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[rwalker]

Hello All,
I read in another board somewhere, I think it was RC Groups and  Pat Tritle making a dive boat, where he ran into trouble with his prop shaft seizing because his shaft was trying to achieve Nirvana with the stuffing tube (trying to become one with the tube), in short by using a brass shaft and a brass tube telescope style, they fused together. His solution was to use a steel shaft. I always thought (based on plans that I've read) that brass tube/brass rod was okay. I was wondering if I could get away with alluminum tube/brass rod, or would the same problem occur?

[Stavros]

But if I am right in thinking and will stand corrected I thought that propshafts were made either of steel or stainless for strength,surely Ali or Brass would not stand the strain


Stavros

[Colin Bishop]

I'd tend to agree with Stavros. Except in the most lightweight applications,e.g. plastic magic, brass or ali would normally be too soft to take much wear and tear.

Colin

[rwalker]

Oh, Hey Stav,
I like your build n paint log on the Wavney lifeboat. I'll have to try that when I paint my recovery boat. And your tag name has me thinking of Bond movies and the father of the Daleks....

[Shipmate60]

And Harry Enfield, "Hello peeps" Kibab anyone?

Bob ducking!!

Bob

[boatmadman]

Phosphor bronze is better than brass for bearing bushes, it accepts water lubrication.

For shafts I use bright drawn steel, good finish and accurate tolerances and wont rust.

Using these shafts with home made phozzy/bronze bushes reamed to size I get a good shaft with just a slight drop of water finding its way up the shaft - just ok for lubrication.

Works for me.

Ian

[GaryM]

Hi
Just a thought from a novice.
Would the expansion of a brass shaft within a cooler brass tube cause it to seize if it got too hot, with possibly no lubricant?

Gary ???

[boatmadman]

That would depend entirely on how much clearance there is between shaft and tube. Using them like a telescope will generate some heat due to friction.

I suspect your problem is more likely to be down to the tube or shaft not being absolutely straight. Is the tube thin walled like k&s tube? If so it can get slightly bent easily, not enough to see but enough to cause excessive friction.

I use thick walled rolled brass tube with the phossy bronze bushes.

Found this forum which may help. http://www.engineersedge.com/wwwboard/posts/10947.html

Ian

[HS93 (RIP)]

This is worth a read he produces shafts for the model trade and specialist ones for research some of his model ones are sealed for life .

http://www.apbu43.dsl.pipex.com/MARINEFRAME.htm

his site is not ready for sales, but you can email him

Hs93

[HS93 (RIP)]

wrong link............... go to shafts