| Author | Message | ||
     Baf |
Is my stator dead now too? I just put the EBR rotor on less than 400 miles ago, and now I'm not charging. It didn't really look burnt to me when I had it all apart (I'll dig out the pics I took of it in a little while). Monday night coming home I noticed it charging oddly, I got caught in some traffic and I was immediately in the 12.x volt range (bike had been started under 5 minutes prior, so it wasn't hot enough to have the harness kick in and single-phase yet). While moving, it was up in the 14v range, so I switched back to gear/AT and didn't think about it. When I got home (~30 miles later) I was around 12.3v, which was odd, but I chalked it up to the traffic light I had just sat for a few minutes at. Parked the bike and didn't think more about it. I pulled the bike out this morning to take it to work. It started up fine, but my accessory line never came on. That's when the red flag started going off. I switched to diagnostic mode and saw that I was sitting around 11.9-12v with the bike running (couldn't check the volts screen because it won't show voltage when it's bitching about coolant being cold). I put the bike back in the garage, threw it on the battery tender, and took the Blast to work. Anyhow, I just did some troubleshooting. Bypassed the harness (in case the relay is to blame), and still didn't get charge. I checked voltage coming from the stator, was getting around 2VAC on all 3 legs at idle, 4-5VAC at ~4k RPM. No short to ground on any legs, and my (likely inaccurate) meter fluctuates between 0 and 0.2 ohms of resistance between each leg. Does this sound like the dreaded stator failure? Could the rotor have somehow gone bad? Before Monday, I hadn't noticed any issues at all (I occasionally check voltage, usually when I'm at a stop light). Then it seemed to only be charging at higher engine speeds, and now not charging at all. I was under the impression that it took more than 20 minutes to go from a 1/3 stator capacity to total failure. As mentioned, I put the EBR rotor in under 400 miles ago, and otherwise, my system is bone stock. Upgrade harness still attached, stock VR, and the original stator that was in there. (Message edited by baf on June 13, 2012) | ||
| Timebandit |
Oh man, sorry to hear the bad news. You know, Murphy's Law dictates that when you DIY your own work, something like this is going to happen. I don't think the stator failed out of the blue. Chances are that there was some sort of mechanical trauma somewhere in the electrical system when you were doing the work, that might have caused a short somewhere. I could imagine something bad happening with the stator wires if you ran into a problem when you hung the ignition cover out of the way when you were working on the rotor. Your data of 2VAC at idle and 5VAC at 4K are definitely abnormally low. do ALL of your stator legs measure that abnormally? The problem is that with a garden variety meter is that it just doesn't have the resolution to give you good readings on the stator. When using a 4-wire kelvin meter to measure a bunch of stators, I learned that the MEAN +/- SEM value for Z = 147 +/- 4 mR. Similarly, when I used an LCR meter I found that L = 888 +/- 0.8 uH, and frequency response was flat from 100 Hz to 1kHz, dropping down to 767 uH in the next decade. If you have access to an accurate kelvin meter or an LCR meter, those numbers should give you hard and fast parameters by which to judge your stator. The problem that you could be having is that with a low-resolution VOM, both the normal and the abnormal values lie within the range of 0.0 to 0.2 ohms where your meter output is bouncing around. With such a low res meter you can't tell the difference between legs that are shorted (which would provide a zero-ohm reading) and legs which are not (which would provide a ~150 mOhm reading). Inexpensive handheld meters aren't very good at that end of the scale, so it's possible that your meter hasn't got enough resolution to be helping you. This reminds me that there is a problem with how some meters display "open loop" data when performing the short-to-ground test. A proper short to ground result should read infinite impedance, or actually something in the high megohm range if your wire insulation is intact. Some handheld meters have fonts that make the "OL" text for open loop look like the number "01", which has confused people in the past. Several people have mistakenly assumed that a 1-ohm reading is normal for a short to ground test, which caused them to get the diagnosis backwards. Now, can you tell me this -- when you measured the stator legs impedances you had the stator completely disconnected from the vreg, right? | ||
| Timebandit |
as far as your rotor goes, the only ways i can imagine your rotor could have been damaged would have been to over heat it, thereby demagging it, or if somebody dropped it or struck it, which could also screw up the magnets. if you got one of tthe 2010 ones, i wouldn't worry too much about trauma happening at the EBR end. OTOH, if yuo got one of the trade-ins, it's always possible that somebody could have buggered it up when taking it off. i'd be running the entire gamut of charging system tests. | ||
| Baf |
I had the stator cover supported at all times, at no point were the stator wires supporting any of the weight of the stator/cover. I wiggled the wire bundle back and forth as well while troubleshooting as well, just to see if it felt like the wires were pinched somewhere from when I rotated the motor, and all seemed fine. All of my stator legs are measuring that low. After letting the engine idle for a few minutes, one of the phases dropped to ~1.86, the other two were at or slightly above 2. When revved to 3-4k rpm, voltage on all 3 phases is in the 3-5VAC range. Even with harness bypassed, bat voltage isn't moving at all whether at idle or revved up (with regulator plugged back in). I suppose I could go for a spin around the block and see if I get juice then, but revving it for a few seconds doesn't move the voltage at all (looking at batt voltage in diag mode on the IC, and also with a meter on the battery). I don't have access to any fancier meters. As far as mistaking OL for 01, my meter doesn't pad the readings out with zeroes like that. It seems like a short to ground would be easy to detect for even the most inaccurate meters. Should a normal multimeter be so inaccurate as to read so far off the mark on the voltage test if the stator were good? It reads 60hz mains power fine; not sure what frequency the AC output is from the stator. I did have the stator unplugged from the vreg, yes. As far as the rotor, I did not apply any heat to it, nor drop it or anything. It's one of the 2010 ones. What other charging system tests are relevant here? Stepping through the flowchart: 1. Battery holds a charge fine, cranks strong and starts the bike fine. 2. The only VR check I see is to check for a good ground. I didn't check this; I can do so though. 3. Milliampere draw test - irrelevant, battery is not discharging while the bike sits. 4. Total current draw test - bike is known not to put pulling up battery voltage 5. Stator check shows no continuity with ground on any legs. Resistance across stator legs initially reads 0.0 on my meter, after a second it starts flickering between 0.1 and 0.2. This test is inconclusive based on equipment available. 6. AC output test fails. Flowchart suggests rotor at this point. Rotor was fine 400 miles ago, so unless it could go bad from prior damage while in the motor, assumption is it's still fine until I pull the motor apart again. The flowchart mentions slipping rotor. How is this even possible? Wouldn't the nut have had to backed off and the rotor to come off the splines to be loose? If so, I assume I'd hear one hell of a racket - engine has no abnormal noises. (Message edited by baf on June 13, 2012) | ||
| Baf |
Here's what my stator looked like when I was putting the rotor on. I now see that one pole does look charred a little - I guess I didn't look closely enough when I was in there. Does this picture look like a stator that may imminently fail?  | ||
| Timebandit |
pic isn't working. | ||
| Baf |
Apparantly dropbox doesn't like it if you embed or directly link an image. Hopefully this works:  (Message edited by baf on June 13, 2012) | ||
| Timebandit |
interesting point that you make about the frequency response of meters. high bandwidth meters are expensive, cheaper meters are typically bandwidth limited. who knows what you'll get if you buy a cheapo chinese meter. but IME even cheap HF meters can handle the frequency response that you'll see on the bike's tach... i doubt that's contributing to your low volts readings. fwiw, the conversion from RPM to cycles per second isn't hard to do. if you had rotor slippage, then you'd have all sorts of other problems. the crank position sensor uses the hall effect to sense when that two-tooth gap on the outside of the rotor passes the sensor to calculate RPM. if you had a slipping rotor, you'd have all sorts of display problems related to CKP. if you're only having voltage problems, i doubt that's it. do your RPM and indicated speed look normal? it sounds like you've got a toasted stator. could either be mechanical trauma from the process of manipulation and installation of the rotor, damage to the wires either under the ignition cover or as they pass through the bike, bad connections, or just a case of bad timing for the darned thing to fail. | ||
| Timebandit |
that one coil is obviously charred. it's the usual suspect. | ||
| Timebandit |
you've seen my close-up charred stator pics, right? | ||
| Timebandit |
interesting -- looks like you've got a charred #2 instead of #1. that's odd. most failures i've seen have charring from 12 to 2 with 1 always being worst. if your stator turns out to be bad, I'd like to have a hands-on look at it. (Message edited by timebandit on June 13, 2012) | ||
| Baf |
Yes, RPM looked normal and speed matched GPS while riding just before failure; RPM looked normal while idling bike. I've seen charred stator pics, not sure if I've seen your up close ones though. It seems weird that it would be total stator failure if only one pole is dead; there must be damage on other poles as well. I was careful with the stator wiring while doing the rotor swap. That, and the fact that I don't have opens on the wiring makes me think it's not a connection issue. I looked as best as I could to see if it was pinched anywhere, possibly shorting it out, but it all seemed good. It sounds like, based on the info I have right now, it was just an untimely death of the stator. Unless EBR is selling stators much cheaper than HD, it looks like some stator re-winding will be happening soon. I do have a spare burnt stator here, thanks to Froggy, so we should be able to work out something so you can inspect my burnt out one if you want, if that's what it ends up being. | ||
| Baf |
Timebandit - what are your opinions on increasing gauge in the windings slightly? It would lower resistance, which may help lower stator temperatures. On the other hand, if my understanding is correct, it will also increase current, which will put more load on the regulator, and possibly negate the thermal load savings in the stator (if the newfound current is all being shunted to ground anyway). I'm debating between keeping the stock 16 gauge windings, vs trying out 15.5 or 15 (a small enough bump to maintain the same number of windings, as not to drastically alter the stator configuration). (Message edited by baf on June 14, 2012) | ||
| Hildstrom |
Baf: Other people have gone a gauge lower (bigger wire) and still had stator failure afterward, so that is not a fix by itself. | ||
| Timebandit |
changing wire size opens a huge can of worms. there are equations that you can crunch to estimate how the stator's output would change if your wire size ended up causing the number of turns on each pole to change. part of the problem is that using these equations requires you to use variables about the core that i don't know. it may be possible to get to the answer by solving sets of simultaneous equations (the core won't change from one wind to the next), but I don't really enjoy transformer math enough to do it. an engineer in a winding shop might be able to help you, but in all likelihood when you call you'll be dealing with a winding technician who will shoot from the hip. ultimately, i don't think changing the wire size is going to solve the heat problem and you're best directing your energy elsewhere. | ||
| Dannybuell |
how would the stator work if it was ceramic coated? | ||
| Baf |
Looking at Hildstrom's photos and notes of 3 layers of 13 windings plus 5 on the last, I was estimating enough room to drop a half to a full gauge without affecting the number of windings. My initial instinct was that, keeping all else constant, a larger conductor lowers resistance, and therefore heat in the stator. But, it will also raise the current, so I suspect it wouldn't be very beneficial, at least as long as a shunt regulator is in use (any heat savings from lower resistance would probably be made up for by shunting off the additional current). Too many unknowns though, so I'll probably just keep it the same. I'm seeing how much a 1190 stator is from EBR; if it's more reasonable than a 1125 stator from HD, I'll probably just buy; otherwise I'll re-wind it. Ceramic coating, as in coating the windings with ceramic rather than epoxy? Someone (Hildstrom?) said ceramic coated wire couldn't be used as the winding radius was too small. Isn't ceramic a poor thermal conductor though (a potential concern if using ceramic instead of epoxy). | ||
| Timebandit |
ceramic? no. in Hild's rewind thread I mentioned the thermal conductivity specs for various metal cores, wires, water, oil, air and various types of epoxy coatings. it showed that even the epoxy that he used had a spec that made it act intermediate between the metal wire and air; in other words, it acts an insulator. they make special-purpose thermally-conductive epoxies for use as stator coatings that are very expensive. about $150 to $200 per pint. that's one of the reasons that properly made stators are so expensive. the bottom line is that you you need a special purpose metallic epoxy, like the silver-impregnated colloid that is seen on the last batch of EBR 2008-spec stators. anything else acts as an insulator. | ||
| Baf |
I took the stator out this weekend and took some pics. There is a spot where I can see bare wire through the burnt epoxy (on that one coil). Rotor seemed fine, it was pulling just as strongly on the ignition cover when I took it off as the old rotor was. Here are the pics: http://www.dropbox.com/sh/s0ua3zgw0fk64wx/xx2xHp5K QP Nothing smelled burnt or anything (stator just smells like oil), but the rotor has plenty of magnetism, and, as mentioned before, I'm not getting very much power out of the stator. Seems weird that all three phases died like in such short order, but such is life I suppose. I'm discussing buying a brand new 1190 stator with EBR; if the price is less exorbitant than H-D's price, I'll likely just do that. I'm also considering either re-winding myself or having a local shop re-wind it. | ||
| Yugi |
What's the price for it? | ||
| Crabby |
Id settle for a 2008 stator and cover. Hopefully EBR comes through for us! | ||
| Baf |
Yugi - no idea yet; still waiting on that. As far as the 2008 stator - yuck. I'll stick with the 09 stator and EBR rotor. Hopefully with a new stator (rather than one that was almost dead before the new rotor), it solves the issues. I am hopeful. | ||
| Baf |
I found the trouble spot in my stator. https://dl.dropbox.com/u/11015924/stator_badspot.j pg I hooked a 12V power supply across the stator. The stator immediately began arcing/sizzling/smoking from the area circled in yellow, no matter which of the 3 phases power was applied across. The stator took less than 30 amps, and the reaction was immediate and always from the same spot, so I believe this is the failure location. 30 amps should be less than the maximum power the stator sees, nowhere near enough power to cause instantaneous failure. RIP, stator. I'm going to try and clear the epoxy away from that area without damaging any of the windings. If it's just a small area of burnt through insulation, I'm wondering if I can get some new epoxy in there well enough to get the stator in working order temporarily, until I get a new stator squared away. |
