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  #121  
Old 10-12-2017, 11:22 PM
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skylor skylor is offline
 
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Quote:
Originally Posted by Chkaharyer99 View Post
Anyone out there running one Pmag and one SDS CPI EI?

Are these two devices compatible together on one lycoming engine?

If the Pmag failed or misbehaved in flight as described in some posts would it/could it adversely effect the operation of the SDS CPI EI?

Anyone else notice that the CEO of SDS participated in this thread? I did. I appreciate hearing from the MFG of products I'm considering.

Anyone notice the conspicuous absence of representation from Pmag?

Nope, nada, nothing. Just saying.
Charlie,

Did you get the chance to meet the aforementioned CEO at Reno?

Skylor
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  #122  
Old 10-13-2017, 06:34 AM
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rv6ejguy rv6ejguy is offline
 
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Quote:
Originally Posted by SHIPCHIEF View Post
Ross;
In Post #115, you referred to single point reliability. Those failures come in 2 kinds: Instant total failure, and progressive failure.
Although modern electronics have a reputation for reliability, they are also perceived to fail utterly and instantly.
A Kettering (points) ignition is less reliable, but has a reputation for slowly failing, giving fair warning so it can be repaired before dire consequences.
I don't need to heap additional cliche stories, and I have a personal experience where my 1988 Harley electronic ignition module failed softly, I changed it before being stranded.
I would be comforted to know that an electronic flight control would have a progressive failure mode.
I think it's best not to group our electronics in with others like those in old Harleys. Our goal is to NEVER have a failure which could stop the engine and we've got over a half million flight hours showing that's possible. Also, remember the bench test ECU with 145,000 hours on it. Nobody here is ever going to fly an RV even 1/10th of that time, even Vlad. The components of today coupled with good design should yield something with a MTBF many times greater than the Lycoming engine they are controlling.

We'll have some new people coming in to the market which have no previous track record in the field trying to convince you their new whiz bang XXX is the best thing since sliced bread. Only time will tell but usually a perfect controller design does not come on the first iteration. We've seen lots of smart people try and fail. Initial lessons are hard won and only with actual experience doing it. Lab testing is important but the real world is the actual proving ground which defines your success and only time will tell if you did well or not.

As a competing manufacturer, we are in a unique position to hear from people using those other products when they fail and come looking for a solution. We hear the good and bad about customer service going along with the failures or problems. We probably never would have developed the CPI if all the other EIs were really good because we'd never get any market share. I could tell you of a conversation with someone using a competing product who had 5 failures in not too many hours and others who've had multiple failures as well. Those people have lost total confidence in those brands obviously.

Some stuff we see on other brands, we shake our heads at after seeing the failures. They were very predictable, at least from our experience.

We've heard of several high end (expensive) ECUs fail almost regularly in the heat and pounding of the BAJA/ SCORE off road races where SDS just keeps running year after year. One of our clients has over a dozen class wins with the same old SDS ECU. Several competitors running the other brands finally switched over to us and have had no more failures. We were very happy to have one of our clients win the SCCA GT3 championship for the 4th time last month. The auto market gives us a chance to test reliability that doesn't present itself in the aviation environment but there have been spinoffs both ways to improve the products overall.

Our reputation for reliability did not come overnight and it did not come without some hard lessons in the earlier days but I'm proud of what our small team has accomplished over 23 years. Hard work but very satisfying. I enjoy going to work every day. We're working to innovate, design new parts to make installation easier on a wider variety of engines, bring customer requested features and ideas into our products and improve them across the board. I've started on a series of videos to help people with installation and use of SDS products-sorry they took so long. I'd like to thank many of our loyal customers who've directly helped us to improve, test and uncover problems during development. We can't think of all these good ideas ourselves!
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Turbo Subaru EJ22, Marcotte M-300, IVO, RV6A C-GVZX flying from CYBW- 415.8 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi.htm



Last edited by rv6ejguy : 10-13-2017 at 08:54 AM.
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  #123  
Old 10-13-2017, 06:43 AM
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Toobuilder Toobuilder is offline
 
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Quote:
Originally Posted by SHIPCHIEF View Post
...I would be comforted to know that an electronic flight control would have a progressive failure mode.
Edit - Ross beat me to the punch again...

Anyway, I'll just add that as long as the failure mode is benign to the ship (no fire, explosion, leaking, etc), then the demonstrated SDS product reliability well exceeds accepted range for aircraft use. Also keep in mind that electronics usually fail on power up, not in use. If I do a runup some day and find a coil has "suddenly" died since the last flight - might be inconvenient, but it's safe. One notable exception to this is P-mag, of all things. The history of "lost timing events" often happened in flight.

Besides, I think that's better than having dying magneto right on the edge and tempting me to make "one more flight"
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WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.

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Last edited by Toobuilder : 10-13-2017 at 08:22 AM.
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  #124  
Old 10-13-2017, 07:25 AM
Chkaharyer99 Chkaharyer99 is offline
 
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Quote:
Originally Posted by skylor View Post
Charlie,

Did you get the chance to meet the aforementioned CEO at Reno?

Skylor
I tried but the SDS CEO was in high demand and the line was long. Didn't want to be pushy. Besides, he was multi tasking what with all that floor sweeping and such.

I did speak with other SDS users and many who are considering SDS. Got many questions answered.

It was great watching you race at Reno. You had quite the cheering section and it was good meeting your very dedicated support team.

Are you considering EI? I think I remember you're running mags. Is that correct?
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  #125  
Old 10-13-2017, 08:33 AM
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Returning to P-mag reliability....



Quote:
Originally Posted by N941WR View Post
I can't answer with certainty because I didn't design the P-mag but I believe you are correct that it is a backup ground. It is really needed for communication through the serial port.
(discussing Pin 1 ground) So what doesn't work if it is not connected...or connected somewhere other than a case bolt? You've been very specific in the past:

http://www.vansairforce.com/communit...6&postcount=10

http://www.vansairforce.com/communit...37&postcount=8

http://www.vansairforce.com/communit...38&postcount=3

http://www.vansairforce.com/communit...45&postcount=4

Quote:
Since 2 and 3 are a serial port, I don't believe it would impact anything in flight. We have shorted them when developing the EICommander with no impact to out test P-mags.
Jumper in = ignore B
Jumper out = use B info.
EIC connected to jumper terminals = use signals from EIC to modify B info, in flight or on the ground.

Recall the mystery below? Since both the EIC and the P-mags were found to be A-OK, the conclusion was it had to be something about Nigel's serial wiring...

Originally Posted by nigelspeedy
Approximately 1 in 20 times I have experienced a fault after sending a new ignition setting. I cant say where the root cause of the problem lies but the symptoms are as follows. After you press the send button the engine begins to run very roughly and lose power. Like a very LOP mag check. Unlike the brief firing suspension that is normal this roughness does not go away. On the EICommander one of the PMags will constantly display the correct new timing value you have just sent (this is normal). The other PMag display will vary between the new value and 19.6 deg about every 5 seconds (this is not normal). The CHT will rise at a rate of about 20F per minute and the engine oil temperature will do the same. I have found two ways of fixing this fault. First, you can reload a new ignition setting, (just repeating the one you just sent has worked for me) but this takes a few button pushes and about 30 seconds all the while you will be distracted by your engine which feels like it is under great duress. Second, you can take the P Lead for the misbehaving ignition and turn it off then back on. This is quicker but be very careful to properly identify the correct ignition. I normally associate top with 1 or left and bottom with 2 or right. On the EICommander display the upper timing advance number is associated with the right ignition. It is labeled as such but the display is quite small and you could easily make a mistake in haste. Although the faulty ignition 'display' is alternating between the correct value and 19.6 deg I don't think this is when the ignition is actually firing as the level of roughness and CHT rise are counter to this. After seeing this fault I checked the PMag timing and they were both at TDC so I don't think timing was lost, as the odds of it being subsequently found perfectly are pretty low. I also sent the PMags back for an overhaul and they were both within spec. They have always run the latest firmware version. I have seen the error on both the left and right ignition, not simultaneously though. My EICommander was also returned and it had one of the comm boards replaced but I have seen this fault a couple of times since. I have never experienced this fault except immediately after sending a change. I never had this fault with just the PMags before I installed the EICommander. I have never used the PMag proprietary software to make changes to the settings.

Quote:
An internal sort to ground would probably kill the generator; however, it would continue to fire, if ship's power is available.
(discussing a short to ground on the Pin 5 wire) Ship's power would not be available; it's a grounded power lead. Right after it grounded, the breaker opened. So, the system is on internal generator power, with the external power lead shorted to ground. Does it provide a path to ground for the internal generator?

Bill, I know these are hard questions, but one can't claim superiority based on immunity to external wire faults without clearly defining exactly what happens given wire faults in the competing system.
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  #126  
Old 10-13-2017, 08:55 AM
rv8ch rv8ch is online now
 
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Default fault testing

Quote:
Originally Posted by DanH View Post
Returning to P-mag reliability....

...

Bill, I know these are hard questions, but one can't claim superiority based on immunity to external wire faults without clearly defining exactly what happens given wire faults in the competing system.
Seems like some bench testing would not take too much time and effort. I'd do it on one of mine but I'm in "get 'er done" mode, and I don't want to fry one of my p-mags. Anyone have any pull with the emagair guys?
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  #127  
Old 10-13-2017, 11:21 AM
ALagonia ALagonia is offline
 
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I am new to Experimentals. Have many hours flying behind regular magnetos. I have read this complete thread and others and still cannot find an explanation of what P-Mags are, how they work and what the advantages/disadvantages are. Or at least I cannot decipher this information. Can someone please explain in layman terms how P-mags differ from a regular Bendix mag, how they work and what the advantages/disadvantages are? I would just like to have an understanding of P-Mags. I am talking to a gentleman that has an airplane I have an interest in with dual P-Mags on an IO360 Superior Engine with Cold Air Induction.
Thank you
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  #128  
Old 10-13-2017, 12:04 PM
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Quote:
Originally Posted by ALagonia View Post
I am new to Experimentals. Have many hours flying behind regular magnetos. I have read this complete thread and others and still cannot find an explanation of what P-Mags are, how they work and what the advantages/disadvantages are. Or at least I cannot decipher this information. Can someone please explain in layman terms how P-mags differ from a regular Bendix mag, how they work and what the advantages/disadvantages are? I would just like to have an understanding of P-Mags. I am talking to a gentleman that has an airplane I have an interest in with dual P-Mags on an IO360 Superior Engine with Cold Air Induction.
Thank you
http://www.emagair.com/
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  #129  
Old 10-13-2017, 12:52 PM
krw5927 krw5927 is offline
 
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Quote:
Originally Posted by DanH View Post
Returning to P-mag reliability....

(discussing Pin 1 ground) So what doesn't work if it is not connected...or connected somewhere other than a case bolt? You've been very specific in the past:

http://www.vansairforce.com/communit...6&postcount=10

http://www.vansairforce.com/communit...37&postcount=8

http://www.vansairforce.com/communit...38&postcount=3

http://www.vansairforce.com/communit...45&postcount=4
The current Pmag manual (v LC114.28) has this to say regarding the pin 1 ground wire:

"Note: You cannot rely on the ignition’s mechanical attachment to the engine to provide ground. Aluminum anodizing acts as an electrical insulator, so the clamp connection to the anodized flange will not be a reliable ground."

Additionally, the Troubleshooting Tips version 04 on the website indicates "not having a proper ground connection" to be one of the most frequent installation errors.

This language seems to indicate the ground wire is pretty darned important.
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  #130  
Old 10-13-2017, 07:43 PM
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N941WR N941WR is offline
 
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Quote:
Originally Posted by DanH View Post
Returning to P-mag reliability....





(discussing Pin 1 ground) So what doesn't work if it is not connected...or connected somewhere other than a case bolt? You've been very specific in the past:

http://www.vansairforce.com/communit...6&postcount=10

http://www.vansairforce.com/communit...37&postcount=8

http://www.vansairforce.com/communit...38&postcount=3

http://www.vansairforce.com/communit...45&postcount=4



Jumper in = ignore B
Jumper out = use B info.
EIC connected to jumper terminals = use signals from EIC to modify B info, in flight or on the ground.

Recall the mystery below? Since both the EIC and the P-mags were found to be A-OK, the conclusion was it had to be something about Nigel's serial wiring...

Originally Posted by nigelspeedy
Approximately 1 in 20 times I have experienced a fault after sending a new ignition setting. I cant say where the root cause of the problem lies but the symptoms are as follows. After you press the send button the engine begins to run very roughly and lose power. Like a very LOP mag check. Unlike the brief firing suspension that is normal this roughness does not go away. On the EICommander one of the PMags will constantly display the correct new timing value you have just sent (this is normal). The other PMag display will vary between the new value and 19.6 deg about every 5 seconds (this is not normal). The CHT will rise at a rate of about 20F per minute and the engine oil temperature will do the same. I have found two ways of fixing this fault. First, you can reload a new ignition setting, (just repeating the one you just sent has worked for me) but this takes a few button pushes and about 30 seconds all the while you will be distracted by your engine which feels like it is under great duress. Second, you can take the P Lead for the misbehaving ignition and turn it off then back on. This is quicker but be very careful to properly identify the correct ignition. I normally associate top with 1 or left and bottom with 2 or right. On the EICommander display the upper timing advance number is associated with the right ignition. It is labeled as such but the display is quite small and you could easily make a mistake in haste. Although the faulty ignition 'display' is alternating between the correct value and 19.6 deg I don't think this is when the ignition is actually firing as the level of roughness and CHT rise are counter to this. After seeing this fault I checked the PMag timing and they were both at TDC so I don't think timing was lost, as the odds of it being subsequently found perfectly are pretty low. I also sent the PMags back for an overhaul and they were both within spec. They have always run the latest firmware version. I have seen the error on both the left and right ignition, not simultaneously though. My EICommander was also returned and it had one of the comm boards replaced but I have seen this fault a couple of times since. I have never experienced this fault except immediately after sending a change. I never had this fault with just the PMags before I installed the EICommander. I have never used the PMag proprietary software to make changes to the settings.
We spoke with Nigel after he experienced this and struggled to reproduce it in our lab. In fact, we couldn't reproduce it at all. This was the first time we had been informed of such an issue.

Not many people ever change their timing in flight, for good reason. While the p-mag did not lose its TDC mark, it appears the shift angle (where it should fire in relation to TDC) was not accepted by the P-mag.

Based on what he experienced, we do not recommend changing the timing in flight. If someone insists on doing it, there are two different ways. One is the On the Fly option, which issues the timing command to the P-mags and is less disruptive to the firing sequence, or do it on the ground when the engine is not running.

We were not aware what Nigel was testing or we would have suggested he use the On the Fly option. This option does change the timing but does not try to write to permeant memory. The idea being that once a pilot finds a setting they like, they can land, and save it permanently.

This really doesn't have anything to do with the P-mag but does have everything to do with how the EIC communicates with them.

The display Nigel mentions is just that, a display. It displays whatever firing angle the P-mag reports to it.

(One other thing, the reason there are so many button presses to send a new timing configuration to the P-mags is so that someone doesn't send them a configuration by accident. That was by design, not a bad programming choice.)


Quote:
Originally Posted by DanH View Post
(discussing a short to ground on the Pin 5 wire) Ship's power would not be available; it's a grounded power lead. Right after it grounded, the breaker opened. So, the system is on internal generator power, with the external power lead shorted to ground. Does it provide a path to ground for the internal generator?

Bill, I know these are hard questions, but one can't claim superiority based on immunity to external wire faults without clearly defining exactly what happens given wire faults in the competing system.
Next time you are at SnF or OSH, stop by the Emag display. Their 114 P-mag is wired to four sparkplugs and no ground wire connects the plugs to the P-mag.

When I asked Brad about this, he said they use the second plug as the primary return path. Remember they fire two plugs at the same time (wasted spark), that was a convenient way to always have an adequate electrical return path. So, they have three return paths; the P-mag body, the ground wire, and the other sparkplug.

One other design feature of the P-mag is that once they are spinning and producing power, there is no way to shut them down. All the P-lead does is stop the plugs from firing but the internal electronics are still alive.

Remember, I am not the manufacture of the P-mag ignitions, nor are our companies connected. Everything I have written on this thread and others is based on what we have learned while working with the ignitions over the past 10 years. For answers as to why they are designed and function the way they do, you really need to go to Emag.
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Last edited by N941WR : 10-13-2017 at 07:45 PM.
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