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skatzman
12-19-2008, 05:49 PM
autohelm ST4000 worked well until a month ago. When I power it on the helm goes hard over to turn the boat to port. I can press standby to stop it. I can adjust the helm back to center using the +10 and +1 keys. When I press autopilot key it steers hard over to port and refuses to pick up a magnetic course. The only variable I can think of is I used power tools nearby it in doing some fibreglass work. I have checked the calibrations and checked the electrical connections, they are good. Per a contact with Raymarine I held the standby key down for 10 seconds. No change. Any one have any ideas?

BobJ
12-19-2008, 06:15 PM
The fluxgate compasses go out - that seems to be the weak link. I just bought a replacement compass on E-Bay because mine went whacko half way to Hawaii.

You can try taking the compass unit off and shaking it to make sure it's not frozen up - somebody recommended that to me. (Didn't solve the problem in my case.)

Where do you keep your boat? Maybe we could try my replacement compass with your A/P before I install it on Ragtime.

skatzman
12-19-2008, 07:25 PM
I keep the boat at Brickyard Cove dry storage#3 at Pt Richmond just down the street from the RYC. I live in South Lake Tahoe. I'll be down again to sail the next January 10 and 11. Thanks for your offer to try that. It's worth a try. I'll contact you in January. Any other ideas?

brianb
12-24-2008, 08:27 AM
Hi,

I have have hacked the Raymarine compass. Here is a data sheet that describes the guts. Electrically the compass module is very simple, nothing more than a several coils of wire wound over a floating ferrite core that is designed to float in a plastic donut shaped housing, hence the rattle when you shake it.

Here is the URL that describes the core. http://www.fluxgateworld.com/802570900035631E/pages/1D3F82FD925C05958025730E0046AA06/$file/AR45-00-00%20Fluxgate.pdf?openelement

If you have questions I can send you measurements of resistance you should see on the terminals.

Since the helm goes hard over immediately at power up, this indicates your not really going into standby as it normally should. Do you have a rudder sensor attached ? If this is out of adjustment you would see that type of reaction as well as driving the helm over in auto mode.

Does the compass indicate a proper course when in standby ?

Good luck,

Brian


autohelm ST4000 worked well until a month ago. When I power it on the helm goes hard over to turn the boat to port. I can press standby to stop it. I can adjust the helm back to center using the +10 and +1 keys. When I press autopilot key it steers hard over to port and refuses to pick up a magnetic course. The only variable I can think of is I used power tools nearby it in doing some fibreglass work. I have checked the calibrations and checked the electrical connections, they are good. Per a contact with Raymarine I held the standby key down for 10 seconds. No change. Any one have any ideas?

skatzman
12-25-2008, 10:30 AM
Brian, Thanks for your reply. No rudder sensor is on the boat. This AP has always gone hard over at power up. The difference is previously it could pick up and steer a magnetic course after touching standby, centering the ram, and then touching auto. The compass on the control head does indicate a proper course, within a few degrees of what I know to be an accurate analog compass. Thanks everyone for your input and I welcome more ideas. Steve Katzman

brianb
12-25-2008, 10:57 AM
Hi Steve,

Well if the compass reads properly that isn't the problem. Since you have no rudder sensor it seems as though you are likely to be suffering from moisture intrusion in the control head and maybe an open or shorted contact on the circuit board.

I would suggest taking the control unit out and warming it up a bit in a dry environment, maybe even a black plastic bag in the sun on a not rainy day in Richmond. Let it bake a bit then retry.

I had this generation of RM instruments on a boat and they would collect water in them over years of use. The circuit boards near the bottom of the case would corrode. I did some reconstruction on one instrument to recover functionality. The cases can be split apart and you can inspect them (as I recall). I swore off RM on then next boat and have BG for the important bits.

I have an ST4000 to which I added a rudder sensor. It does not go hard over at power up. However since I added the rudder sensor it declares itself to be a ST5000 after I tweaked settings, so that might be the diff. My boat is in Richmond as well. If you want someone to hold a beer and offer words of questionable value while you take apart the instruments I am around.

Brian

brianb
01-07-2009, 12:25 AM
I keep the boat at Brickyard Cove dry storage#3 at Pt Richmond just down the street from the RYC. I live in South Lake Tahoe. I'll be down again to sail the next January 10 and 11. Thanks for your offer to try that. It's worth a try. I'll contact you in January. Any other ideas?

Hello skatzman,

ANother comment. You mentioned the AP started functioning again after drying it out. The PC boards are made with fiberglass and the fibers absorb water that will work into the circuit area. This is especially an issue along the edges of teh board. You might take some RTV (silicon sealant, clear) and seal the edges of the board once you are convinced it is dry. RTV is electrically neutral and will not affect circuitry. Epoxy could also be used, just a bit more permanent.

Brian

skatzman
01-08-2009, 10:56 AM
Thanks for your continuing input. After much bench testing and another 48 hr drying session it is working as it did before: upon power on the drive steers the boat hard to port, correctable by stdby, centering the drive and then I can push auto and it holds a course. That is as good as it ever worked. The one glitch that I see is there is an inteermittent tendecy to steeer the boat to port by continuously small increnments of the drive. This can be corrected by turning the ap off, waiting 5 minutes and starting again. Oh Well! I plan to install it in the boat Friday the 9th of Jan, trial it, then go sailing in the midwinters this weekend. My thought is the brain in the head is stuggling toward complete non function, I can buy time by drying it out but I will eventually need a new head. Any 4000 heads out there?

Fun Zone
01-08-2009, 10:28 PM
My RM 1000ST has a moisture issue also. If left on the boat on a damp night I have to set it in the sun for a while or use a hair dryer to cook the moisture out of it. I would never trust it offshore. No more Raymarine for me either.
Fun Zone

skatzman
02-03-2009, 06:03 PM
So roughly a month after reinstalling and it working ok it is now back to it's old trick of steering the boat to port only, I'm convinced the head(brain) is totalled. Anyone have a head for a ST4000 they want to sell?

Thom
03-15-2009, 09:33 AM
Don't trash until you check the power leads. Upon installation of my most recent autohelm it passed the "at the dock" trials but after leaving the harbor for the sea calibration it did just as you describe, tiller hard over. Reading the instructions I found a very small print note that when this happens the leads to the tiller control unit should be reversed--did that, works fine. Dunno why it would work at first then stop working, though; but thot you might check it before giving up.

skatzman
11-22-2009, 01:45 PM
After many drying sessions and reinstallation on Diannehe original ST 4000 head would function well, the only quirk being it would put the helm hard to port upon being powered up, but I could get it back by pressing standby and correcting with the +/- keys. Back in September a guy contacted me from PNW and offered a 4000 head that worked, had been repaired by a Seattle shop. I bought it from him for approx $50 with his gaurenttee if it didn't work he'd refund. Upon installing it and doing the calibrations it worked very well and I used it in the Vallejo 1 race with good results. So I now have the old head for a spare. I wouldn't trust either one for a long race but they work fine for the occasional single hand that I prefer, and they work fine for single handed day sailing. Thanks to Terry C for support and the loan of a ST 4000+ as a trial, thanks to Greg N for the words on not being too concerned about magnetic deviation.