Paddleducks
Old Yahoo Group => Yahoo Messages => Topic started by: Mike Mayhew on June 18, 2005, 12:37:54 AM
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Hi Paul. J. Thanks for your interesting reply from Canada, I have worked on' Faithful 'Paddle Tug in the late 50's and when we sailed from Plymouth to Portsmouth the shafts were locked up and one set of generators/motors were turned off for the light run. if both were independent and travelling at speed, and one set went down the resulting drag and turn could spell disaster. I hope my comments have helped others to see some of the problems one has with paddlesteamers. I enjoy sailing my Big un as it is the nearest I can get to reality having been a Tug Master for more years than I admit to.
I have made a simple cone piece with interlocking inserts for various motor shafts which I secure to the motor shaft and then use a standard rev counter. I load the motor to check amps and will often run the thing for a morning to see temprature ok. If all is well I work out the gearing Via belts etc to my main shaft. Too many revs and you get foam and froth too few and it crawls. I find that up to 95-100 rpm the most reasonable over this and it looks stupid. Waverley moves away at 5rpm and soon has steerage way on. Paddles are laser cut 4mm steel plate frames and the floats are 4" x1.5" feathering.
Dennis Kerr mentioned using the mud/banks to turn with the current, we did this on the River Severn with the steamers.
I have done a set of drawings which I will get posted so folks can see what I mean regarding rudders and ship handling.
Best Regards ..... Mike Mayhew
http://www.waverleymodels.co.uk
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On 29 Sep 2002, at 8:58, Paddleducks@yahoogroups.com wrote:
> Message: 2
> Date: Sun, 29 Sep 2002 12:57:31 +1000
> From: "Derek Warner" <derekwarner@bigpond.com>
> Subject: Wiper Motors Again - Version 447.5
>
> on Sunday, September 29, 2002 11:08 AM Brett [PS Industry] wrote
> >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> > Interestingly I could not find out how they stopped the travel of the window ? There was no 'limit' switches
> > fitted to the winding mechanism, maybe they depend upon the current draw to 'cut out'
> >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> Hey Brett - I think all the rest of the PD group around the world may be getting sick of wiper motor communications, but
> that's because they have never tried and experienced the beauty and technical superiority of them over high priced AMP
> guzzling model shop alternates - is ohm's Law still V= IR?
Your probably right !, I feel that too many modelers dont look around at other options and just run off to the model
shop for their gear, me, I head for the wreckers!! Did you know that the current models of BMW cars have over
60 different electric motors ( in each car) -- what a smorgassbord of possibilities.
I'm going to try and find some VOLVO headlight wiper motors, which I assume are quite small.
>
> This brings me to the next questions, does it rain any where else in the world?, or is it only Australian vehicles that
> have window wipers & motors fitted?
>
Apparently not!, I think british cars still use the MANUAL winder fitting used on early LANDROVERS, where
the back of the mostly unrealiable motor had a small handle. :-)
> Mike Mayhew's 13 foot paddler uses a 1/3 HP 12 V motor which = consuming 224 Watts of power - if Mike had only
> considered a wiper motor the current draw would have been 1/10 of that [mind you with a model @ 2 cwt, battery
> weight would have been a blessing] - and yes I do acknowledge that Mike is to re-engine with steam
>
> Mike also posted a note "shame on those" resorting to differential paddle use which I thought was fair and constructive
> comment - however Mike did make note on his use of a balanced rudder in the said model
>
Cant agree here, differential stearing IS a legit method of controlling a paddle boat, I know the P.S Cumberoona
based at Albury has TWO wood fired steam engines ( motors circa 1906 & 1908, hull 1986 ), fitted because
when going downstream in a running river the rudder is useless and differential steering is used.
But direct drive is obviously just as legit, not better , just a different method.
> Is this a double standard here Mike? - like below water it's ok to fudge it, but above water must be true?
>
> Back on a serious point, my lay understanding of a balanced rudder is that the rudder plane extends both FWD & AFT
> of the rudder vertical axis shaft - again I understand the turning advantages [extra bite of water], however this by
> necessity must put extra strain on the rudder servo drive
>
No!, balanced rudders are the way to go, if thats the style option on the boat design, most Murray River Paddlers
have Barn Door type hinged along one edge. Balance rudders should have the pivot shaft 1/3 back from the
leading edge. Most modern yachts use this style as the rudder is free standing and not fitted to the keel itself.
Also if you check some aeroplanes , the rudder have a small counter balance tab protruding forward from the
hinge line to offer balance. A proper balanced rudder offers very little strain back through the system.
The barn door is the worst type.
> So another question Mike - I am sure all PD's would be most interested in learning how a 240 lb [2cwt] is steered,
> literally from the servo to the rudder etc
>
> Having said all this, the motor wreckers are open again tomorrow - so I will look further @ wiper motors & keep all
> posted with further developments - regards Derek
>
Send info direct if you dont feel other paddleduckers are interested :-)
>