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[simmer1470]

sorry to ask such a simple question but would a 540 style motor be suitable for a 5ft long mono hull boat or would it need to be geared or just have a bigger motor
i dont want a fast speed boat just a moderate speeder

any help welcomed

[essex2visuvesi]

Possibly but I would think a brushless would be a better bet

[grasshopper]

It would really depend on the type of 5' 'mono' hull we're looking at....if it was long and thin like a warship then possibly, if it's a tug type hull it would probably struggle, if a speed boat or launch then definitely a problem. A little more info or picture would help the situation.

[simmer1470]

its 5ft long 17inch wide


the red prop and shaft came with the boat but are siezed
 ive got a new  black prop (50X M5) and shaft (BALLRACE PROPSHAFT M5 5mm 9")

[grasshopper]

As regards the 540 option....Forget it!

To make a 540 do anything half-way decent in a hull like that, you'd have to run it at high voltage and then gear down to give it enough torgue to turn that prop.
A 700  (9.6v) or 850 (or even better -  twin's)  would be a reasonable start on 12v - but that looks an awfully heavy hull and superstructure.

Essex2's suggestion of brushless would be worth investigating - even for moderate speed, with modern batteries you could get it to perform well. What sort of budget are you considering?

[simmer1470]

the hull and top decks are both thick fibre glass

the twin idea is some think ive been looking at
 the under side is like this


could possible to have a twin set up i think but would it still need bigger motors or what size brushless motors

[TomTheKraut]

Hi there,
... in this hull, a twin-setup of 2x 700 9,6V brushed motors on 3S or 4S LiPo or 4S LiFePo should produce the sort of speed which is just that bit over "scale speed" to make it fun on the pond. Plus, it's a relatively cost effective solution.

If it were my boat and I'd go for single and brushless, I'd look for an outrunner, capable of handling about about 18V and producing about 1000 rpm/V under load (if only unloaded figures can be given by the manufacturer, look for around 1300 rpm/V). Then run this motor with 4S LiPo or 4S LiFePo.

[simmer1470]

So something like this off ebay 250793170252

[pompebled]

So something like this off ebay 250793170252

Hi Simmer,

No, a Ø 28mm motor won't cut it (unless you gear it down like in a helicopter)

This is more like it, but I'd go for one with a longer can to have more torque for the large prop you'll need:
http://cgi.ebay.de/80A-ESC-Brushless-Power-18-KV1020-Outrunner-motor-new_W0QQitemZ400203814150QQcategoryZ123849QQcmdZViewItemQQ_trksidZp4340.m263QQ_trkparmsZalgo%3DDLSL%252BSIC%26its%3DI%26itu%3DUCI%252BIA%252BUA%252BIEW%252BFICS%252BUFI%252BDDSIC%26otn%3D8%26pmod%3D250793170252%252B250793170252%26po%3D%26ps%3D63%26clkid%3D8035712963748966957

Regards, Jan.

[BJ]

sorry to ask such a simple question but would a 540 style motor be suitable for a 5ft long mono hull boat or would it need to be geared or just have a bigger motor
i dont want a fast speed boat just a moderate speeder

any help welc/quote]

Once again, the (old) Prop Shop bible....