Geared boats and why? please respond want to know a little kite about why they useit

[Zackthrills]

hey guys as you know I am new to this. But I can cross this posting on fine designs http://www.finedesignrc.com/turbotranssetup.asp and I would like to know a little bit more on why they do this I know like on RC cars you can have to speed transmissions and allow the car to start off and go faster is this the same principle for what? And what they use this in a SAW boat to make it go faster as gearing will you allow you to get hire top end speeds to my knowledge with RC cars is it the same for boats? If anyone knows we're there is a guide on this or a little bit more information I would really appreciate it. Thanks Zack

[Alexgar]

in the days of lower powered brushed motors the transmissions were used to create more torque ie a larger prop nor needed today as some of the brushless motors put out 2 to 3x the wattage. Hope that helps

[Zackthrills]

Ok thanks

[Zackthrills]

Would it do anything for brushless or not at all???

[tlandauer]

Would it do anything for brushless or not at all???

Don't think it is needed, as you can see, recently made boats out of FD do not use them, at least I have not seen one picture that had that trans. in it.

[kendt]

It would be interesting to try. Id love to see a big ol t600 outrunner on a gearbox and see what kind of prop it would turn.

[Zackthrills]

if it works like a transmission allowing the engine to turn a larger prob at higher RPM's would that not make the boat faster even if it is brushless? To me it seems like you could almost make the boat havs a two speed gearbox which would allow the boat to have greater speed by being able to turn the room mass of the prop faster

[marko500]

All the guys above are right. Not really needed with the brushless motors we use today. I bought a used cat with a FD gear drive in it. With a 8xl motor it could turn an x648 prop and not even get warm. Gears also allow you to fine tune prop rpms a little bit more. Mine was set up as a gear reduction ( motor turning faster then prop). I did read somewhere about guys using it as overdrive (motor turns slower then prop). Worked good but the COG was higher with the motor mounted higher, more driveline drag with the gears and shafts and finally broke a gear and decided to get rid of the gear box and go direct drive. Another problem with turning too large a prop is that torque roll from the prop starts to become an issue.

[Zackthrills]

I can see that. That makes sense

[jevmax]

The gearbox makes a boat more versatile. You can take a low rpm/high torque motor and get all the rpm you want by using an overdrive gear ratio. You can also use a motor that has a very high rpm, and bring it down to a reasonable level. The best attribute I ever used a gearbox for, was once you find the best set-up and ideal prop for a hull, you can keep using that prop/set-up and simply change the gear ratio to get either more speed or more runtime. I think that FDM is the only source for gearboxes for boats. Unless you like to experiment a whole lot, you may be better off just going direct drive like most guys these days.

JMHO

[Zackthrills]

Us direct drive is the way I'll go. Just wanted to know about it in boats that all.