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  #81  
Old 04-08-2017, 09:37 PM
AirHound AirHound is offline
 
Join Date: Oct 2006
Location: OFallon IL now, everywhere before
Posts: 113
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Quote:
Originally Posted by RFSchaller View Post
I got about 400 hours out of my first VR, and I wonder if I overreacted to a low bus voltage after start. I'm not sure that ROTAX and Vans deserves the condemnation focused on them for the VRs.

I do carry spare spark plugs, VR and electric fuel pump when I am on the road since they are not readily available at Podunk Airport, USA!
Expecting the unexpected I see...

A mechanical pump?

What's the plan for a flat?
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  #82  
Old 04-08-2017, 09:42 PM
AirHound AirHound is offline
 
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Location: OFallon IL now, everywhere before
Posts: 113
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Quote:
Originally Posted by MMiller View Post
4/8/2017 update

This improvement may cause other issues...see post 78 below


Dave,

Iíve been giving a lot of thought to your question about improving the regulator while itís opened up. We know these regulators fail from stresses in the power component leads. I always assumed these were operationally induced stresses. Iím beginning to rethink this theory. Yesterday I took apart a regulator (from the Sport Cruiser community) that was sent to me last week. This was a real eyeopener into the poor build quality by Ducati. Iím now wondering if these stresses were loaded on the components during manufacturing. With the new pliable gel potting compound the Operational vibrations induced on these pre-stressed leads may be enough to fracture the solder joints. This could explain why some last 10 hours and some hundreds of hours. Anyway, back to your question. There is a screw that holds down the bridge rectifier. My thought is to remove the screw, add an insulator and a washer to the screw and clamp both the PCB and the bridge. Then resolder the bridge and SCR leads to relieve any stresses. This will prevent any relative movement between these two parts.




As for that Sport Cruiser regulator

Thinking hi-adventure for those mounted in the cockpit which smoke and sputter to a short...
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  #83  
Old 04-21-2017, 02:39 AM
omerward omerward is offline
 
Join Date: Jul 2005
Posts: 17
Default VR repair

Mike, I can't thank you enough for your thorough analysis of the VR failures. Mine had a burned G pin just like your photo. I opened it up and the solder connection from the pin to the PCB was cracked. I made a good solder connection on both G pins and it is working fine so far. Thanks again for your analysis.
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  #84  
Old 04-21-2017, 08:00 PM
MMiller MMiller is offline
 
Join Date: Oct 2010
Location: Babylon NY
Posts: 49
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Great job Sam, You're welcome and thanks for the feedback.
One suggestion, to increase the current carrying capacity of the G pins, donít use the black Rotax plug. Connect the fastons directly to the regulator. This will give you 100% mating contact.


Vanís, Rotax, Ducati, if you are listening...The Rotax 965-349 Ducati 362001 rectifier regulator is not a lost cause, but you need to deal with the design and manufacturing deficiencies if you want to put this behind you;

1) Eliminate the manufacturing induced lead stress on the power components.
2) The potting compound is too soft, and it's unstable over the rated operating temperature of the regulator. (95 Shore A to 30 Shore A)
3) Operating stresses (vibration) acting on the pre-stressed leads (item 1), in a potting compound that softens with temperature (item 2), over time results in PCB solder joint separation failures.
4) PCB connections that were never soldered indicate a poor (or nonexistent) inspection/QC process.
5) Insufficient clearance between an un-fused, high current carrying PCB trace and the rectifierís grounded metal case. The design relies on the insulating value of the PCB's solder mask layer.
6) Poor connector/plug/tab length design. The design of this 22 amp connection only allows about 80% of mating capacity between the connectorís male tab and female AMP fast-on.
7) The material for the male tab is 7.5mm thick, this equals .0295", the AMP faston is designed for an .032" tab thickness. The design falls 8% below optimum thickness.

Mike

Last edited by MMiller : 04-22-2017 at 08:19 PM.
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  #85  
Old 05-15-2017, 03:32 PM
Slane Slane is offline
 
Join Date: May 2008
Location: Hillsboro, OR
Posts: 148
Default VR Meltdown

During a flight last week, I had a faint smell of something burning. Upon landing I examined the voltage regulator, which is located under the instrument panel. The following images display what it is I saw.

https://srlane9.tumblr.com/post/160707507168/vrmeltdown

This is the second VR I've installed. The first was installed on the shelf forward of the firewall. The first VR lasted approximately 75 hours while the 2nd one lasted 200 hours.

There didn't appear to be an indication of a pending VR failure with no irratic fluctuations in either voltage or amps.

Next step for me will be to download data from skyview to see what it is that I missed.

Looks like some wiring repair and another VR installation.

Scott
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RV12 Completed & Flying 2013
#120043 N728SL
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Last edited by Slane : 05-15-2017 at 03:42 PM. Reason: Adding photos
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  #86  
Old 05-15-2017, 03:40 PM
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DaleB DaleB is offline
 
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Location: Omaha, NE (KMLE)
Posts: 1,528
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That looks like it could be just a connection failure. The regulator may be OK. I'd suggest taking the wires out of the connector and seeing what damage there is to them.

It's been observed before that the standard connector doesn't fully mate the spade connectors, even when fully engaged. If you had a wire not quite completely seated it could have caused a flaky connection, heating, arcing and the results you see.
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  #87  
Old 05-15-2017, 09:14 PM
Slane Slane is offline
 
Join Date: May 2008
Location: Hillsboro, OR
Posts: 148
Default VR Meltdown

Thanks for the replies. I removed the VR and upon closer inspection, the "R" connection may not have had an adequate connection. I like the idea of skipping the black connector but want to be sure the VR is still viable. Is there a way to test the VR?
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  #88  
Old 05-16-2017, 12:18 AM
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Piper J3 Piper J3 is offline
 
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Location: Hinckley, Ohio
Posts: 546
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Quote:
Originally Posted by Slane View Post
Thanks for the replies. I removed the VR and upon closer inspection, the "R" connection may not have had an adequate connection. I like the idea of skipping the black connector but want to be sure the VR is still viable. Is there a way to test the VR?
Yes, place it in the round can in your garage that you haul out to the curb once a week...
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Jim Stricker
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PPL - 1970
80 hrs Flying Aeronca Chief 11AC
1130 hrs Flying 46 Piper J3-Cub
RV-12 E-LSA #120058 AWC 7/12 Bought Flying 10/2015 with 48TT - Hobbs now 231
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  #89  
Old 05-16-2017, 04:30 AM
rv7charlie rv7charlie is offline
 
Join Date: May 2006
Location: Pocahontas MS
Posts: 1,859
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If you're doing the mod anyway, do it now & plug the individual fastons onto the current regulator, & try it.
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