Do I still need big motors if its geared on a larger sub?

[skiprch]

Hi all,
I have an Engel Gato that needs new motors. I want to change the layout of my propulsion compartment. I do not know what size or ratio the Engel motors are but looking at a Aero-Naut geared 400 with numerous gear ratios. I am looking at the Aero-Naut line because of the offset gear reduction and a longer output shaft.
They have numerous ratios in the 400 size. They have a 3.5 to 1 in the 600 size. The 500 size is not offset and not an option. There is a big difference in cost between the 400 and 600. Any input would be greatly appreciated as I want to get her running!
Thx, Walt

[mylo]

Walt,

Any gear reduction is

Walt,

Any gear reduction is going to give you more torque on the output shaft. The higher the ratio, the more torque but less rpm. If actual prop speed rpm (which equates to how fast the model will travel) isn't as much of a concern to you, then I would say that the gear reduced 400 will suit you just fine. In fact, a motor drawing less current (which is typically a smaller, less powerful motor in general) will allow for longer battery life. If you want your GATO to get up planing to pull a water skier, then you're going to need something bigger.

If it's me, I'm going with the smaller, less powerful but gear reduced motor over a larger motor with a direct drive. ....which is exactly what I plan on doing.

Mylo

[mike dory]

Motors

One of the best systems that I've found for that size boat is Two 6 volt Dumas or old Pittman motors with a 3 to one belt drive reduction, (Less radio interference then if you use gears) and then run both motors on 12 volts. I've used this set up on several boats in the 6 - 7Ft. size with nothing but great success. Long run times with great torque. You will love it. Mike's Sub works should have the reduction units I believe. Best Wishes on your project. Mike Dory

[mylo]

Mike,

I would have never

Mike,

I would have never guessed that the gear drives caused radio interference. Would this be because of the friction of the plastic gears causing a static electricity buildup ? Would this be true regardless of radio frequency ? I've never run across this comment before.

That's the kind of thing that would drive a guy nuts trying to trouble shoot if you were having radio problems.

Mylo

[Guest]

Metal gears would cause more

Metal gears would cause more of a problem. i can't imagine why plastic gears would create radio glitching, but everyday is a school day, and I'm happy to stand corrected.

Andy

[mike dory]

Guy's, I only had the

Guy's, I only had the static electrical interference once with plastic gears, this was years ago and I can't recall the type of plastic or what were they mounted to or on for a bearing. You are so right about driving you nuts... Of course it is also true that the R/C receivers of today are more narrow banded then those of a few years back, So interference isn't near the problem that it was in the past. I just remenber going to a belt drive reduction ended all of the interference problems that I was having completely. Dumas motors are one of the few motors that you can run at twice the stated voltage without overheating or causing other damage to your boat. A 6 volt Dumas motor running on 12 volts with a 3 to 1 reduction. is one of my favorites setups for boats in the 5 to 7 ft. size. Two of my boats are over 25 years old now and still running great with that system in them. You could say they have stood the test of time. My Best Wishes, Mike Dory