Hey Snapper HG , that brings back memories
I USED TO HAVE ONE OF THESE KITS, I BUILT THE BOAT ALONG TIME AGO - RAN IT FOR YEARS AND I ENDED UP SELLING IT ON -SO AS TO MAKE WAY FOR NEW MODELS I WANTED TO BUILD !
BIG STURDY BOATS !- mine was powered by a pair of electric motors,
as for what to power your model with then i suggest you consider where you plan to run the model, my local lake does not allow internal combustion models as it is also a nature/ wildlife reserve,
i chose electric motors and rechargeable batteries, - your experience of RC cars means that you will be aware of the types of cells available, Nicad, mimh, lead acid, and now li-po- they all have pros and cons....some can be fast charged, others cant, some deliver endurance others deliver short fast bursts of power....do you want thrilling fast short runs or a leisurely 2 hour sail at the lake ?
as the model is big- you will need to consider ballast, the boat will need some ballast to make it stable and to acheive the correct waterline....my preferred option is usable ballast, ie batteries rather than lumps of lead !- i used lead acid gel cells for power a pair of 6 volt cells to make up the 12 volts i needed, they were a sealed cell so could be laid on their sides or whatever, you want the weight as low as possible in the hull, to keep the model stable, - the downside of lead acid gell cells is they can only be slow charged unlike nicads or nimh.....but they are cheap and are available from maplins and similar, they are the type used in some burglar alarms or fire alarm systems... the boat is big so a good cruising speed was what i hoped for, - its not a power boat so i was not looking for tremendous speed but i did not want a plodder, - my boat had 2 motor set ups over the years...my choice in the end was for a pair of decaperm motors, ( these were expensive but efficient )- they had a motor shaft that came out of the motor at both ends, one end was geared output the other end was direct drive, i used the direct drive end.... i chose some non scale propellors which i found suited the boat, they were smaller than those shown on the plan, as i wanted my boat to be a usable working model - i never wanted it to be an exact scale model only used for static display so i was happy with the use of the 2 bladed non scale props- they were sports type 2 bladed props, this kept the motor current draw very low, the speed was good, the boat would handle well, and in the event of needing to stop quickly the motors would go from full ahead to full astern quickly and the boat would stop nearly in its own length, essential if you sail on a busy lake or have lots of new or junior members in your model club as we did !- the low current draw also meant i got over 2 hours per run on a set of lead acid cells....
(my recommendation is to obtain a few different type of props and try them, some will suit the model better, you can also check the current draw on load - with a meter with props in the water.....
sometimes the speed is not changed from a 3 blade prop to a 2 blade prop but your batteries may last say twice as long as the current draw is massively reduced...also play around with sizes, i found very little difference in speed from a 45 mm diameter prop to a 35mm diameter prop- but current draw was reduced by 3 amps on load )
the decaperms were abit over kill - the motors were under no real load,they did not have to work hard, they did not get warm and they ran and ran with no problem - the decaperms come with a pre moulded mounting, these w motors were screwed to a timber plate on the inside of the hull that were matched to the angle of the propshaft...
the previous motor set up was a pair of como drill motors from model flight accessories ( MFA) these too did the job and the boat performed well but they drew a fair few more amps- they were more like the buggy type motors you will be used to- they were average 540 sized can motors, pretty oridinary but the got warm in use and did deplete the batteries quicker !- i bought some metal motor mount plates with these motors, these plates also screwed to the wooden plate in the hull... the metal plates and the higher revving motors were also a little noiser when in use.- the battery life was then about 55 mins with this set up...speed was comparable as with the decaperms.
one thing to consider the boat has twin prop shafts..... when you set up the model and the props you will need ' handed' props ones that rotate in opposite directions, the props will both rotate in towards the keel for example and when reversed both props will rotate from the keel outwards....
when i was trying to set my model up i struggled to find suitable props in handed pairs.... (and in the 2 bladed sports props i could not get handed props in pairs at all.... ) so i ended up buying 2 identical sports props and i reversed the polarity of one motor, so both props ran clockwise and when reversed went anticlockwise they both span in the same direction..
you sometimes get a model that wont run in an exact straight line so i offset this with a little rudder trim on the transmitter..then all was well
the model has twin motors so you could if you wish also set up each motor as independant with either a mixer or with the radio transmitter set up, so you could in theory spin the model on the spot with one motor going astern and one ahead.....it depends if this is what you want !
otherwise the two motors could be run by one speed controller, you could use a mechanical type but electronic items now are very cheap, but again you need to consider the actual current draw of the motor to get the appropriate rated ESC.
marine type ESC have no brake like the car varieties ! and are usually reversible, input voltages are usually upto 12 volts, there are others that go higher...
if you really want out and out speed then you could consider brushless set ups and lipo batteries, - just take several packs with you to the lake for several fast runs.....
but whatever you do enjoy it, these are biggish boats, the scale means you can add loads of super detailing, the broad beam means the models will cope with rough water too, and they are fine models, - if you dont know of it take al ook at the website Model Boat Mayhem
there are a few useful links on that site, one is to a site featuring these 44 foot boats and the models built as a result !
i am sure if you also contact the RNLI at poole or the assoc of lifeboat modellers you will get your questions answered too.....
where are you in the country, there are several events in the UK dedicated to model lifeboats, it maybe worth seeing if there is one near you...
any more questions just ask !
