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  #191  
Old 04-04-2018, 11:38 PM
SHIPCHIEF SHIPCHIEF is offline
 
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Thanks Dan;
I took the file Graham sent me to a local waterjet shop, but the proprietor backed out on the old 'Liability' excuse when he asked me what it was for...I just couldn't lie.
Also, he suggested that .015" was his tolerance limit, so I'll try a few other local shops for better when I get a few days off. I think this guy is more into art than mechanics.
My work/airplane mentor just got the EDIS bug, so I brought my demonstrator rig to his hangar and we put it on his lathe. I love how the pickup can be about 1/4" away from the trigger wheel before spark is lost. I made sure the trigger wheel was running crooked too.
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EAA 668340, chapter 326 & IAC chapter 67
RV-8 N89SE first flight 12/26/2013
Yak55M, and the wife has an RV-4
There is nothing-absolute nothing-half so much worth doing as simply messing around with Aeroplanes
(with apologies to Ratty)
2019
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  #192  
Old 04-15-2018, 07:01 PM
slngsht slngsht is offline
 
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Location: Purcellville, VA
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Is there a page with images on how the pickup wheel is mounted to the flywheel? Images on early pages in this thread are no longer available.
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  #193  
Old 04-19-2018, 09:21 AM
SHIPCHIEF SHIPCHIEF is offline
 
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I received the Megajolt/E controller yesterday. It is the new (just released!) Mark II version, and has been upgraded including a USB mini port for programming and a new smaller case.
This morning, I'm reading the instructions, and particularly the programming portion:
https://wiki.autosportlabs.com/MJLJ_V4_Operation_Guide
I'm wondering if anyone using the Megajolt control would like to share their programming or comment on programming preferences?
Right off the top, it looks like the ten RPM bins could be divided across 4000 RPM instead of 10,000RPM.
The Rev limiter is an option not available with magnetos....and the ignition advance could be programmed to retard at an excessive RPM as well.
Cockpit control of advance (could be used for leaning) is available via an auxiliary input, or could be automatic based on a thermistor (oil or cylinder temp?)
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Scott Emery
http://gallery.eaa326.org/v/members/semery/
EAA 668340, chapter 326 & IAC chapter 67
RV-8 N89SE first flight 12/26/2013
Yak55M, and the wife has an RV-4
There is nothing-absolute nothing-half so much worth doing as simply messing around with Aeroplanes
(with apologies to Ratty)
2019
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  #194  
Old 04-19-2018, 04:04 PM
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DanH DanH is offline
 
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Quote:
Originally Posted by SHIPCHIEF View Post
Right off the top, it looks like the ten RPM bins could be divided across 4000 RPM instead of 10,000RPM.
Try:

1000
1500
2000
2100
2200
2300
2400
2500
2600
2700

It extrapolates between bins, so the big jumps down low don't matter.

Quote:
The Rev limiter is an option not available with magnetos....and the ignition advance could be programmed to retard at an excessive RPM as well.
Cockpit control of advance (could be used for leaning) is available via an auxiliary input, or could be automatic based on a thermistor (oil or cylinder temp?)
I'm switching to get the hard rev limiter, one box now and one later (the conservative approach with new hardware).

The dual map function is a single wire, ground to activate, so two brains can be tied to the same cockpit switch without risk. It's a single flip to change from a ROP map to a LOP map.

I suppose it could be rigged to un-ground based on temperature or something, but KIS has a lot of merit. Since we can map 100 points (RPM x MP), there is no virtue in a hardware based return to the ROP map just for high manifold pressure. Enter retarded timing values for the high manifold pressure area of the LOP map. That way, if you go to full throttle with the LOP map engaged, who cares? We don't use that part of the map up high in lean cruise anyway.

It is possible to enter a timing offset based on an external input, via pin 9.
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  #195  
Old 06-12-2018, 10:38 AM
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DanH DanH is offline
 
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Previously I wrote...

Quote:
The dual map function is a single wire, ground to activate, so two brains can be tied to the same cockpit switch without risk. It's a single flip to change from a ROP map to a LOP map.
...which is true enough, when both ignitions are powered. What I didn't realize was that with one ignition OFF, it apparently becomes a path to ground for the other ignition, even with the map select switch open. Flip one to OFF, and the other changes to map 2.

The way my maps are configured (all high power settings are low advance), it doesn't seem to make any difference. However, it could with a different map. So, going forward I'd suggest wiring the map select grounds through separate switches, or through a DPST rather than ganging them on a SPST.
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  #196  
Old 06-29-2019, 08:37 PM
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rjcthree rjcthree is offline
 
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Default Current EDIS4

Iím building a bench mock-up of a megajolt/EDIS4 ignition system to get to know it before laying out more concrete plans to put it in an airplane. What current should I plan for for the ignition when running? Iím setting up for 20A on three separate feeds, but I canít sustain it indefinitely on my power supply Thanks.
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RV-9A N183RC/90432: tip-up, O320H2, Ellison, Dynon D180
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  #197  
Old 06-29-2019, 09:07 PM
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DanH DanH is offline
 
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Quote:
Originally Posted by rjcthree View Post
What current should I plan for for the ignition when running?
Current Draw, EDIS plus Megajolt:

Engine not running 90ma

1200 RPM 0.52 amp

1800 RPM 0.80 amp

2700 RPM 1.08 amp
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  #198  
Old 06-30-2019, 07:05 PM
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rjcthree rjcthree is offline
 
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Default Thanks....

Thanks Dan, I might have asked the wrong question. In the same scenario, what is the current draw of the coil?
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RV-8 83718, wing kit in work with a four year plan
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  #199  
Old 06-30-2019, 09:35 PM
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DanH DanH is offline
 
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Quote:
Originally Posted by rjcthree View Post
Thanks Dan, I might have asked the wrong question. In the same scenario, what is the current draw of the coil?
As I recall, the above includes the coil.
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  #200  
Old 08-08-2019, 04:55 PM
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rjcthree rjcthree is offline
 
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Default Current

Dan, do you recall how you measure current? Did you use a scope and picked up the individual coil dwells or some other fast instrument that would give an average value? I ask because I may be on the opposite side, where my admitadly Amazon shunt based ammeters I have in my bench setup are showing much higher current flow. At about 1000 rpm, Iím recording ~2A, 2400 rpm is ~4.5A., itís linear with rpm, which makes sense. Iím guessing my setup is showing peak current snapshots. Running at 2700rpm, neither the coil nor EDIS have more than 35F temperature rise over ambient in still air, so it seems efficient.

Overall, the Megajolt/EDIS/coil setup runs really well. There are some quirks to the Megajolt software, but the system is simple to execute.

I have a vac pump and the tone ring/timing wheel on variable speed drives, an old school timing light to verify reported advance. I can isolate the Megajolt, dropping the EDIS in to backup, and have the two map switch installed. Iím going to work with it some more, but I think itís going in the airplane. The tone wheel may be tricky. I also need to decide what to do about the D3000.
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