Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Sports Boats R&D: => Topic started by: 3838Derrick on June 01, 2019, 05:55:51 pm
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Hi all. I have a 36" genesis racing catamaran and I'm looking to fit it with twin brushless motors.Can anyone recommend what size motors I will need and what size props too.
Thanks, Derrick.
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What motor does it come with?
The Aliexpress says:
Genesis 1122 Catamaran Racing Boat / Electric Brushless RC Boat Fiberglass with 3674 brushless motor KV207, 125A ESC with BEC
HobbyKing:
Spec.
Total Length: 1045mm
Width: 245mm
Height: 115mm
Weight : 2.5kg
Motor: 36-74Size 2075kv Watercooled Brushless Inrunner
ESC: 100A watercooled (Required)
Drive system: 4mm
Video on Utube comment:
I have since put a Turnigy 4082 1500kv motor + 45mm prop in the genesis, it's very quick now!!
Approx speed in this video 70km/h, with new setup 85+km/h
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Go onto rc groups theres tons of information on that boat there .https://www.rcgroups.com/racing-boats-electric-57/
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Thanks guys. Another question...……..Looking facing the transom, which would be the best way to have the props rotating (Port clockwise & starboard anti clockwise or vice versa?
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You need counter rotating props on a twin ,most cats seem to have them spinning inwards so you will need a left and right hand flexshaft and props .
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Always wondered why counter rotating, the twin nitro hydros we run both turn the same direction. Is it to reduce prop walk?
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If both props spin the same way your never going to get the boat running at its best as you will always be fighting prop walk etc . ALL real offshore boats including catamarans run cr props for the same reason .
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I guess maybe the big turnfins on the riggers and only turning right helps. Not like offshore where you have to turn both ways :-) .
O.P. I built a Genesis with single Leopard motor, I upgraded the strut and flex to 3/16”, did some cf reinforcing and I tried the rudder extension but I thought it performed worse in the corners with it and I changed it back.
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Thanks again for all your thoughts. I have now fitted left & right flex-shafts and props plus 2X 3674 brushless motors.
Waiting on delivery of 2 esc's ,then I can finally get her into the water!
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I think I should explain...…
I've had this boat a while now with a single motor and she performed well. Due to eyesight problems, she did encounter some pretty heavy obstacles and ended up pretty much wrecked!! So I decided to repair her and, as I like building more than I do actually sailing, I've gone with twin motors. Maybe I'm going over the top here (the wife says I am).
The eye problem has been sorted now (cataracts), so I can't use bad eyesight as an excuse for any crashes!
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Lots of people have built the genesis with twin motors twin 36 series motors might be a tad overkill it depends on how many cells each as the boat sits very low in the water as it is so weight can become an issue . I know this from my own experience of my own 36" cat i build , some have done twin setups but most opt for single just because its easier .
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I'm going to start with twin 3s wired in tandem. I'll let you know how I get on.