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Rotax Voltage Regulator issues Again

bob1393

Active Member
Good morning everyone. Our Ducati VR on our RV12 failed after only 223 hours of service. Now the second one has failed after 109 hours!! Both of them lasted about 10 months each.

I spoke to Van's technical dept. this morning and they are aware of the short life of this VR. Vans has discussed this with Rotax but there doesn't seem to be any action taken to correct the issue.

Other than the John Deere VR I've seen mentioned here on this forum, is there any other VR that someone would recommend that works well on the Rotax? Any info somebody has would be appreciated.

Thanks guys for your help.

Bob1393
 
Bob -- Were your Ducati R/Rs located forward of the F/W or under the avionics tray? Do you usually fly with all the bells and whistles (i.e., lights and electronics) powered up? -- David
 
Other than the John Deere VR I've seen mentioned here on this forum, is there any other VR that someone would recommend that works well on the Rotax?
The German made Silent Hektik works, but I would only recommend it if your flights are mostly longer than half an hour or so. Because of the way it was designed for Li batteries, it doesn't reach its full output for a while after engine start. It works fine, but if your normal flight is pretty short I wouldn't recommend it.

My JD clone regulator only lasted about 10 hours. That seems to be an anomaly, but I'm probably not going to use another. I'm trying to "un-pot" my Ducati regulator to see if it can be repaired to keep it or the SH as a spare.
 
Dave and Dale - thanx for the replies. Our VR is located in the cabin under the avionics tray - they both were.

I talked to Dean at Lockwood Aviation and he recommended that they be wired per the Rotax manual and not Van's manual. The difference is Rotax wants the three spade lugs - R +B and C wired together and they are not in Van's version according to Dean. I haven't checked it out yet.

Bob
 
I saw a picture of it wired that way on a Zenith. That wires the two AC pins and the voltage sense pin (or whatever that "C" pin is called) right?
 
The problem with wiring R +B and C together is that the master switch will no longer shut off the electrical system while the engine is running. I know because I tried it. If there is smoke in the cockpit, the only way to shut off the electrical system is to pull the 30 amp alternator fuse. Will you remember to do that?
 
A friend had VR failure with his Rans Rotax last week flying out for breakfast, same issue, second time, it does not last long.

He take is it needs cooling, the heat is killing the unit.
 
The German made Silent Hektik works, but I would only recommend it if your flights are mostly longer than half an hour or so. Because of the way it was designed for Li batteries, it doesn't reach its full output for a while after engine start. It works fine, but if your normal flight is pretty short I wouldn't recommend it.

My JD clone regulator only lasted about 10 hours. That seems to be an anomaly, but I'm probably not going to use another. I'm trying to "un-pot" my Ducati regulator to see if it can be repaired to keep it or the SH as a spare.

Depends on which SH voltage reg you order....I have both. With the normal Van's supplied battery (I'm not at hangar so I'm guessing), the model xx14 puts out 14.7 volts. The other one xx18, puts out a stepped voltage starting out at 13.4; and every 20 minutes, jumps up till 14.7...which is good for LiFi batteries.
 
1200 hours and 11 years on my Rans S-7S, voltage regulator has never moved from 14.0 volts. Electric load in the Rans is lower then my 12, wonder if that is the problem.
 
The facts

If you have a pre 2010 regulator, it will fail because of INTERNAL cooling design issues, if you run these at low power, they will last forever.

If you have a 2010 or later version it will likely fail from operational vibrations acting on manufacturing induced, prestressed component leads, in a potting compound that is temperature unstable.

Anyone who tells you the failures are caused because Vans didn't follow the Rotax required wiring plan doesn't know what they are talking about, they don't have a clue to how this regulator works.

Mike
 
Thanks guys I appreciate all the comments. As there are 3 of us who own this plane together, it makes the cost of the VR about $60 each. We will no doubt continue to use the Ducati VR, wired per Van's plans, and just hope we can get a longer life with them, as some others have had.

Bob
 
If you have a pre 2010 regulator, it will fail because of INTERNAL cooling design issues, if you run these at low power, they will last forever.

If you have a 2010 or later version it will likely fail from operational vibrations acting on manufacturing induced, prestressed component leads, in a potting compound that is temperature unstable.

Anyone who tells you the failures are caused because Vans didn't follow the Rotax required wiring plan doesn't know what they are talking about, they don't have a clue to how this regulator works.

Mike
Mike, I have one with a fairly hard, light green potting compound. The plane was completed in late 2011, but I have no idea when the FWF package was purchased. Any idea of a solvent that will work on this stuff? I'd like to get the PCB out and touch up the solder joints. So far it's coming out in crumbly chunks. I've got the bottom of the board mostly exposed, but no luck getting further than that.
 
Mike,
That makes sense to me since my Rans is glass smooth and my 12 feels somewhat buzzy. I just figured that was the difference between a tube fuselage and 10K pieces of aluminum flying in formation. Do you think it would help to use rubber vibration isolators to mount the VR? Mine with 212 hours is starting to get sloppy with voltage control.
 
Dale, you have a pre 2010 version, that's how those come apart. It will have PN 343620 stamped on it. The date code is above the word DUCATI, the first two digits are the year, I'm not sure if the second two are month or production run of that year.
These are not repairable, mostly because you can't fix the design issue, but there is a workaround. These fail from diode/plate separation. The inability to adequately transfer heat to the case causes the diodes to unsolder themselves. You can add a 35-50 amp 1000v bridge rectifier externally and jump the the two A/C pin to the regulator G terminals and jump the + pin to the R & B terminal. The bridge - pin is unused. This bypasses the damaged connections and moves half the heat out of the regulator.
If the connector is good, you could Install a new PCB and rework it like a current version regulator.

Bajapilot, I don't know if that will help, and I doubt it will hurt. Vibration is only one part of the problem. You still have prestressed component leads and a potting compound that is too soft and unstable. If you try this, you must ground the regulator case to the airframe.

Mike
 
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4-digit date code is most likely a two-digit year and two-digit week, from 01 to 52. Thanks for the tip about using the half bridge... I can see how that would work. Not a bad idea, as long as the SCRs are good.
 
Yup, month and week is the industry standard, but in all the regulators I've seen, the second set of numbers never went higher than 10....maybe Ducati doesn't follow industry standards.

It's Italy. Maybe they only count work weeks.

:D
 
Silent Hektik regulator F4118 for sale

I have one brand new SK voltage regulator, which plugs into the RV12/Rotax 912 for sale. https://www.silent-hektik.de/UL_R_912.htm

I ordered two for my RV12, installed one and have the second for sale.
I'd like $300 shipped to ConUS
thanks
joe

Ok guys... The regulator is sold..
thanks
joe
 
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Would recommed NAPA Part# SME 7068102

About $100 bucks

Mount on cockpit side of firewall with a 12V computer fan blowing on regulator.

My fan is about 5" diameter wired to master switch.

Have been flying with this regulator for 18 months with no issues after my ducatti burned out.

Heat is the enemy of these regulators.

Regards
Ramrod25
 
Would recommed NAPA Part# SME 7068102

About $100 bucks

Mount on cockpit side of firewall with a 12V computer fan blowing on regulator.

My fan is about 5" diameter wired to master switch.

Have been flying with this regulator for 18 months with no issues after my ducatti burned out.

Heat is the enemy of these regulators.

Regards
Ramrod25

Did the same thing a year ago/150 hrs. . I used a 30$ amazon clone and a two inch cooling fan that cost about 4$. The power come right off the hot terminal on the regulator. Switched by the master. Charge rate is typically 14.2 volts. Very satisfied so far.
 
John Deere Update

My wife's RV-12 ELSA originally had an under-the-panel $180 Ducati voltage regulator that lasted 120 hrs, followed by a JD $20 replacement that failed yesterday after 150 hrs.

Five minutes after takeoff I smelled hot electrical insulation, the EFIS lady screamed "warning," the voltage digital readout flashed red 29.9 volts, and I instinctively grabbed and removed the 30A generator fuse while wisps of smoke flowed from the center panel.

A friend flying from the left seat turned off the master switch and controlled the airplane while I tried to figure where to aim the fire extinguisher. Simultaneously I pondered why the light smoke continued with everything but the Dynon backup battery deactivated. Then I realized the generator fuse probably disconnected downstream of the VR, meaning the generator was still feeding it. Yanking the wires off the VR killed the smoke. We restored the master and flew home using the ship's battery.

Fortunately when I bought the JD unit, I bought a spare too. Also I installed nutplates to mount it. Putting in the spare, working only from under the panel took ten minutes. During a flight today, the new JD produced 14.1 vdc.

The first JD unit was a bit flakey during its life as the buss voltage varied from 14.0 to 14.4 vdc regardless of load. Its temperature also varied from warm to hot, but usually showed 140F on a non-contact thermometer. So when the voltage began to work higher over the last few flights, I thought that it was normal variation for this VR. Finally it settled at 14.7, which is the top of the charging range acceptable to Odyssey.

Now I realize that the rising output was warning of coming failure. When I see that again, I will prophylactically put in the new spare that I just ordered from Amazon.
 
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I always thought heat was the biggest problem those V.R.s had (the heat they dissipated doing their job, not ambient temp they live in). Every V.R. I've tried, two Ducattis and, I think, three different J.D.s, have run too hot to touch. What I'm trying now is to mount a small computer cooling fan I had lying about directly to the V.R. I actually tie-wrapped it directly to the cooling fins, blowing air up into the fins. So far, the two V.R.s I've tried that both ran really cool. I guess we'll see how well the J.D. I have in now lasts.
 
680hrs and still ticking Ducati voltage regulator

Made one change to fix this problem.
Cut a spoon shaped scoop on the end of the blast tube and made it stick out into the air stream.
 
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Good morning everyone. Our Ducati VR on our RV12 failed after only 223 hours of service. Now the second one has failed after 109 hours!! Both of them lasted about 10 months each.

I spoke to Van's technical dept. this morning and they are aware of the short life of this VR. Vans has discussed this with Rotax but there doesn't seem to be any action taken to correct the issue.

Other than the John Deere VR I've seen mentioned here on this forum, is there any other VR that someone would recommend that works well on the Rotax? Any info somebody has would be appreciated.

Thanks guys for your help.

Bob1393

Seems I'm a bit late to the party. If you're still looking for a replacement for the Duc VR:
http://torstensrv-12.blogspot.com/2015/03/replaced-ducati-regulator.html

There's the whole story of my installation of the F4112 Silent Hektik VR. I am very happy with it. The Odyssey seems to like the higher Voltage of 14.7V in cruise and I haven't had any glitch ever since I put it in (~140 hours ago)
 
One of the problems with the SH VR, though, seems to be how to get one here in the States. Last I knew they didn't ship here.
 
One of the problems with the SH VR, though, seems to be how to get one here in the States. Last I knew they didn't ship here.

When the topic was hot a while ago in a different thread, I remember posting some links of shops that ship to the US. One was in the UK, I think. The search tool should be able to find this information.
Yup, found it. It wasn't me posting it but it was in the UK:
http://www.vansairforce.com/community/showpost.php?p=1024028&postcount=3
Apparently, you can also find them on ebay from motorcycle shops.
 
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My first Ducati lasted 300 Hours on the engine side of the firewall. I have 370 Hours on the second in the same spot and it?s still going strong. I put temp strips on them and they blackened up to the 180F marker. Don?t ask me how, but they seem to hang in there even in the Phoenix heat. I guess you guys just haven?t made the right blood sacrifice to the Ducati gods!😜
 
I just installed the JD regulator after my original VR started to show signs of failure at 175 hrs. I’m now seeing voltages occasionally hitting 14.6V, which gives me an audible “voltage” warning through the Skyview. I’m sure this is normal, as the JD VR is set to 14.4v, but I’m wondering: have people reset the voltage limits on the Dynon, and if so, what are appropriate new limits?
 
Yes, you have to change the upward limit. I just bumped mine up to get rid of the nuisance warnings. I don't recall exactly, but it was either 14.8 or 15.0. If it "runs away", it will go much higher than that.
 
Yes, you have to change the upward limit. I just bumped mine up to get rid of the nuisance warnings. I don't recall exactly, but it was either 14.8 or 15.0. If it "runs away", it will go much higher than that.
I would like to see Jolly check in on this and provide some guidance.
I have a similar issue.
 
I am not taking anything away from Jolly?s expertise and experience in the Rotax area, but F-1?s advice works fine. There are many of us using the John Deere regulator ( in my case, a amazon $20 knock off). In my experience the $200 Ducati is no more reliable than the $20 Amazon. The Amazon has a bit higher charge rate. I have always carried a spare Ducati and now I carry a spare John Deere. This practice really saved my bacon a few years ago when my Ducati failed in the mountains of N.C. on start up one Saturday morning. 20 minutes later we were ready to roll with the John Deere.
 
I plan to replace my second Ducati with the SK next time it shows signs of weakness. See below email I received very recently from Supplier in UK.

Personally I am willing to pay the price for what seems to be a quality product, in exchange for not getting stranded somewhere with a dead battery.

I have not heard of a single SK failure. Has anyone else?

On a subsequent email Ian offered a 10% discount for an order of four units.



Hi John,

Thanks for making contact, apologies for the slow response.

We can order you in an F4118 with the connector block as per the attached
picture, we would be delighted to ship it to you in the US. We do not keep
these controllers in stock and they take something like 10 days to get to us
from the factory.

The pricing is:

F4118 = ?198.00gbp
F4116 connector = ?9.50gbp
Shipping = ?19.00gbp

We can accept cards no problem, order form attached, if you let us know a
number and a time to call we can take the card payment over the phone if you
prefer.

Best regards

Ian


Ian

www.motoguzzisales.co.uk


-----Original Message-----
From: John Peck <[email protected]>
Sent: 22 March 2018 11:51
To: [email protected]
Subject: SK Regulators

I understand you sell the SK F4112 and F4118 regulators. What is your price
for these shipped to the USA?

Sent from John Peck's iPad

______________________________________________
This email has been scanned by Netintelligence
http://www.netintelligence.com/email


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
 
Running at 14.2 is good and even up to 14.6. My 1800 Honda Goldwing motorcycle runs at 14.2 - 14.4
14.2 is better than some see that are around 13.2 - 13.6 with these newer AGM and LiPo batteries. So setting a high voltage alarm at 14.8 - 15.0 volts is fine. You just wouldn't want 14.8 plus as your norm. Some instrument fluctuation also accounts for some of this bounce. The shunt wires can be scotcbrited and put a dab of dielectric grease on them can sometimes calm this down a fluctuating ammeter. A weak ground can cause fluctuations or lose wires on the battery.
Dynon says the Rotax is a noisy engine and that's why the ammeter can fluctuate.
The two yellow wires from the back of the engine that provides AC current to the VR may not be pressed in all the way and this may cause voltage swings and fluctuating ammeter readings.
 
VR variable temp

My VR is located in the cabin under the instrument shelf. Occasionally while flying, I can reach over and feel the VR for temperature. Some times it's very warm to the touch, not burning hot but uncomfortably warm. Other times the temperature is cool. Any thoughts about the differences? I've not tracked this difference but each time it is with strobes on, landing light pulsing, etc. Ideas?
 
My VR is located in the cabin under the instrument shelf. Occasionally while flying, I can reach over and feel the VR for temperature. Some times it's very warm to the touch, not burning hot but uncomfortably warm. Other times the temperature is cool. Any thoughts about the differences? I've not tracked this difference but each time it is with strobes on, landing light pulsing, etc. Ideas?

My guess is the VR gets hot when recharging the battery after engine start (cranking), electrical loads prior to engine start, and negative imbalance until alternator is spinning fast enough (cruise flight). When battery regains full charge the VR is just passing enough current to maintain flight loads.
 
Silent Hektik

I have the Silent Hektik Regulator F4118 and the recommended Aliant X3P LiFePo4 battery on my plane (Savannah-S). The duo workes just great. I took the 12Ah version, because the are so light anyway. The engine starts very easy. This VR is designed to take care of the spezial needs of LiFePo batteries and make charging them safe.

https://translate.google.com/translate?hl=de&sl=de&tl=en&u=http://www.silent-hektik.de/UL_R_912.htm

Good thing, if you want to upgrade from a ducati regulator, F4118 has the same connector.
 
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Is a low voltage problem fixable?

My RV12 with 360 hours has shown low voltage for some time. It occurs to me that there might be a loose wire keeping the voltage low. Thoughts? Mark
 
Low voltage was the symptom that has caused me to replace the voltage regulator, at least 3 times. Replacing the VR corrected my low voltage each time. My opinion is heat is killing my VRs. Mine is located in the cockpit under the avionics tray. The blast tube I rigged up seems to be keeping the heat under control, it remains to be seen whether that'll svae the VR.
 
I also have the Silent-Hektik unit and love it. It's been working flawlessly for a LONG time now. Was it expensive, yup, but I won't have to replace it every year or two.

The voltage output ramps up over a 30 minute period. After about 30 minutes I see 14 to 14.3 volts and the unit never reaches 149° and its mounted on the firewall in the engine compartment. I have a Thermax temp strip on it to monitor the temp.

This is a great unit and I also bought 5 of them at once for me and an group of owners. Saved on shipping and got a better price. :D

We also only bought the voltage regulators, it uses the OEM Ducati connector and is a direct plug in as stated by Major-Tom. Make sure all your spade connectors are tight in the connector before you slip it on.
 
Another problem

A few day ago I completed wiring my Rans S-20 power circuits. I turned on the Master and about 30 minutes later smelt something like very hot electrical. The regulator was too hot to touch. Pulled its fuse and let it cool. Am still a ways from running the motor so I just left it until today. Checked the wiring six times, it was correct.

I removed the regulator and the potting compound. The problem was readily apparent. The L and C connections to the circuit board were sloppily soldered and flowed together. Zero ohms between the L and C connections. The L goes to a light used to indicate charging. With the two soldered together, something got very hot.


Very obvious to the casual inspection, as said somewhere in the thread, very poor quality (with a small q) control.


Fixed it, but who knows if something is blown. I will find out when the engine runs.


PS I noted that the R and B+ are soldered to the same land, so the wiring diagram is incorrect in that the connection need not be made externally.
 
Scratch built replacement regulator

A few weeks ago I scratch built a new voltage regulator to replace the Ducati.

My design goals were;
  • Low cost ?experimental? replacement
  • Repairable
  • All components are off the shelf (no custom extrusions, CNC, or molded parts)
  • A regulator with known ratings, all components have data sheets.
  • Built with common builders tools
  • Increased heat sink area
  • Eliminate Faston connections for the power leads
  • Maintain the Ducati mounting bolt hole spacing
  • Optional cooling fan

This is what I came up with;

Overview

hxqlkd1PkB7ZAL7gPtPZ9jYHsJiOrQ2B4gO4MA6UPvlK0eVkvcvw-E-uzJpkFmYNsyPf75ls2IIGtdYbZeccT9VtAWeV2ndXfuH6_nkL-WRbHqZFhJ5EFkq0o2VRZ7-iumetfTZW2NmbKOo55tB3QTg-EQyYOn6AcjwoFv9NcPzxFzHI4UxzMlacjpqYDqGiGLKoNLGJ7zQHTRlzw_eF8a3zdxXnbuUy3upGnCefzbDHT1pZoElKmWlsgA17dM01HJBGT_YRMJ_cd1lz6HOUmB-miwycLxXLDU-3HMgF6yUL1N2ZzauBgW4CvgB0Vm9qVlU4qYiTZZsibTa8kaYVNdqkqd9_ZHEGBXjoPZLb8jIdPHurFX-2nOzYoHCEQkoT_c9_kSpxY-OFCNgbugRoz0N9XzXoX5pqeDaCTFwkEODbEfSXkcu5l7CWACoUR83b46DHyF6WVAeyHKKyS8RQxreubWD1JTHanfOi5zzPvB7W9XDHRuQs7q4YJYTz4hR2bLwZDJ4Te1yAktHtV6lR8YEiPZCgt8A7uM3jMwzAaelSS9XtIJ-HUMPEKbck7t30lP2PTQy0o9iM_vxq6Rf8BrbXL-TpxBKMABacA7lh-7mdDAGqFDvx-johjDPf20RJBRIhGPwButz_QISm47f_oVCemUhs75w=w700-no



The parts cost about $60, not including the PCB.

I?ve only got a few hours on it, so I wouldn?t consider it a proven design. If you have an interest in building an experimental replacement regulator, all the details can be found in this pdf file;
https://drive.google.com/open?id=1d6nHOb2YgIeO-T3Ra6fIhzrB4gktR3Ok
 
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This should get the Academy Award this year for greatness in the true spirit of homebuilding!

Find a real problem, develop a solution and freely put it out to the population desperate for an answer.

Thanks
 
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