60 Inch raf crash tender

peep31 #2 of 8 15 years ago 2

new build from resized 60 inch plans,great project,plan to run with 850 motor,16 inch propshaft and 2 1/4 inch prop,so far its going well any advice please feel welcome

peep31 #3 of 8 15 years ago 2

60 Inch fire tender

new build so far,

peep31 #4 of 8 15 years ago 2

60 Inch cras tender

need plans for a good quality mast is there any out there

peep31 #5 of 8 15 years ago 2

60inch crash tender

I have now made the mast from brass and fitted a 850 motor

3 comments

Huntsmanman
Able Seaman15 years ago
Unless you are contemplating fitting a gearbox to the 850 I would in terms of motor efficiency really be looking at a twin brushless setup, particularly for a craft of this size. Brushless motors are now in very wide use in model aircraft where they really do excel,from the very smallest to the extremely large models and are equally suitable for marine use. Unlike a brushed motor they are particularly efficient, they do not require a gearboxes to Improve their output so they are well suited for direct drive. Brushless motors also offer the best power to weight ratio when compared with a standard bushed motor and produce fantastic torque equaling and in many cases exceeding that of many I.C.engines. Also Important with the Fire Tender try to keep the overall build as light as possible, the original Fire Tender built entirely from birch ply and with all of its solid metal fittings was needlessly quite a heavy lump and thus often resulted in disappointing performances. it is as well to remember that heavy aircraft don't fly well and similarly heavy boats will take disproportionately more power to get up on plane,and will be more prone to dig in on turns, a light build will always outperform a heavier one, with the exception of displacement hulls of course. in terms of guidance I have an EMAX BL4030/10 which can easily turn a 15 x 7 aero prop, it is extremely powerful and runs on between 18 - 30 volts, the mounting is easily adaptable for a marine installation, one or two of theses would give you an powerful and efficient setup for a scale performance with power to spare, you will of course need the appropriate speed controllers preferably water-cooled. Finally always set up using a Power Analyser so you know exactly what current the motor drawing and can observe that your speed controllers/batteries are not over stressed. Good luck with you
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peep31
Petty Officer 1st Class15 years ago
what would be your advice on motor size
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am35

Able Seaman15 years ago

Hi, this looks a great project, are you sure one 850 motor is enough for this big boat?

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peep31 #6 of 8 15 years ago 2

60inch crash tender

just a few more pics of the build,its in the painting stage and soon will be installing fittings

peep31 #7 of 8 15 years ago 2

60 Inch crash tender

a few more pics of progress,hand made mast cleats hand made search light and a bit more painting of rear deck also decals.still plenty to do though,now need a 50 amp brushed esc if anyone can point me in the right direction

6 comments

Minimow151
Recruit15 years ago
Sorry to jump in but I would love some advice on the same boat. I am about to try and update my boat for my son. I built it (with my dad!) 32 years ago. it is very slow running off a 6v hectoperm motor and the original futaba controls could do with updating. W have used it a few years ago and it ended up with me taking a very cold swim to recover it when it stopped working.

I would like to Improve the speed. Poss as you suggest twin motors and rudders. Any photos, drawings and what to buy would be a great help. Many thanks and happy Easter.
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Gregg
Sub-Lieutenant15 years ago
I have sent reply, but in the interests of your own security, please remove your email address from the post.
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peep31 #8 of 8 15 years ago 2

60 Inch fire crash tender

have now stripped out the single prop shaft and installed two and two 850 motors and two nylon props to start with, just awaiting for two esc units and then I can start some trials fingers crossed,so far I have had some great advice from steve on this great web site. any advice on making windows would be a great help

2 comments

peep31
Petty Officer 1st Class15 years ago
hI boat shed,yes this is the enlarged plans I got from the guy in canada they were good quality prints too.yes I have got both motors running the same way,some people say it would be okay and some don't but I will post results after trials.I will gladly put some video on the site if I can get someone to carry out the video for me,thanks for the post and you like my boat.I have just added two more rudders so it has three now as I say I will post results later.
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BOATSHED
Captain15 years ago
HI been watching your build and she's looking great, is this the enlarged version that the guy in canada will enlarge to your own requirements ?
Also looking at your wiring are you running both motors the same way or are they contarotating? if running the same way this may give too much torque,and she may not run too flat on the water or turn too well.
Looking forward to hearing how your trials go, will you be posting any video? 😀 Happy sailing
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peep31 Opening post 15 years ago 2