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Black
| | Posted on Monday, November 08, 2010 - 06:27 am: | 
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Thanks Jules and +1 Zack,
This thread begins to look like a meeting of the Flat Earth Society. An earlier post by Bad_boy plus the post by Anonymous simply end any argument in my book. Bad_boy's post also pointed out that there appear to be a significant number of stators that have been replaced for no reason, other than perhaps a battery light caused by running the bikes below the required RPM for the alternator to actually charge the system. I said many months ago that without stators to examine, we might as well be discussing poetry. Well, it appears that the evidence is in. |
Boogiman1981
| | Posted on Monday, November 08, 2010 - 06:34 am: |
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i do wonder if there is a way besides oil to connect the stator in a more thermal friendly way to the case? i think in the pics i have seen there is a gap between the iron core and the case itself. perhaps i am mis-remembering but if i am correct then maybe a thermal 'bridge' that is better than the small flow of oil that's there would be the solution? |
Dannybuell
| | Posted on Monday, November 08, 2010 - 10:29 am: |
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Easttroy - your arguments are becoming more interesting than ever!
I am no math major. Please correct me where I am wrong.
Watts 08/09 -> 440/540 = 0.814814815
BTU's 08/09 -> 1501.72/1843.02 = 0.81443299
looks like a 19% difference to me.
When you introduce the engine heat as a variable these percentages drop to almost nothing.
The fire hose floating ground analogy you made in a previous post was fantastic, you completely made your point.
There was mention by Erik Buell Racing from inside HD that many of the stators being replaced were not faulty..
http://www.badweatherbikers.com/buell/messages/290 431/601431.html?1288005217
That seems to indirectly support your argument.
I have had my Erik Buell Racing ECM in for a few days now and it too seems to be responding better with higher voltages and less battery lights. |
Easttroy
| | Posted on Monday, November 08, 2010 - 11:57 am: |
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Jules,
You also need to start taking things into context. Pixie dust is so far out of context in this argument, I can't believe you didn't use fairy dust.
The thing you must remember is that the entire system impacts everything in it. Just because you are concerned about the stator doesn't mean that the heat that the engine produces doesn't impact it.
If there really was a heat issue, you have to consider all the heat in the system, not just what the stator does.
(Message edited by easttroy on November 08, 2010) |
Easttroy
| | Posted on Monday, November 08, 2010 - 12:00 pm: |
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The reason I didn't state that the difference was 19 or 20% is that compared to the entire system, it's not. You are directly comparing the output of the stators, my point is that even if the stator is 20% higher output, it's still sub 1.5% of the entire system. Look at the bigger picture.
Again, I'm trying to get people to see more than just the stator, whether or not it's at fault and directly causing the issue. There's more to this puzzle than a simple stator suspended in mid-air like Jules wants to believe (because such things do occur in his world obviously). It just doesn't happen.
You can't look at things individually and say with exact measure that it's the only piece causing the issue when the system contains multiple variables. |
Dannybuell
| | Posted on Monday, November 08, 2010 - 12:09 pm: |
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Easttroy - I like the way you think. :-) |
Reepicheep
| | Posted on Monday, November 08, 2010 - 12:46 pm: |
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quote:"I am only trying to think outside the restrictive boxes that most others have placed on themselves via anonymous people (and other conventional wisdom)."
Nothing personal... out of the box is fine, but wrong is still wrong.
Start here. You have a stator developing 100 amps from a coil with .4 ohms resistance (no matter where the current goes). How many watts are you dissipating in the stator coils? Hint: Power equals I*I times R.
The way a series regulator could reduce stator heat is because it could open the leg of the circuit so no current flows. Voltage doesn't create heat... voltage times current creates heat, or current (times current) times resistance causes heat. Voltage could cause arcing which could damage things, but the 65 or so volts these stators make isn't hard to insulate.
And with your heat calcuations, you are doing it wrong. What has to fail in order for a stator to stop working? We don't need to melt the thing into a pool of copper before it stops working, we just need to create a single short or open in the windings. So all that is necessary is for a very thin layer of insulation to exceed some thermal capability and start some sort of failure death spiral, and that's all she wrote.
And if you don't think a circulating oil bath can make a big difference there, pull the heat sink off your modern desktop computer CPU and boot the machine up and see how long it lasts before it lets the magic smoke out. With the heat sink in place, it will last about 20 to 50 years. Without the heat sink in place, you will be lucky to count to 100.
(Message edited by reepicheep on November 08, 2010) |
Jules
| | Posted on Monday, November 08, 2010 - 03:22 pm: |
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There's more to this puzzle than a simple stator suspended in mid-air like Jules wants to believe (because such things do occur in his world obviously). It just doesn't happen.
LOL - it's not suspended in mid-air, it's emersed in an oil bath.. I understand your point, it is quite well made.. It's still wrong, but it is eloquent (IMHO) |
Renzo750
| | Posted on Monday, November 08, 2010 - 10:13 pm: |
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FWIW _ My 1125CR story:
Bike new Oct '09 (build date 09-08 #664)
Harness upgrade was done in spring 2010 @ 412 miles...HD steps up and gives me a Cali can update about 1200 miles and rear signal is replaced (all warranty)
No issues for first 2100 miles never saw a BATT light or any other warning light flash. Lots of long hot rides, cold rides, short rides in town, open road blasting.
Cool late October day ...I see BATT light flash a few times and then after a gas stop…after a long freeway run, I see Low Volts flash at start-up - See Eng light + BATT light - ride a few miles and rev it...volts rise to 13.8 or so, but drop under 12 at a stop sign...I turn and head home with a ride of about 50 miles...
Read Badweather forum...battery load tested
Add Ground Wire from VR to Batt...go for ride - things seem better right away, I do see a very brief flash of BATT light after slow ride and a stop. Volts right back up to 14 on HWY. A 30 mile ride has me hopeful. I test charge rate at idle – 14.3...perhaps battery was a tad low when I left home...was not on a tender.
This weekend I rode over 250 miles, most on HWY/two lanners playing "Isle of Man” really fun to power lift at a ton  After about 100 miles I purposely put in a long slow town ride, putted, idled...did not see a BATT light all day. I did not watch the volts constantly, but on spot checks was always over 13..and typically at 13.8 to 14.1
I am satisfied that the VR has a floating voltage problem (vibration compromised paste ground) and the added ground has fixed this issue. I did not “push” the issue when I first saw the light, perhaps saving the component..after all, if you can read 14.3 volts at idle the stator works great - I am of the opinion that the “regulator” was not regulating properly...I'm convinced, based on my experiences of many years working on Euro bikes that the ground wire has fixed it
Cheers
Jim |
Easttroy
| | Posted on Tuesday, November 09, 2010 - 02:35 am: |
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Reepicheap,
Nothing in what I stated indicates that I'm waiting for the thing to melt into a pool of copper.
Too many people are assuming that all the damage comes from the stator it's self. My point is that there are too many variables in the equation to dictate that there is one source of failure.
And since we are stating what is wrong in our posts:
Power is the rate at which work is performed, which can be both electrical or mechanical. A BTU is the amount of energy needed to heat 1 pound (0.454 kg) of water 1 °F.
In a lossy system (and all our current systems are lossy), heat != power. |
Dannybuell
| | Posted on Tuesday, November 09, 2010 - 09:48 am: |
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Easttroy - lossy system?
http://www.bretl.com/mpeghtml/exam1d.HTM
I'm lost, could you back up to layman's terms? |
Easttroy
| | Posted on Wednesday, November 10, 2010 - 12:28 am: |
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lossy is loosely related to the loss of heat in this case. A non-lossy system retains all it's heat without loss to another system (read: Heat Transfer)
For example, start with a temperature of 370K in water and transfer the heat via air (steam) to a steel plate with a temperature of 270K. In the process of heating the steel plate, there is a loss of heat to the surrounding air that can't be reclaimed or absorbed by the steel plate.
The water will decrease in temperature to 300K while the steel plate increases in temperature to 280K. The heat lost in the process of heating the steel plate is heat loss to the air (60K). Hence forth, it's lossy. (K is kelvin)
A non-lossy system for the example above would be that the loss of heat from the water is directly changed to a temperature rise in the steel. In other words, 1K loss in water temperature would result in a 1K gain for the steel.
Such system are not possible in our world as there is always some loss in an unexpected way. |
Alteng
| | Posted on Wednesday, November 10, 2010 - 12:47 am: |
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If you've seen one of the failed stators, it becomes readily apparent that this is a heat issue - not an overvoltage condition. Plus, agreeing with reepi above, the voltage in these things shouldn't get high enough to arc through magnet wire insulation.
A primer on how these things work:
The permanent magnets spinning around the stator are the source in the magnetic circuit (like a voltage source in an electrical circuit). In this circuit, magnetic flux is equivalent to current. Concisely, this constant movement of flux around fixed coils of wire (in the stator) generates voltage (a physical phenomena detailed by James Clerk Maxwell and described by his namesake equations).
Thus, AC voltage is generated (note that DC voltage does not come as a raw output of a permanent magnet alternator). Now, this voltage powers/drives whatever loads you have on the other end of the system - in this case, the load would be your voltage regulator. Regardless of a grounding issue, the 08 and 09 stators are seeing the same load - one fails, the other does not.
Losses (read heat) in a stator include (but may not be limited to):
1. I2R loss (zac, nice work on catching that resistance increases with temp...though I may debate the validity of your first effect)
2. Eddy current loss. This is in the steel core that the copper is wound around. The phenomena described by Maxwell's equations don't really care if they're inducing voltage in copper or steel - hence you get little short circuits popping up all over the place. Using laminated steel decreases the area of the "steel coil" to keep this loss to a minimum. Why not just use a polymer frame to hold the copper coils? Simplifying a little, ferrous metals (read iron) are relatively unique in that they provide a 'low resistance' path for magnetic flux (again read current). But, ferrous metals also exhibit:
3. Hysteresis loss. This one is a little more complicated than I'd like to get into right now, but know that it involves iron and the fact that flux is changing direction in the steel.
4. Stray loss. These are losses that vary from system to system.
In my experience, I2R loss (also described by reepi above) is the primary culprit in heat related failures. The magnet wire insulation is only rated for a certain temperature and can breakdown beyond that.
I will agree with Easttroy on one point: the system that the stator lives in does make a difference...unfortunately for his arguement though, the engine and VR are for all intents and purposes the same '08 to '09. Thus, the culprit is either a stator self heating issue (exacerbated by low oil flow per anony) or that the '09 stators have a lower operational temperature.
Ultimately, these things keep failing due to self heating and likely would be fine with better oil flow. If I had the two systems side by side, I would check out the wire gauge used in each, the number of turns on each coil, the subjective amount of coating on each (tends to be a great thermal insulator), and even the permanent magnet strength. These might give clues into the differences in design and why 09 fails but 08 does not.
Recommended fix: replace the stator with a better wound version
Alternate fix: no guarantees as to how well you'll stay charged with this one, but changing out the permanent magnets with slightly weaker ones might help...just be sure to alternate North/ South (assuming that's what's on there now)
Source: I used to make motorcycles for a living; now I work with Maxwell's equations. |
Naiguy
| | Posted on Wednesday, November 10, 2010 - 01:41 am: |
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Heat burns up stator
fix turns off stator partially to reduce heat
relay in update harness does?
Vr see voltage from stator sends it to?
if relay goes bad?
over voltage from floating ground?
where is it floating from?
why is it floating?
why is the charging system failing
(Message edited by naiguy on November 10, 2010) |
Dktechguy112
| | Posted on Wednesday, November 10, 2010 - 10:33 am: |
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"Regardless of a grounding issue, the 08 and 09 stators are seeing the same load - one fails, the other does not. "
Why do you say this? the 09 stator is higher output, around 520W, and the 08 stator is 4xxW. |
Boogiman1981
| | Posted on Wednesday, November 10, 2010 - 11:59 am: |
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because the draw on the 2 bikes is the same the later bikes 'should' be giving their owners more headroom for additional farkles etc |
Devil_car
| | Posted on Wednesday, November 10, 2010 - 01:53 pm: |
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I'm not an 1125 owner, but I was going to buy one until I started seeing the threads regarding electrical system issues... knowing how poor the service I have gotten from HD has been over the years, I won't buy one until a known fix exists. A fix that I have to do on my own is ok by me...
Having said that, I've been wondering all along if it is possible that the issue is one of two things:
1. Low quality wire was used on the 09/10 stators. If the wire insulation is breaking down on the stator due to crappy insulation then the stator will short.
2. The stator is getting too hot, whether it be from generating too much energy, not enough cooling, or a combination of both. If this happens, the insulation on the wire will break down and again cause the stator to short.
With these two things in mind, it would be helpful if someone would attach a thermocouple to a stator and find out what the temperature is when cruising at low speeds and high ambient temperatures (or whatever conditions seem to be causing the failures). If the temperature is above 400 degF, then there is a problem. I'm not sure what type of insulation is used, but most high quality magnet wire insulations will not survive at temperatures above approximately 420 deg F.
Otherwise, there have been talks of having stators rewound. This is also a good idea to try. Get a reputable company to rewind the stators using a known high quality magnet wire. Of course in order to know this is actually the fix several people that have had failed stators would need to ride bikes with rewound stators for a significant amount of time in order to know that it really is a fix.
I know most of this stuff has already been mentioned, but I sure would like a REAL fix to be identified. Being a long time Buell owner, I was excited when the bike I always wanted Buell to build finally was built.... now if only we can find a solution to the one major flaw, since HD won't! |
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