My little piece of peace

Hi PDW,
Thanks for the info (Vesconite & HDPE)

 

10% oversize !!!!!! it will rattle like a sausage in a tin can.

Thats 4 mm slop on 40mm is it April 1st.

The bottom of the rudder will be moving 6 inches.

 

No Hole cutting 50mm ID "washer" and it all comes together nicely, No worries...

 

Look, Frosty, it's better to shut up when you don't know what you're talking about.

You rough machine, immerse in water to get the expansion, then finish machine when it's all stable. No slop. Cheap and simple. We're not talking about 0.01mm or better fits, here.

Or you use more stable material at a higher price initially.

Depends on your budget, tooling and time.

I immersed a chunk of oil filled nylon in hydraulic oil for a couple of months to see what'd happen. Under that environment all I needed to allow for machining was approx 0.1mm for a loose running fit. For bushings exposed to water, I bought Vesconite on MikeJohn's advice.

PDW

 

Ok now you explain what your doing better but you still changed from 10% to o,1mm.


I can only read what you write.

 

Hi Frosty,
I am still having difficulty in finding a local supplier for the rudder bushes... It fits tightly over the rudder post (but not necessarily so), as it keeps the blade from rubbing or fouling the underside of the hull, (as the rudder floats and is held up by a similar bush on the top side), and the stainless steel bracket bolted to the rudder post and forms the steering arm, (with Ackerman angle that can be set but has now been removed as normal autopilot steering angles are so slight, it seems unnecessary)...

188871

 

The fit can be very sloppy by machinist standards... its only there to stop the rudder rubbing on the bottom of the hull... dont worry about water swelling mas, its not the kind of bushing that will jam up the shaft, its just a spacer washer type thingy... a peice of cut up milk bottle would just about do it.... if you can find a thin chopping board, we could cut a washer out of that (UMWMPE)

It really doesnt have to be this difficult...

 

Hi Groper,
Now That is a good idea... I have several white chopping-boards and a variety of hole saws, and one should be just a little bigger than required and one hole say large enough for the outside size... OK a trip to the boat to find the board and hole saws - or the kitchen plastics shelves in the supermarket and Bunnings for a hole saw or two...

Easy - Tomorrow will get... Today is rubbish day at the local transfer station as we do not get a rubbish removal service so a fortnightly trip is necessary...

 

They need to be really thin chopping boards tho... no more than 3mm thickness... i have hole saws...

 

Hi Groper,
I have acquired 6 identical to the original bush... Ready when you are?...

 

I think best to beach the boat, wait for the tide to go out, and we dig a hole in the sand to feed it back in... probably have to clean out the shaft tubes as there are probably a bit of marine growth inside which will make it difficult to get them back in... its high tide today at 4pm, but the tides are reducing in magnitude over the next few days, theres only about 1 meter of difference...

 

Hi Groper, Yep I will go down tomorrow and start to prepare positioning the boat...

 

Now that is TEAM work!

 

Hi Groper,
Just got back and high tide will not be enough - Sat 22 Dec 2012 has a high of 2.3M at 06:25 and a LOW of 1.4 at 12:05Hours - - Will not get me onto the sandbank...

Tues 25 December (FULL MOON on MOON river) has a HIGH of 2.7M at 08:08h and a LOW of 1.3M at 14:02h - - Almost perfect... http://tides.willyweather.com.au/qld/far-north/cairns.html

But will that afternoon "away" screw your Xmas festivities? - a further deferral is OK if the tides are inconvenient...

The New Moon on Friday 12th January 2013 http://www.tides4fishing.com/au/queensland/cairns has a LOW at 15:50h of 0.9M after a HIGH at 09:35h of 3.2M (almost lapping the road)...

 

Yeah no go on xmas day...