Replacing ST50 masthead anemometer bearings -how to

skyflyer

skyflyer

Well-Known Member
Joined
26 Jan 2011
Messages
1,433
Location
Worcester, UK
Visit site
I originally posted this as a reply in someone else's thread and realise its a bit lost as it isn't an obvious search result if you search on "ST50 wind" (i couldn't find it myself when looking to show a friend how to do it) ) so here it is again in its own thread, for anyone that might be able to use it

If photos appear truncated look at post #8 on original thread
http://www.ybw.com/forums/showthrea...ind-speed-slowing-down&highlight=smb+bearings


1p6j2p.jpg



2el8cu8.jpg



2vnqpn6.jpg



359crxg.jpg



2eecti0.jpg



2w7qucy.jpg



34pflzp.jpg



2j1oaj8.jpg



qqbxio.jpg



2hhptew.jpg
 
Great post and perfect timing for me. I need to do mine over the winter.
Can you tell me the best place to source the bearings? I take it I'll need 2 sets, one for each end?
Thanks
David
 
I bought a kit from eBay but since then discovered SMB bearings who can supply just about any type and size, imperial or metric, for peanuts compared to the ebay seller! However I cannot remember nor do I have a note of the size, I'm afraid. maybe someone else can help with that?
 
Rats!
ST50 Early ST60 Wind Vane Transducer Service Step 1 Remove the black plastic anemometer cups and wind direction feather using a 1.5mm
allen key to remove stainless grub screws.
Step 2 Remove pods from housing. Carefully grip pod and rotate back and fore while pulling gently don't pull to hard as damage to wires / sensors can result. When pods are free they can be rotated several times to unravel wires, which will make step 3 easier.
Step 3 Remove PCBs sensors are very fragile so take great care. Plastic is also brittle with age. Method I use is place small flat screwdriver in slot and use it to push on underside of PCB. Don't lever plastic clips they break. Work round from slot to slot pushing PCB up a little at a time. The important point here is that PCB comes out square if it get twisted ceramic sensors will be damaged.
Step 4 Now you have pods separated remove and discard old O-rings.
Step 5 Wind speed pod has 4 small magnets in plastic carrier. Pull the 4-magnet carrier of
end of shaft with short nose pliers
Step 6 Warm plastic pods with hair drier this prevents brittle plastic cracking. Then while
supporting pods push shafts and bearings out from inside.
Step 7 Remove old bearings from shafts. I use a vice to shatter small bearings (wear eye
protection). Remove brass magnet from end of wind direction shaft.
Step 8 Clean shafts with some fine wet and dry. Fit new bearings to shafts, replace brass
magnet to wind direction shaft.
Step 9 Warm Qla~tig pods with hair drier then push shafts and bearings back into pods. Push the 4-magnets in carrier back onto wind speed sfiaft, Fit new 0- rings. Now hold shafts and spin pods they should spin free.
Step 10 Replace PCBs taking care that the locating key lines up with slot in PCB and that PCB goes in square. The fragile ceramic sensors need to slide into 2 slots inside the pod, Take great care not to damage ceramic sensors.
Step 11 Apply very small amount of silicone grease to 0 rings. Rotate pods several time to rave wires back up to make them short again then push pods into housing.
Step 12 Apply a little silicone grease to top of bearings to keep weather out.
Step 13 If your wind direction shaft doesn't have a flat on it you will have to modify your wind direction feather moulding using a 3mm drill to remove flat. Also use 3mm drill to open up hole in cups moulding as it can be tight.
Step 14 Fit new grub screw with thread lock to wind direction feather. By placing square nut in slot inside moulding. Fit other grub screw to
Step 15 Fit new black plastic anemometer cups and wind direction feather using 1.5mm allen key to tighten stainless grub screws. You want grub screw points to go into groove in shaft ..

Sorry folks thats all I have!seems to be the lot, more or less?
Sorry the size limit for .pdf is only 19kb

 
Nigel - I don't have access to the forum (I don't have a Bav either!)
I was abit confused as I posted the photo montage on how to do it but then someone else posted a more detailed text version. I guess the two compliment each other but I had hoped the notes I added to the photos were sufficient - oh well, best intentions etc!
 
Thanks skyflyer for your initial useful photos and instructions.
My unit is all plastic, no alloy.
Hopefully the text I posted and the .pdf I sent to Nigel refer to the earlier model (is it D135?)
I have a kit, just need to get a youngster to fetch down the jammed unit for repair!
I was allowed to join the Bav site even though I have the wrong brand of AWB!
There is much commonality of issues with various modern boats and engines, enough I hope to be able to contribute to Nigel's site when appropriate!
Fair winds,
Paul.
 
Last edited:
I know it's an old thread but it is still relevant. Post 1 picture 9. The brass magnet housing won't come off my shaft. It is supposedly push on, has anyone any good ideas. The bearing behind is is fine, so I could leave it, but I would really like to change it as well.
 
Im sorry I don’t recall how I did it for the photo. Maybe it was just a simpler fit
You could try freezing the assembly and then did only the brass bit into boiling water to try and get some differential thermal expansion. Not sure I’d apply a lot more heat as I don’t know how the magnet is held in. Maybe a hot air gun?
 
Laysula said:
I know it's an old thread but it is still relevant. Post 1 picture 9. The brass magnet housing won't come off my shaft. It is supposedly push on, has anyone any good ideas. The bearing behind is is fine, so I could leave it, but I would really like to change it as well.
Click to expand...

I've put the shaft in a small vise (with plastic pads) and then tapped a needle-nose pliers in between the vise end and the brass magnet housing (with the smooth side of the pliers, not the grippy surfaces). The pliers get thicker the further they go in and pulled it off pretty easily.
 
Thank you for the advice, I tried thermal expansion and also thin nose pliers. I don't think the pinion puller will work on the brass bit as it has a blind hole. As the bearing behind seems fine I have decided to leave it on and reassemble. I bought the bearings and "o" rings on line for less than the price of a London beer and it's all ready to go back on the mast.
Thank you all for the advice
 
This is the sort of thread that should be kept in a special repository of excellence, or made into a sticky. Brilliant advice made the job enjoyable and rewarding. Thank you!
 
You must log in or register to reply here.

Share this page

Top