Hi,

I'm new to rc boats model etc, but have had a love of boats since I was young, I have drawn up some plans for a hull but have little idea on what I'll need to drive it.

The hull will be 600mm ( 23.6" ) long and 120mm (4.7" ) wide (yes I know it's very narrow, thats the look I'm after) and built from ply and balsa. The super structure is still undecided but I like the look of Aphrodite (picture shown).

I don't need it to go Faaassstttt , the lake/pond is only about 20mx100m ( 60'x300' ), but I do want it to be able get up on the plane.

First thoughts are to drive it with two 400 or 480 sized motors running graupner 30mm props. Will this do the trick ?

I also need advice on what speed controller and batteries I should run. As I said top speed is not a priority and since hull space(width) is small, smaller motors are preferred.

Attached are screen shots of a rough 3D model of the hull taken from the hull frame drawings that I've done, the limitations of the 3d software means the bow is a bit ugly but you'll get the idea.

As I mentioned before, I've included a photo of the Boat Aphrodite which just looks amazing, I'm NOT trying to recreate it but draw ideas from it.

Enough rambling, Anyhelp would be much appreciated, hull design stuff too.

Geoff

Where can i get a program at like that. I have a few designs i been working on myslef and that program would be great to use.

Deathwish,

go to http://www.metaseq.net/english/index.html it's a freeware download, although looks like there's been a lot of updates since I downloaded it.

I created the 3d model from hull frames that I'd drawn in auto cad from a side view and a top view, then used the dimensions to locate each point of the hull on the keel/chine etc, or you could just do the whole thing in metasequoia.

The software was originally designed for modeling areoplanes for FMS which is an RC plane trainer have a look at this link it will help you get started

http://rcp.web.infoseek.co.jp/Rc_hp2...asequoia_e.htm

There are also a number of hull design software programs out there, but I've never had that much success with them.

Geoff

Yeah, that is Billy Joels boat? It is really nice!

Can Someone PLEASE!!!!!!!!!!!!!!!!!! give me some advice on this []

Geoff

Geoff,
A boat that size, with that type of hull ought to move right along with a pair of '400's, or '380's for that matter. Naturally keeping the weight down would help, and 'ballancing' the boat (weight fore/aft) will determine if it will even plane or not.
I'm not that familiar with the '400' size motor but they can't be that different from the '380's. A pair of '380's would need an ESC that could handle something on the order of 20 amps at whatever voltage used. Most ESCs should handle 20 amps of current, but check the specs. Using an ESC that's 'bigger' than needed is preferable to using one that's marginal. (Bigger is better till you get to some ridiculou$ point.) Not sure what the current draw of the motor(s) is/are? Do a stall test on one, double that amount of current, and that's the maximum current draw a single ESC would need to handle. The size/pitch of the props also makes a big difference. So does the voltage and 'Ah' capacity of the battery. Most motors can handle a range of voltages. On the average, something between about 6 and 12 volts is most common, sort of. The 'Ah' or 'mAh' rating is another one of those 'bigger is better' thingys. Then you get to the 'is there room in the boat' for the thing? Your guess about that would be just as good (or better) than mine.
Good luck!
- 'Doc

I will be powering my 28.5" PT boat with two brushless motors. They are HG2015-4166 geared motors. These are 4100 rpm per volt motors. They are geared 6.6 to 1 so I figure the no-load rpm to be around 7,800 at the output shaft. They are small and very light but should do the job very nicely. In a boat this size, lightness is of utmost importance. See them here:

http://www.maxxprod.com/pdf/HG20xx-xx66.pdf

If this link doesn't come up right away, hit your refresh button.

Marine ESCs for brushless motors are very hard to find. I bought these (1 for each motor):

http://www.himodel.com/electric/HiMo...Y-40-OPTO.html

Although these had to be purchased directly from the company in China, it was a very good and straight-forward experience. Lots of email communication from them on the status of the order. I just got them yesterday, 4 days after I placed the order. Very well packaged and protected.

I purchased spade type rudders and stuffing boxes for the rudders from:

http://www.mackproductsrc.com/Power%20p2.htm

I ordered, but have not yet received, my propshafts, stuffing boxes, motor couplers, and propellers from:

http://www.loyalhannadockyard.com/

The props I ordered are Raboesch 30mm diameter 3 blade scale props.

The batteries I plan to use are 2600MAH, 3 cell lithium polymer types, 1 for each motor.

The radio I will use is my Spektrum DX6. The reciever is tiny and virtually weightless. I will only need one servo on the rudder function to make the boat operable.

Steve,
Sounds like you have done some research. Lets us know how those brushless motors and esc work. I have been wanting to try brushless motors for some time but I still have many other motors still on hand. I know they are lighter but the cost is higher.
Danny

Whats the price on those brushless motors? How much did the ESC cost?

I don't recall the price on the motors as I bought them at the 2006 Toledo show and paid cash. they are listed @ $58 here:

http://www.maxxprod.com/pdf/HG20xx-xx66.pdf

The ESCs were $31 and change. I can't tell you how reliable they are as I have never used them before but they ought to be fine rated at 40 amps with motors which will probably draw less than 20 amps. Shippping added another $15 or so but delivery was very fast. 4 days shipped from China.

Thanks for the help LtDoc,

That's exactly the sort of advice I needed.

Geoff