Paddleducks
Paddler Modelling => Paddlewheels/Drive Systems => Topic started by: jeff1949 on October 13, 2015, 09:01:13 PM
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Hello all,
Just joined Paddleducks, and have already found a lot of great information.
I am interested in building an almost scale Murray River paddle boat based very loosely on the PS Mary Ann, first paddle steamer on the Murray River.
Have read Brett Hallet's detailed build process for his Enterprise and I will be following his methods more or less. About to start planning, so will try and keep members informed of progress.
When I was 15 I built a scale model cabin cruiser but never finished it, although I have lugged it around with me through all my various moves. I am now 66, and I finally completed the boat and motorised it about 2 years ago - and it goes just as well as I hoped it would when I was a kid. 2 channel radio control with a great ESC gives very realistic scale speeds and reverse.
Once I have constructed the hull of Mary Ann I am going to experiment with - wait for it - the motors and gears from an electric side mirror off a car. On the bench the worm drive and gear gives about 120 rpm and seems to have very high torque. The motor is not much more than an inch long, so if a couple of these can push my 1.12metre boat along (with 10.5cm paddles) I will be happy - if not I will use them at a later date for a smaller model.
Would be interested if any other members have tried using these motors/gears?
Will keep you posted - with pics I hope - of my progress with Mary Ann.
Jeff
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Hi PD's and welcome Jeff .....sounds like 1949 was a good year :bravo
It has been years since anyone mentioned any of Bret Hallett's build work, but I have a feeling that Bret himself discusses 12 volt motor vehicle window winder motors.......yes massive torque and the right speed range, however they had a different usage/frequency rating & hence a higher current draw over windscreen wiper motors which are continuously rated and hence the design offers extremely low current consumption...and which were used by Bret & many others
The Many Ann, features descriptively well in 'Ships of the Inland Rivers' by Parsons....[page 100].........the original 1852 vessel built for Randell, was the most celebrated
So, any questions, just post away ............... Derek :beer
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Welcome Jeff. We look forward to your posts and pictures.
Damien.
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I am brand new to the forum, and about to start a Brett Hallet type construction of PS Mary Ann.
Was wondering today....why are spoked wheels used for the paddles instead of a solid disc?
There must be a very good reason, after all the spoked wheel IS what is used, but I would love to know the advantages.
Making solid discs would be so much easier :)
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At a guess I'd venture that it's about weight. A solid wheel of strong enough construction would be considerably heavier than a spoked wheel.
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Thanks so much for the warm welcome.
The motors I was referring to are the tiny motors in the electric side rear vision mirrors. I was wondering if anybody had used them before? If not, and if they work, it might start a new trend.
The difficulty will be in aligning the worm drive on the motor shaft with the main gear, but I can make an adjustable platform to do this...I think.
Will keep you posted.
Jeff
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Sorry if I have this in the wrong place - new member getting used to things.
I mentioned in the new members introduction spot about my probable use of the small motors from car rear view mirrors as drive units for 10.5 cm wheels on a 1.2 metre PS Mary Ann.
Have attached (I hope) a pic of the motor and drive wheel. 60 teeth on the gear, 10 on the worm. Gear has a 7mm hole for shaft. Motor is a bit over an inch long and 3/4 inch wide. I have a motor and gear set up in a temporary test rig and I have trouble stopping the gear shaft from turning , using very tight finger pressure - appears to have very high torque. Even with medium finger pressure the shaft roes around 120 rpm.
Anybody else used these motors? I will have to actually build the hull and wheels before I can see if the motors will work as needed.
Any comments welcome.
Jeff
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Hullo Jeff.....
You now have 3 post threads, however essentially all relating to your proposed Mary Ann paddler build
Your call, but I would be inclined to ask Moderator DamienG to link them all in one new thread called PS Mary Ann by Jeff
This just makes for easier reading for all, including you reading members responses......
PS......sorry I misunderstood side mirror 12V motors in lieu of side window winder motors .......Derek
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I'd hazard a guess It's for ease water evacuation from the blades. There bye saving on power needed.
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A few more details please Jeff dimensions of these motors and any idea of the RPM and if you apply 12v can you stall it with your fingers?
Damien.
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I'd hazard a guess It's for ease water evacuation from the blades. There bye saving on power needed.
Of course, that why waterwheels are solid sided to retain the water and use it's weight. That said, a large proportion of side wheels are iron construction and solid versions would take some moving especially if they were lifting large amounts of water.
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Hi Damien, the motors I have are 28 mm long and 20mm wide. They are 12 v, and while I can stall the motor with my fingers, it is VERY hard to stall the driven gear. Don't know what speed they free rev at, but would hazard a guess at around 3000 rpm. In my test rig, the driven gear rotates at somewhere between 120 and 140 rpm unloaded. Given the high torque I am hoping that they will drive the paddles at around the same speed.
Got the old broken mirror from the local tip recycle shop for 2 dollars - there are 2 motors/driven gears in each mirror. Different makes of mirrors may have different sized motors with different gear set-ups. I am going to get another mirror today and wreck it to see what I find.
Seems to me there could be a lot of applications for these strong little motor/gear set-ups, other than driving paddle wheels.
Thanks for the interest.
Jeff
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A 1:1 drive from worm pulley should be ok.
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As Jeff says.......'a pic of the motor and drive wheel. 60 teeth on the gear, 10 on the worm'
So whilst there may be 10 teeth on a helical worm on the motor output shaft, essentially there is only one helical tooth in full engagement with the worm wheel at any time
From this, if the worm wheel has 60 helical teeth, the actual ratio is 60:1
This is naturally assumed that the worm on the motor shaft is a single start......if it were a double [x2] start the actual pitch is halved and the ratio can technically double ...or to 120:1
Hope this may clarify :whistle and not confuse the basics .................. Derek :sorry
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Thanks Damien and Derek. I will try a 1:1 drive and see what sort of torque I get. Bought another 2 dollar mirror today - will dismantle this evening and see what the drive system is like, and let you know.
Jeff
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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
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What car is this mirror from Jeff?
I'd like to check this out further.
Damien.
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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
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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
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I think, those motors are not made for long term running?
Andy
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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
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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
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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
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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
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Thanks Derek - makes sense to me now.
Jeff
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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
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I'll look forward to your build :clap :clap
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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
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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
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Another pic - this one didn't upload as I thought it should have.
Jeff
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More work done. Have got the side 'planks' on now, and hull very roughly shaped, well, bow at least. Stern is going to take some time to get the hull curves looking OK. One more row of planks to do, then time to start planning for location of the couple of beams that will run across the hull to support the wheel boxes and sponsons? (the decking bits that extend past the hull sides around the paddle boxes).
Gorilla Glue is great stuff. I have quite black fingers (as pre-warned by others) but have discovered that the magic WD40 removes wet glue from hands, tools, the bottle, etc with ease - but not apparently once it has dried. Have also been following the instructions re storage, ie remove all air from the bottle, wipe tip very clean, and store bottle upside down - seems to work as the glue hasn't shown any signs of going stiff yet.
Will get a pic up tomorrow night if I can. Purists will shudder!
Jeff
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There'll be no shudders from me Jeff Just praise for doing the best you can. :clap :clap
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Well, had a half day off, so sanded the hull to a decent shape. Used the 90mm angle grinder with a coarse disc, and a palm sander also with coarse paper. Hull now looking pretty presentable compared to last Sunday. I am have some pics, but also having trouble uploading them from this end, so maybe tomorrow evening.
Time now to start planning the innards and how the deck is going to look. I am using a 12 v 7.2 amp hour battery for power - heavy. So will maybe need to wrap Mary Ann in glad wrap and put her in the bath to see how balance will work out - and also see what sort of displacement I might have. I have a feeling she is going to sit fairly high and not be terribly stable until I get the wheels on.
More as time permits.
Jeff
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Here there be progress pics. Should be up-front - the patches in the hull are Plasti Bond. Had to fill in a few gaps but I am not too worried about the final appearance at this stage. As an aside, I mentioned elsewhere that a couple of years ago I finished the scale cabin cruiser that I started when I was 15. It was largely held together with Plasti Bond, which must have been a fairly new product way back then (50 years ago!). The hull has stayed firmly held together all these years and didn't need structural repairs when I decided to complete it - a brilliant product I reckon!
I have cleaned up the inside of the hull (angfle grinder and palm sander again) since I took these pics. Have worked out a deck plan to put into action.
Jeff
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Another pic
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and another
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Something of a quandary. The hull is pretty well done. Should I test just the hull in water to check balance and stability with the battery fitted before I proceed with fitting the other structures for decking and the out-rigger type decks (around the wheels - don't know the proper term), or should I do the other structural stuff first and figure out balance etc afterwards?
Suggestions appreciated.
I think I will make the rudder assembly next before floating.
Jeff
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Jeff..........it is always best to know what you have to work with....
1. you could estimate the displacement of the hull by the block coefficient calculation method :hehe
[eg.,....... lets say your hull is 1000 mm long x 200 mm wide and sits 50 mm deep in the water
1000x200x50 ..so in cubic mm ~~ this is approximately 10 litres of water or 10 kg of mass required to get the vessel down to it's 50 mm draft line ~ well that is for a plain pontoon shape.........you will need to make some estimations of the reduction in volume with the pointed bow & stern...so depending on the form of the hull......this same 100 x200x50 may be reduced in volume by say 1.2 kg?]
2. slap a few coats of wood primer or varnish on the hull & perform a physical displacement test.....simply adding cans of anything....beer, beetroot, pineapple + batteries ....until the hull is resting at the desired waterline......then weigh all of the temporary ballast + the hull by itself, then the sum of both = the hulls displacement
Some have attempted cling wrap, but this is fraught with danger :sobbing......
From there you can understand the required positioning of the battery & motor + ancillaries' to give you the desired fwd & aft trim
Single story Australian style paddlers didn't really suffer from stability/windage issues, however naturally SLA type batteries can be laid on their sides to offer lower centre of gravity
Saying this, there is a short documentary on PS Marion [3 stories high above the waterline]......and the skipper equates the wind against the superstructure as being similar to an ocean going yacht under sail............ Derek
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Thanks a heap Derek. I will do as you say over the weekend and report back when I can.
Many thanks,Jeff
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Busy weekend - no float test yet. BUT - got the hull painted with 3 coats of polyurethane, and got the rudder assembly built. Will have about 50 degrees each way of centre - probably sufficient - it will have to be! Will post some pics later, but basically the rudder has a top and bottom brass tube as a bearing and the stern post has one, in the middle (should have made it the other way around), with another tube which is a smooth fit inside the 'bearings' going the full length of the rudder. This inner tube will swing the rudder, via an arm to the servo and a long pin which will sit down inside the rudder and be soldered to the inner tube and servo arm.
Made it this way so I can easily remove the rudder if I have to (the inner tube will just pull out and the rudder will separate from the boat). But a picture is worth 1000 words so I will post a picture later on.
Not real bad progress since this time last Sunday!
Jeff
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Some progress pics - hoping they upload together!
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Think I have the rudder/servo set-up worked out so that I can get full rudder swing. Not installed yet, will leave that for a few days until I get some more structural stuff done. Have fitted motor mounts (removable in case those tiny motors don't drive hard enough) and about to start making a frame for the paddle decks.
The motors will drive a brass tube as an axle, housed in a snug fit outer brass tube as a bearing. Will mount a tube-bearing on the top of the hull, with another at the outer end of the wheel, and 2 bearings on the motor mount. I am pretty sure that this will give sufficient support for the axle. The drive gear is held to the axle with a tiny split pin, and the wheels will also use split pins to hold them to the axle. This will make wheel and motor removal fairly simple, if needed.
As you all know, time is the critical ingredient.
Must say it is really nice having to build in weight, as opposed to building in lightness as with R/C gliders!
Jeff
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Had a spare hour so have fitted the frames for the paddle decks, made the bushings for the drive shafts. I will be using both motors initially, and if they seem to work in unison - i.e. same speed - and the rudder will swing the boat, I may leave them at that. Although at a later date I will fit the reversing switches as in Brett's article. By the way, the motors draw about 240 ma running free, and about 500ma when the shaft is held firmly between fingers.
This is a contrast to my model cabin cruiser, which has a 12 volt drill motor in it, driving about an 1 1/4 prop. Haven't measured the current draw, but it will blow a 40 amp fuse if I put too much power on too quickly, through the ESC.
Pics will appear in next day or two, of progress.
Jeff
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Hello again!
I am pleased to say that Mary Ann is almost ready for the water. Very briefly, after my last post some 18 months ago, I got stuck on the paddle wheels - that is, how to make them quickly. I didn't want to go to the trouble of spending hours creating intricate wheels that may not have worked. About 2 weeks ago I decided to make some thin sheet metal discs, and use Loctite Epoxy Weld to glue the paddles into place between them. With a brass tube as the bearing (pinned to the brass tube axle) the wheels are now done and fitted to the boat.
Had a trial run in the bath to see if the tiny motors would drive them without stalling, and the boat very near leapt out! Plenty of power, no sign of stalling - and between them they only draw about 240ma.
Since then I have completed the decking, permanently installed the drive system, and given the decking a coat of polyurethane. I am now ready to start installing the ESC - which I will need because the boat is going to be too fast - and the rest of the electrical stuff. Intending to run 2 servos with a Y lead for rudder and wheel steering. One servo turning the rudder, the other servo to operate a micro switch for each wheel - to turn one motor off on turns.
And just this evening I realized that the wheels will probably cause stability problems, and have decided on a method to fairly quickly make some timber wheels. Current wheels have 16 paddles - I think the new ones will only have 9. But will decide this once I have had the boat in the water to see how she handles.
Will post some pics in the next couple of days. Just wanted to say it is good to be back on the forum and to see what others have been doing.
I should add that these tiny motors, apart from being very cheap, appear to be really appropriate for paddle boats, and pretty easy to set up. An ESC should control speeds well, and the way I see it, the motors already come with a pretty good reduction ratio and it seems a lot less fiddling around with belts and pulleys, etc.
More to come. Best wishes to all. Jeff
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Welcome back Jeff good to hear the Mary Ann build has progressed.
Damien.
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a word of warning
my personal recomend isc 300/350 rpm , at the paddle wheels, and i use either 1 or two motors of 540 size , about 42mm diam, these motors seem too small to me ?especially w the size of the model
I normally drive a paddle wheel in 1/24 scale, about 170/190mm in diam., via tooth belts 3:1 reduction, so 1000 rpm motors and g/boxes via ebay
but another fellow has used 150 rpm jaycar motors/g/box , and over driven them to get enough revs,1:2 ratio
you need the top of the floats about 6 mm below the water line to allow for water scoop
i use HTD belts in preference to MXL, i have stipped MXL by not turning on the TX first , and brass paddle wheels, have a fly wheel effect , taking 3 teeth off each belt
if you get into trouble , try these ideas, but you may be ok
good luck
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there are a few paddle models at goldsmith steam rally, every time