rudder bearing specs

[Mike]

Hi,

Anyone know the diameter of the rudder tube on a mk 1?

I've had the rudder out to dry over the winter, and will be back down in tas from a season working in Alice Springs soon to glass it up and reinstall it. Seems to make sense to make the most of having the rudder out and fit new bearings at the same time. I'll have a fairly short window on the slip so hope to pre-order bearings from vasco plastics to have them waiting for me when I get there. I believe the shaft is 25mm, and the inner diameter of the tube between 30-32mm? I'm hoping one of the stock sizes from vasco will fit.

Maybe someone else has replaced these and can remember what the id and od of the new bearings was?

Looking forward to a summer of sailing in tas,

Michael.

[Phillip]

Mike,

It's not a plastic bearing, it's two cutless bearings.

I put in two 100mm lengths in, top and bottom.

I can't remember the size so I will measure it this week for you.

If the shaft is 25mm [it will be imperial] you may need the cutless bearing turned down to the correct ID of the tube, that's a worst case, it should just fit.

The cutless bearing is glued in with Industrial grade aradite.

My Mk 1 had cutless bearings top and bottom in the rudder shaft tube glued in with Aradite. I've replaced them once [1st time?].
Cut the bearing longways with a hacksaw blade and they came out OK.

[Mike]

Thanks Phillip.

I'll do a bit of Google searching for cutless bearing suppliers.

Cheers,
Michael.

[Iluka82]

Hi Mike,
I replaced my bearings on my mk1 a few years ago. I used Vesconite plastic bearings, as Philip said there is one in the top and one in the bottom of the tube. I bought a standard part off vasco plastics, I think it was a 25mm ID and 30mm OD however I had to file down the OD by about .5mm to get them to fit in the tube. I glued them in with epoxy resin.

Cheers
Nick

[Mike]

Thanks Nick.

I've done a bit of looking online, and vesconite seems to be the in thing for these sorts of applications these days. Apparently they only have 20mm id by 30mm od tube in stock (the 25 by 30 isn't a big seller apparantly) but its easy to get machined, and cheap to buy.

I was looking at the cutless style bearings also. As far as I can tell they rely on water lubrication, which while being very suitable for the lower bearing (and prop shafts), might run a bit dry on the upper, which I'm guessing stays out of the water most of the time?

Anyway, postage time is very quick so I'll probably wait til I get back to the boat in a couple of weeks and make a decision then.

Cheers!

Michael.

[Sailtime]

Hi Micheal - I was having a look as well.. these from Vesco plastics seem the right size?

Cheers
Shea

Vesco.jpg (71.9 KiB) Viewed 3268 times

[Phillip]

Michael,
If you go the plastic way could you post what you did and the size used so others can see what to do.

[Iluka82]

Just had a look at the invoice for the bushes I bought and the size was imperial 1.25x1x2 inches (ODxIDxL) I had to cut the OD down to about 30mm. The ID was perfect for my MK1 rudder post.

[Phillip]

Just had a look at the invoice for the bushes I bought and the size was imperial 1.25x1x2 inches (ODxIDxL) I had to cut the OD down to about 30mm. The ID was perfect for my MK1 rudder post.

So exactly which bushes were they?

[Iluka82]

Hi Philip I replaced with Vesconite. When I pulled out the old ones they also appeared to be some sort of plastic. So they my have been changed before.