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[marklincs]

All,

I have a Fireboat Aerokits I'm refurbing and Research has revelled I could ideally do with an electric motor equivalent to a 46 I.C motor

Thinking Brushless and do not mind out runners either, then a decent ESC to handle it all.  Prop needs to be a 2Blade X type 45mm

anyone got an recommendations ?

[dodgy geezer]

Hmm - I've never worked up at that power before, but it's worth putting some estimate figures together so that you can check that you are in the right ball park. Here are my guesses:

A 46 motor puts out about 1.5HP. That's about 1KW. You would be using 1KW if you had a motor running at 20V taking 50A. Modern brushless are pretty efficient, so go for a 60-70A motor at 20V - a 6S. Pro Rata for lower voltages. You should be able to get one from Giant Shark for £40 odd. Here's one at £33 - but I don't know enough about the KVA implications to know it it will be any good - 5000rpm may be a bit slow....

http://www.giantshark.co.uk/xyh6354-250kv-outrunner-p-404607.html

[barriew]

The fireboats web site used to have details of one with a brushless motor - can't remember now if it the 46" version, but it was certainly fast. I saw it in action at one of the Fireboat Fun Days held by the Burton on Trent club. In fact, Burton are having another of those this September 9th. A good place to get advice about your re-furb.

Barrie

[bj]

All,

I have a Fireboat Aerokits I'm refurbing and Research has revelled I could ideally do with an electric motor equivalent to a 46 I.C motor

Thinking Brushless and do not mind out runners either, then a decent ESC to handle it all.  Prop needs to be a 2Blade X type 45mm

anyone got an recommendations ?

One of the recent (August onwards) UK boat mags had an advert for the new OS brushless motors on the back page. In the corner of each brushless motor picture was a  profile of an IC with the equivalent size as a comparison .

[nick_75au]

I've found that direct IC replacement brush-less are not exactly the same, It seem that the brush-less equivalent has an RPM of around half of the IC and compensates with the prop pitch and diameter, the power is still the same. So can you provide the prop size intended and the system voltage you would like to use, can definitely give you an answer on what you need from this info.

Edit should have read the post proper;y, a 45 mm prop will want about 9000-12000 RPM for a fast-ish boat, a 36 mm out-runner of about 1000 Kv will power the boat on 12 volts (3 cell Li-po or 10 cell Ni-mh) If you want a faster boat then a 42 mm higher Kv of around 1200

Cheers
Nick

[spearfish99]

I have just ordered 3 of these for a project from Hobbyking UK warehouse.

They list this outrunner as at least equivalent to .46 motor. Looking to run mine on 4-5S lipo.  At £13 a time, worth trying. Also comes in slightly lower KV value as an alternative

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=25982