Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: stoksey25 on June 18, 2009, 07:02:43 pm

Title: Small electric boat help
Post by: stoksey25 on June 18, 2009, 07:02:43 pm
Hi there Help needed for a new boat sailer . I have been given a small boat and it has a old tamiya motor and a 110 amp speed controller which can handle up to 12v (apparently) what motor and prop would anyone recomend for this boat. I have 2 8.4v stick packs but thought of spliting then so they can go either side of motor as it is not very big at all  any help would be great
(http://img5.imageshack.us/img5/9801/24103185.th.png) (http://www.postimage.org/image.php?v=gxsfq7A)

(http://img5.imageshack.us/img5/8734/87578082.th.png) (http://www.postimage.org/image.php?v=gxsfsCJ)

(http://img5.imageshack.us/img5/1161/79616646.th.png) (http://www.postimage.org/image.php?v=gxsfv6S)
Title: Re: Small electric boat help
Post by: Bill D203 on June 18, 2009, 09:07:42 pm
Hello, What motor do you have in it?  If it was me I would start with an X20mm prop then they X25mm and X30mm.  Keep an eye on hot hot the motor is getting. It would pay to put a water cooling coil around the motor. This will save it from over heating and burning out. Having a second look at what you have got fit a water cooling coil then give it a go. It should be lively on the water. I take it you know how fit a water cooling set up?
Have fun??
Title: Re: Small electric boat help
Post by: stoksey25 on June 18, 2009, 09:28:16 pm
Hi there this might be a stupid question but is that what size i ask for prop wise . and the motor is a tamiya sport tuned motor i think out of a car
What do you think of the graupner speed 500 race motor
( http://www.astecmodels.co.uk/catalog/product_info.php/products_id/271?osCsid=4612e92c1b39da36c9a2251d712a1741 )

thanks for your reply
Neil
Title: Re: Small electric boat help
Post by: Bill D203 on June 18, 2009, 09:55:21 pm
Neil Try it with the motor you have 1st. Do you know the prop thred size. 5mm or 4mm is normal. I pick up Props at Hobby shops as and when I come across them. Ithink J perkins have some props in stock but your local model shop should be able to get them in for you. try this  http://www.jperkinsdistribution.co.uk/list.php?subcat=101&cat=Propellers&Navmain=Marine
Title: Re: Small electric boat help
Post by: andyn on June 18, 2009, 10:36:11 pm
old tamiya motor

 {-) Thats one of the hottest motors Tamiya make, keep it in there and run the pack you have. Start at 35mm prop, then move up to a 37.5

Also, it most definately needs water cooling.
Title: Re: Small electric boat help
Post by: stoksey25 on June 24, 2009, 08:38:39 pm
Hi there tried that put water cooling on it and to be honest its no good. I dont know if the hull is set up right as the model is going in a straight line but tilting to the side. If anyone can give me any sugestions or should I scrap it and look for a different hull I just want a fairly fast boat to run with the electronics out of this one many thanks Neil
Title: Re: Small electric boat help
Post by: knoby on June 24, 2009, 10:12:21 pm
Hi, its usual for most fast electrics to have a slight list when running straight. its caused by the torque of the motor. you can offset it but moving the battries or radio gear across the hull slightly, but as the batteries run down the list will lessen. Its just a matter of experimenting. I usually try to adjust it so the boat runs level when half way through your total run time, i find this to be the best compromise.

what appears to be the trouble with the water cooling, is there no water flow, or is the cooling not effective?

i wouldn't give up on this hull just yet, all performance boats take time to evolve to the maximum potential, thats half the fun!!! & what you learn from this project can be used to help avoid mistakes on your next project. (hopefully)  O0

post some pictures if you are able & I'm sure the mayhemmers will help sort this hull out.

Hope this helps, good luck   :-)) :-))

Cheers Glenn