crackle
New Member
On a recent sailing trip on my friends boat his Raymarine ST2000+ tiller pilot failed. When it was setup to steer automatically to a compass heading it just put the tiller hard over and refused to work correctly.
This was not the first time this had happened, it did the same last season, but following a recalibration of the fluxgate compass it continued to work.
I have now taken it apart and discovered the real reason for the failure is 2 rubber buffers which cushion the ram worm gear at each end of its travel had broken up and pieces of rubber were floating around inside the tiller pilot, some of these pieces had become jammed in the fluxgate compass gimbals preventing the compass from operating.
This would explain why the fault was happening intermittently, as each time the autopilot was put away the pieces would have been shaken free.
Below is a photo of the shaft end buffers after I glued the pieces back together.
Or at least there would be if I was allowed to post images.
On my friends behalf I contacted Raymarine to enquire about spares to replace the rubber buffers and a new seal to fit on the end of the shaft to prevent the ingress of water and salt atmosphere. The only help they could offer was to contact a local marine electronics specialist.
I did as suggested but they did not have any spares either. But did say something was needed to act as a buffer as without them the mechanism could jam on the end stops and lock up the motor. They suggested using 4 suitably sized "O" rings 1 fitted over each end of the aluminium guide shafts.
I discovered the shaft seal is a standard imperial sized one, (although rather uncommon, the size was 3/4" internal x 1" external x 1/8" thick) I finally located one ,https://www.bearing-king.co.uk/products.php?d=19.05&D=25.4&bt=3 and ordered it along with another odd sized "O" ring, 3/4" internal x 1/16" thick) https://www.ebay.co.uk/itm/METRIC-NITRILE-70-RUBBER-O-RINGS-1-5MM-CROSS-SECTION-13-5MM-ID-TO-25-5MM-ID/371790018519?ssPageName=STRK%3AMEBIDX%3AIT&var=640765372517&_trksid=p2057872.m2749.l2649 which seems to act as a primary seal in the push rod shaft seal.
I joined the Ramarine help forum and made 2 posts concerning the repair of the autopilot for the benefit of others who may have had the same symptoms, the posts were not approved. Below is a reply from the moderator as to why.
"Raymarine does not support modification of its autopilot equipment designs and will not approve threads/posts which recommending such modifications. In the case of the failures described, the recommended action to address the reported symptoms is to have the drive serviced by Raymarine's Product Repair Center."
My opinion of Raymarine as an organisation and the ST2000+ autopilot has changed. Considering these autopilots cost approximately £600 10 years ago, and strangely enough they still seem to be current today.
It is let down by the poor design of the mechanics, the cheap materials and lack of spares available.
The only possible option for parts offered by the "Marine Electronics" specialist suggested by Raymarine themselves was the possibility of a complete new motor and ram shaft assembly, costing in excess of £300.
The pilot is powered by a cheep little DC motor, available on Ebay, type number is RS 555SH.
https://www.ebay.co.uk/itm/253306258046?
On the outer end of the ram there is a silly little spring clip retainer. I have never seen these used in an application where reliability is paramount.
The main ram shaft end seal does not have an anti magnetic garter spring, it is positioned less than 2 inches from the compass, proper marine grade stainless is anti magnetic. It may be a cheaper type of stainless so if it fits I will reuse it in the new seal just in case it is less prone to attack by salt water, this one looks in good condition but the seal lip does have some wear which is why I am replacing it.
I forgot to mention the "O" rings used for the end of travel buffers were 6mm x 2.5mm "o" rings I happened to have in my metric O ring kit.
I hope this thread can help someone else when they suffer the same failure.
I have not finished and tested the repair but I dont expect any problems. I will update after this weekends sailing.
If you want to see the images which I would have included in this thread, if allowed, then you can see them in another forum here.
http://www.golbornevintageradio.co.uk/forum/showthread.php?tid=6920
Mike
This was not the first time this had happened, it did the same last season, but following a recalibration of the fluxgate compass it continued to work.
I have now taken it apart and discovered the real reason for the failure is 2 rubber buffers which cushion the ram worm gear at each end of its travel had broken up and pieces of rubber were floating around inside the tiller pilot, some of these pieces had become jammed in the fluxgate compass gimbals preventing the compass from operating.
This would explain why the fault was happening intermittently, as each time the autopilot was put away the pieces would have been shaken free.
Below is a photo of the shaft end buffers after I glued the pieces back together.
Or at least there would be if I was allowed to post images.
On my friends behalf I contacted Raymarine to enquire about spares to replace the rubber buffers and a new seal to fit on the end of the shaft to prevent the ingress of water and salt atmosphere. The only help they could offer was to contact a local marine electronics specialist.
I did as suggested but they did not have any spares either. But did say something was needed to act as a buffer as without them the mechanism could jam on the end stops and lock up the motor. They suggested using 4 suitably sized "O" rings 1 fitted over each end of the aluminium guide shafts.
I discovered the shaft seal is a standard imperial sized one, (although rather uncommon, the size was 3/4" internal x 1" external x 1/8" thick) I finally located one ,https://www.bearing-king.co.uk/products.php?d=19.05&D=25.4&bt=3 and ordered it along with another odd sized "O" ring, 3/4" internal x 1/16" thick) https://www.ebay.co.uk/itm/METRIC-NITRILE-70-RUBBER-O-RINGS-1-5MM-CROSS-SECTION-13-5MM-ID-TO-25-5MM-ID/371790018519?ssPageName=STRK%3AMEBIDX%3AIT&var=640765372517&_trksid=p2057872.m2749.l2649 which seems to act as a primary seal in the push rod shaft seal.
I joined the Ramarine help forum and made 2 posts concerning the repair of the autopilot for the benefit of others who may have had the same symptoms, the posts were not approved. Below is a reply from the moderator as to why.
"Raymarine does not support modification of its autopilot equipment designs and will not approve threads/posts which recommending such modifications. In the case of the failures described, the recommended action to address the reported symptoms is to have the drive serviced by Raymarine's Product Repair Center."
My opinion of Raymarine as an organisation and the ST2000+ autopilot has changed. Considering these autopilots cost approximately £600 10 years ago, and strangely enough they still seem to be current today.
It is let down by the poor design of the mechanics, the cheap materials and lack of spares available.
The only possible option for parts offered by the "Marine Electronics" specialist suggested by Raymarine themselves was the possibility of a complete new motor and ram shaft assembly, costing in excess of £300.
The pilot is powered by a cheep little DC motor, available on Ebay, type number is RS 555SH.
https://www.ebay.co.uk/itm/253306258046?
On the outer end of the ram there is a silly little spring clip retainer. I have never seen these used in an application where reliability is paramount.
The main ram shaft end seal does not have an anti magnetic garter spring, it is positioned less than 2 inches from the compass, proper marine grade stainless is anti magnetic. It may be a cheaper type of stainless so if it fits I will reuse it in the new seal just in case it is less prone to attack by salt water, this one looks in good condition but the seal lip does have some wear which is why I am replacing it.
I forgot to mention the "O" rings used for the end of travel buffers were 6mm x 2.5mm "o" rings I happened to have in my metric O ring kit.
I hope this thread can help someone else when they suffer the same failure.
I have not finished and tested the repair but I dont expect any problems. I will update after this weekends sailing.
If you want to see the images which I would have included in this thread, if allowed, then you can see them in another forum here.
http://www.golbornevintageradio.co.uk/forum/showthread.php?tid=6920
Mike
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