Author Topic: Jefa Auto Pilots DU-TS Problems  (Read 1201 times)

stevem

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Jefa Auto Pilots DU-TS Problems
« on: March 25 2019, 22:41 »
Jefa auto pilot problems on Vision 42 2015 . The auto pilot on my boat went wrong at the end of the first season and was “Swopped” by the yard in Greece that worked fine for one year and finally packed up in June 2018. I removed it and took it back to U.K in July

To see the previous posts refer to Page 5 Oct 2018.
I sent my auto pilot back to Jefa in Dec 2018. They say that they have tested it twice and found no problem with the unit. They have sent it back to the yard in Greece so will find out in April if it will work. The notes on testing the rudder feedback are very helpful, thanks for posting them. This is obviously a serious fault ,if it was on a car there would have been a product recall. Why don’t we get it on our boats?

SofiaB

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #1 on: March 26 2019, 05:48 »
I have a 2016 Vision 46 and I had an issue with the autopilot where my Garmin 820 Chartplotter kept alarming a rudder limit error. Recalibrated several times and garmin assisted with different troubleshooting steps without success. They pointed to the rudder limit switch which is actually in the Jefa drive. So I removed the drive, removed the rudder sensor which is actually a 5v pot. I tested the pot and found no issues. I then tested the pot turning it very slowly and found a dead short at approx 2.5v or half a turn. Unless you turn it very slow you won’t see it on the meter. $10 pot available locally and I eventually received one from Bavaria Germany under warranty. No problems since.

The alarm would occur three times and then the autopilot would shut off and the boat would turn n suddenly. Not the safest alarm recovery!  Perhaps heading hold would be better with the alarm.

Hope this helps. If this is your error I do have manual info and manuf info on the pot. [/img]]
Cheers,  Stuart  (Sofia)

Conralph

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #2 on: April 10 2019, 15:43 »
I had the same mistake. Please also note the older posts.

After the mistake, I sent the device to Jefa, but it should also be sent back, because they have "found no error". I insisted on changing the sensor because I also measured a fault with the voltmeter. The sensor was then changed and I drove the last season without further error.

SofiaB, if it happens again, how did you change the sensor in the device? Is there a manual ?

Thanks Ralph

Alphadug

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #3 on: April 11 2019, 17:32 »
Hi SofiaB,  I have exactly the same problem as I posted earlier, 3 errors and then a hard right turn. So, what is the pots resistance? In ohms or Kohms. 5V is just the V drop across it, or do I need to apply ohms law and figure it out myself? I can't seem to read any of the files you attached. Thanks, Doug

SofiaB

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #4 on: April 12 2019, 01:10 »
Doug, Set your meter to one setting above 10K Ohms.  Start by testing at 0 Ohms and turn clockwise very slowly.  When I tested initially I turned the pot too fast and noticed no issues.  I then turned very slowly and almost exactly at 5kOhms, it went to zero indicating a short.  This short causes the rudder error message and when it occurs several times, it turns off autopilot and the boat turns rapidly. 

I replace the pot and have had no issues.  Attached is a photo of the POT.  Bavaria sent me a replacement but it tooks 6-8 weeks to arrive. In the meantime I found one at my company in our Maintenance Dept!  It cost $10 and can be purchased from any electronics store or online.  I used the existing sprocket as the replacement did not have one.  I have uploaded photos and hopefully they will load.  I will post a "manual" of sorts which provides additional info. 
Cheers,  Stuart  (Sofia)

SofiaB

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #5 on: April 12 2019, 01:12 »
Ralph, Doug,

Manual attached.

Stuart
Cheers,  Stuart  (Sofia)

Alphadug

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #6 on: April 12 2019, 17:07 »
Perfect.
Thanks Stuart!

Doug

Conralph

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #7 on: April 18 2019, 09:56 »
Great, thanks. Ralph

hidrotherapy

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #8 on: April 18 2019, 14:15 »
This is usual problem with combination Jeffa - Garmin.
It is necessary to instal Garmin rudder feedback (cca 200 eur) and everything will be ok.
That problem I had on several boats and after that all function great.

canuck

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #9 on: April 18 2019, 23:58 »
I agree with Hidrotherapy - replace the Jefa part with a separate Garmin rudder sensor. It may require a bracket to support it.
I had problems with the Jefa part for two years. |Exactly as described by others. They found the dead spot at mid rudder position after replacing every other part of the system under warranty.  They changed the Jefa for a new one, and it was better for a few months, but then started to do the same thing - couldn't rely on the autopilot not to kick out on rudder calibration error.
They finally changed it to a completely separate unit by Garmin, and it has been working faultlessly for several months now.  Fingers crossed !

SofiaB

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #10 on: April 19 2019, 04:48 »
I also considered adding a Garmin rudder sensor as modification to the original design and this was actually suggested by Jefa.  This would require some engineering with fabricated brackets for mounting, along with testing. 

But, the original pot is very inexpensive ($10 US) and I was not convinced that I pot was simply defective so I replaced it and ordered a few spares.

However, I also found another pot with the same specs as the ETI Systems MW22B-10-10 Pot.  ETI Systems MH22B-10-10 is rated with a higher precision and wear.  MW22 is rated for 1,000,000 turns where MH22 (Hybrid) is rated for 10,000,000 turns.  So, I ordered one of these in case the MW22 fails.

Since August 2017 I haven't had any issues.  If I do have issues, I will try the Hybrid option.  My Spares bin actually has 3 MW and 2 MH, so I should be good. 

The Hybrid option is, however, a much higher price at around $80 (US). 

If both versions fail, perhaps I will try other options; possibly a servo based POT, which they also have as a special order item in the same case.  Time will tell.
Cheers,  Stuart  (Sofia)

canuck

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #11 on: April 22 2019, 12:46 »
Hope you have better luck with the replacement Jefa rudder sensor than I did.  THe second one lastest a few months and then started the same old fault tripping on rudder calibration error.
The new Garmin sensor seems to be working fine, but it does as you say involve a bit of mucking around to make a bracket.
Good luck !

Conralph

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #12 on: April 24 2019, 10:27 »
Google Übersetzer !

Hello, that the error occurs again after successful repair makes me worried. The feedback from Jefa was actually that the error can no longer occur. We go from Baltic in the Mediterrian this sommer (3000sm). Now I would get me a replacement sensor.

Stuart, I added some photos of the sensor, how is the gear fixed on the shaft, just clamped with the O-rings?

Canuk, do you have a picture of the external rudder angle sensor installed? How did you create the connection to the rudder control?

Thanks Ralph

canuck

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #13 on: April 25 2019, 09:06 »
HI Ralf - the dealer actually did the install for me, and had to make a wooden bracket off the rear bulkhead to accept the Garmin sensor, which has a link onto the rudder arm. I will try and get a photo and post next time I am down at the boat.  I definitely have no long term confidence with the Jefa sensors, although I don't know why they cant make it work - it is essentially just a potentiometer, but for some reason the Garmin system does not like to see any dead spots at the centre rudder position.
Nigel

SofiaB

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #14 on: April 25 2019, 11:45 »
Conralph, yes the sprocket simply presses on with the washers. 

I suspect that the Pots from Jefa have defective winds, most likely the entire lot was defective.  The replacement I found was in my company's maintenance department and had been there for years.  Pots last a very long time, but they are wound and if a single winding is bad, the pot will not work in this application.  For other applications, the defective pot would most likely not cause any issues whatsoever. 

The "hybrid" pot has a poly lining which seals the winding and may correct the issue.  I suggest this option before engineering a completely different solution.
Cheers,  Stuart  (Sofia)

Alphadug

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #15 on: April 25 2019, 17:58 »
I think what happens with the wire wound pots is this: When the autopilot is engaged (especially when motoring) the wiper in the pot sits in the centre position and oscillates slightly to maintain a heading, this oscillation in one place wears out the winding in the "centre" of the pot causing an open not a short. The pilot has now lost the feedback and loses track of the rudder angle and goes haywire. Ours lasted 3 years. I couldn't find the ETI part so have sourced the "hybrid" replacement from Bourns. Will install it when I get it and see how it holds up. I assume you need to install the new pot in it's central position ? or does the autopilot calibrate it?

Doug

Conralph

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #16 on: April 26 2019, 05:11 »
Thanks for the answers,
i will get a sensor, if there are problems. The question of the installation position of the potentiometer is interesting. I would bring the AP to the middle position, then remove the potentiometer, install the new one also in the middle Position.

Canuck, pictures would be great.

Ralph

canuck

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #17 on: May 06 2019, 06:04 »
Hi Ralph
sorry for the delay in replying with photo of the Garmin sensor mounted behind the rear bulkhead.
You have to be a contortionist to access this compartment to even take a photo let alone work in there.
the photo shows (or tries to show!) the new sensor mounted on a wooden bracket, with a new arm to the existing main steering arm. You can see on the right of the photo the main ram from the Jefa steering device which is mounted on the starboard side of the rudder stock in my boat, with the new sensor and shaft on the port side of the rudder stock.
Hope this helps
Nigel

Conralph

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #18 on: May 16 2019, 18:39 »
Canuk, great,
Sorry also for the delay. I was out of office. We start in 2 weeks, i hope we have no problems with it. on the trip i will proved if the position is possible in my boat.
Thanks Ralph

hidrotherapy

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #19 on: May 16 2019, 21:09 »
This is Garmin rudder feedback on Bavaria 46 cruiser (2015).
Everything work perfect.
This rudder is on port side.

SofiaB

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #20 on: September 20 2019, 03:13 »
Well, I guess I need to eat crow.  I posted options for additional pots (hybrid pot) and provided some docs regarding the pot and swap-out.  But, the second installed pot has now failed. 

So, I purchased and installed the Garmin Rudder Sensor (GRF 10).  Installation on my Bavaria Vision 46 was simple and the standard cable reached back to the Garmin Autopilot Reactor. 

I have spares of the 10k pots so if the Garmin sensor does fail, I could switch back to the original sensor.

Now that I have had two failures, I must admit that the original solution was a poor solution.  I should have realized this when both Jefa and Garmin mentioned changing to a Garmin rudder sensor.

I have posted photos of the installation on my Vision 46. 
Cheers,  Stuart  (Sofia)

Conralph

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #21 on: September 21 2019, 19:45 »
Great, I needed that. On our trip to the Mediterranean, the new sensor repaired by Jefa has given up again after nearly 3000sm. Luckily we had a replacement sensor with us. Now we were hoping for the "hybrid" controller. But I will now also convert to the external sensor. The photos are very good, so I would have to cope. Was there any special dimensions that needs attention?

Ralph

SofiaB

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #22 on: September 22 2019, 00:55 »
Ralph,

I installed the rod 110cm from the pivot point of the sensor and the rudder shaft. On the sensor that is one hole back from the end.

I received the attached drawing from Jefa.
Cheers,  Stuart  (Sofia)

Conralph

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #23 on: October 08 2019, 16:12 »
SofiaB,
thank you for the information. I also saw your mount in the photo. The situation in the Vision42 is a little different, I report when I finish the bracket. Also thanks for the documentation of Jefa.

Ralph

Jjackson18b

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Re: Jefa Auto Pilots DU-TS Problems
« Reply #24 on: October 10 2019, 03:36 »
All, this is a great thread.  I’ve had 2 pots fail in my V42 I will be ordering GRF10 for next season.  Conralph please post the bracket you make.

Cheers JJ
Jon J.  SV Ruck-Up