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Rcexl sensor problems

Old 09-25-2015, 04:01 PM
  #26  
w8ye
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Originally Posted by BadAzzMaxx
Timing is set at 28-30 degrees before top dead center, checking as the magnet passes the magnet, If it fires as the magnet goes under the sensor that is one of the sensors causing a problem.

Makes no difference what name is on the ignition, If you look on the ignition box it will say RCexl on it somewhere.


I have about 150 of them that I changed out before I shipped ignitions.

I think RCexl knows about the problem but seems not to concerned about it.


As I posted above I just got a new order and they still have the problem sensors.

Milton
This is the symptom of the problem sensors . . .
Old 09-26-2015, 12:55 PM
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Talked to Jim at RCexl yesterday......I am interested in the CDI for Zenoah G62...but am now having second thoughts due to the sometimes faulty sensors...
Hoping he chimes in here soon ( I sent him a link )...so that we can get some clarification from his side on the issue.......
Old 09-26-2015, 04:37 PM
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CARS II
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Got the Sensor from RC Exreme Power.

Video is done.

Last edited by CARS II; 09-27-2015 at 12:23 PM.
Old 09-27-2015, 12:08 PM
  #29  
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Here is the video of the RC Extreme Power sensor,

The sensor works just fine, easy to install, one very small mod, I clear some material to allow the screw to slide closer to the center of the bracket to get me the 26-28 degrees that I was looking for, the other thing I did was to cut the mounting bracket short for my needs.

Notice the position of the magnet, right where it is suppose to be when we get a spark, the sensor has been positioned or slide to the sweet spot, that spot for this set up is a tad forward from the edge of the prop hub.

Thank you Milton for all your support and suggestions.

https://www.youtube.com/watch?v=H57j...ature=youtu.be

Last edited by CARS II; 09-27-2015 at 12:27 PM.
Old 09-27-2015, 03:53 PM
  #30  
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Thanks Carlos for posting that Video ! Loos like I will be ordering a whole conversion kit from RC Extreme Power tomorrow.
Seems like it all works like it's supposed to and that flexible sweet spot that was mentioned earlier in this thread makes good sense.
I was leaning towards the RCexl system because I had read a lot of good things about them...but faulty intermittent sensor issues I don't need.....
Eric
Old 09-27-2015, 07:22 PM
  #31  
CARS II
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Welcome Eric
Old 09-27-2015, 09:35 PM
  #32  
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Sometimes when we try to explain things, it just doesn't sink in. For example, I have and still have a hard time understanding just how you can determined TDC using a piston stop. I must have a mental block trying to follow the logic to a piston stop.

Maybe I can offer a different way to check timing that may be easier to understand than the usual methods. I have to make an assumption that with a typical sensor the spark will occur just about when the magnet is half way outside the left edge of the sensor (rotation is in a counter clockwise direction). Half the magnet will be seen outside the edge of the sensor and half underneath the sensor.
If you get a spark as the magnet is just starting to go underneath the sensor (right side of sensor) then there may be a defect with the sensor.

Okay. Here is what I do. I always check the timing of my engines before I install them on a plane. With the muffler off you can observe the piston by looking inside the exhaust port as it travels up and down as you slowly turn the engine over by hand. It is easy to see when it gets to the top before starting back down. There is also a slight play right at TDC for a few degrees as the piston stops going up and transitions to going back down. I believe Milton refers to this as TDC rock. If the muffler is on you can get TDC by removing the spark plug and insert something like a popcicle stick or toothpick so that it rides the top of the piston. You simply slowly turn the engine and watch the stick. When it starts to transition from up to down you are a TDC (verified by the TDC rock).

Okay, now you have the engine at TDC. I now put on the degree wheel and a pointer as have been described numerous times elsewhere. I set the pointer to zero degrees on the degree wheel. I have my degree wheel clearly marked at 28 degrees both left and right of the zero mark for easy reference. If you are at top dead center and the degree wheel is set at zero all you have to do is turn the engine clockwise to the 28 degree mark on your degree wheel. That puts the piston at 28 degrees BTDC which is where you want the spark to fire. Now simply look at the relationship between the magnet and the sensor. The magnet should be about half way outside the left edge of the sensor. If it is you are pretty much right at the 28 degree firing point.

Perhaps this is just a somewhat different way to check your timing and see that the spark is occurring at the right moment and may be a bit clearer to understand than some of the other ways that have been presented. I hope this helps.
Old 09-27-2015, 10:43 PM
  #33  
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Mike
I did as you suggested, I inserted a marked dowel through the spark plug hole to ID TDC but found the piston stopper technique more accurate. This been the first time for me timing an engine I wanted to be as accurate as possible, I also confirmed that the piston stopper technique is accurate by checking that the piston was at TDC via the spark plug hole.

From now on this is how I'm going to time all my future gas engines.

Last edited by CARS II; 09-27-2015 at 10:55 PM.
Old 09-28-2015, 02:23 PM
  #34  
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The CH Ignitions sensor arrived at home today, got a picture taken by my son, I won't be home 'till Thursday night, I will try to install and do the video that day.


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Last edited by CARS II; 09-28-2015 at 07:26 PM.
Old 09-29-2015, 08:49 PM
  #35  
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INDIOMIKE, (and everyone):

The "Positive Stop" method eliminates that "rock" at top dead center that you speak of in your post. That rock can be several degrees and if not accounted for can throw your timing setting off enough to make a difference.

The Positive Stop method splits that "rock" precisely in half and when you set up your degree wheel using that method, you can be assured that when the degree wheel indicates zero, you are truly at top dead center. Using other methods, you will more likely than not be off on your settings. This is not some obscure method invented for model engines by some amateur. It is a tried and true method used by engine builders of ALL types of engines, especially race engine builders, all over the world for precise checking and setting of valve timing events, ignition settings, etc., etc.

Further, while your method of just looking at the magnet/sensor positioning may work as a very general, "down and dirty" field check of the timing to see if the timing has slipped, it should never be used to initially set the timing. There are just too many variables with that method, such as magnet strength, magnet to sensor gap, sensor specific characteristics, magnet diameter, etc., etc. to just rely on a visual aspect of the sensor/magnet locational relation to set the timing. You need to know when the spark ACTUALLY occurs, and where TDC REALLY is to properly set the timing. It only takes a few minutes to do it correctly.

The difference between a great running engine that is a pleasure to use, and a "so so" engine or a "dog" is in the details.

AV8TOR

Last edited by av8tor1977; 09-29-2015 at 09:07 PM.
Old 09-30-2015, 06:38 AM
  #36  
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What he said
Old 09-30-2015, 07:37 AM
  #37  
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Thinking back when I was starting my DLE 35RA on a few occasions I got a kickback or backfire, it makes sense now that I know about the bad Rcxel sensor. The fuel mix was been ignited too soon, the engine run good as far as I knew ( remember, I'm still green as far as gas knowledge goes )

I'm anxious to run this engine again to see if the differences are noticeable, this engine is flying my Citabria really nice, it pulls her straight up on a vertical, imagine now with a corrected timing?

Mmmmmmm..........

Last edited by CARS II; 09-30-2015 at 10:29 AM.
Old 10-03-2015, 10:06 AM
  #38  
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This is the vid demonstrating the CH Electronics sensor in action, this is also an excellent replacement choice for the faulty Rcxel sensor.

If you get this one the Rcxel bracket can be modified to house it.


https://www.youtube.com/watch?v=C0cQNtprfUU
Old 10-04-2015, 09:12 PM
  #39  
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Originally Posted by CARS II
Ok
I've been learning about timing, my DLE 35RA has a timing of 46 degrees from factory, I recently checked the timing out of curiosity and found it timed at 46 degrees, on the other hand I turned the shaft the opposite way and it sparked at 26 degrees.

There is no way I can make the timing 28 degrees since the sensor bracket can't be move, I was wandering if the factory timed the engine rotating the shaft the opposite way.

The engine runs good at that timing, the question here is will this engine run better if set at 28 degrees? and should it be re drilled to be able to move the bracket?

Any suggestion or recommendations?

Thank you.
LEAVE IT ALONE,It is OK.Can not be timed at 46 BTDC It would kick the snot out of you if hand starting.
BCCHI
Old 10-04-2015, 09:31 PM
  #40  
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Well, it has at least twice.
We are here now not to just ignore what's going on with, is it 46 degrees or is it 47 degrees, we are here to clarified once and for all what the heck with this different degrees.

We know now for sure that the RcXel sensors are useless and the solution is to replace the sensor with a CH Ignitions or with a RC Extreme Power sensors to get the 28 degrees that we are looking for.

I'm not going to be doing all this work to find once and for all what's going on here so I can be told to just forget it, no señor, nope.

I'm one of those that wants to know how every wheel turns in a clock. I've been running my engines successfully for over thirty years because of my approach.

So, please don't come telling us to just leave a long.

Note.
Everyone is entire of his own opinion and sincerely respect your opinions and thank you for participating on this thread.

Last edited by CARS II; 10-05-2015 at 02:55 PM.
Old 10-04-2015, 11:13 PM
  #41  
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Whoever wrote the DLE manuals for Tower or Hobby Services didn't know what they were doing and turned the crank clockwise instead of counter clockwise.

So they put in all the manuals that the correct timing is 46 degrees on the 35RA instead of 28 degrees

Last edited by w8ye; 10-04-2015 at 11:19 PM.
Old 10-05-2015, 07:15 AM
  #42  
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And they have been informed of this, yet they refuse to correct it. Go figure.
Old 10-05-2015, 05:28 PM
  #43  
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This summary is based on my observation and measurements. Not all ignition module (spark generators) are the same. Most will generator the spark as the senor go pass the magnet, in either direction. The sensor conducts when exposed to a magnetic field. DLE, CRRC, EME, NGH engines using Rcexl modules that create the spark when the senor passes the magnet. PTE36 will spark as soon as the senor is under the magnet. That is at the leading edge. The firing point is dynamic with engine RPM so the firing point means when auto advance is at minimum or above whatever RPM the ignition profile is set to. DLE's are around 3000 RPM while PTE is about 6000 RPM. The real static trigger point is where the magnet is located on the crankshaft. Adjustment slots of sensor will allow only +/- 4 degrees of change. I have seen a senor the would latch. That is it would stay on when pass the magnet and release on the next pass across the magnet. If anyone is interested I have Microsoft xcel file of ignition module profiles. These show the auto advance measurements. My test method ignition timing is using a LED to show the status of the Hall Effect Sensor.
Old 10-05-2015, 06:23 PM
  #44  
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The spark with the RCEXL ignition module is supposed to occur when setting the timing as the magnet starts to leave the Hal Effect sensor and the sensor opens and collapses the field of the coil.
Old 10-05-2015, 07:54 PM
  #45  
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Originally Posted by BadAzzMaxx
Timing is set at 28-30 degrees before top dead center, checking as the magnet passes the magnet, If it fires as the magnet goes under the sensor that is one of the sensors causing a problem.

Makes no difference what name is on the ignition, If you look on the ignition box it will say RCexl on it somewhere.


I have about 150 of them that I changed out before I shipped ignitions.

I think RCexl knows about the problem but seems not to concerned about it.


As I posted above I just got a new order and they still have the problem sensors.

Milton
Hi Milton and all,
I sure do not no what is going on with the RCEXL sensors.Xu Liang is aware of the compliant.He sent me six ignitions and a bunch of sensors. I could not make any of them double fire.I tried all of the new HV rcexl units my old system My new system . Adrians new unit.I tried a bunch of old sensors no double fire.I think xl is useing the Allegro bug same as I have been useing and I think Adrian also.Maybe he is useing a clone with alegro no.I no I am certenly no help.
Sorry. Could you send me one of the sensors that is double firing or a couple of them.Wish you could still get the old Panasonic buggs we used for years.Sensor must be Uni Poler not Bi Poler. My old circuit would double fire if batt voltage got to low,under 4.2 volts.
BCCHI Tired old CH guy.AMA 2500 origenal no. Too tired to spell check.












sorry
Old 10-06-2015, 09:04 AM
  #46  
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Bill
PM me your shipping address.

Milton
Old 10-06-2015, 09:50 AM
  #47  
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Originally Posted by CARS II
Well, it has at least twice.
We are here now not to just ignore what's going on with, is it 46 degrees or is it 47 degrees, we are here to clarified once and for all what the heck with this different degrees.

We know now for sure that the RcXel sensors are useless and the solution is to replace the sensor with a CH Ignitions or with a RC Extreme Power sensors to get the 28 degrees that we are looking for.

I'm not going to be doing all this work to find once and for all what's going on here so I can be told to just forget it, no señor, nope.

I'm one of those that wants to know how every wheel turns in a clock. I've been running my engines successfully for over thirty years because of my approach.

So, please don't come telling us to just leave a long.

Note.
Everyone is entire of his own opinion and sincerely respect your opinions and thank you for participating on this thread.
Cars ll

Please continue to pay close attention to details.

I have been using Rcxel sensors for years. Just like any company today they might have vendor problems. They are not "known to be useless". Known to be useless is a pretty hard phrase.

I have bought hall effect ICs sensors from electronics stores and made my own years ago. But lately I use those being discussed in this thread. The only problems I have had was with a batch of CRRC Pro sensors that the + and signal wires were crossed, lucky me that cost a handful of hair I couldn't afford.

You should know though that bcchi is the founder of C&H Ignitions and has been involved in the development of almost all the ignitions being discussed here.

Unless you have the ability to check the spark @ RPM this method of timing shows you the timing at full advance. Inside the module a calculation of low RPM retards the subsequent sparks until a RPM that changes the calculation is reached. My meaning here is that unless you see the running at 2000 rpm timing at 4 degrees and the 8000 rpm at 46 degrees (see edit note) the timing that you see in a single slow counterclockwise rotation may be misleading. I no longer have an Oscilloscope to check these points.

I believe this thread maybe going on to long for a sticky unless more technical data is added so that no misinformation is presented that might permanently damage one company.

My .02

Last edited by kmeyers; 10-06-2015 at 03:47 PM. Reason: 28-30 degrees is what I would want see. 46 is what has been mentioned in this thread
Old 10-06-2015, 10:31 AM
  #48  
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Bill ask me to send him a couple of the sensors that fired two times, I got 12 out of the storage box and tested them and two out of the 12 would fire two times, So that tells me that not all of them are doing it and they all have the same product numbers on the sensor.
This has been going on for a while, started for me a little over a year ago when a customer notified me he could not time his engine because of it firing two times.

On FG there are a lot of post about it in different threads and showing some with cut fingers because of kick back.

GP engines was the most posted thread about it.

Not trying to damage any company just posted what I have seen.

Right now beside CH RCexl is the only company that makes a good twin ignition.


Milton

Last edited by BadAzzMaxx; 10-06-2015 at 10:56 AM.
Old 10-06-2015, 12:16 PM
  #49  
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I meant only to comment on the tone of some posts and add a small amount of technical information.
I believe the reported problems exist.
Old 10-06-2015, 01:02 PM
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Well, besides the problems with faulty sensors, one thing is for sure. If anyone mistakenly times the engine in the proper counter clockwise direction at the incorrect 46 degrees, they have a problem. The timing will be way too advanced both at starting rpms and at speed. It will definitely try to "bite" you upon starting, and the engine could be seriously damaged during use. Seems like Tower Hobbies has left themselves open to serious liability concerns with those improper instructions. Look at all the confusion just in this one forum and imagine how many people truly have been affected.....

AV8TOR

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