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[philgg1946]

I think the wrong propeller is fitted as at full speed it moves very slow ,it;s a 3 bladed m4 but I don't know any more about  it , I've put on some pics of prop  , Phil

[canabus]

Hi Phil


What diameter prop, type of boat, battery type and ESC (speed controller) ????


Canabus

[Tug Fanatic]

And tell us about the motor.


I am not seeing the picture of the prop.

[philgg1946]

Thanks for replies, the boat is model of a raf fire launch 34.5 inchs long 6.5 inch beam the motor is a new turnigy 3650  3100kv brushless with a 60amp ecu,  the prop is a 3 bladed 30mm diameter ,at full power it'

And tell us about the motor.


I am not seeing the picture of the prop.

s doing 11500 rpm

[philgg1946]

And tell us about the motor.


I am not seeing the picture of the prop.

[philgg1946]

I'm trying to get pics of prop up

[Tug Fanatic]

Not my area of expertise but 3100kv sounds very high to me.

What voltage are you running?

[Stan]

Looking at the picture it looks like a plastic prop.

[Leaky Bottom]

Not my area of expertise but 3100kv sounds very high to me.

What voltage are you running?

It does sound like a very high kv rating to me.


Is it a inrunner or outrunner type of motor
I would of thought a motor with a 900- 1100 kv outrunner on 3 cell lipo would be more appropriate for this type of model

[tonyH]

There doesn't appear to be space between the end of the shaft and the rudder for a "fast" prop, so that's a hades of a rev drop at full power, assuming it's on 2S or a 7.2 Nimh or more, unless the 30mm prop is almost either very flat or side on to the shaft either intentionally or distorting incredibly

[philgg1946]

 I've been informed that the prop is rubbish so I'll replace it and take it from there,

[Stan]

Having spoken to this fellow member this evening it would appear this model was fitted with a brushed motor when built. It is quite obvious the prop is a cheap plastic one with very little pitch. So my advice would  be to check the following.


Contact Prop Shop and dump the plastic one.  Make sure the collet near the coupling is not binding.  And finally change the coupling this has been used to running on a brushed motor. If this is slipping revs could be affected. It is clear the shaft is turning freely allowing the motor to do its job. Final points stay with the 7.4 volt battery and be aware the rudder is quite large so be careful when turning.


Stan.

[Colin Bishop]

Prop Shop propellers are excellent and prices not bad but might take a while to be delivered. Raboesch are a pretty decent alternative for most applications.

Colin

[Tug Fanatic]

..........but 3100kv and 7.4v = 22940 rpm. Even when reduced by load that sounds like an awful lot or rpm for a scale type 34in model.

[tonyH]

As a follow up to Stan, I'd reduce the size of the rudder (a) to give a bit more clearance between it and the prop and (b) leaving it that size will almost certainly make the boat very twitchy and likely to spin out a lot.
 
PS. If you can't get to the steering linkage you can always use a Stanley knife an sandpaper.

[philgg1946]

Hi Guys, I've now increased space between my prop and rudder, also a new coupling and made more room for motor, I'm going to test it tomorrow I'll increase speed very slowly , thanks for all the fantastic help, I'm going to try and put pics up, Phil

[philgg1946]

 PS thats more like ,the roses for all you gardeners out there, Phil

[Stan]

I wish all goes well tomorrow. .


Stan 

[philgg1946]

Cheers for that Stan, I'll let you know 

I wish all goes well tomorrow. .


Stan 

[tonyH]

I wish all goes well tomorrow. .


Stan

Absolutely!