Instrument Panel - Proposed Layout

[dothedr3w]

Hey everyone! I've just recently put my Kitfox deposit down, and have been slated for a Q1 2025 delivery; it's a ways out, but I'm alright with that time frame since it'll give me time to save up, familiarize myself with the build process, and start designing...hence the purpose of this thread! This is the 23rd evolution of my proposed instrument panel, and it's finally at the point where I feel I can share it with the forum and not get totally ripped apart. I would really love whatever feedback you guys can come up with. I'm not looking to get my tires pumped, honest feedback good or bad is much appreciated. I'm pretty junior in my flying journey so I'm very open to suggestions, and have implemented many thus far.

This was done on powerpoint, so things aren't perfectly to scale, but they're close enough for now. To note, this is a VFR panel meant for mixed use between backcountry and airports, and cross-countries less than 5hrs. I estimate that I will regularly be transiting through controlled airspace (nature of living near an international airport).

DYNON COMPONENTS
-SkyView HDX 10”
-SkyView Autopilot Control Panel
-SkyView Integrated COM Radio
-SkyView Knob Control Panel
-SkyView Stereo Intercom Module
-SkyView Dimmer Module
-Autopilot Disconnect Button
-USB Port Panel Mount
OTHER COMPONENTS
-Guardian Avionics smartPanel mount
-Apple iPad Pro 11”
-LX Navigation iris EFIS Pro 80
-Skybox Vigilus
-McFarlane Vernier Throttle
-Artex Remote Switch, Standard 8304
-Radiant Technologies USB-C/A Dual Charging Port

Other Notes
- The registration number on the panel isn't real, for demo purposes only
- I recognize the panel is quite busy, but I figure the space is there so use it
- Plan is run dual EarthX batteries which will parallel on a bus bar downstream of the master switches, so it could operate on M1, M2, or M1+M2 (I think this should work)
- iris EFIS Pro and FlyBox Vigilus will be linked directly to the master
- Radio has its own switch so I can load shed all other avionics/electronics in the event of
- iris EFIS has 3-5hr built in battery to serve as backup for SkyView HDX failure
- VPX solid state breakers not seen in pic, but explain lack of visible breakers
- idea is to reduce as many single points of failure as possible (dual battery/alternator/pumps)
- cabin light will be coloured red, and behind the panel aiming at feet
- ignition is an ON-OFF-ON momentary toggle (for fun and easier landmarking)
- all the "DO NOT TOUCH" buttons are red, not just master/alt

Unknowns
- LX Navigation compatibility with Dynon?
- Too many/little warning lights up top?
- Dynon pitot heat require a dedicated switch? or is it all automatic or built into their hdx software?

[Eric Page]

For a PowerPoint rendering, that's a remarkable effort; well done!

I'll offer some comments, questions and suggestions. Feel free to accept, reject or mock them, as you wish!

1. Since you have Lane switches, I presume that you're using a Rotax iS engine. The ECU and Fuse Box for those engines manage DC power generation without pilot intervention. Alternator switches are not required.

2. If you are using a Rotax iS engine, then you also need Start Power and Battery Backup switches (they can be combined in a single switch). Perhaps that's your "Ignition" toggle? If so, the Battery Backup side should be maintained, not momentary.

3. I don't see an Engine Start switch.

4. If this is a VFR airplane, why install a very expensive standby EFIS? If you're VMC, then there's zero need for an emergency attitude indicator. You might consider a multi-function instrument like the MGL Blaze ASV-2 (https://www.michiganavionics.com/product/asv-2/) or the Radiant Instruments UMFI-22-GEN2 (https://www.radiantinstruments.com/product/multi-function-asi-vsi-altimeter-umfi-22-temp) as cheaper alternatives that will provide altitude, vertical speed and airspeed.

5. Do you have a diagram of your electrical system design? I ask because I've never seen an airplane with two Master Switches and it seems unnecessarily complex. Consider reading Bob Nuckolls' book, The AeroElectric Connection (http://www.aeroelectric.com/Books/Connection/R12%20Searchable%20Merged%20Chapters.pdf). Since publishing the book, he's developed a new electrical architecture (Z-101B (http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z101B.pdf)) that he considers state-of-the-art for Experimental aircraft. It's not directly applicable to Rotax engines, but it's a good starting point and a valuable learning tool.

6. Keep in mind that the Kitfox is not a "load-hauler" airplane; you're working within a limited max gross weight. Given that the iS engines include two stators, carrying two main batteries and an avionics backup battery is probably overkill for even an IFR platform, let alone VFR. The likelihood of losing two stators or two batteries in the same flight are near zero. Recommend eliminating one battery and sizing the remaining one IAW Rotax guidance (see chapter 24 of the engine installation manual (https://www.rotax-owner.com/en/support-topmenu/engine-manuals)).

7. Why install a heated pitot tube (and associated wiring and warning light) in a VFR airplane? Unless you plan to install an external alternator -- a third(!) source of power -- this will be a significant portion of your available amps.

8. Radiant Instruments' catalog is sprinkled with re-badged off-the-shelf products from other companies. Their USB charger (https://www.radiantinstruments.com/product/usb-c-a-dual-charging-port) is one example. It's a Molex product (https://www.molex.com/molex/products/part-detail/io_connectors/0795405067) that Radiant resells. Buy it from Digi-Key (https://www.digikey.com/en/products/detail/molex/0795405067/11195061) at half of Radiant's price. Here is the Molex Mini50 connector (https://www.digikey.com/en/products/detail/molex/0347910040/3202544) to feed power to the unit, and here are the crimped sockets (https://www.digikey.com/en/products/detail/molex/5600230548/7428699) to populate the connector (buy ten; you'll need to practice crimping them to find the right crimping tool die and to master the technique).

9. Consider eliminating the Avionics Master switch. It's a single point of failure for all avionics wired through it and it's a very old idea that hasn't been necessary to protect avionics for at least several decades. Same with the Radio switch. A properly sized and maintained main battery will barely notice a few minutes with the Master Switch on (all avionics powered) to collect ATIS and talk to Ground.

10. The Dynon EFIS can display and record all necessary engine data through the SV-EMS-221. The Flybox Vigilus is unnecessary. If you want to be able to move engine instruments to another display, it might make more sense to install a 7" HDX screen instead of the Vigilus and iPad.

11. For ergonomics and ease of use, consider putting the SV-AP-PANEL, SV-COM-PANEL and SV-KNOB-PANEL next to the HDX screen. At a minimum, confirm that the viewing angle of the LCD displays on the SV-COM-PANEL will work from a low mounting position.

12. Unless they can be dimmed, you may find that illuminated switches are annoying at night. It's common practice in airplane design to use a dark cockpit concept. This means that no lights are illuminated in normal operation. When a light comes on, either something is wrong or is in an abnormal configuration.


Consider fuel pumps: if the engine is running then the pumps are on; the lighted switch is a distraction that complicates wiring. Unless the light is wired to a fuel pressure sensor and comes on to indicate low pressure (i.e. pump failure; already indicated on the EFIS), then it provides no useful information.

13. If you use illuminated switches for the Lane circuits, then the associated warning lights are redundant. The switch lights can be used for Lane fault indications. In normal operation, no light should be illuminated when a Lane switch is turned on. If you prefer separate Lane Fault lights, then the illuminated switches are unnecessary.

14. EMS warnings will be displayed with a blinking red alert on the EFIS, and optionally, an aural alert. The EMS warning light is redundant.

15. What are the two warning lights on the left, next to (I think...) the USB data port? Their legends look like "M1" and "M2"...

16. Finally, my most controversial comment: ATC fuse blocks are lighter, simpler and vastly less costly than a VP-X system, and there is significant danger associated with the temptation to reset tripped circuit protection devices in flight. If something goes wrong with a VP-X, your plane is grounded until the box is repaired. If something goes wrong with a fuse or its wiring, you trace the fault, fix it and go flying.

[bumsteer]

One thing I learned the hard way is that not all illuminated switches will work with the VPX (luckily mine were not expensive). If the entire switch has to be energized for the light to illuminate, they won't work with the VPX. From reading most everything Eric has written on the forum about electronics/wiring, he knows of what he speaks so at least with me his words carry some weight.

Rick

[dothedr3w]

Well Eric, that was a proper undressing lol. Thanks alot for this reply man, you obviously put alot of thought into it and that's not lost on me :) I'll address each one of your points one by one so nothing gets missed!


For a PowerPoint rendering, that's a remarkable effort; well done!

I'll offer some comments, questions and suggestions. Feel free to accept, reject or mock them, as you wish!

1. Since you have Lane switches, I presume that you're using a Rotax iS engine. The ECU and Fuse Box for those engines manage DC power generation without pilot intervention. Alternator switches are not required.
- The plan is to run an Edge Performance EP912STi. Is neither alternator switch required? or just not the primary alternator?

2. If you are using a Rotax iS engine, then you also need Start Power and Battery Backup switches (they can be combined in a single switch). Perhaps that's your "Ignition" toggle? If so, the Battery Backup side should be maintained, not momentary.
- Again, EP912STi. There's not nearly as much info on these as Rotax engines, but from the pics I've seen online they don't use the same starting method. I could be totally out to lunch here though.

3. I don't see an Engine Start switch.
- That's my bad, the ON-OFF-ON momentary toggle marked "ignition", should be marked "STARTER", because that's what it is lol

4. If this is a VFR airplane, why install a very expensive standby EFIS? If you're VMC, then there's zero need for an emergency attitude indicator. You might consider a multi-function instrument like the MGL Blaze ASV-2 (https://www.michiganavionics.com/product/asv-2/) or the Radiant Instruments UMFI-22-GEN2 (https://www.radiantinstruments.com/product/multi-function-asi-vsi-altimeter-umfi-22-temp) as cheaper alternatives that will provide altitude, vertical speed and airspeed.
- You're absolutely right. I just went off the first example a buddy of mine sent me without doing enough research myself, I'll definitely look into your suggestions.

5. Do you have a diagram of your electrical system design? I ask because I've never seen an airplane with two Master Switches and it seems unnecessarily complex. Consider reading Bob Nuckolls' book, The AeroElectric Connection (http://www.aeroelectric.com/Books/Connection/R12%20Searchable%20Merged%20Chapters.pdf). Since publishing the book, he's developed a new electrical architecture (Z-101B (http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z101B.pdf)) that he considers state-of-the-art for Experimental aircraft. It's not directly applicable to Rotax engines, but it's a good starting point and a valuable learning tool.
- I have not yet sketched up the electrical system. I figured once the panel was laid out I could do a proper power audit and flowchart/wiring diagram, this step is likely a ways off for me. I'm currently building an all electric tiny house, so I'm thankfully not a complete stranger to this world now. I will absolutely read The AeroElectric Connection. As for the 2 masters, unless I'm missing something critital, I don't think it's all that complicated. I don't plan to run backup power for the Dynon suite if I run a second paralleled battery. I figured if I'm going to haul around extra battery weight, it might as well help with both the efis AND the engine...plus it'll help get the CoG a little more rearward, which, if I'm reading things correctly, is something people need to get creative doing (short of just adding dumb weight).

6. Keep in mind that the Kitfox is not a "load-hauler" airplane; you're working within a limited max gross weight. Given that the iS engines include two stators, carrying two main batteries and an avionics backup battery is probably overkill for even an IFR platform, let alone VFR. The likelihood of losing two stators or two batteries in the same flight are near zero. Recommend eliminating one battery and sizing the remaining one IAW Rotax guidance (see chapter 24 of the engine installation manual (https://www.rotax-owner.com/en/support-topmenu/engine-manuals)).
- I'm not sure if the EP912STi has 2 stators, I will definitely look into this. Wont be running an avionics backup battery, just two Master batteries....but again, very open to being talked into a single larger battery, or single normal size battery.

7. Why install a heated pitot tube (and associated wiring and warning light) in a VFR airplane? Unless you plan to install an external alternator -- a third(!) source of power -- this will be a significant portion of your available amps.
- Heated pitot tube is more of a future proofing thing in the event I want to configure for IFR in the future; plus the cost differential is pretty negligible. I believe the EP912STi comes with a single alternator, with the option to bolt on a second. It has been recommended to run a 32A alternator, and bolt on an 18A as backup. I like the piece of mind a 2nd alternator adds as well. Open to suggestions!

8. Radiant Instruments' catalog is sprinkled with re-badged off-the-shelf products from other companies. Their USB charger (https://www.radiantinstruments.com/product/usb-c-a-dual-charging-port) is one example. It's a Molex product (https://www.molex.com/molex/products/part-detail/io_connectors/0795405067) that Radiant resells. Buy it from Digi-Key (https://www.digikey.com/en/products/detail/molex/0795405067/11195061) at half of Radiant's price. Here is the Molex Mini50 connector (https://www.digikey.com/en/products/detail/molex/0347910040/3202544) to feed power to the unit, and here are the crimped sockets (https://www.digikey.com/en/products/detail/molex/5600230548/7428699) to populate the connector (buy ten; you'll need to practice crimping them to find the right crimping tool die and to master the technique).
- Absolutely will do this....I just discovered DigiKey relatively recently and I love that place. Fair prices, good inventory, fast shipping. I should probably look for non-illuminated switches there as well!

9. Consider eliminating the Avionics Master switch. It's a single point of failure for all avionics wired through it and it's a very old idea that hasn't been necessary to protect avionics for at least several decades. Same with the Radio switch. A properly sized and maintained main battery will barely notice a few minutes with the Master Switch on (all avionics powered) to collect ATIS and talk to Ground.
- So are you saying to have all this power-up with the master? Is 'load shedding' antiquated notion with the lower consumption of modern avionics? This is all very new to me

10. The Dynon EFIS can display and record all necessary engine data through the SV-EMS-221. The Flybox Vigilus is unnecessary. If you want to be able to move engine instruments to another display, it might make more sense to install a 7" HDX screen instead of the Vigilus and iPad.
- The idea behind the vigilus was just to give engine instruments a dedicated display, plus it cooperates well with the Dynon, and can piggyback its sensors. I like the idea of an iPad becomes it's completely independent of the aircraft systems....alright let's be honest, it's so my passengers can watch cat videos on longer flights once they're sick of asking "how fast are we going", "how high off the ground are we". BUTTTTT, you raise a very good point regarding the 7" HDX screen; that could replace the Vigilus and iris EFIS, and serve the function of both.

11. For ergonomics and ease of use, consider putting the SV-AP-PANEL, SV-COM-PANEL and SV-KNOB-PANEL next to the HDX screen. At a minimum, confirm that the viewing angle of the LCD displays on the SV-COM-PANEL will work from a low mounting position.
- Absolutely valid! I wont be putting any pen to paper until I've actual sat in a kitfox, preferably one with a Dynon, and see how it all looks. Super super valid, and my previous designed had them mounted between the iPad and 10" HDX.

12. Unless they can be dimmed, you may find that illuminated switches are annoying at night. It's common practice in airplane design to use a dark cockpit concept. This means that no lights are illuminated in normal operation. When a light comes on, either something is wrong or is in an abnormal configuration.

Consider fuel pumps: if the engine is running then the pumps are on; the lighted switch is a distraction that complicates wiring. Unless the light is wired to a fuel pressure sensor and comes on to indicate low pressure (i.e. pump failure; already indicated on the EFIS), then it provides no useful information.

- Point taken. All illuminated switches will be eradicated...I just got mesmerized by how cool they look. You're absolutely right that they're a distraction and serve no real purpose.

13. If you use illuminated switches for the Lane circuits, then the associated warning lights are redundant. The switch lights can be used for Lane fault indications. In normal operation, no light should be illuminated when a Lane switch is turned on. If you prefer separate Lane Fault lights, then the illuminated switches are unnecessary.
- Will keep the fault lights up top with the rest, and go with non-illuminated buttons!

14. EMS warnings will be displayed with a blinking red alert on the EFIS, and optionally, an aural alert. The EMS warning light is redundant.
- This idea came from the department of redundancy department. Consider it removed!

15. What are the two warning lights on the left, next to (I think...) the USB data port? Their legends look like "M1" and "M2"...
- M1/M2 are Master 1/Master 2. The internets told me that the BMS internal to the EarthX batteries can be rigged to a fault light. Idea with the dual batteries/master switches is I could just swap to the alternate and flip off the problem battery without any interruption to service. Again, I could be totally out to lunch here.

16. Finally, my most controversial comment: ATC fuse blocks are lighter, simpler and vastly less costly than a VP-X system, and there is significant danger associated with the temptation to reset tripped circuit protection devices in flight. If something goes wrong with a VP-X, your plane is grounded until the box is repaired. If something goes wrong with a fuse or its wiring, you trace the fault, fix it and go flying.
- I wish you hadn't said this...this is going to result in many sleepless nights. You're absolutely right about all the above, but I'm going to have to do some serious soul-searching here, cause that VPX system is très nice. What are the Pros of the VPX system in your opinion? I just like how it integrates with the displays.



Awesome, awesome info and insight, Eric! At this rate I'm going to be on version 50 before I'm ready to share again! lol

[dothedr3w]

Alrighty Eric! I couldn't help myself so I made some quick changes that should address some of the things you brought up. Had to take the scale a bit more seriously to make sure the 7" HDX fits, so what you're seeing now is much more representative of their true sizes. Round 2...lemme have it!

[desertdave]

That looks like an overkill for a non transport category, VFR aircraft to me. I have flown airliners with way less stuff but that is just my personal opinion. Also how much weight is all that plus the wiring going to add? Lots of things to think about before buying anything.
Here is a simple, 100% functional design with a 2 channel autopilot. If I was going to fly IFR I would add a heated pitot tube and a standby Garmin G5 or a peanut gyro/airspeed combo and call it good.

32162

[olsonCCR]

I am so glad you all are discussing this again right now. I'm in the final stages of designing my panel before purchase. I've gone back and forth for months and would love a second set of eyes re: the switch layout and if I'm missing anything.

I do plan to stick w Dynon and use the Fastrak Trays on back of my panel to house most modules to keep wiring challenges to a minimum. My layout is designed the way it is to allow me future space for a G5 and GPS175 (IFR) if I ever wanted it (but unlikely). I chose 2 screens, so I can fly from either seat. A little concerned about weight compared w a 10" screen and G5 backup only but I do like the symmetrical look.

Here are my questions I'm hoping to get clarification on.

1. I have space to add a dimmer switch (dual or two separate knobs) but is it necessary? I am thinking of switching out the "round black switches" with ones that have red lights in them. If I do, concern is those could be really distracting at night if I can't dim them.

2. Any recommendation on the round black switch order for my lights and Cabin Heat? I imagine always turning on my Nav lights, so am changing the order (from left to right): to:“Nav”-“Strobe”-"Cabin Heat”-”Landing (and/ or)WigWag”-“Taxi"

3. I just emailed Kit Fox but haven't heard back yet due to the weekend. I am unclear if the Wig Wag function is used with the Aero LED Pulsar or Sunbeam light, and if the Wig Wag function needs a separate switch or if it's wired with the Landing light?

Lastly, I did purchase a Cowl Flap control knob which I plan to place to right of Throttle. No room for labeling but if I can, I will have it laser etched on end of knob.

Any constructive criticism or recommendations would be great!
32168
Thanks,

Kevin Olson
Building KitFox S7 STi (Rotax 915)

[dothedr3w]

I agree, it is quite busy.

- If you already had an iPad, would you would you not provision your panel to be able to accept it?
- by the time you buy a Garmin g5 you might as well just add another full size g3x if you have the space since price difference isn't that much
- heated pitot. Might as well just have it in the first place for future proofing (my thoughts anyway). And there's certainly no downside besides weight and cost to having it, and if it saves your butt even once it will have been worth it.
- I think 3/4 extra modules in the middle from Dynon are pretty much unavoidable. I think they're all pretty much required except for the heading bug quick button piece.
- this panel could definitely be slimmed down a lot by choosing Garmin over Dynon, there's certainly no arguing that!
- I want engine monitoring to have its own dedicated screen, so why not install a screen that can also do more?

If weight/cost was no object, would you fill your panel up?



That looks like an overkill for a non transport category, VFR aircraft to me. I have flown airliners with way less stuff but that is just my personal opinion. Also how much weight is all that plus the wiring going to add? Lots of things to think about before buying anything.
Here is a simple, 100% functional design with a 2 channel autopilot. If I was going to fly IFR I would add a heated pitot tube and a standby Garmin G5 or a peanut gyro/airspeed combo and call it good.

32162

[Eric Page]

The plan is to run an Edge Performance EP912STi. Is neither alternator switch required? or just not the primary alternator?

There's not nearly as much info on these as Rotax engines, but from the pics I've seen online they don't use the same starting method. I could be totally out to lunch here though.
Ah, OK. I'm certainly no expert on that engine. As I understand it, that's a modified 912ULS. I don't know the specifics of the Edge Performance EFI, what ECU they use or how any of it is wired. Perhaps one of the guys here who flies that engine can chime in with details.


Heated pitot tube is more of a future proofing thing in the event I want to configure for IFR in the future; plus the cost differential is pretty negligible. I believe the EP912STi comes with a single alternator, with the option to bolt on a second. It has been recommended to run a 32A alternator, and bolt on an 18A as backup. I like the piece of mind a 2nd alternator adds as well. Open to suggestions!
Copy re the pitot tube. You may want to fly a Kitfox before you invest money in making one IFR capable. They're known for being very maneuverable, not for Bonanza-like stability...

If the EP912STi has a different electrical system then my comments may not be applicable. If you only get one alternator as standard on the engine then perhaps a second one makes sense. I'm using a 912iS, so I have the luxury of two DC generating systems from the factory. I'm installing a single battery that's sized to carry engine and minimal avionics loads for a reasonable length of time when the battery is near the end of its life. That said, you have to be comfortable with your plane, not me -- I'm just some random guy on an internet forum!


I just discovered DigiKey relatively recently and I love that place. Fair prices, good inventory, fast shipping. I should probably look for non-illuminated switches there as well!
You should have seen their inventory before COVID ruined the world. There's a lot more of their catalog out of stock now than there used to be.


So are you saying to have all this power-up with the master? Is 'load shedding' antiquated notion with the lower consumption of modern avionics? This is all very new to me.
Not necessarily; I'm just saying that the worry about depleting the battery by turning everything on while listening to ATIS and asking Ground a couple of questions about local departure procedures is overblown. There's definitely a case to be made for separately powering some of the avionics to permit load shedding. I'm doing it in my airplane. My Battery Bus will power a Main Bus and an Essential Bus, but the Essential Bus will have a second feed, via a relay tied to the battery side of the main contactor. On the 912iS, in the event of stator/regulator failure, the ECU/Fuse Box will run the engine from the remaining charging circuit and battery charging is lost. I'll flip one switch to load-shed the entire Main Bus, leaving me with the standby instrument (MGL ASV-2), comm radio, interior lights and landing/taxi lights -- just enough to get safely on the ground in this exceedingly unlikely scenario. The Essential Bus alternate feed path is there to bypass a failed main contactor, but it can also be used as a "radio only" switch for pre-flight activities.

Bob Nuckolls' book shows dual batteries paralleled for engine starting in designs with large engines or remote batteries (he even has a design for an Aux Battery Management Module), but his architectures do not run them in parallel for normal operation. Two Earth-X batteries would be massive overkill for starting a 1.2-liter four-banger.


The idea behind the vigilus was just to give engine instruments a dedicated display, plus it cooperates well with the Dynon, and can piggyback its sensors. I like the idea of an iPad becomes it's completely independent of the aircraft systems. [SNIP] ...you raise a very good point regarding the 7" HDX screen; that could replace the Vigilus and iris EFIS, and serve the function of both.
A separate engine display does allow more real estate on the EFIS for PFD and moving map, and there's nothing wrong with that if you want it that way. The iPad can also serve as an ersatz EFIS, minus the air-driven instruments and airframe-referenced ADAHRS. The 7" Dynon could definitely serve the functions of the Vigilus and Iris, but if it's part of the overall SkyView network, I'm not sure it could be powered from a separate bus for emergency backup. Perhaps that's a question for the Dynon forum (https://forum.flydynon.com/).


All illuminated switches will be eradicated...I just got mesmerized by how cool they look. You're absolutely right that they're a distraction and serve no real purpose.
Again, I'm just some random guy on an internet forum with my own opinions and biases. I'm sure there are other guys on this forum who are perfectly happy with their illuminated switches and don't find them distracting. Techniques and standards that are used by certificated airframers aren't de facto applicable to Experimental builders. I guess what I'm saying is that you should weigh what you read in this forum, or any other, through a safety-vs-preference lens. There are definitely right and wrong ways to do some things, but for many others it's just a matter of choice.


M1/M2 are Master 1/Master 2. The internets told me that the BMS internal to the EarthX batteries can be rigged to a fault light. Idea with the dual batteries/master switches is I could just swap to the alternate and flip off the problem battery without any interruption to service. Again, I could be totally out to lunch here.
OK, got it. I had forgotten that the Earth-X battery's BMS has a fault output. That too could feed to a configurable input on the Dynon (either directly, or via an EMS input).

Take a look at Bob Nuckolls' Z-101B architecture and see how he handles what he calls the Endurance Bus and electrically-dependent engines. Single battery with dual feed paths for critical items. Incidentally, Bob has no beef with two alternators.


I wish you hadn't said this...this is going to result in many sleepless nights. You're absolutely right about all the above, but I'm going to have to do some serious soul-searching here, cause that VPX system is très nice. What are the Pros of the VPX system in your opinion? I just like how it integrates with the displays.
I suppose the pros of the VP-X are ease of installation, seamless integration with the EFIS, load monitoring and alerting, and so on. The VP-X website probably has a comprehensive list. I want to be very clear that I'm not suggesting there's anything wrong with the VP-X hardware or software; I'm sure that it's all designed by competent and conscientious engineers. My argument is a philosophical one: I don't believe in spending money on up-front convenience that results in an electrical system design that's run by a box whose internals are unknown to me, that I can't service myself, and that forms a single point of failure for the entire aircraft. Yes, you could make a similar all-eggs-in-one-basket argument about the Rotax 912iS ECU, but I'm pretty comfortable with the engine's service history and with the "Rockwell-Collins" sticker on the ECU. If any other item of avionics in my plane goes dark, oh well. I've thought about what I would do if each item failed and the answer in a VFR airplane is the same for almost everything: land when convenient. Other than both fuel pumps and the ECU/Fuse Box, there's nothing that represents an emergency.

As long as the VP-X can't stop the engine from running, and if you like the unit's benefits and have room in your budget, then by all means go forth and enjoy!

[desertdave]

I agree, it is quite busy.

- If you already had an iPad, would you would you not provision your panel to be able to accept it?
- by the time you buy a Garmin g5 you might as well just add another full size g3x if you have the space since price difference isn't that much
- heated pitot. Might as well just have it in the first place for future proofing (my thoughts anyway). And there's certainly no downside besides weight and cost to having it, and if it saves your butt even once it will have been worth it.
- I think 3/4 extra modules in the middle from Dynon are pretty much unavoidable. I think they're all pretty much required except for the heading bug quick button piece.
- this panel could definitely be slimmed down a lot by choosing Garmin over Dynon, there's certainly no arguing that!
- I want engine monitoring to have its own dedicated screen, so why not install a screen that can also do more?

Sounds like you have your mind made up. I look forward to seeing the end results.

If weight/cost was no object, would you fill your panel up?

​Nope, I am a simple man with simple needs


https://youtu.be/8eNoms9wsGc

[Eric Page]

I think 3/4 extra modules in the middle from Dynon are pretty much unavoidable. I think they're all pretty much required except for the heading bug quick button piece.
All functions of the SkyView system (setting comm frequencies, autopilot control, heading and altitude bugs, altimeter setting, etc.) can be done via the touchscreen interface. The only function-specific control module that's required is the comm radio head, as the EFIS cannot control radio volume. See t (https://forum.flydynon.com/threads/need-advice-about-adding-radios-to-hdx.13859/post-80250)his post (https://forum.flydynon.com/threads/need-advice-about-adding-radios-to-hdx.13859/post-80250) by a Dynon tech on their forum.

[Shadowrider]

Eric brings up a good point. The G3X is the same way as far as interface. Some like to have an interface, but the G3X can control all functions via the touchscreen including autopilot. It was advertised early on that if you don't put in the autopilot head unit you would lose some functions but this is not the case. We opted for no head units for the "clean" panel look. Just FYI for prospective builders.

As for the questions for the VPX here is our experience. VPX has been rock solid! Not even a single weird boot up or glitch in any way. I have 400 hours and Cory has almos 300. In fact Cory had a votlage regulator failure that caused a voltage spike. VPX shutdown the input for the voltage regulator and sent him a CAS message alerting him of a over voltage situation. I happen to be flying and he radioed me and told me. I told him to shutoff his primary alternator, and run it on the backup alternator. Super awesome in my opionion. Cool is how the VPX talks with the G3X or EFIS. IF you wanted to go with only a master switch you could because you can control all switches via G3X. So you could have a switch go bad or stop working bypass the switch and just control it via EFIS.

Initially we thought we had a bad unit in Corys plane, so we returned it to VPX. Long story short, the wigwag feature got selected onto the ADAHARS circuit so when speed came alive the ADAHARS lost power and rebooted. When we where talking with VPX, in all the units they have sold, they have not had one failure. Because of this they where very skeptical that a box had a failure but still agreed to send us a different box to try. When the new box came I figured out the error that was made. They also described to me that they build the box in different "channels" so if a channel where to fail, it doesn't take out the entire unit only ciruirts on that channel. I love all the functions of the VPX and they rewards out way the risk IMO.

The Edge Performance EP912STI is a Rotax912ULS (100hp) With fuel injection and turbo. The fuel injection is running Autronic SM3 ECU. Its a very robust ECU that has been very proven and running on hundreds of EFI kits for Edge performance. Its powered by the battery bus/essential bus. The EP912STI comes with the stock rotax alternator/generator. It only provides 18 amps so if you are running EFIS, Lights, Heater, you will not have the power you need. Edge performance makes another 32amp additonal alternator. It attaches to the back of the engine and extends the engine a few inches. So there are two stators stacked. It comes with additional voltage regulator. So, basically you have two available charging systems. 18amp and 32 amp. You can run them seperate or both if you like. I ran 30 amp breaker switches for each charging system to protect each charging system and to allow the ability to isolate each system. Before heading to the back country, I shut them both off and test each one making sure I am charging. If one fails while flying, one provides plenty of power to operate almost normally. If I am on the stock rotax, I will have to limit lights and heater.

[Redline]

Here's my Dynon panel for a Kitfox STi and 915. Some of the same components you listed, but with much less redundancy. We (my dad and I) were trying to keep it somewhat simple. This uses the Advanced Flight Systems ACM in place of the VP-X, which has been pretty slick so far. 32176

[VictorV]

One other important factor to consider is the size of the component behind the panel. In some cases it can be larger than the visible footprint. For example the Guardian
iPad mount is larger on the back than the opening on the front. You also have to make sure that none of the components are deep enough to touch the angled part of
the airframe or the panel support tubes.

Not necessarily part of the panel but if you want to have trim controlled by buttons on the stick grip you may have to install something similar to the TCW Safety Trim
Booster since the small buttons on the stick grip typically can't carry the amount of current required for the trim motor.

Victor

[Eric Page]

...if you want to have trim controlled by buttons on the stick grip you may have to install something similar to the TCW Safety Trim Booster since the small buttons on the stick grip typically can't carry the amount of current required for the trim motor.
Good point, Victor. The Dynon SV-AP-PANEL autopilot control panel has inputs for trim switches and outputs to drive an elevator trim motor, but those outputs are limited to 2 amps. The linear actuator used in the Kitfox can exceed 2 amps current draw.

[dothedr3w]

this is all super good info!

What the general consensus regarding trim on the stick grip? Most pics I see, guys are just running a bicycle grip or something similar, but a trim switch there seems like it'd be awfully useful

[Shadowrider]

I prefer bike grip with less clutter. Just like push button on top for the radio. I also prefer avionics master so minimal amp draw on the battery so I can run my under wing lighting when camping!

[jiott]

Regarding trim switch on the stick grip-I find the trim on my SS7 is so seldom used it really doesn't matter where it is. I kept mine on the center console where Kitfox recommends and have been very happy with it there. Typically I trim for takeoff before taxi then maybe make a very small adjustment (sometimes none is required since takeoff trim is essentially the same as climbout) for climbout after flaps are raised. Another very small adjustment for level cruise flight may be necessary, and then I never touch it, even if I change cruise altitudes. For landing descent it is still not touched until flaps have been brought in and then I make a major nose up trim adjustment for landing approach speed. At this point I usually land with 1/2 flaps and no further trim adjustment is necessary because full nose up trim is already in place for landing. As you can see, trim is not a frequent thing in flying the SS7 standard wing, so having it on the stick is no major convenience. I of course cannot speak for flying the STi or any of the earlier models. I like to keep my stick simple and not have to install and wire in a module for handling the relatively high current to the trim actuator. Just one guy's opinion.

[airlina]

Regarding trim switch on the stick grip-I find the trim on my SS7 is so seldom used it really doesn't matter where it is. I kept mine on the center console where Kitfox recommends and have been very happy with it there. Typically I trim for takeoff before taxi then maybe make a very small adjustment (sometimes none is required since takeoff trim is essentially the same as climbout) for climbout after flaps are raised. Another very small adjustment for level cruise flight may be necessary, and then I never touch it, even if I change cruise altitudes. For landing descent it is still not touched until flaps have been brought in and then I make a major nose up trim adjustment for landing approach speed. At this point I usually land with 1/2 flaps and no further trim adjustment is necessary because full nose up trim is already in place for landing. As you can see, trim is not a frequent thing in flying the SS7 standard wing, so having it on the stick is no major convenience. I of course cannot speak for flying the STi or any of the earlier models. I like to keep my stick simple and not have to install and wire in a module for handling the relatively high current to the trim actuator. Just one guy's opinion.

I rarely disagree with Jim on his posts but I have a different view with my IO-240 powered Series 5 and maybe that is the difference. My 5 requires trim adjustments constantly . speed changes, configuration changes and power changes all require trim. So much so that when I built mine 20 years ago , I added a selectable slow fast function of the trim speed for precise trimming under different conditions. I like "hands off, feet off" flight in cruise so precise stab trim and cockpit controlled rudder trim was required for me. This is also very important for autopilot use ,if you plan on installing one. Having said all that , my trim on the console has worked fine as it is in a good location and easy to reach. I do like my PTT button on my stick grip. Bruce N199CL

[jiott]

I hear you Airlina, and I expected some differing comments, which is good. We all fly somewhat differently and our airplanes are not identical. It just turned out the way I described for me personally. I found that even major power changes require no trim change because when I increase power its because I want to climb and the nose naturally comes up just the right amount automatically. Conversely, when I pull power its because I want to descend and the nose drops just right for a normal descent without trim change. I also had an instructor who made it a point to teach me to fly with a bare minimum of adjustments thru the flight envelope. For instance, my takeoff trim setting was fine tuned so that that setting worked for takeoff with 1/2 flaps, climbout with flaps retracted, and needed very little if any adjustment for level cruise hands off. Actually even with perfect trim a Kitfox is not really a "hands off" cruising airplane for any length of time.

[dothedr3w]

I think I've been heeding everyone's advice as best as possible, and this is what I've come up with.

- iPad removed: there was definitely alot of screen up there, but I do like having a second so I kept the 7" HDX since it'll sync with everything else

- I like the extra modules that Dynon offers. Touch screen is unbeatable, but sometimes is nice not to have to access menus for everything. Some people like a clean panel, so I totally understand why people might disagree with this choice.

- EP912Sti has 2 ecu lanes, and 2 fuel pumps seems like an obvious choice, so that's why those each have 2 switches. The EP912STi comes with an 18A alternator, with a 32A bolt-on option. I've put 2 switches there to easily isolate them for checks during run up, or in operation, and they can be "stacked" if I want to run an AC inverter or some other high draw item (who knows!?)

- I'm with most people here in that a clean stick grip aside from PTT seems like the way to go, and trim next to the throttle seems like it might be handy. I've put a little lip on top to serve as a hand rest/guard for the trim. Thoughts?

- Starter is a momentary ON-OFF-ON, Master is a locking ON-OFF. As per Eric's advice, a radio and avionics master do seem like an unnecessary feature/single point of failure, so they've been removed. Yes, the buttons are still illuminated, but they'll be wired to have an independent power source which will be dimmable....if I cant make this happen, they will not be illuminated.

- Passenger reading light seemed like a nice idea since I took away their iPad

- Still undecided between Vertical Power VPX, and standard breakers/mini fuses

- You guys were right, this thing is definitely never going to be an IFR flyer, but I'm still hanging onto that pitot heat unless for now. Maybe someone can give me a nice alternative to take its place on the panel?

[dothedr3w]

All functions of the SkyView system (setting comm frequencies, autopilot control, heading and altitude bugs, altimeter setting, etc.) can be done via the touchscreen interface. The only function-specific control module that's required is the comm radio head, as the EFIS cannot control radio volume. See t (https://forum.flydynon.com/threads/need-advice-about-adding-radios-to-hdx.13859/post-80250)his post (https://forum.flydynon.com/threads/need-advice-about-adding-radios-to-hdx.13859/post-80250) by a Dynon tech on their forum.


hmmm very interesting! Do you know if the intercom module is required? It would be weird if the HDX couldnt handle basic intercom functionality itself

[Eric Page]

hmmm very interesting! Do you know if the intercom module is required? It would be weird if the HDX couldnt handle basic intercom functionality itself
There's no intercom functionality in the EFIS. It must be added separately.

[Eric Page]

Starter is a momentary ON-OFF-ON...
What are the functions of the two ON positions of this switch?

How is ignition different from the ECU Lanes on this engine? Is the ignition system pilot-controlled separately from the Lanes?


Passenger reading light...
Located where shown, it will be pointed at the passenger's knees. You might consider mounting it to a small bracket in the overhead structure, and put it in the middle so either occupant can use it.

How much flying will be done at night with passengers who want to finish their book enroute? ;)

[dothedr3w]

What are the functions of the two ON positions of this switch?
Start and start, so it works in either direction...for fun


How is ignition different from the ECU Lanes on this engine? Is the ignition system pilot-controlled separately from the Lanes?
I thought the ecu lanes each controlled the ignitions?


Locatee where shown, it will be pointed at the passenger's knees. You might consider mounting it to a small bracket in the overhead structure, and put it in the middle so either occupant can use it.

How much flying will be done at night with passengers who want to finish their book enroute? ;)
I guess it's pretty obvious I'm just looking to spend money on useless **** eh?

[jiott]

I would give more thought to mounting the trim switch next to the throttle. You have to deliberately hold your arm up, supported only by your thumb. Down on the center console in the standard location is so natural because that's where your arm naturally goes when at rest; its so easy to just extend your finger and operate the trim. I find most trim adjustments are made without changing throttle settings, so your hand is not near the throttle. IMHO

[airlina]

I would give more thought to mounting the trim switch next to the throttle. You have to deliberately hold your arm up, supported only by your thumb. Down on the center console in the standard location is so natural because that's where your arm naturally goes when at rest; its so easy to just extend your finger and operate the trim. I find most trim adjustments are made without changing throttle settings, so your hand is not near the throttle. IMHO


I'm with Jim on this as well , the trim on the console is in a great location where your hand goes naturally, and you usually just need to "bump" the toggle for the right amount. Trying to do this by holding your arm out to the throttle area would be more cumbersome. Bruce N199CL

[Redline]

We’re still building so I can’t speak to how some of our options will be to fly with, so take what I say with a grain of salt!

Our trim is on a bike grip with a four-way toggle/ptt button. Tracstarr used this set up on his build and was happy with it.

Take a hard look at the Advanced Flight Systems ACM. It integrates seamlessly with the Dynon avionics and you can also order pre-built wiring harnesses for 90 percent of what you’ll need. Saves a ton of time and so far AFS has been great to deal with.

Like Shadowrider, I wanted everything off during engine start except the HDX, so an avionics master was used.

[dothedr3w]

We’re still building so I can’t speak to how some of our options will be to fly with, so take what I say with a grain of salt!

Our trim is on a bike grip with a four-way toggle/ptt button. Tracstarr used this set up on his build and was happy with it.

Take a hard look at the Advanced Flight Systems ACM. It integrates seamlessly with the Dynon avionics and you can also order pre-built wiring harnesses for 90 percent of what you’ll need. Saves a ton of time and so far AFS has been great to deal with.

Like Shadowrider, I wanted everything off during engine start except the HDX, so an avionics master was used.

Is it the Otto T5 tracstarr and yourself are using?

https://www.otto-controls.com/t5-4-way-plus-center-pushbutton-mini-trim

[Shadowrider]

I think trim button on the center console at stock location is the best because you’re close to the flap lever. Drop the flaps and hit the trim, or pulling flaps and adjust trim. Pretty seemless motion with right hand as your flying and radioing using your ptt on your stick with left hand. Allows for all to happen at same time. I often find I am talking on the radio, dropping flaps and then trimming, plus power adjustments all seem to be seemless with right hand.

[Eric Page]

Start and start, so it works in either direction...for fun

I thought the ecu lanes each controlled the ignitions?
OK, I assumed that since the start switch had more than one active position, it had some ignition-related function -- hence the question. I don't know how Edge's ECU works; you're probably right about the Lanes.

[dothedr3w]

OK, I assumed that since the start switch had more than one active position, it had some ignition-related function -- hence the question. I don't know how Edge's ECU works; you're probably right about the Lanes.

Shadowrider is the expert on these engines!

And to everyone who nay-sayed the trim next to the throttle....I agree. I was obviously a bit gluey when I thought that up. It shall remain in the usual position.....perhaps doubled-up on the left stick, but not the passenger's.

[Redline]

Is it the Otto T5 tracstarr and yourself are using?

https://www.otto-controls.com/t5-4-way-plus-center-pushbutton-mini-trim

Yep that’s the one.

[dothedr3w]

32213

Well I just can't help myself. iPad re added, but downsized to a mini.

Green lights taken off the red switches. Replaced with red lights to illuminate only when there's a problem

Trim switch removed from panel (that was a real dumb idea)

Dumb light removed

General rearrange and cute little kitfox logo plate added

[dothedr3w]

Ok, here we are at version 56! It took a while for everyone's advice to soak in, but I think we're getting close!

[dothedr3w]

Well I might be steering towards Garmin for the sake of better autopilot servos (apparently), and a more useful AP panel. I've added a disconnect for the AP servos, as per shadow rider's advice on his build thread. I'm torn whether or not to keep the avionics master switch. As usual, feedback always welcome!

[jiott]

My opinion would be to move the throttle back down to a small sub-panel like you had before. Would leave more room on the main panel for future additions, and be more ergonomic IMHO.

[dothedr3w]

My opinion would be to move the throttle back down to a small sub-panel like you had before. Would leave more room on the main panel for future additions, and be more ergonomic IMHO.

Funny you should mention that...I moved it to the panel because I thought the sub-panel might be overkill, then I looked through the 'show us your panel' thread, and quite a few people use sub-panel idea, even if their panel isn't crowded.

What are your thoughts about a panel mount radio to occupy that space as opposed to a remote mount radio?

[dothedr3w]

Some along these lines? I don't think there much sense in an audio panel if I'm only running 1 comm radio, and skipping NAV/comm all together.

[jiott]

I would prefer a remote mount xspndr and a panel mount radio. You are fiddling with radio frequencies a lot and not having to go thru a touch screen is better IMHO. The xspndr is rarely touched.

[desertdave]

With a Garmin touch screen you can skip the autopilot panel (save $ and panel space) and run it off the PFD.

[dothedr3w]

I would prefer a remote mount xspndr and a panel mount radio. You are fiddling with radio frequencies a lot and not having to go thru a touch screen is better IMHO. The xspndr is rarely touched.

I agree entirely. Thats the GTR 200B radio on the panel.

[dothedr3w]

With a Garmin touch screen you can skip the autopilot panel (save $ and panel space) and run it off the PFD.

I do love the idea of a nice clean panel and everything running off the G3X, but the AP panel is non negotiable to me. Just the ease of getting it all fired up, the Yaw damper, and most importantly the 'level' button...moreso for my eventual passengers should something happen to me, it at least buys some time.

Still undecided on the panel mount radio....but playing music over Bluetooth seems like a nice option.

[rv9ralph]

I have been following this thread and have a few observations.

An Avionics Master is obsolete, everything will be on during engine startup to monitor engine. Modern avionics are not affected by low voltage at engine start.

What engine do you plan on? If it a Rotax 9xxiS, the you will need Lane A/Lane B lights, start power switch and I didn't see/notice fuel pumps.

[dothedr3w]

Planning on an edge performance ep912sti (basically a Rotax). I've got the 2 lanes titled as 'ECU', and the fuel pumps are just called 'FUEL'. It's my understanding that the Edge Performance doesn't require a 'start power' switch, I should get away with a normal starter switch running thru the Vertical Power PPS.

The generally consensus seems to be that avionics switch is obsolete, and I totally understand that sentiment; I went like 20 design iterations without one, but it somehow found its way back lol. I kind of like the idea of being able to power cycle the avionics without killing the master. For example, in flight and something is acting up, I can do the ol' turn it off and back on...if I'm out to lunch with this one I'm all ears!

[Eric Page]

I kind of like the idea of being able to power cycle the avionics without killing the master. For example, in flight and something is acting up, I can do the ol' turn it off and back on...if I'm out to lunch with this one I'm all ears!
That's why each item has its own power switch, or in the case of the EFIS, a key sequence to force a reboot. With modern electronics the Avionics Master switch is unnecessary and is nothing more than a single point of failure for every item powered through it.

The worst problem you might see is an EFIS reboot during engine cranking. That's easily addressed with a small backup battery like the TCW Technologies IBBS (https://www.tcwtech.com/product/integrated-battery-back-up-system-ibbs/) or the EarthX ETX104 (https://earthxbatteries.com/product/etx104-back-up-battery/). Dynon has their own EFIS backup battery; perhaps Garmin has one too.

If you haven't done so, I'd recommend reading Bob Nuckolls' book, The Aeroelectric Connection (https://tinyurl.com/AeroElectric-Connection). Bob's current state-of-the-art design for an E-AB aircraft with an electrically dependent engine is his Z-101B (http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z101B.pdf). Review the diagram, read the notes, and feel free to ask questions, either here or on the AeroElectric-List forum (http://forum.matronics.com/viewforum.php?f=3).

[jiott]

Maybe I'm old school, but I still like the idea of an avionics master. I had a voltage regulator (yes the Rotax/Ducati one) fail once in flight and was slowly losing battery voltage. It was easy to shut off all non-essential avionics with the avionics master (transponder, radio, intercom, ADS-B) without having to start pulling breakers. My EFIS of course with engine info is not powered thru the avionics master. The so called disadvantage of a single point failure is in my opinion nil to none; how often does a mechanical switch suddenly fail. I also like the ability to turn off the avionics master before I kill the engine, protecting the sensitive avionics against a possible voltage spike (I know this is rare, but it is more probable than a switch failure). Just another set of thoughts to throw into the mix.

[dothedr3w]

I certainly appreciate the different perspectives from everyone on this thread. I don't have a ton of my own experience to draw on...actually zero experience with a glass panel. So to everyone weighing in, thank you! I expect this panel will evolve more, but the changes are becoming more and more subtle.

[bbs428]

Just my 2cw - Keep it as simple as possible!

A good clean design has an elegance all to its own.
Look at the standard that Kitfox themselves are producing and follow that template if possible.
I'm all into making it your "dream panel" but be careful on making it too "busy" or complicated.

I refer to the instruments at the proper times, especially the engine ones, but mostly my eyes are outside the cockpit!

[dothedr3w]

Did the moderators remove like half of this thread? I went to review prior suggestions and they're gone, along with a bunch of the uploaded photos.