I am building a 52 inch mono hull and need some help with hardware. I think i am going to use a prather 280 prop, but i dont know what size rudder i will need.

I am also building a radio box for it but cannot figure out how to run servo connections without compromising waterproofing. how would i go about this

any other advice would be helpful.

I am on a tight buddget so i will try to make anything if it is cheaper than buying it. i have plenty of time.

I use a snap top tupperware with 4 tabs use a hot wire or small tip soldering iron for the holes seal with hot melt glue. put switch in the top with a small "o"ring to seal. For the push rod thru transom feed a push rod through a piece of hollow carbon fiber and shrink tube around carbon fiber and about an inch over the push rod glue in place with 3m 5200 and lube both sides of push rod to water proof. you cxan find tupperware at walmart for about 2 dollars, good luck

Thankyou for the photos they will be a huge help.
I am going to be using a fly sky fsgt-3b controller and reciever system and am wondering what servos and batteries i should use. remember i am on a very tight budget

Keep your linkage, especially the pushrod to the rudder, as straight as possible to maintain positive control of the boat. I hope nobody is offended but I have to say the rudder control rod example pictured is a very bad example...that would bend under the slightest load and not allow good control of a moving gas boat.

The tupperware type boxes do work for an economical radio box alternative. I've used the lock'n seal type found at Walmart in the past with success. For sealing the control rods, there are many ways to accomplish it, but I really find it hard to beat the radio box seals sold by Aeromarine. Cheap and get the job done very well. Here is a link: www.aeromarinerc.com/index.php...emart&Itemid=53

thankyou for the link, i may try to use some of those.
I would agree the linkage is a little thin, i will probably use a bike spoke as i have heard they work well and i have tons lying around.

The problem in the linkage shown isn't the size, it's the double 90 degree bends before it connect to the rudder. That's killer. Have is go straight from the radio box to the rudder. If you have to make bends, do them in the throttle linkage. But if the installation is well planned out, you can normally get to both without any major bending.

marc wrote:
Hi folks

I do very much agree with Marc on the importance of keeping the rudder rod linkage as straight as possible.

I recently tried a slight bend in my 2mm piano wire linkage to accommodate moving in the linkage at the servo arm. I was amazed at how much flex it caused. I was so uncomfortable with the potential compromise in control that I moved the rudder servo to enable a straight rod to be maintained without binding on the exit hole of the radio box.

In respect of budget radio boxes, personally I’d make one out of plywood and hardwood timber with a Perspex lid seated on sealed foam. A well made wooden box has a lot going for it:

1 Materials are relatively cheap.
2 It is tailored to fit the boat with no compromises that are often needed with bought boxes.
3 It is easy to fix things to it in a secure water proof manner.

In respect of linkages there are only two methods I have used:

1 Steel push rods running through a quality rubber bellows seated in the exit holes of the box.

2 Flexible cable running inside a plastic tube glued into the exit hole of the box (for throttle linkage).

In my opinion irrespective of the type of box used, the most critical thing is that it is properly tested to be confident that when a serious dunking happens out on the lake, the gear inside it remains dry!

All too often we see even experienced boaters come a cropper after water gets into the radio box.

Cheers
Craig

very true. i did not think about the bends but know that i do i realize what yall are saying. i will probably us a wire linkage for throttle and a bike spoke for rudder.

I am still in need of suggestions for servos and batteries if anyone has a reccomendation.

also i am using a weedeater as an engine and wondering how to use a prather 280 prop with it or a prather 270.

Hi

I’ve no experience of your power plant so could not comment on props. Those that have might need some information on the hull and intended set up to be able to help.

In respect of radio gear, there are a lot of products on the market. For servos I use Hitech, a standard servo for the throttle and a high torque metal geared servo for the rudder. I’d want a minimum of 9kg/cm torque for the rudder servo.

My battery pack is a 5 cell (6 volt) 2000mAh Sanyo Eneloop Nimh. When they bring out a higher capacity equivalent of this model I will be upgrading.

Regards
Craig

thankyou for the info on servos and battery i will probably be getting a set of hitec servos.

with respect to the hull it is going to be 52 inches wide by 13 inches wide. the the weedeater is a john deere which i will be converting to an rc motor. i have not seen a john deere engine ever run in an rc boat so i will most likely not get much info but hoping for some.

i am wondering what colors to use for the hull but am thinking of using green and yellow to stay with a john deere theme. i will probably start the hull this weekend so any advice will be great. i will post pics very soon.... hopefully

I still need info on what prop aqnd rudder i should use and also how i should connect the prop to drive shaft. also need suggestion on strut.

a strut and rudder assembly would be great.