Wifey and I flew to wild and beautiful Ashe County, N.C. for the weekend to visit Mt. Mitchell, the highest point east of Colorado. Great weather and we were not blown off the top of the mountain. All was great until Monday morning when we were packed up and strapped in. I started the mighty Rotax and the voltage went right into the red. Thankfully, I have been carrying a spare Ducati. My luck usually doesn't fair this well, but I am very thankful. My first regulator lasted 150 hrs.. I adapted to the jd and it lasted 60 hrs.. My advice? Whatever regulator you are running, carry a spare.
Van's Air Force
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How long did your JohnDeere VR last?
- Thread starter Dave12
- Start date
DaleB
Well Known Member
Welcome to my world. I think I got 8, maybe 10 hours out of mine. I'm looking for a better idea now. Half tempted to build a home-brew regulator into the JD case.
[edit: I'm assuming this is either infant mortality, or "luck of the draw" cruddy supplier. Obviously others are having much better success.]
[edit: I'm assuming this is either infant mortality, or "luck of the draw" cruddy supplier. Obviously others are having much better success.]
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RFSchaller
Well Known Member
My first Ducati lasted about 400 hours. I always carry a spate VR and mechanical fuel pump along with two extra spark plugs. So far, knock on wood, I have not had to use any spares on the road.
Staying with Ducati
Having followed all the threads on the VR, have decided to stay with the Ducati regulator. My first one lasted 300 hours in the original location w/ blast tube. Lately I have weighed the advantages and disadvantages of the inside location and decided to move it inside too. I am in the middle of a panel upgrade so everything is very accessible and the engine cables are out of the way. I installed it with nut plates to make it very easy to change the regulator if it does fail again. Take out the two AN3 bolts, drop it down, pull off the connector and replace. I carry a spare, just in case
No panels or cowl needs to be removed to change it.
I do notice that the brake lines touch the back of the regulator in this location. I don't know how hot the thing will get in this location but don't want it to burn the brake tubing. I am going to put an aluminum angle on the bolt to hold the brake lines from touching.
The old location looks pretty bare now, and I appreciate the clutter reduction.
Blast tube gone, but not missed:
Having followed all the threads on the VR, have decided to stay with the Ducati regulator. My first one lasted 300 hours in the original location w/ blast tube. Lately I have weighed the advantages and disadvantages of the inside location and decided to move it inside too. I am in the middle of a panel upgrade so everything is very accessible and the engine cables are out of the way. I installed it with nut plates to make it very easy to change the regulator if it does fail again. Take out the two AN3 bolts, drop it down, pull off the connector and replace. I carry a spare, just in case
No panels or cowl needs to be removed to change it.
I do notice that the brake lines touch the back of the regulator in this location. I don't know how hot the thing will get in this location but don't want it to burn the brake tubing. I am going to put an aluminum angle on the bolt to hold the brake lines from touching.
The old location looks pretty bare now, and I appreciate the clutter reduction.
Blast tube gone, but not missed:
?........ I installed it with nut plates to make it very easy to change the regulator if it does fail again. Take out the two AN3 bolts, drop it down, pull off the connector and replace. I carry a spare, just in case
Smart! I wish I had thought to do that when I moved mine. If I ever have to change it out again I will go the nutplate route.
I sort of feel that way myself, but they don't seem to actually fume when they fail. No one has reported fumes, except BigJohn. His had a connection burnt due to misalignment.
Anyway, I'm going to give it a go on the inside. It is possible to reach the connector and pull it off if she started to stink.
The relocation to the inside is factory approved and a change to a JD is not, if that means anything.
Just looking at my own data, they last as long or longer under the cowling. I have a slightly redesigned blast tube and shroud built if I move it. I have also built a mount that covers the regulator fins and plan to mount a small cooling fan to blow air on the regulator whenever power is on. Still trying to decide which is best. What do you think Joe? I will say that having it in the cockpit made for a very quick swap out during our recent cross country.
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Wherever the rectifier/regulator is mounted, it needs to be kept cool. Mounting it with heat conductive paste will help as will forced air circulation. Bob Nuckolls recently posted that, lacking thermally conductive paste, anything is better than air. He suggested that E9000 is better than nothing.
If mounted inside of the cockpit, how about mounting the regulator so that the avionics cooling fan will move air through the regulator fins?
A double pole switch would allow the pilot to shut off both the AC input and DC output of the regulator in case of smoke.
If mounted inside of the cockpit, how about mounting the regulator so that the avionics cooling fan will move air through the regulator fins?
A double pole switch would allow the pilot to shut off both the AC input and DC output of the regulator in case of smoke.
Funny you should mention the cooling fans. During the build on this 12, I mounted the regulator just next to the fan holes on the intake fan. I have not created any ducting. I thought I would wait and see if the new location solved the problem. I like the double pole switch for a number of reasons. Can you recommend one? I also used some longer an4 bolts with aluminum spacers epoxied on to them. It makes removal and install a flash. I am still leaning toward a small dedicated fan for the reg. As always, many thanks for your input Joe.
DHeal
Well Known Member
Here are my ROTAX/DUCATI VR operational data points:
3/2014 - "0" hours - My RV-12 ELSA first flown with original Ducati VR #965-335 installed per Van's plans (i.e., on engine compartment shelf with shroud and ducting).
3/2015 - 135 hrs HOBBS - Original VR (above) failed - Autopsy suggested failure due to heat and vibration - no sign of burning/smell, just open solder joints. Replaced with new Ducati VR #965-349 relocated per Van's notification to inside the cabin under the avionics shelf. I used nutplates to secure the VR and to aid in its quick replacement if needed. I did not use any heat-transferal paste under the mounting. In addition, I added a small aluminum shroud to generally route the avionics compartment fan exhaust (like warm baby's breath) towards the VR fins - not sure this is worth the effort.
11/2016 - 410 hrs HOBBS and all is well (likely this post will doom my current VR). I typically indicate 13.9 volts and 1 amp when in cruise - frankly, I disregard all other indications (you'll go crazy trying to make sense of the voltage/amp indications during varying engine power settings) unless I see a constant voltage loss and constant negative amps during high engine power which likely means another failed VR.
I always carry a spare Ducati VR in my plane. I also try to minimize use of electrical current during low engine power periods (i.e., no lights during daytime taxiing) and maximize my current use during high engine power periods (i.e., everything "On" during takeoff/cruise/approach). Don't know if this helps the VR's longevity, but it beats sacrificing more chickens ($$$) at the Ducati altar.
My new VR is very warm when in use - I can hold onto it without scorching my fingers, but it is a tad toasty (it is useful however for warming up your passenger's left knee cap or heating up one's leftover snacks inflight). I may rig up a little air scoop on the right-side exterior of the fuselage to route some external air across the VR fins. The journey continues.....
3/2014 - "0" hours - My RV-12 ELSA first flown with original Ducati VR #965-335 installed per Van's plans (i.e., on engine compartment shelf with shroud and ducting).
3/2015 - 135 hrs HOBBS - Original VR (above) failed - Autopsy suggested failure due to heat and vibration - no sign of burning/smell, just open solder joints. Replaced with new Ducati VR #965-349 relocated per Van's notification to inside the cabin under the avionics shelf. I used nutplates to secure the VR and to aid in its quick replacement if needed. I did not use any heat-transferal paste under the mounting. In addition, I added a small aluminum shroud to generally route the avionics compartment fan exhaust (like warm baby's breath) towards the VR fins - not sure this is worth the effort.
11/2016 - 410 hrs HOBBS and all is well (likely this post will doom my current VR
). I typically indicate 13.9 volts and 1 amp when in cruise - frankly, I disregard all other indications (you'll go crazy trying to make sense of the voltage/amp indications during varying engine power settings) unless I see a constant voltage loss and constant negative amps during high engine power which likely means another failed VR. I always carry a spare Ducati VR in my plane. I also try to minimize use of electrical current during low engine power periods (i.e., no lights during daytime taxiing) and maximize my current use during high engine power periods (i.e., everything "On" during takeoff/cruise/approach). Don't know if this helps the VR's longevity, but it beats sacrificing more chickens ($$$) at the Ducati altar.
My new VR is very warm when in use - I can hold onto it without scorching my fingers, but it is a tad toasty (it is useful however for warming up your passenger's left knee cap or heating up one's leftover snacks inflight). I may rig up a little air scoop on the right-side exterior of the fuselage to route some external air across the VR fins. The journey continues.....
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After my first flight I reached in under the panel and touched my newly relocated Ducati and it was a little warm but not a lot.
Ambient temp 72F and after a 30 minute flight.
E. D. Eliot
Well Known Member
Bottom Line
Not flying yet so this is all theory. So why is (relatively short lives of VR) this happening to the RV-12? There seems to be no definitive answer or the problem would have been solved - right?
Many have tried to solve the problem and it seems that we are still guessing. Or is it that there are hundreds of 12 flying with no problems and we on the VAF are reading reports of only failures, not successes. Many other types of aircraft fly with the 912 without any trouble? Just sayin ---
I'll locate my VR inside with a dedicate computer blower aimed at it and be sure that the connectors are secure - I'm guessing that it may last awhile.
I plan to fly my 12 cross country and so far have learned that it is wise to carry a spare VR, mechanical fuel pump, electric fuel pump, inner tube and tire, spare wire and connectors, tools, etc. That will add about 25 # to my gross on every flight and cost .8 aero units or more. Man########
Not flying yet so this is all theory. So why is (relatively short lives of VR) this happening to the RV-12? There seems to be no definitive answer or the problem would have been solved - right?
Many have tried to solve the problem and it seems that we are still guessing. Or is it that there are hundreds of 12 flying with no problems and we on the VAF are reading reports of only failures, not successes. Many other types of aircraft fly with the 912 without any trouble? Just sayin ---
I'll locate my VR inside with a dedicate computer blower aimed at it and be sure that the connectors are secure - I'm guessing that it may last awhile.
I plan to fly my 12 cross country and so far have learned that it is wise to carry a spare VR, mechanical fuel pump, electric fuel pump, inner tube and tire, spare wire and connectors, tools, etc. That will add about 25 # to my gross on every flight and cost .8 aero units or more. Man########
The issue of voltage regulator failures on RV-12s has certainly captured my attention as I notice my cruise power voltage now slowly dropping from it's previous 13.8 to 13.9, now sometimes as low as 13.4 volts. I have about 150 hours on the engine now.
As I review other forums I find mention of VR failures but not to the extent as the RV community. I myself also have a Rans S-7S with 1100 hours with the original VR mounted to the firewall without any additional cooling and it's been rock solid at 14.0 volts since day one.
I do agree that it seems to be a heat problem caused by additional load and firewall temps. My Rans only powers a com, transponder and portable GPS. Much lower load then the RV-12. Also reaching under the panels, the Rans firewall is warm but the RV is quite hot to the touch.
I think until Vans or one of us came come up with a way keep this regulator cooler, this will continue to be a problem.
Bill
As I review other forums I find mention of VR failures but not to the extent as the RV community. I myself also have a Rans S-7S with 1100 hours with the original VR mounted to the firewall without any additional cooling and it's been rock solid at 14.0 volts since day one.
I do agree that it seems to be a heat problem caused by additional load and firewall temps. My Rans only powers a com, transponder and portable GPS. Much lower load then the RV-12. Also reaching under the panels, the Rans firewall is warm but the RV is quite hot to the touch.
I think until Vans or one of us came come up with a way keep this regulator cooler, this will continue to be a problem.
Bill
