zmajcek13

Hello, guys.

I am building a Yacht.
the plan was on my local forum but the thread in dead.. So i am asking for help here .
The build is going well but i have problem with the hardwarei am looking for advice which motor, speed controller and prop to use.. no need for some high speed.. It doesn t matter if it is outrunner or inruuner something not too expensive..

Here are some specifications:
the length is one 1m, weight don t now currently
shaft is standard not flexible 30cm long, ruder is 45*68mm with standard servo.
battery is LiPo 4s 4500 mah
Thank you for any advice or proposals for which hardware to use..

here are pictures from previous month...

yellow-bird

Hello zmajcek

Do you know what diameter propellor shaft you have? Is it 3.2mm or 5mm or something else?

To move the boat at scale speeds (20-25kph) you will need a motor with maybe 300 watts of power and a suitable ESC. You can find suitable brushed motors cheaply like the Traxxas Titan 775:

http://traxxas.com/products/parts/motors/titan775

but suitable brushed motor ESCs are becoming rare now and quite expensive. They are also sometimes not compatible with lipo batteries. Here is one that is that you may find on eBay:

http://traxxas.com/products/parts/escs/3019Revx2lvd



For a big boat you need high torque so I suggest a 36mm or 40mm diameter brushless motor with 1500kv or less to keep the motor rpm in the range of 20,000-25,000rpm with a 4S battery pack.

I would suggest something like this:

http://www.hobbyking.com/hobbyking/s...er_1025kv.html

It is high torque and has a cooling fan , but you could also add a water cooling coil or jacket if needed.

For an ESC I would recommend the Hobbywing Seaking 60A:

http://www.hobbywing.com/product_show.asp?id=223

Try Googling for a local supplier for you.

For a propellor, something like this is a good cheap option for a metal propellor, but it depends on the shaft diameter.

http://www.proboatmodels.com/Product...ProdID=PRB4019

There are also many plastic propellors available in the 40-50mm size which would give you some tuning options as well. Here are some examples:

http://www.offshoreelectrics.com/pro...d=ose-2bld-316


yellow-bird

zmajcek13

Hello thank you for help

Today i have managed to do some work and weiht the yacht. Current weiht with battery installed is 1,9kg so finsihed shouldn t have more than 2,5kg. O yes and the shaft is 4 mm
here are some pictures from progress :

tested the waterproof - no leakage


install servo for rudder


finished the bodywork - primary coloring is finished

yellow-bird

Hello zmajcek

If the propellor shaft is 4mm, does the propellor need to be threaded (M4) so it screws on directly?

If so, Graupner makes a wide range of plastic propellors for 4mm shafts which would be suitable - see below for examples:

http://www.cornwallmodelboats.co.uk/...submerged.html

At the other end, 4mm is not a standard size for motors - standard motors have 3.2mm or 5mm shafts, so you will need a suitable coupler or universal joint if the prop shaft has not already been reduced to 3.2mm.

Will you buy your parts from a local hobby shop or by the internet? If by internet, do you know which company (website)? - maybe I can make some more suggestions for motor and speed controller for you.


By the way, it is not typical to have two link rods from the servo to the rudder. Unless the rod spacing on the servo arms and the rudder arms are exactly the same length the two rods will fight each other as the rudder turns and could damage the servo - you only need one of them sop take one off it the steering will work better.

-yellow-bird

zmajcek13

Hello!

Thanks for help and replies. I am sorry for a late replies but I have a severe lack of time so

For the servo i have removed rode so its s only one now (friend already warned mee)

so i was thinking about that motor :
http://www.hobbyking.com/hobbyking/s...00Kv_550W.html

The copuler for motor i now and is not problem..
That abiut the shaft i don t understand very good.. it is this shaft :
http://www.der-schweighofer.at/artik...ohr_m4x310_mm#
and you just put on propeller and srew it with bolt.

There is one more problem in diameter of the propeler.. which one?
For airplanes is program drivecalc where you can see how much current and volts is used on selected motor
and propeler.. is there for boats propeler anything like that?

huck1199

Z

Very nice work on the hull; hope you give us more pictures with the deck attached.

yellow-bird

Hello zmajcek

I see the picture of the shaft. This is Graupner and has a M4 (4mm diameter) thread for the propellor so a Graupner M4 propellor will fit directly on - no need for an extra bolt.
Graupner makes lots of different propellors with M4 screw threads (see my earlier post). I suggest you start with something about 40mm diameter and see how the boat runs - the Graupner props are not expensive so you can try bigger ones later if everything is OK to see whether the boat runs better.

The motor you showed me is designed for an airplane not a boat, and may not have enough cooling - normally the air from the propellor cools this motor.

Boat motors should have at least a built-in cooling fan and ideally water-cooling, depending on the power level. This one is in stock at Hobbyking at the moment and would be better suited for your boat:

http://www.hobbyking.com/hobbyking/s...er_1100kv.html

However motors are not very expensive so you can always experiment.

Here are links to some boat prop calculators:

http://www.radiocontrolinfo.com/RCca....php#Brushless
http://www.props4u.com/prop_chart.htm

-yellow-bird

zmajcek13

Thank you huck!
Pictures will follow as the work continue, but becasu i dont have much time is most of the work done for the weekend. As for motor i hade some discussions with some guys who has boats in my country. I have decided for this motor :

http://www.hobbyking.com/hobbyking/s...er_770kv_.html

it should bee enough..

zmajcek13

Here it is bodywork finished now starts waiting for motor so that work keeps on pictures are bad quality because are taken with phone..
But that is final look yust a several layers of coat and that it is.. Here are some pictuers:





With Regards Matjaz

Goldenduff

Looks good. How's the mini jet ski coming along!!!?

diy-pro

Nice build get that thing sealed tight and running, Did you get any parts on the way yet?

zmajcek13

Thanks these one comes with helicopter on board so sorry duff no yet ski on board The order must wait for now until the 18 that the mastercard is billed( i have monthly limit) .. So one good month... But while I wait :





one project afther another..

zmajcek13

zmajcek13

Finally managed to get some spare time and continue with project.. Slowly it is coming too end. So far I managed to this Hope to find soon some time to finish this project..
Here are some pictures..

zmajcek13

This is it.  It needs a few small touches but mostly this is it... Thank you guys fore help! Here are some pictures..





When the weather gets better, hope to make a test ride... following a video and a few more pictures

*delete M i k e u p delete*

Motor 770kv or what. 770 = 17094 rpm on 6S???? Pretty foxy boat, got your heli license?

zmajcek13

Motor is 770 kv and 4S battery.. : 11 400rpm

http://www.hobbyking.com/hobbyking/s...dProduct=14400

Pilot comes along with boat so no need for licensea few posts back it is seen in case of emergency (it sinks) still got plane license