At this point I am kind of lost myself. Steering rams are rated for
operating more or less perpindicular to a tiller arm off the pivot
point. Alternately they are mounted off the transom at an angle as with
an outdrive.

What I think Garry is talking about is mounting the rams off the stern
parallel to the 7.5 sq.ft. rudder to brackets extending about 8" off
either side of the rudder. To me that seems to be a very odd
configuration that can't be calculated using the normal vendor supplied
formulas.

Brian Whatcott wrote:
I was unwise to attempt to help on the basis of too little
information. I hope that Glenn can visualize this
arrangement better.
But better yet would be a diagram to put in front of a person
familar with hydraulic steering layouts, I'd think.

Brian W

On Tue, 16 Dec 2003 14:31:19 -0000, "garry crothers"
wrote:



Perhaps I am missing something in my calculation, taken from Vetus calalogue
I had contemplated using approx 20cm brackets set back from the pintels by
same 20cm distance.
(using Vetus MTC72 ram with a stroke of 225mmm I would need 196mm lever to
give me 2 x 35 degree rotation of rudder)

Area of rudder 0.69 m2
Max Speed 16 Kmh
Force on rudder = 23.3 X 0.69 x (16 x 16)
approx 4000N

Torque = Force on Rudder x Lever.
4000 x 0.2
800Nm


This figure is just outside of the rated capacity of the MTC72, thats why I
was asking if I used two Rams , one on each side of the rudder, can I divide
the torque required by 2.

///

garry




--
Glenn Ashmore

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