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One more bad Voltage Regulator

WingedFrog

Well Known Member
Failed at 95 hours. Typical symptoms, positive amperage kicking in later and later on start-up, even higher RPMs did not help much at the end. Gave me the feeling it was temperature related as once it had kicked in it worked well in flight. I Have started the tedious work of opening the case to see what component may be involved. I have removed the packing stuff from the bottom, it did not look like overheated. The circuit board may be tricky to extract from the case any hint to do that?
Although I have reservations about the relocation inside the cockpit I will probably do it at my next annual. This regulator cost me about to $2/flight hour... Well, it could be worse, I could fly on Avgas! :D
 
Curious

Will you use the same type of regulator? And I hope you will post your decision to just replace or replace and relocate.

I am in the middle of annual and had recently checked the carb sync and noted only 1 to 0 amps during this operation. I started trying to check my voltage regulator functionality based on some prior posts and was interested in a different type and the relocation done now. Also only 61 hours.
 
I got a new copy of the original voltage regulator and put it in the starboard knee well. I think the failure was due to heat....in my factory bird the VR was about 6 inches from the exhaust manifold with a blast tube and plenum around it. Not good.

I think is a list of design flaws in the RV12 and that they will bite us in the butt increasingly as time goes on. The latest SBs are and example. I have another one--the port side canopy strut broke at the upper end while on a trip. The rod ends are made of plastic and if you look you will discover that the canopy moves side to side very easily thus producing a long lever arm on the struts that will eventually make them break.
EBB
 
You guys who had to replace your Voltage Regulator, I would be interested to find out if you had the same problem and I would not be surprised if you did. The way to connect a component by having one pin going through the PC board and bending to dip on the circuit side into a big glob of solder is something I have never seen during my career in telecommunications. If you still have the failed unit, just cut the soft rubber-like filler at the bottom all around with a cutter and then pull the filler with pliers. There are two layers, one 1/4" thick and one 1/8" thick. You need to be patient!
Too many people experienced the same symptoms of failure that I explained above. It might all revolve around this weird connection which would be clearly a quality issue and should be covered by Rotax/Ducati whatever the age of the unit. US car manufacturers had to face million $ recalls for lesser things. This could also make the relocation of the Voltage Regulator unnecessary by explaining the high rate of failure.

Correction: the layers are 1/8th and 1/16th inch thick
 
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Mine's going out too!
Just under 130hrs
Just ordered the replacement.
I'd be curious about the relocation and plans for such. Are they available from Van's?
 
You guys who had to replace your Voltage Regulator, I would be interested to find out if you had the same problem and I would not be surprised if you did. The way to connect a component by having one pin going through the PC board and bending to dip on the circuit side into a big glob of solder is something I have never seen during my career in telecommunications. If you still have the failed unit, just cut the soft rubber-like filler at the bottom all around with a cutter and then pull the filler with pliers. There are two layers, one 1/4" thick and one 1/8" thick. You need to be patient!
Too many people experienced the same symptoms of failure that I explained above. It might all revolve around this weird connection which would be clearly a quality issue and should be covered by Rotax/Ducati whatever the age of the unit. US car manufacturers had to face million $ recalls for lesser things. This could also make the relocation of the Voltage Regulator unnecessary by explaining the high rate of failure.

Any idea what component is associated with the charred area of the circuit board? Also, do you see a fix for this issue? Maybe we should be proactive in a preventive fix, other than relocating the regulator, or waiting for a failure.

Tom
 
AZLeeJay

When yours went out what was it doing or not doing?

Your replacement...was it the same type of VR you had?
 
Any idea what component is associated with the charred area of the circuit board? Also, do you see a fix for this issue? Maybe we should be proactive in a preventive fix, other than relocating the regulator, or waiting for a failure.

Tom

There is no charred area, what you see is some rubber sticking to the board after removing most of it. The fix is easy in this case: just redo the solder with a soldering iron. The only problem is replacing the rubber or at least sealing the bottom to prevent humidity to come in. I don't know what component is on the other side and it does not matter as the failure was likely due to this bad contact. I will know for sure after doing the repair and re-installed the box which is not my priority as I just installed a brand new one. No need to be pro-active, the sign of failure is unmistakable, the amp meter goes negative in the -2 to -4 amp range depending on your equipment in use. With a battery in good shape this leaves you some time to land before you lose your SkyView.
 
Mine failed in a test flight after doing the carb float SB. I had a 12.2 V indication on the battery and no amps on the amp meeter...obviously no VR.
EBB
 
Everybody blames temperature, but I have 270 hours of trouble free operation over three years out here in Phoenix. Maybe I'll eat these words, but this is a pretty tough environment and it seems to soldier on.

I would be reluctant to blame temperature without a rigorous root cause of failure investigation.
 
Everybody blames temperature, but I have 270 hours of trouble free operation over three years out here in Phoenix. Maybe I'll eat these words, but this is a pretty tough environment and it seems to soldier on.

I would be reluctant to blame temperature without a rigorous root cause of failure investigation.

I agree with you Rich. I did not find any evidence of overheating, the rubber compound used to seal the electronic was intact and the printed circuit board is like new. I had placed temp strip a few weeks ago and even the lower temp at 71 deg C has not turned. Granted it has been cold lately.
I am surprised that nobody had the curiosity to find out what was wrong with the serial failures at low time by opening these boxes. I know it's more Rotax than VAN's problem but VAN's in my opinion has not been on solid ground in this relocation operation, unless they know something we don't.
 
If you do a little searching on line you will find a number of different sources where people did investigate the failure modes.

In at least a couple of them I have seen where it was analyzed in detail, the person felt it was heat related. One in particular the person felt that there were components actually getting hot enough to melt solder which caused intermittent problems. As in when things cooled down the solder re-solidified and remade the connection, only to fail multiple times again because it has now been compromised.
 
EBB given those exact symptoms wasn't your VR kinda working, but not providing enough volts? If the VR was not working at all you would have seen -4 to -6 amps, with the Skyview being powered from the ships battery. Just like when the master is on but engine not running.

When it is working in flight you see 0 amps unless your ammeter is wired differently and being SLSA it shouldn't be.

My VR was starting to fail at about 110 hrs. It was starting to need to see high engine rpm before it would kick in. Replaced it and intend to relocate the new one. Have kept the old one for an emergency spare, think I might open it up now. Very interesting.

AZLEEJAY - a search here will find another thread with the details of the plans showing the relocated regulator.
 
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If you do a little searching on line you will find a number of different sources where people did investigate the failure modes.

In at least a couple of them I have seen where it was analyzed in detail, the person felt it was heat related. One in particular the person felt that there were components actually getting hot enough to melt solder which caused intermittent problems. As in when things cooled down the solder re-solidified and remade the connection, only to fail multiple times again because it has now been compromised.

Actually I did, Scott and I came with this:
http://pointsforpilots.blogspot.com/2014/08/cooling-rotax-912-voltage.html
There are a few interesting findings by this owner of a Zenith 601, who did a terrific experimental job. Particularly interesting for us is that he uses the blow tube and VR cover from VANs and that his VR is in the engine compartment. To make his long report short, he came to the following conclusion:
He definitely had bad cooling of his VR because the blow tube was not providing enough ram air when on the ground. When he relocated the blow tube inlet to a position that received ram air from the propeller, his VR overheating problems disappeared. In our case, the inlet of the engine shroud pipe on which the blow tube is connected is close to the root of the propeller where little air flow is generated on the ground. I believe it would be better to connect the blow tube to the radiators cooling conduit which opens around the middle of the propeller blades.
This is about the overheating and relocation problem, not the bad connection problem I have found. It still would be interesting to know what was the mode of failure of the large number of VR that failed at low Hobbs time. There may be a mix of overheating and other factors like the one I found. Beside identifying quality issues, finding which is what might help us determine what's the best solution between relocating the VR or relocating just the blast tube. We are experimenters after all!
 
One data point would be to connect a manometer at the blast tube source point and get a reading with the engine running on the ground at idle and at cruise. Then do the same from a point in the coolant duct back near the radiator. That pressure is what drives air through the blast tube.

Changing to the coolant duct involves one more disconnect to remove the lower cowl. Also it would need to be forward of the Bender Baffle if that is installed.
 
My VR was starting to fail at about 110 hrs. It was starting to need to see high engine rpm before it would kick in. Replaced it and intend to relocate the new one. Have kept the old one for an emergency spare, think I might open it up now. Very interesting.

AZLEEJAY - a search here will find another thread with the details of the plans showing the relocated regulator.

Thanks Bill, I found it. My regulator is demonstrating a similar failure mode to yours.
 
One data point would be to connect a manometer at the blast tube source point and get a reading with the engine running on the ground at idle and at cruise. Then do the same from a point in the coolant duct back near the radiator. That pressure is what drives air through the blast tube.

Changing to the coolant duct involves one more disconnect to remove the lower cowl. Also it would need to be forward of the Bender Baffle if that is installed.

I was wondering what was this "Bender Baffle" and almost looked-up Bender in the dictionary (like fender-bender) then I remembered Joe Bender! :D
I am posting this because some new fellows could have the same problem.
 
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Melted solder! That's hot! Sounds like something more than just low air flow. If it was chronic overheating I would expect the solid state components to fail, but maybe that led to the over current melting the solder. Without more facts it's just a guess.
 
Well, how appropriate a post. Went flying this morning (with a newbie non-the-less) and the voltage regulator burned up just after take off (TTSN: 123 hrs). There was a blast of burnt electron smell in the cabin (the heat was on) and the battery voltage started dropping and the usage went negative and the main bus fuse (30 AMP) blew. I has suspected this was going to happen as I started getting symptoms a few flights ago. Of course, it always happens when you are flying a new person for the first time. :(

I took the VR off and there was black goop on the bottom. Where ever it shorted out at, it was hot enough to melt the rubber on the bottom.

Guess I'll be researching replacement options.
 
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OK guys - I think it is now time that ALL of us that have had VR failures send the official form to Vans. But I cant find the form on Vans website! Obviously we need to report our serial number, date we received the engine kit, details of the failure, how many hours, and what we did. And if we still have the old regulator, opened or unopened.

Can someone please find the form? Or Scott, is it enough to just email the above to Support at Vansaircraft dot com?
 
I'm looking for field reports of the following:

1) Anyone have a VR failure with it mounted inside the cabin?

2) Anyone have a failure using the John Deere replacement VR mounted in either location?

I am hesitant to mount another Ducati VR given the reports of widespread unreliability of the design. I don't mind moving it to the inside of the cabin if that actually fixes the problem but there seems to be much opinion that it just extends the MTBF of the unit.

Hey Torsten, how have your tests gone? Do you have a recommendation for a replacement of the Ducati unit?
 
Whilst I am a huge fan of Rotax and their engines, there are two issues which are well known regardless of airframe manufacturer (ignoring the floats...).

One is the oil pressure sender which hopefully will be cured with the latest mark of sender.

The other is the voltage regulator. I have no idea why Rotax persevere with the Ducati voltage regulator and its well documented high fatality rate.

For those wanting to go after Van's, I'm not sure what that will achieve. What is needed is an electronics guru to design a reliable alternative.

In the UK we never did trust Italian electrics.... ;)
 
My VR was starting to fail at about 110 hrs. It was starting to need to see high engine rpm before it would kick in. Replaced it and intend to relocate the new one. Have kept the old one for an emergency spare, think I might open it up now. Very interesting.

Although in my case I thought the increase in rpm was helping the VR to kick in, I believe now that rpm have nothing to do with this: you can increase the rpms only when your oil temp has reached the 122 level. The combination of oil reaching 122 and high rpms increases the warming of all components. In one of my last trial before complete failure, the OAT was in the low thirties and the VR did not kick in even at 4K rpm for a while. Then suddenly it kicked in while the engine was idling and just as I was going to shut it down. Just by curiosity I went flying (in the pattern mind you!) and everything worked well for about one hour. Only on the next flight attempt did it not kick in at all although I might not have waited enough, I was fed-up anyway and decided to replace it.
 
Here are a couple of more questions in addition to Randy's:
Has anyone replaced the regulator with a John Deere one?
Has anyone had a regulator failure after they mounted it with heat conductive grease?
 
NWMDC


As soon as my local NAPA store opens Monday morning, this will be going into my RV-12 in the engine compartment. No more Ducati VR's for me. I will mount it with conductive grease and I am planning to make a fiberglass plenum that blows the cooling air across the fins. I may change the mounting location to improve cooling but I am NOT moving it into my cockpit. In my airplane, I am not shoving two always hot wires into the same firewall grommet as control cables and bringing them into my cockpit. In my opinion, that MIGHT fix one problem but increases the risk of another problem (FIRE). I simply prefer to not do that. YMMV.
 
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Randy,
That voltage regulator should work. But it is not plug and play. The Ducati connector will not fit and the wires will have to be switched around. And the mounting holes most likely will not have the same spacing. Of course you probably knew that.
Similar looking regulators are for sale on eBay for half of the NAPA price. Who knows if they are identical parts or not. Search for AM101406
 
Randy,

I applaud your efforts, let us know how it goes. Just a point, the two "always hot" wires you are referring to are the AC wires from the alternator. You don't have to run them through the control cable opening, you can make a new hole for them, as I did. Also they are well protected by the big braided sheild, and in fact only carry the alternator output, which most likely couldn't push enough current to start a fire even if directly shorted.

Good luck with your mod, let the forum know how it works out.

John
 
NWMDC


As soon as my local NAPA store opens Monday morning, this will be going into my RV-12 in the engine compartment. No more Ducati VR's for me. I will mount it with conductive grease and I am planning to make a fiberglass plenum that blows the cooling air across the fins. I may change the mounting location to improve cooling but I am NOT moving it into my cockpit. In my airplane, I am not shoving two always hot wires into the same firewall grommet as control cables and bringing them into my cockpit. In my opinion, that MIGHT fix one problem but increases the risk of another problem (FIRE). I simply prefer to not do that. YMMV.

What's NAPA's part number for that VR? Thought it might be the 170 number in the URL but that didn't work.
 
Need Regulator/Rectifier

The VR for this application is both a VR and Rectifier. The B&C unit is just the voltage regulator.
 
I also intend to drill a new hole in the firewall just for this wire, with grommet and sealant.
 
Better check that again brother... :D

I should never doubt you ... :D The B&C is a VR/Rectifier !

However, it looks like it will be operating at or near its peak capacity. The Rotax outputs a nominal 20A with max of 14A continuous recommended. The B&C regulator looks like it was designed to support the 12Amp B&C 200G at the high end. The temperature chart in the installation instruction show a temperature of between 146F to 161F at 12 to 15 amps. The temperature limit in the instructions is spec'd at 175F.
 
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There must be a voltage regulator that will work on these engine and not be so finicky. We have lots of room on that shelf area, and changing connectors is not big deal. I would just like to eliminate the problem by installing a device that will end the problem, perhaps even offering some sort of built in protection of it's own. Do we have any small engine engineer types around that can offer a solid solution?? It's just way above my pay grade.

Tom
 
Randy,
That voltage regulator should work. But it is not plug and play. The Ducati connector will not fit and the wires will have to be switched around. And the mounting holes most likely will not have the same spacing. Of course you probably knew that.
Similar looking regulators are for sale on eBay for half of the NAPA price. Who knows if they are identical parts or not. Search for AM101406

There are a ton of cheap Chinese knock-offs of the AM101406. They do not have much fin area to dissipate the heat. I suspect using them might be problematic. The NAPA model, although I don't have it in my hand, appears to have much more surface area.

Yep, I knew the wiring would have to be changed. No biggie. I like the fact that if I get stranded somewhere, a local NAPA can bail me out.
 
Hi All,

Yes I was doing the big tour of the South Island and the rectifier regulator went at about the 300 hour mark. I was lucky as I had just done the big tour into the Southern Ocean to Stewart Island. I even manage to get a replacement and have it installed on the same day.
I wonder how many are going and possibly Vans don't think it is a problem at this stage. It is fairly expensive part to replace on a regular basis. I guess I need to stop flying and relocate it to the new position.

Cheers
Julian 120316
 
I see 12 Amps max which is way too low.
20-22 is safe

The SME 7068102 is rated at 20 amps. I've also found a number of motorcycle voltage regulators that are rated at 22 amps if need be but they are more expensive.

I'm not an EE, but I'm guessing that I can find a regulator that will last more than 123 hours. :cool:
 
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The SME 7068102 is rated at 20 amps. I've also found a number of motorcycle voltage regulators that are rated at 22 amps if need be but they are more expensive.

I'm not an EE, but I'm guessing that I can find a regulator that will last more than 123 hours. :cool:

I would be glad to pay a little extra for a part that solves the problem that the Ducati VR seem to be plagued with, and I'm sure other would do the same. Figuring out what is the best replacement is the difficult part.

Tom
 
From what I have seen the mounting of the reg/rec right behind the #4 exhaust pipe and within 4" isn't a good location. Why not move it over to the left 6" and or apply some header wrap cloth to the exhaust pipe. The wrap MFG claims a 70% heat reduction. I don't know if it is truly that much, but the difference in heat radiated and connected heat is very significant. How many would run their engine and then grab the bare exhaust pipe. Not without leaving skin behind. I have wrapped my pipes and I can put my hand on them after shut down and the surrounding parts are quite a bit cooler. Using the cloth header wrap on our stainless exhaust is no big deal and it keeps the temps down on hoses, rubber engine mounts and wire insulation.

I have tempature strips on my reg/rec. the magic number to keep away from for the reg and the ignition modules is 170F+. I have never seen over 140F with either one in my plane.

Most people have the reg/rec in the engine compartment so this may only need to be moved or protected verses moving it into the cockpit.

Before you get too stuck on temps I would place a temp strip on the ignition modules and especially the reg/rec.

Go to Amazon.com and type in:
TIP Temperature products TLCSEN023 for a temp strip of 149F-199F for $18.74 a pack.

An easy test would also be to do the same temp test with the reg/rec moved over 6" with header wrap cloth on the #4 exhaust pipe. I bet the temp is lower.
 
Loki - I've seen really scary pics, on this forum, of corroded exhaust pipes after wrap is removed.

Also, the RV12 regulator is finned and the fins covered with an aluminum cap into which a blast tube is connected, making stick on temp indicators essentially impossible for gauging the actual regulator temperature.
 
Loki - I've seen really scary pics, on this forum, of corroded exhaust pipes after wrap is removed.

If you think a corroded exhaust pipe is scary, how about a regulator burning up inside the cockpit? Now that would be scary.

From the posts I see here, there is evidence that poor quality control causes the failures and possibly not temperature. Moving it inside with the pilot and passenger would not seem to be the best idea.

And I'm not sure you can turn off the current to the VR with the master switch. Maybe you have to stop the engine.

If I'm being an scaredy old lady over this somebody say so, but in the meantime, I'm leaving mine out on the firewall until a good fix turns up.
 
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