A Special Rudder Linkage

[Jim Allen]

This rudder linkage was designed to allow right rudder actuations to be done by pulling the rudder rod rather than pushing the rod. All the linkage moving metal parts are made of AISI O-1 full hard tool steel. Metal to metal bearing points are insulated with machined teflon pieces. The mechanism works very smoothly & is designed to last indefinitely. A hardened steel 1/8" rudder blade is mounted in the precision machined slot.

Jim Allen

 

[Terry Keeley]

Nice! What a fertile mind...

 

[Danny King]

Very nice.

 

[brad nichols]

Too many little pieces for big fingers, but it does look nice!
Brad

 

[David Santistevan]

Love the engineering!

 

[Jim Allen]

Special rudder blades are being made for the special rudder linkage. They are 1/4", full wedge, 7075-T651 aluminum blades that have a 5/32" water inlet hole. The ID of the entire water line is 5/32" ID, without any restrictions, up to the engine. This will be the largest water inlet hole ever to be used in a blade of this thickness which has a tapered back edge towards the bottom. At the point where the side of the blade's inlet hole is placed the rudder will be .215" wide. This means that both drilled holes must be on center which will give .0295"/side wall thickness at this point. I use a precision angle block to hold the rudder blank square in two axes for drilling the back edge water hole. Another fixture will hold the rudder blank for the blade's 5/32" ID side water inlet hole drilling operation. This same fixture will be used for the rudder's final wedge shape. The rear water line barbed fitting is pressed into a bored hole. The last photo shows how the side 5/32" inlet hole is started on a flat surface after clamping an additional 1/4" thickness to the blank's side.

Jim Allen

 

[Hydro Junkie]

What size and style hull is that designed for?

 

[XtremeRcBoats]

Nice work Jim, as always.

 

[giuseppe gallegra]

This rudder linkage was designed to allow right rudder actuations to be done by pulling the rudder rod rather than pushing the rod. All the linkage moving metal parts are made of AISI O-1 full hard tool steel. Metal to metal bearing points are insulated with machined teflon pieces. The mechanism works very smoothly & is designed to last indefinitely. A hardened steel 1/8" rudder blade is mounted in the precision machined slot.

Jim Allen

Hello Jim, this is very innovative rudder,congratulations.I'm very interested, Please let me know if it's for sale?

 

[Terry Keeley]

Sweet!

 

[Jim Allen]

What size and style hull is that designed for?

Both hardened steel & aluminum rudders are used on large size riggers & cat type boats. The two type mounts shown are interchangeable as well as all of the blade clamping devices. The blades when mounted can be in only one precise location for the clamp screw & shear pin to pass through. There is a hardened steel piece pressed into the rudder that will cut the shear pin without damage to an aluminum rudder blade. I can easily change the riding attitude of a boat by changing the width of rudders that have the same shape but different wedge thicknesses. Wider thickness rudders, typically 1/8" to 1/4", of the same shape, always generate more lift, even when their bottoms are rounded. The most important thing is to make sure the leading edge is perpendicular to the water line at speed. A tapered rear edge seems to make the rudder less sensitive to incorrect mounting.

The photos show the new fixture mounted for drilling the side water entrance slot & milling the rudders wedge shape. The same fixture is used for both operations, only the rudder blank itself is inverted for the side milling operation. The rudder blank is turned end to end for wedge milling of opposite sides. A 5/32" ID hole is the largest hole possible in a 1/4" thickness full wedge rudder.

Jim Allen

 

[Jim Allen]

The 1/4'' X 1.5" full wedge rudder with a 5/32" water inlet is now mounted to the cat's transom. I also have mounted the 5/32" piano wire actuation rod with its rubber boot. I'm working on a special 3 piece steel strut to get the propeller as close to the transom as possible.

Jim Allen

 

[mr_fons]

This rudder linkage was designed to allow right rudder actuations to be done by pulling the rudder rod rather than pushing the rod. All the linkage moving metal parts are made of AISI O-1 full hard tool steel. Metal to metal bearing points are insulated with machined teflon pieces. The mechanism works very smoothly & is designed to last indefinitely. A hardened steel 1/8" rudder blade is mounted in the precision machined slot.

Jim Allen

Well done, great piece on engineering/machining.
Will they be available for the masses?

 

[Jim Allen]

Sorry Alfonso. I never have enough time to produce production pieces for the public. However, I have no problem sharing what & how things can be done to raise the level of model boat engine & hardware reliability.

Jim Allen

 

[Jim Allen]

The 5 pieces shown make up the strut assembly. The strut & its skeg will be silver soldered to the housing after both are keyed to the housing. All the pieces will have tapered leading edges. Precision Brand Tool Black will be applied to the steel parts to prevent rusting problems. A brass reinforcing sleeve at the prop shaft, cable joint, prevents loss of the prop shaft if the cable should break any place between the reinforcing sleeve & the engines collet. The prop shaft bushing is precision machined from B-2 Barium Metal. It is held in its housing with a 3-48 screw.

Jim Allen

 

[mr_fons]

Sorry Alfonso. I never have enough time to produce production pieces for the public. However, I have no problem sharing what & how things can be done to raise the level of model boat engine & hardware reliability.

Jim Allen

Would you have cad drawings for this?

 

[Joseph Durnya]

Nice work Jim, what kind of mill u got there ?

 

[Jim Allen]

Sorry again Alfanso. I'm a highly trained tool maker & there are no cad drawings of any kind ever used to make parts for my boats or engines. Basic trigonometry, precision gage blocks, a precision sine vise, precision planer gage, surface plate, hundreds of different types of cutting tools, height gages & many measuring tools are all that is used, to name a few. Sometimes drawings are made on .100" grid precision graph paper to a scale of 1 to 10 or 20. Many sketches are also made to keep track of important measurements of a part being machined.

Jim Allen

 

[Jim Allen]

Nice work Jim, what kind of mill u got there ?

 

[Jim Allen]

I have a manual mill with digital readout.

Jim Allen