Joystick TX

I repeated the testing on my one of my Syssa A01 and one of the DLE A02 modules and I stand by my results on the chart I posted.

My test setup is simple, RCEXL tester to simulate the pulse from the hall sensor at various RPMs, a frequency counter connected to the ignition module, spark plug, Tektronix 60MHz O'Scope, and a digital power supply. The results from the freq counter and O'Scope are entered into an EXCEL spreadsheet to calculate the data for the RPM and degrees BTDC chart.

There is a 26 degree jump in timing, (from +19 to -7 degrees BTDC), with only a 30 RPM difference, (between 1480 and 1510 RPM). That could cause erratic operation at that range, it may or may not be noticed, depending on the weight, diameter, and pitch of the propeller used. If a large high pitch prop is used the advanced timing may cause the engine to die at the lower RPMs.

That jump is reflected on the chart that I posted. All of the modules I've tested behave in a similar manner. I have not had any issues with the four engines I'm currently using.

I haven't tested my newest A02 module, it's too hard to get out of my plane, but I have tested at least 10 of them in about three years and they all have that jump. It does not seem to cause a problem with the DLE 35, nor the DLE 20. If the ignition timing was firing after TDC on a big engine like in a car you would be able to hear it and it would be causing damage.

Truckracer

My Feedback: (19)

I completely respect your results as you performed the test but have some questions? Do the individual pulses from the Rcexl tester vary in width with RPM change like they would from a sensor mounted on an engine? Are the the pulses spaced the same as they would be from an engine at the various RPM settings.The spacing would change in direct relation to RPM. Also, is there any way you could recreate the test using a real sensor, magnet and hub on an engine crankcase / crankshaft? Simulation is great but the test is only as accurate as the inputs.

Joystick TX

I haven't done extensive measurement on the tester pulses. Never saw a need. The critical timing is that the pulse be wide enough to apply power to allow the ignition module capacitor to charge and have a sharp drop to trigger the module.

I have also done the tests with my total ignition "system tester" which has an electric motor turning a hub with two magnets on it to check sensors with both polarity, that feeds the ignition module just like it would on the engine. It's on a plate to also do vibration testing, as well as environmental. Same results.

I posted a picture of my module tester on the 'Rcexl sensor problems' thread and it didn't get rejected so we may move all this over there. So far, there is nothing new to report that isn't already on there.

Truckracer

My Feedback: (19)

The system tester would certainly simulate a real engine. I'm just surprised I never detected that extreme retard condition you exhibit so consistently. And that I have never sensed a condition like that when using the engines in flight. OH well ..... all good stuff. I really haven't read of many problems with the RCexl stuff over the last several years .... other than supply voltage issues. Occasionally someone reports of a kickback problem with on older engine that is easily fixed with a new sensor. Pretty quiet otherwise. But .... our hobby is pretty quiet in general these days.

cathurga

Quiet the hobby may well be, but this information is waay to interesting and relevant to many of us, and I for one appreciate all the feedback, as well as all your efforts in figuring this out so that the rest of us may learn.

Since Joystick has transferred some of the information over to this thread: Rcexl sensor problems it might be best we continue the discussion there. Hopefully we havent angered the OP too much with the off-topic, but hopefully others can move over there if there are any relevant needs.

...and Joystick...keep fighting brother....and fight hard o7

Joystick TX

I checked the testing files on my old computer to see what the SN's and dates of the modules were and the first module I tested was in 2012, the latest one was 2016, so they have not changed that funny curve during that time frame.

All of my engines run great in the air and dead sticks are almost a thing of the past with the DLE-35. I'm using a 19-8 prop, so I stay out of the RPM where the timing jumps.

I had a lot of dead sticks with the Syssa engines until I figured out how to get them tuned right.

One thing I did learn - DLE does NOT set, or ever check, the timing on their engines at the factory and neither did Tower when they made repairs. They told me they just center the sensor between the screws. It they get a spark, it passes. I don't think they even know how to set it which may be why the manual still says 46 degrees. As you and I've found out, the sensors are not all created equal and can cause quite a bit of problems. Most of them seem to have been solved lately.

I've found that the DLE engine timing is usually set four or five degrees too far in advance on the new engines,.