.

I'd purchased a low cost laptop with Windows and installed the SDS dashboard and data logger software.  Following instructions from Barry @ SDS, got the logger to see the USB port as COM 4 and the dashboard was displaying multiple channels of info.  The laptop was also loaded with the VPX software and the O2 power was set to come on when the Alt Field was turned on.  Another application that I needed was the Seattle Avionics Data Manager which downloads the Dynon charts and databases.

The laptop didn't come with an Ethernet port, so a USB to Ethernet adapter was purchased.  It also has 3 USB 3.0 ports which will be nice for updating the Dynon and Avidyne charts.

The ACK ELT large (5 year) battery expires this month and was $279 to replace.  The EarthX battery that was 2.5 years old failed.  EarthX gave me a discount on a new battery since it should have lasted longer than that.  It was interesting to see the PCB module inside the battery with a bunch of power MOSFETs.  I connected a battery charger directly to the internal packs and charged it (safely outside).  One of the packs had read less voltage than the other before I force charged it.   In the failure mode, it was reading 1.7 volts which the tech commented, "It should read zero."  He commented that it sounded like the electronics failed.

Karl Riley stopped by and gave me some non-skid adhesive for the foot area to make egressing easier.  He also gave me some double sided adhesive to use where some of the weather stripping and other items weren't sticking well.  Vance stopped by and also Jayson Van Every too.  

The Dynon USB memory sticks have a new home in a dedicated panel socket.   I have two sets of sticks so that the new charts can be loaded on the spare set and swapped when the old ones expire.

The Airworthy and Registration documents were moved to a document holder that is visible from the outside.  I'd been keeping them in the center map pocket.