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Author Topic: Motor Choice for King Orry Rebuild  (Read 1015 times)


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Motor Choice for King Orry Rebuild
« on: July 05, 2010, 11:32:58 PM »

I am about to undertake a MAJOR refurbishment of my model of IOMPSCo’s King Orry, necessitated by the dropping of a 3’ TID tug on the after end of the Orry’s superstructure. <:(

I am using the opportunity to replace the motors, shafts and ESCs (which have been nicked for a more recent build). She sails well on 6v with a couple of generic 380s and Hitec ESCs. 540s were used initially but, though having a huge margin of reserve power for emergency conditions, would not allow a slow start, at least not with the fitted controllers. 385s were woefully underpowered. She currently runs for around 75 mins on a 6v 4AH battery (40-60 minutes with gadgets/lights in operation). There is no spare ballast capacity for heavier batteries.

I would really appreciate any advice regarding motor selection, speed controllers etc. Things have moved on since I last built a boat. Do brushless motors justify their cost? Is the complexity of gearing worth the effort, and what is the best way to accomplish this (the current installation allows the use of near-horizontal shafts which looks good, but a larger diameter motor/gear/pulley would need more incline)?  I would prefer a switch to 12v to enable use of better smoke generator etc. but don’t know how this would affect choice of ESC and motor.

Boat is 48” long on a 6” beam and she weighs around 5-6 Kg.

All advice would be welcome.



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Re: Motor Choice for King Orry Rebuild
« Reply #1 on: July 06, 2010, 05:31:15 PM »

Were the 385's running at or near their max voltage? What size props?
I have one running half voltage shoving a 2.5-ish KG boat at real performance plus a bit lot for luck, so two on full voltage should be adequate.  More modern ESCs of known manufacture will give all the control thats needed.  A pair of ESCs with a built-in mixer even better.
NiMH batteries seem to pack more A/H capacity into less weight than SLA.
"With the right tool, you can break anything" - Garfield


  • Guest
Re: Motor Choice for King Orry Rebuild
« Reply #2 on: July 06, 2010, 06:03:45 PM »

A pair of 12v 555 motors sounds like the job, along with maybe a dual ESC/mixer from a certain manufacturer much mentioned in these columns  %)
PM me for further info if you like.


  • Guest
Re: Motor Choice for King Orry Rebuild
« Reply #3 on: July 08, 2010, 09:42:45 AM »

Cheers guys. 385s were running on 6v so would probably do the job at 12v. Will use twin ESCs but forego the mixer as I'm using a twin throttle setup and would like to keep it. Can turn boat on its axis with full astern/quarter ahead and full rudder.

Will bear the much mentioned company in mind, FLJ. Have been impressed by a couple of their products already ACTually.  ;)
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