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-   -   SDS EM-6 EFI ECU (https://vansairforce.net/community/showthread.php?t=158304)

rv6ejguy 03-03-2018 11:56 AM

SDS EM-6 EFI ECU
 
We've got 10 new features planned for the new EM-6 which will commence hardware development sometime in April it looks like now. We have 3 other optional ideas to explore as well and we've explored and discarded 2 other ideas already.

While we won't be able to make the design process on the EM-6 as open and interactive as on the CPI2 ignition system due to other players in the field, we are very interested in having customer input on features they'd like to see in the new ECU. We often find that great ideas come from outside.

I won't be able to confirm much of what will be new for sometime but we'll listen to your feedback for the next 30-60 days or so before we freeze the wish list and get down to full scale hardware and software development.

We hope to release the EM-6 in the late 4th quarter of 2020 but that depends on how many new features are incorporated and how long they take to develop and properly test. We see one possible avenue, if adopted, may extend the development time past this date.

Development time available is also impacted by our order backlogs for EM-5, CPI/ CPI2 and our other aviation and automotive products. This varies considerably with the time of year. We have to take good care of our customers and keep money flowing in the door to finance the new R&D projects.

As I mentioned previously in another SDS thread, we have the well proven EM-5 EFI/EI systems currently available and all FULL AVIATION system buyers (complete EFI kits) in 2018-20 will be eligible to receive a free EM-6 ECU when they are available. This way, there is no delay in getting your project flying but you can enjoy the additional features of the new ECU when it's released.

rmartingt 03-03-2018 05:54 PM

I probably won't be ready to buy for at least another year, but...

Some form of closed-loop mode (with a toggle switch to enable?) and selectable AFR would be really neat.

RPM and MP defining an array of fuel and timing values instead of independent lists would maybe give a way to automatically go lean at certain conditions?


Basically, I'd just be looking for a way to avoid having to deal with mixture at all. Not having actually used your system yet I can't really think of anything else.

bluskydreamin 03-03-2018 08:10 PM

ideas
 
Hi Ross,

just spitballing here but.. how about eliminating the need to manually select injectors AorB and the associated relays for this IF an ECU goes out?

maybe better said... a full up autonomous running system if an ECU goes south.

Thanks for requesting the input from the field!

DanH 03-04-2018 06:09 AM

I second dual systems with no external relays, and no required pilot intervention to maintain power after a system failure.

Human pilots will never correctly diagnose a power loss and flip the right switches 100% of the time, in particular at low altitude.

M McGraw 03-04-2018 06:49 AM

EM-5 switches
 


For those not sure about this conversation, the areas circled in red are the necessary switches for an EM-5 setup.

My electrical system is very similar to a Nuckells Z-14. ECU 1 runs 4 sparkplugs ECU 2 runs the other 4. In order to lose all ignition I’m having a really really bad day, As such I don’t have an inflight ignition emergency checklist. The plan is put it on the ground ASAP.

The switch in question on this thread is on the far right, “INJ”. The fuel injectors can only be run by one ECU at a time.

Engine runs rough:
1) Swap fuel tanks - assumes starvation or single tank contamination.
2) Flip the three yellow switches - assumes bad fuel pump or bad INJ power, I don’t really care which one at this point.
3) Engine runs good, yay! engine still bad, look outside and land.

I could eliminate this procedure with two changes:
1) Automatic fuel pressure sensing and redundant pump engagement.
2) Automatic fuel INJ switching as suggested in this thread.

If the above enhancements are included, I would really like it to trigger the red Error Message LED and send a notification to the controller screen.

NOTE: Error message LED and Controller screen not shown in the picture above. Also not shown are the two coil switches only used for preflight.

rv6ejguy 03-04-2018 08:53 AM

Nice clean layout Marvin.

With regards to auto switching of fuel pumps and injectors. We've considered this before and it comes back to a lot more hardware in between the controller and device. To have a true backup, you need to isolate the dead or shorted component or it's useless. This almost always involves relays which adds more wiring and connections.

If we take the case of the CPI2 where we went down this path, it more than doubled the size of the PCB and component count to do the OV and auto switchover and tripled the development time. You start to question if this is really more reliable than having the pilot flip a switch, especially when historically, these events are exceedingly rare.

I'm not saying we won't investigate these ideas but we'll be taking a harder look on benefits vs. complexity weighting after the CPI2 experience. One of the reasons why we've had such good reliability on our hardware for a couple of decades is that it was simple. The first word in SDS. Components which aren't there can't fail.

Is it wise to add many layers of complexity for events which almost never happen?

Chkaharyer99 03-04-2018 09:01 AM

"Simple" for who? The builder/supplier or the operator/pilot?

"Is it wise to add many layers of complexity for events which almost never happen?"

It depends on your prespective.

M McGraw 03-04-2018 09:03 AM

Thanks Ross
 
Quote:

Originally Posted by rv6ejguy (Post 1243527)
Nice clean layout Marvin.

With regards to auto switching of fuel pumps and injectors. We've considered this before and it comes back to a lot more hardware in between the controller and device. To have a true backup, you need to isolate the dead or shorted component or it's useless. This almost always involves relays which adds more wiring and connections.

If we take the case of the CPI2 where we went down this path, it more than doubled the size of the PCB and component count to do the OV and auto switchover and tripled the development time. You start to question if this is really more reliable than having the pilot flip a switch, especially when historically, these events are exceedingly rare.

I'm not saying we won't investigate these ideas but we'll be taking a harder look on benefits vs. complexity weighting after the CPI2 experience. One of the reasons why we've had such good reliability on our hardware for a couple of decades is that it was simple. The first word in SDS. Components which aren't there can't fail.

Is it wise to add many layers of complexity for events which almost never happen?

I?m actually good with the memory item of ?flip the three yellow switches?. Mostly, I was just interested in explaining the conversation to people less familar with the SDS product.

Toobuilder 03-04-2018 09:06 AM

Quote:

Originally Posted by M McGraw (Post 1243500)
...For those not sure about this conversation, the areas circled in red are the necessary switches for an EM-5 setup...

Your panel looks fantastic, but for clarity the switches you have shown are personal choice - not "required". For example, I do not power my ECU's independantly, nor do I have a separate switch for the fuel pumps. I have a single "Engine On/Off" switch, and the Pri/Sec. The engine switch powers both ECU's, the coils, and a single fuel pump. Just like a car. My second fuel pump is in my old "boost pump" location on the throttle, and it is used exactly as we have been trained for generations: takeoff, landing, and "as required". There are many ways to skin this cat and personal choice is going to dictate what we are comfortable with.

rv6ejguy 03-04-2018 10:13 AM

Quote:

Originally Posted by M McGraw (Post 1243530)
I?m actually good with the memory item of ?flip the three yellow switches?. Mostly, I was just interested in explaining the conversation to people less familar with the SDS product.

My RV is set up similarly. All critical backup switches are marked in yellow and my training reflex is to lower the nose and flick these all up if the engine dies at low altitude. I follow this with the fuel selector. If it doesn't come back, I'm looking for the best landing spot.


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