PS Mary Ann by Jeff

[jeff1949]

Dismantled the second mirror tonight. Gear ratio 1:55. The case can be cut to preserve the gear/motor enclosures.

No more mirror motor pics - these are for general interest and hopefully modellers might find a use for them in their own projects.

Jeff

[DamienG]

What car is this mirror from Jeff?

I'd like to check this out further.

Damien.

[jeff1949]

Hi Damien,
Sorry, no idea. Where I live in Victoria, the local councils often operate recycling centres as an adjunct to their domestic waste/tip services. Really handy, you can get used bits and pieces that other folk have tossed out but are still serviceable. Our local recycle depot just happens to have a number of various car bits including a few of these mirrors. Sadly there is nothing in or on the mirrors to indicate what make of car they are from.

This is partly why I have dismantled 2 mirrors, as I suspected that the principle of operation is the same but the layout and gearing varies between manufacturers. It may be possible for you to pick up a mirror or two from a local car wrecker if recycle depots aren't in operation near where you live.

I would be happy to get the remaining mirrors from the depot, dismantle them, and send you the innards, if you have trouble getting them.

Best wishes,
Jeff

[jeff1949]

Damien,
Just did a quick google based on the KA number on the motors - they MAY be from a Ford KA, circa 2000 to 2004.
Jeff

[andy]

I think, those motors are not made for long term running?

Andy

[jeff1949]

Crossed my mind too. I will set up my test rig this weekend and load the motor up a bit and see how it goes - and report back.
Jeff

[jeff1949]

Have had one motor running for about 10 hours now, with a moderate load, reducing the revs to about 90 rpm. Motor is only 'warm' - but so is the weather. Running the motor from a 12v dc power pack, not a battery, but I would be pretty happy to put this motor into my Mary Ann I reckon.

Have drawn up some rough plans based on      http://www.murrayriver.com.au/paddleboats/building-of-the-mary-ann/      drawings and intend to start cutting up some old pine timber I have in the shed, to make the bottom of the hull, as per Brett's ideas. Bought some Gorilla Glue today, and will be interested to see how well it performs.

This will be very much a 'built like Brett' boat,       http://web.aanet.com.au/dragoncity/dcs_models.html         but if it turns out to be half as nice as his Industry model, I will be more than happy, especially as this is my first paddle wheeler. I am going to use his wiring diagrams too, for motor control. I have a decent speed controller in my large cabin cruiser model, but will try Brett's methods first before going ESC. By the way I have emailed his last known address but not heard back, and he is no longer listed in out local phone book (he lives/lived only 20 km from me). Has anybody heard of him of late?

I am going to make the wheels (17.5 cm) from 1mm sheet metal (recovered from the case of an old microwave oven) as a trial. They will be solid sides, (as opposed to spoked), but I will make them easily removable so that I can replace them with proper spoked wheels if needed. And I intend to put 7 floats on the wheels, also as an experiment. If they don't work out, will just have to make different wheels.

As a side note, I have been unable to find any definitive drawings or photos of the original Mary Ann, but have discovered a few photos of the 'mock' Mary Ann. Figured I might as well use the 'almost plans' referred to above. I am sure nobody will really know how close I am to the original, and as this is my first attempt I am happy to make mistakes - best way to learn I reckon!

Jeff

[jeff1949]

Will be starting to cut timber for Mary Ann in the next few days.

I was wondering - being new to this game - if the location of the wheels has an impact on  'steerability' of the boat? By this I mean if the wheels are located more to the forward or aft of the boat. Mary Ann has her wheels more forward, I guess making them 'pulling' wheels. If they were somewhat aft of midpoint I guess they would be 'pusher' wheels. My simple mind suggests that if the wheels are to the aft of mid-point, and closer to the rudder, the action of the rudder would be enhanced somewhat. Is this likely to be correct?

Thanks for any thoughts.
Jeff

[derekwarner_decoy]

Jeff...all other things being equal, the 'steerability' of any vessel is a function of both the volume and velocity of water over the surface of the rudder

Taken to the extreme, paddle wheels mounted far fwd will have their flow dissipated along then length of the hull to a greater degree over paddle wheels mounted to the opposite extreme far aft

The function of the wheels by rotation and the displacement of water outby the direction of rotation is the same irrespective of the location far fwd or far aft.......ie., the term pushing or pulling relates more to dynamic linear movement rather than resultant flow paths in water

Water accelerated by force does not act in direct shear planes, however the action is more like a billowing movement..... Derek

[jeff1949]

Thanks Derek - makes sense to me now.

Jeff

[jeff1949]

I have just drawn out a very rough plan for Mary Ann, to get a better idea of my scale dimensions, and will do a more detailed drawing from these.

I am using      http://www.murrayriver.com.au/paddleboats/building-of-the-mary-ann/      as my reference. I realize it is a 'concept' plan drawn up some time ago, but it will do me OK for my first boat, and from what I can gather there are no really useable images of the original boat, and this plan looks pretty much like the couple of images I have been able to find.

Just for interest sake: I enlarged the screen image to 200%, which gave me a useable scaling ratio of 1cm on the screen equaling 65cm on the full size boat. This is almost exactly spot on given that the Mary Ann was 16.8 metres long. I then found that 1/15th was a good scale ratio for my model.

So 1cm on screen = 65cm full size and divide that by 15 to find the dimensions for the scale model.

I am sure this is not new to experienced modellers, but it might be useful for the other beginners  (like yours truly).

So next task - after turning my rough sketch into a workable dimensioned plan - will be to rip some pine timber into 19mm x 19mm planks, and start to glue the bottom together at the weekend.

Any comments on the above will be most appreciated.
Jeff

[DamienG]

I'll look forward to your build

[jeff1949]

Have just cut up and glued the bottom of the hull timbers together - 19mm square pine - as per Brett's instructions. Used Gorilla Glue. Also cut up some cedar panel boards that I had in the shed, to about 12mm x 10mm. The 12mm face will be the glued surface, making each 'plank' 10mm high. Cut into 200mm lengths as per Brett - hmm, a lot of gluing to be done to build the sides. 

Thinking ahead, did Mary Ann have a steering wheel or was steering done by a bloke at the rudder? In the few images I have looked at there appears to not be a wheel, and going by the almighty handle on the rudder I am guessing someone was always at the helm to avoid snags and bars  (which is excellent advice for the young folk of today ).

A pic of the hull bottom tomorrow. Jeff

[jeff1949]

Probably best if 'proper' modellers don't look at these images. As mentioned, this boat is being built as per Brett's ideas. So, the hull bottom was cut into 19mm square logs from a length of pine board. The side planks from some scrap cedar wall panel boards. Gorilla Glue has been used so far. The hull was glued and clamped for a few hours - seemed very rigid and 'well stuck'.  I started gluing the 200mm side strips, but got impatient with having to wait for the glue to dry - so out came the flat head brads, 10mm, and as I glued I nailed. This enable rapid progress. I doubt that too many bots out there have been nailed together, but what the heck - it works and they won't be seen.

Used my bench saw (in the Triton work table) to make the timber bits - my big angle grinder to get the curves on the hull bottom, and my bench grinder to shape the cedar at bow and stern as needed. NOT the usual modeling tools that I am used to! (I have in the past made many radio controlled gliders - scalpels, pins, super glue, tiny clamps).

Yes, it looks rough as guts and will do so for another few nights, but I am confident it will become a decent hull in time.

For those who know Mary Ann, she had her sides raised a couple of feet after a rough trip. I am planning on building her as she may have been prior to the sides being raised. Will have to see how the hull looks when most of the planking has been done.

More pics in a couple of nights...
Jeff

[jeff1949]

Another pic - this one didn't upload as I thought it should have.
Jeff