Stowe Navigator Wind Masthead Unit Disassembly

[NOHOH]

The anemometer stopped going round two days ago after decades of reliable service. I have ordered new bearings and they should be here in a week or so. What I would find really useful is someone who has already successfully tackled this job to `walk me through` the disassembly and bearing change sequence. Also...if someone could supply me with an exploded diagram/ engineering drawing and/or details of pitfalls to avoid....that too would be much appreciated. Many Thanks

 

[alteredoutlook]

if memory serves me right:

to remove the anemometer - firstly unscrew the oil lubricator at the front of the unit. The anemometer cups will simply pull downawards.

to remove the wind direction indicator - pick off the black cap (about the size of a 5p piece) - then undo the nut beneath.

Replacement of the innards then becomes possible.

I may have an old one lying around somewhere - if I do I'll investigate the sequence a bit more. But probably someone else on the forum will beat me to it!

 

[KREW2]

I did one a few years back.
The centre does pull out but be careful, ease it out so the bearings don't fly everywhere.
I found just cleaning mine was good enough for it last for 5 years until I sold the boat. i hope they are still going well.

 

[Plevier]

If you do a search, there is at least one excellent thread with exactly the series of photos that you want.
Meanwhile, some photos here https://plus.google.com/photos/113567095843010399028/albums/5812859456502746897
Be VERY careful pulling out the wind vane end, terribly easy to break off one of the sensors inside (there are 2). You can get from RS but about £17 each from memory.

 

[NOHOH]

Thank you Plevier, Krew2 and alteredoutlook (though not necessarily in that order). When the bearings arrive and the wind drops I`ll go up the mast and bring the mhu down and start `the voyage of discovery` to see if I can fix this thing.....not forgetting to first completely seal the socket at the masthead against the weather. I will post again to let you know how I get on.....and I might even do a "how to" if it goes well.... If not...then its going to be expensive. Cheers

 

[Plevier]

Er - I think I had a senior moment this morning - the delicate Hall effect bits are in the ST60 not the Stowe. I have done both and got confused. Sorry!
If it's an old Stowe like I had, wind direction uses a weird endlessly turning potentiometer. More recent ones are Hall effect but i haven't seen one of those.
Richard at http://www.stowemarine.com/ is pretty helpful.

 

[pagoda]

Er - I think I had a senior moment this morning - the delicate Hall effect bits are in the ST60 not the Stowe. I have done both and got confused. Sorry!
If it's an old Stowe like I had, wind direction uses a weird endlessly turning potentiometer. More recent ones are Hall effect but i haven't seen one of those.
Richard at http://www.stowemarine.com/ is pretty helpful.

It is a bit weird, but clever also. It manages to output 3 separate phases from a 12VDC power supply. The phase offsets define where it is pointing. An early alternative to a rotary encoder system. That might have been possible when Stowe designed these devices, but less robust for the environment they work in.

 

[GrahamM376]

Ours stopped turning last year. Took it off and dripped some sewing machine oil into the oil hole and it's working fine again.

 

[alteredoutlook]

if memory serves me right:

to remove the anemometer - firstly unscrew the oil lubricator at the front of the unit. The anemometer cups will simply pull downawards.

to remove the wind direction indicator - pick off the black cap (about the size of a 5p piece) - then undo the nut beneath.

Replacement of the innards then becomes possible.

I may have an old one lying around somewhere - if I do I'll investigate the sequence a bit more. But probably someone else on the forum will beat me to it!

Further to the above:
I've taken to pieces one that I had lying around.

Removing the anemometer is as described i.e remove the brass(?) oil lubricator screw completely - it sticks through the housing and in to a slot on the rotating axle of the anemometer preventing the cups from coming out. Pull the cups downward - this is quite a snug fit - they aren't attached to anything so no harm in pulling hard.

To remove the anemometer potentiometer, poke a hooked tool up the hole and pull gently downwards. It is attached by wires and so too much force will damage the wires. You will only be able to remove the potentiometer by an inch or so (the amount of 'free wire' in the unit). But you might be able to gain a bit more 'free wire' by also removing the wind direction potentiometer.

To remove the wind direction potentiometer, prise the black cap off the unit and undo the nut holding the direction finder in place. Take off the direction finder.
Now undo the tiny grub screw that exists about an inch above the brass lubricator screw at the front of the unit. Technically, (I think) this should allow the wind direction potentiometer to 'drop out' ( you just push the wind direction axle southwards, (may be best to use an oversize socket so that it pressure isn't directly on the axle)). However, my unit was has been previously 'butchered' and was also stuck in.

Hope this is useful - resoldering the connections looks fiddly! Have fun!

 

[Ruffles]

Ours stopped turning last year. Took it off and dripped some sewing machine oil into the oil hole and it's working fine again.

Me too. Except that I oiled ours some 6 years ago.

What an amazing bit of kit. Ours has been spinning continuously (as far as I know) since the boat was built in 1990.

 

[SimonP85]

Meanwhile, some photos here https://plus.google.com/photos/113567095843010399028/albums/5812859456502746897

Resuscitating this thread as our Stowe Wind Monitor has recently become reluctant to spin.

I've had a look back on old threads and cannot see any photos of the procedure still available and Plevier's link no longer works unfortunately as Google Plus now doesn't exist.

Plevier - by any chance do you still have a copy of the photos that you could re-share?

Many thanks.

 

[chockswahay]

I'm having the same issues with mine. Does anyone know hoe many bearing units the stowe has (I only managed to remove the one at the open end)....... also any advice on exact size and where to buy?

Many thanks team

 

[LowMan]

Hi, I am just fighting with this pesky IS11 right now.
Anemometer was completely blocked, but nothing that finite amount of oil did not solve. That allowed me to disassemble it (someone must have rebuilt is +10 year ago as it was wrongly assembled - oil pin on the top, bottom blocked with top screw screwed till the end and then some some standard screw sticking out over an inch. How did that work for over 10 years, no idea.

So I opened, cleaned all I could, assembled and oiled. Works to some degree.
I would love to replace the bearings, but I am not sure how to remove them in the first place. Do I just push them out by force ?

Thanks in advance.
LowMan