another model of the PS Alexander Arbuthnot

[echidna]

It had been my intention to build a model that looked "a bit like" a Murray River paddlesteamer.

I made another trip to Echuca recently, and while I was there I decided to build a model of the Alexander Arbuthnot, instead of something "generic". I made this decision when saw a model of the A.A. that had been built by the legendary model builder, Robert Dingey in 2001. The placard on the model said it had been built from a small drawing obtained from the Port of Echuca. So I purchased a copy of the drawing to take home ($10). It was a photocopy on A3 paper, which said it was 1:25 scale. That would mean that it was probably meant to be printed on an A0 sheet. The drawing was done by Keith Mealey, in May 1996.

I took the drawing to a copy shop, and had it enlarged by 294% (on to A0 paper). The resulting drawing is, I believe, close to 1:24 scale.

Echidna

[kiwimodeller]

Take the plunge - make it steam powered!

[bill stafford]

gday , Float a Boat au. has plans for the AA in 1/24 ,also possibly paddle wheel kits , in HIPS , i would recommend a jaycar motor +g/box for the model , if you wanted , twin , in dependant motor drive , keep the motors low in the hull,and drive them by HTD tooth belts ,if you use the jaycar motor , use over drive belts , 1:2 ratio.
 be carfull of top weight and don't skimp on the draft too much , i think you need at least 40 mm draft , to carry the weight of the model , lead can always be added ,if you use 50 mm draft , but im still sorting out draft issues .
 should make a nice model , good luck bill s

[echidna]

Dear Kiwimodeller, I am starting with the hull, and that will be the same whether it is steam or electric. I will keep my options open for as long as possible, but I am pretty sure that this model will end up being electric powered.

The sort of steam installation that I would like to have is always going to be quite expensive (either in money to buy a ready-built unit, or in time, effort, and money to build something from scratch).

It would have to be self-starting (meaning at least 2 cylinders), and it would have to be reversing (by remote control). There are no insurmountable problems in making it steam powered, but most model boat builders find it just a bit too much trouble and expense.

A boiler like this one would suit me: http://www.miniaturesteammodels.com/prod259.htm , but the price is beyond my budget.

[echidna]

Thanks for the suggestions Bill.

I have made several purchases from Float A Boat, for other projects.

I am sure that the price of their plans is justified (something like $50 I believe, or more if there are multiple sheets). However, I already have plans which didn't cost as much so I will make do with those (and the occasional trip to Echuca to check on some details). My copy of the FAB plans catalogue doesn't list the A.A., but maybe it's a later addition.

[derekwarner_decoy]

Hi PD's......& without seeming to add water to dampen your bucket echidna  ........that 2" boiler from miniature steam...would not be sufficient for a 1.5m long model of the AA

I understand your points for an electric drive........  ....however for interest have a look at the maccsteam boiler WEB site in our links........

It provides a few fundamental calculations on the boiler sizing

According to the calculations......the same manufacturer "miniature steam" twin cylinder GEM reversible engine would require more steam than their 3.5" boiler produces

I too thought that Float a Boat had the AA plans........however when I checked ...the cupboard was bare............

Which ever way you decide to go........just keep us posted with piccies.........naturally any construction issues or questions  .....just ask.....one of our world wide members will only be happy to assist .....

Have just added a few images of my current 13 year old paddler steam build.......... .......Derek  ...........

[echidna]

Derek, your steam plant is lovely. The point I was trying to make in my previous post is that such a set-up is expensive, and beyond my budget.

Echidna

[DamienG]

My models will always be electric I have considered Sound effects and steam generators and wonder is it worth it for 3 or 4 good sailing days a years myself always answers NO

I admit since by body has become worn out I get 90% more out of building than lugging the to water.   

[echidna]

I haven't cut any wood for this project yet, but I have started looking at what materials I have on hand.

I want to start with the keel. On the drawing, this is shown as approx. 12 mm wide, and it protrudes below the bottom planking by approx. 6 mm. I think that I have some mountain ash in stock that I can use for it.

I have send an enquiry to the Port of Echuca resident shipwright, and living treasure, Kevin Hutchinson, to confirm the details of the keel, because I have not seen the A.A. out of the water.

Echidna

[echidna]

I have been giving some thought to how I will control the rudder. From my observations, on Murray River paddleboats, the rudder can swing through an arc of almost 180 degrees, and is operated by chains that run around pulleys on the deck.

I want to reproduce this arrangement. I think it would be hard to do with a standard r.c. servo (which is a shame, because I have a spare one on hand). Model yachts use something called a sail winch, which could be what I want. I have a friend in Bendigo who sails model yachts, so I will have a talk to him.

Echidna

[bill stafford]

gday , you are right about the rudder , but a sail winch is no good , doesn't centre well, what i did was play w the length of the servo arm ,to increase travel , my servo arm is a piece of alum., about 125/150mm long , back to the frame on top of the rudder , approx. 50/65mm long ,i have full rudder travel .
i have seen others w a normal length servo horn , connected to a push rod , w a false frame above it
i use string to push/pull rudder control ,chain tends to be trouble-some , cord coloured w coffee/tea + cord runs better in rudder pulleys
I also use a larger , heavy duty servo , but this centres well
you could also use ssteel fishing trace , to push/pull rudder , connect LH cable to RH point , to keep ferals from fowling rudder deck pulleys
hope this helps , there are other ways to do jobs , keep asking

[bill stafford]

keel issues -i think you have the shape down pat ,a capital T is a good starting point , but
inside the hull, i fitted a false deck,hull bottom,about 20/25mm deep , to create a wooden girder ,to stop the hull from hogging ,as you remove model from water , this added a LOT of strength to hull
if you look at the side profile ,there is not much thickness there ,and that is all the strength you have , the real boats hulls would hog ,to get off sand bars .
 your model at 1/24 if a long , heavy hull
my hull is a long , basic wooden box ,covered in f/glass ,printed deck, out riggers "planked" in 1/16 ply , rubbing strips 1/16 ply , hull radiuses planked in balsa , covered in f/glass , hull formers in 6 mm ply , built from only photos , over 10+ yrs ago
good luck , start building , its fun

[derekwarner_decoy]

Guys....I will be in the same preverbal boat  .....with the rudder for PS Adelaide.......she has a twin fall of chain & the rudder moves very slowly

Installing this function is the easy bit......just by using a servo slowdown....which allows full or 1/2 direct movement of the RC transmitter stick.......& adjusting the slowdown electrically to simulate the slow movement...this way using a standard servo can also set or limit the arc of rudder movement so there is no danger of snapping a chain

I am yet to find any welded scale link chain of approx. wire size of 1.3 mm diameter x 9 hoops per 25 mm length......

I am also unsure of the function of the rope attached to the rudder pintail  ..........Derek

[bill stafford]

g day derek,
 i will take a stab at that rope , only a guess, but i think it is used to support the rudder , when they hog the hull ,as there is a lot of rudder hanging out the back of the hull, also if they were to loose a rudder ??
servo issues - take a look at servo city , not cheap , but they have a gear driven servo w 180 degrees travel !! you may be able to copy ?? but i think they alter the servo electronics , but i dont know .
 i wouldnt slow the rudder down too far , as you know , paddlers can be lumbering beasts ,and need all the help to turn well .
 i have altered a servo to increase travel ,for a small yacht sail winch , but it tendered not too centre as well , good enough for a winch !
side note -I love your steam work , but did you manage to get the boiler certified ?? i am in the process of building a centre flue soon , and trying to deal w all the red tape, no help from ME clubs ,they seem not to want anything but loco boilers being built
regards bill s

[derekwarner_decoy]

Thanks Bill

1. The Float a Boat plans for Adelaide indicate that the rudder stock & securing mechanism is rather substantial
2. From the geometry & securing point for the rope....suggests that is not related to any form of emergency steering
3. There are a few PD members who have engineered on Adelaide so I may get a response from there
4. I have a spare FUTUBA high torque retract servo....however from memory it has no centre position nor will it respond to trim adjustments via the Tx 
5. Ideally I think a Tx centre stick position for straight ahead would be best
6. The two falls of chain for Adelaide's rudder means 180 degrees of servo arc would only produce 90 degree included angle of rudder movement .....Derek