Servo City Gearbox ratio choice

[Shane Bastick]

Does anyone know which ratio to choose on the Servo City website for the Servo City Gearbox, its for a gas tunnel, and the choices are 3.8-1 or 5-1

thanks in advance

 

[RobertDoak]

Shane...
Looking at the web site...it looks like the servo selection needs to first be addressed...lots of options including up to 7:1 ratio....speed...or torque.....I would start with the servo selection....and its not like the engine need to turn a lot...It just need to turn with authority..I would choose torque over the speed...

 

[Shane Bastick]

thanks, the selection servo I choose for the options mentioned was the Hitec 805MG,

https://www.servocity.com/tm-805mg-180-servo-gearbox#

 

[RobertDoak]

Holy smoke...thats a monster torque servo...343oz @6.0 volts....analogue
Add the gearing and all...thats 1715 oz. Torque or 107lbs ...235 kilo......well I dont think steering will be an issue....being the ratio options are several...if it was me I would choose a middle of the road ratio....5:1 and be safe.

 

[Shane Bastick]

many thanks for the advice Robert

 

[michael faszcza]

I use the standard size gearbox .7950 servo 3to1 .steers very fast and strong as hell

 

[michael faszcza]

 

[Shane Bastick]

thanks for the pics Michael, looks like a better size, smaller and probably a little lighter in weight

 

[michael faszcza]

Yes it fits in the radio box and reaction is faster due to bigger pinion gear .

 

[michael faszcza]

Any questions you have just message me. There is nothing more aggravating than wrong info .

 

[Shane Bastick]

thanks very much, will do

 

[Daniel's Racing]

Important is to run the external pot on the output shaft of gear box so it works like a normal servo should. Trying to use the gearboxes without this modification being done and you will not like how it steers. It must be done for proper centering and drive ability. The 805 is a antiquated power hungry servo. The higher end standard sized digitals are plenty.

 

[Lee Whiteley]

I'm curious about the use of a gearbox for steering. As I think about it is it for smoother movement of the rudder as well as more torque?

Please fill me in on this as I think this could be very important when the boat is moving along at high speed.

Thanks,

Lee

 

[Paul Dadswell]

I do believe I went with the 7:1 ratio. It works quite well.

 

[michael faszcza]

How do you seal the radio box ? And with how much that pinion has to spin to turn it's got to be slow in turning . My gas tunnel turns faster then my 21 .

 

[Paul Dadswell]

Outboard turning

• Paul Dadswell
• Dec 24, 2019

Outboard turning.

It turns quite fast.