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[Captain Povey]

Les, Derek is correct and Hudco couplings are very good but I see from the photos I posted earlier that I did not use one in this model. The reason was lack of  space. They are quite long so I made a short rigid coupling on my lathe and mounted the motor in a bracket suspended from a cross beam. This means any misalignment is taken up in the mount which flexes. Since I built mine there are now available shorter couplings suitable for smaller boats. I am struggling to remember the name, it is something like model boat bits. Graham

[Captain Povey]

Les, Have a look at Mobile Marine Models for  a small coupling. Graham

[derekwarner]

 ....so Les says......

'PS Passed 5 miles off Wollongong many times during the 50s & 60s on the way to our berth in Pyrmont but mostly never got past Montgomery's Hotel'

Yes here is your old watering hole [currently the Pyrmont Bridge Hotel]...renamed to the Monty's in the late 30's ............ still standing & serving large cool pints

Taken over by the inner city trendies now, but I guess she would have been a bit of rough & tumble in the 50's         Derek

[portlineapp]

Latest problem to emerge is fixing the rudder to the rudder stock.
It's my guess that if the joint is going to be submersible,some other method than glueing would be necessary.
Also,gluieng the rudder on to the stock would make the whole assembly non-demountable which,with my extremely limited experience,seems to be undesirable.
I have come up with an idea (see attached pic) which would make the rudder stock demountable.The two brass cramps I've knocked up would be soldered to a brass plate rudder & tightened on to the stock by the two 6ba csk cramping screws.
I've still to fine up my handiwork,but they're obviously not very pretty and I wondered if anyone had any other ideas before I invest further time & effort into plan A>
Thanks,
Les

[portlineapp]

Whoops.
Forgot the photo.
Les

[portlineapp]

Thanks Graham & Derek
I've only just dicovered how to get on to the second page.
Monty's was famed as one of the world's favourite sailors' pubs in those days.
I have,and I believe Monty's has changed considerably since those days,but it was good to see the pic of the disreputale old joint again.Our berth was just a 100yds down the track looking straight ahead.
I've already ordered the universal joint so I'll have to see about siting the motor,
Regards,
Les

[Captain Povey]

Hi Les, Gluing the rudder has been satisfactory for me and I have never had the need to remove the rudder yet. 6 ba does sound a bit big for such a small rudder. Why not go down to 8ba or equivalent mm size. Graham

[portlineapp]

Graham,
You'll probably know that old British motorbikes were known as oil-rigs because of their lack of oil-tightness,so I've utilised a bit of this learned knowledge to include a 3mm 'O' ring on the prop-shaft outer housing.It's inside the thicker, theaded portion which also takes the oiling tube.See attachment.I hope my bodge-engineering is good enough to make it water-tight.
I've also included a pic of the rudder securing arrangement.It still isn't very pretty,but I'm inclined to leave it as is -  if I have a change of heart I can always change it later.
I think I've now got all the parts except the steering controller so can now begin to site the motor & it's ancilleries.
Any further advice still welcome.
Regards,
Les

[Captain Povey]

Les, Yes I did have some leaky old bikes in my time and usually the leaks were from worn lip seals or split gaskets. O rings are good face seals but not so good for rotary seals. I have not used them as prop shaft seals as the friction might cause unnecessary load on the small motor resulting in high current draw and short running time. As I think I said in an earlier post a well fitted shaft and a bit of grease is usually enough for this type of model. Graham

[portlineapp]

Graham,
Thanks for the advice.
The only part of the paraphenalia that isn't reversible at the moment is the rudder stock housing.So it's a simple job to experiment with the 'O' ring on the prop shaft and if it's no good I can just remove it. Just by good fortune it's just about tight enough to stop the shaft dropping out of the housing if held vertically  - so fingers crossed!
The universal joint sets the motor very nearly amidships longitudonally so that should be O.K.The batteries are fairly heavy so siting them might be more of a problem.I'm not sure yet,but don't think I can get them on the C/L so may have to resort to my sailing days nous and put a bit of compensating ballast in one of the double bottom tanks!
It's time to order the steering servo so I'd appreciate a bit of advice on what make & model to go for,
Thanks,
Les

[Captain Povey]

Its ok if the battery is off centre as you will have to add ballast to get it to the waterline. I am no expert on servos and usually just use the standard ones that often come with an Rc set. If space is a problem a mini or even micro might do the job as it is not a big turning load. Try a search on here for servos as I think there have been previous threads on the technical aspects. Graham

[markjames68]

This tug and kit grows on me the more i look, nice work