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[Malc Reade]

Has anybody got any experience of removing an existing brass prop shaft from an old GRP hull and replacing it?

I bought a lovely example of Caldercraft's Cumbrae Clyde Pilot Cutter at Brighton early this year.  It seems to have a slightly mis-aligned prop shaft and I would like to replace it, and also the whole power train with some nice quality equipment, motor, coupling, shaft and prop etc.

Can anybody offer any suggestions as to how I should go about removing the old one, and also any suggestions for replacement parts, manufacturer's etc?

Regards, Malc

[cbr900]

MALCOM,


Cannot suggest where to get the new replacement but to remove the old one, I have used a dremel with a medium burr bit and cut as close as possible to the hull and then with a smaller burr bit ground away the holding material on the inside and the shaft will come out fairly easily, with no damage to the hull or the shaft......



Roy

[DickyD]

                 Deans Marine do all the bits you want including prop shaft with oiling tube

                                                                                       Richard

[andywright]

Give the shaft a eal sharp tap with a hammer, so long as the hull is sound no harm will come, otherwise its a drill it out job.

[riggers24]

Malcom,

I have just removed 2 shafts out of a static model I am converting to RC, small pointed burr mounted in a mini craft drill and gently removed the filler around the outside then on the inside. Took 10 minutes a shaft and no damage to the hull. Just don't go in heavy handed, take your time.

Marc

[justboatonic]

Malcom,

I have just removed 2 shafts out of a static model I am converting to RC, small pointed burr mounted in a mini craft drill and gently removed the filler around the outside then on the inside. Took 10 minutes a shaft and no damage to the hull. Just don't go in heavy handed, take your time.

Marc

Wonder what boat that was on Marc? 

[riggers24]

I wonder.

Here is a piccy of the hull with one shft removed

[Shipmate60]

Use some brass tube a tight sliding fit over the old shaft, file teeth in one end and use this to cut out the filler.

Bob

[warspite]

Could you use some kind of dremel and cut the shaft as short as possible in side and outside (if enough room) and then grind the remaining shaft tube down with a burr tool from the inside of the tube out?

[Malc Reade]

Thanks for the help so far gentlemen.

From the above posts it would seem that chances are that the existing shaft may well be really tight and difficult to remove?

I'm reluctant to start grinding the existing shaft out as the surrounding material will certainly be softer than the brass tube and the chances of me slipping with my Dremel and damaging the hull are significant?

What are the chances of me driving it out with a sharp blow with a blunt instrument? (Given that the surface of the original shaft was probably roughed with Emery paper to ensure good adhesion to the resin)?

Any further input would be much appreciated.

Regards to all, Malc

[GOGSAMWE]

Could you use some kind of dremel and cut the shaft as short as possible in side and outside (if enough room) and then grind the remaining shaft tube down with a burr tool from the inside of the tube out?

Malc,

I too would go with this suggestion... using any force with "your blunt instrument" is much more likely to  damage your hull..

As for adjacent damage "limitation" what about covering the area with several layers of thick masking tape.? you could use duck tape or similar...  but it may pull your paint off.

You can easily re-fill any holes...   But repairing  "crash n bash damage" will be much harder 

Steve
 

[Martin (Admin)]

I once removed an old shaft by heating the end - VERY carefully - with a soldering iron, (once even a blow torch)  and twisting it with heavy pliers.  I snapped completely clean from the resin & glue and and slid straight out.

I think Prop Shop do a nice range of propshafts.


Martin (Danger man ) Mayhem 

[Malc Reade]

Thanks Martin

That one sounds a possible.

Do you think I might have to re-name the model 'Puff Of Smoke'?

Malc

[tonyH]

Malcolm,

Do you have to completely remove the old tube?  Could you not cut away as much as poss, protecting the hull as noted. Tidy up outer end and then insert a narrower system through the old one, adding filler between the two?

Tony

[Malc Reade]

Hi Tony

That's another possibility.  My problem is compounded by the fact that the (planked) deck is securely fixed to the hull, making any attempt to work on it extremely difficult.

Malc

[cbr900]

MALCOM go back to the second posting, safest way mate, just take your time...


Roy

[chugbug]

      I heated a mild steel rod with a blow torch and shoved it up the prop tube,waited for a slight pong and it slid out a treat.It works. Good luck. 
                                                                          Chugbug.

[GOGSAMWE]

    I heated a mild steel rod with a blow torch and shoved it up the prop tube,waited for a slight pong and it slid out a treat.. 
                                                                         

He hee

the mind could boggle with that sort of treatment 

Steve

( yes a GOG and a Warped Gog at that !)
 

[Colin Bishop]

I heated a mild steel rod with a blow torch and shoved it up the prop tube,waited for a slight pong and it slid out a treat.It works. Good luck

No wonder the masthead lights of a Pilot Boat are white over red! (White cap over a red face as we were taught on out RYA lights recognition course)  Mind you, on second thoughts maybe it ought to be a white face...

[Jonty]

Wasn't that how they polished off Richard II?

[Colin Bishop]

That's right, I think. Red hot poker in the bowels. leaves hardly a mark on the body. I need another drink....

[tonyH]

Alternatively, getting back to business (how sad!) and if the bent bit is outside the hull, cut off  the bent bit, fit flexi-drive end tube and run flexi up the current pipe after tapping out the top bearing.

Tony

[Shipmate60]

Remove the whole tube.
I have done several, use whichever suggestion is best for you.
I used the brass tube with teeth, takes a bit of time but leaves a clean hole.

Bob

[Malc Reade]

Thanks guy's

Actually the tube isn't bent, it just leans to starboard when you cast your eye along the length of the model.  The shaft is very sloppy in the tube though and the whole thing makes a helluva noise when I run the motor.

I'm going to have a go at removing it over the weekend, will provide feedback with pics next week.

Regards

Malc

[Doc]

Malc,
If I'm understanding you correctly, the problem isn't with the stuffing tube, but with a wobbly drive shaft and or bad bearings.  I think I'd try just replacing the drive shaft/bearings before tackling the stuffing tube.  Yeah, I certainly understand about it not being 'right' if it's angled off to one side, but that really isn't going to be ~that~ much of a problem.  If you find out that it is that much of a problem later, then you can replace the tube.  Sounds like sort of a sloppy repare job, but why do more than is really required?
 - 'Doc