Will need to put this on hold for a bit as I have just discovered a guy working in the next industrial unit to mine is into boating and has offered to give me a motor and ESC that he has 'outgrown'.
In the mean time I need to replace the propshaft as it is not man enough plus a metal U/J. Bit of hacking required.
Will need to put this on hold for a bit as I have just discovered a guy working in the next industrial unit to mine is into boating and has offered to give me a motor and ESC that he has 'outgrown'.
In the mean time I need to replace the propshaft as it is not man enough plus a metal U/J. Bit of hacking required.
This looks like a BEAST https://www.rapidrcmodels.com/ntm--4248-650kv-v2-brushless-outrunner-motor-5562-p.asp run it on a 4s battery ( ok go 5s and a smaller prop)
"that's not a bug its just an undocumented creature."
Sir Terence David John "Terry" Pratchett, OBE (28 April 1948 - 12 March 2015)
Seen this====https://www.designnews.com/automation-motion-control/small-controller-delivers-brushless-dc-motor-efficiency/131652937959694?ADTRK=UBM&elq_mid=6234&elq_cid=1081809
depending upon the type of motor cooling it can be a problem. Most brushless motors are out runners so the case rotates! in runners are usually for higher speed applications (or driving a gearbox). if you have an idea as to the size of IC engine the boat was intended to have then this list may be a help
.049 or .051 = 100 watts
0.10 = 200 watts
0.15 = 300 watts
0.25 = 500 watts
0.32 = 640 watts
0.40 = 800 watts
0.45 = 900 watts
0.51 = 1020 watts
0.61 = 1220 watts
0.75 = 1500 watts
0.91 = 1820 watts
Since Watts are Volts * Amps ( I know this is not accurate for a reactive load like an electric motor but its a rule of thumb)
This gives you a ball park next point is the KV ( revs per volt) of a motor. The higher the KV the smaller the prop. Finally buy a Watt meter they are not expensive and give you a chance to " fine tune" a setup.
https://www.ebay.co.uk/itm/FT08-RC-150A-Hight-Precision-Watt-Meter-and-Power-Analyzer-w-Backlight-LCD-U3F1/223101148808?epid=23023179441&hash=item33f1dd5e88:g:LYAAAOSwV3pba1JA:rk:11:pf:0
Car ESCs ( usually) have a reverse function while the airplane versions do not. They are generally cheaper than boat specific ESCs.
depending upon the type of motor cooling it can be a problem. Most brushless motors are out runners so the case rotates! in runners are usually for higher speed applications (or driving a gearbox). if you have an idea as to the size of IC engine the boat was intended to have then this list may be a help
.049 or .051 = 100 watts
0.10 = 200 watts
0.15 = 300 watts
0.25 = 500 watts
0.32 = 640 watts
0.40 = 800 watts
0.45 = 900 watts
0.51 = 1020 watts
0.61 = 1220 watts
0.75 = 1500 watts
0.91 = 1820 watts
Since Watts are Volts * Amps ( I know this is not accurate for a reactive load like an electric motor but its a rule of thumb)
This gives you a ball park next point is the KV ( revs per volt) of a motor. The higher the KV the smaller the prop. Finally buy a Watt meter they are not expensive and give you a chance to " fine tune" a setup.
Any specific reason you refer to a 'car' ESC?
What size (dia.) shaft should I use?
Will I need to cool that motor?
Cheers
Steve
Hi Steve
I started with the Hobbyking 3639-1100 kv in my Huntsman with a 2 blade 40mm prop, 3S 5800mah Lipo and a car 60 Amp ESC.
Upgraded to the 100Amp car ESC and a straight change over to the 3648-1450 motor.
All from Hobbyking.
Good units and have no problems.
Also a the price will not break the bank book!!!
Note, change the uni-joint to metal as the plastic ones will not handle the power and break.
Canabus
Hi Steve
I started with the Hobbyking 3639-1100 kv in my Huntsman with a 2 blade 40mm prop, 3S 5800mah Lipo and a car 60 Amp ESC.
Upgraded to the 100Amp car ESC and a straight change over to the 3648-1450 motor.
All from Hobbyking.
Good units and have no problems.
Also a the price will not break the bank book!!!
Note, change the uni-joint to metal as the plastic ones will not handle the power and break.
Canabus
Again, as not wanting to nick someone else's thread.
Huntsman 31 currently has a geared (belt) brushed motor which was probably quite a good spec. many years ago. I don't remember how quick it was but having watched brushless boats running this morning in Southsea I have decided now is the time for change before I start painting.
I've been reading various threads and gleaned some info but it is still a minefield. Whilst this boat (original) is twin screw I am not yet ready to go that far so will stay single screw.
A thread suggested 3639 -1100KV which is fine as a spec. but there are a zillion different makes and models for that spec.
Cornwall models seem to offer 6 or 8 so I am looking for more specific advise for make and model of each piece of the power system...motor, ESC, battery, charger.
I'm not going to say 'money no object' just that I don't 'need' to buy bottom spec.
I suspect there will be as many different suggestions as 'Cornwall' have motor makes but something good will come out of it.
Many thanks
Steve
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Again, as not wanting to nick someone else's thread.
Huntsman 31 currently has a geared (belt) brushed motor which was probably quite a good spec. many years ago. I don't remember how quick it was but having watched brushless boats running this morning in Southsea I have decided now is the time for change before I start painting.
I've been reading various threads and gleaned some info but it is still a minefield. Whilst this boat (original) is twin screw I am not yet ready to go that far so will stay single screw.
A thread suggested 3639 -1100KV which is fine as a spec. but there are a zillion different makes and models for that spec.
Cornwall models seem to offer 6 or 8 so I am looking for more specific advise for make and model of each piece of the power system...motor, ESC, battery, charger.
I'm not going to say 'money no object' just that I don't 'need' to buy bottom spec.
I suspect there will be as many different suggestions as 'Cornwall' have motor makes but something good will come out of it.
Many thanks
Steve
