require rudder shaft specs for nonsuch 30 ultra to fabricate locally here in Grenada,
shaft is solid 316 stainless steel.
Gary,
On the INA website at www.Nonsuch.org, log in, click the MEMBERS tab and select NONSUCH SHOP DRAWINGS. Then click on Nonsuch 30 drawing PDFs. You’ll find one titled, N30 Rudder Fabrication.pdf.
That’s the one you’re looking for. You’ll also find a wide selection of other potentially useful shop drawings there, as well.
(There’s also a set of Nonsuch 30 Ultra drawings, but those are only for components that differ from the Classics.)
-- Bob
I think shafts today are made of a type of steel called Aquamet. Basically stainless steel designed for marine shafts
thanks for replies, my NS 30 hull 447 has solid 316 stainless, newrudders.com advised me the nonsuch 30 rudder shafts they sold were 2 3/8 solid 316 stainless, the drawing in INA l think may be from early production models? wiggerscustom@rogers.com advises me they no longer have the mold or fabricate anymore.
It’s the only drawing that’s been shared with the INA, that’s all I can tell you.
In the PDF versions of the N30 manuals on the website, there’s a side view drawing of the steering assembly. It’s on the 57th page of the C manual and the 45th page of part 2 of the U manual. In both, you’ll see a bearing tube called the “rudder port” that holds the lower part of the rudder shaft in place as it goes through the bottom of the hull.
2 - 3/8" is exactly the same as the 2.375" that the drawing shows for the section of rudder shaft that runs through the rudder port. In the drawing, the part that is underneath the boat hull (embedded in the rudder fabrication itself), is a larger diameter. But the section inside the the rudder port is machined down to that 2 - 3/8" dimension.
I can only guess that if newrudders.com fabricated N30 rudders, they kept that smaller diameter of 2 - 3/8" all the way through the shaft and welded the rudder blade internal elements to that smaller rod. As drawn, the outer diameter of the hollow rudder shaft would’ve been only a little more than a tenth of an each wider than the solid shaft that newrudders.com seems to be telling you about. Its walls would have been just under half an inch thick, so either version is probably plenty strong. I doubt that the structural strength differs enough to matter.
An expert might differ, but in my humble non-expert opinion, it’s probably pretty close to to-ma-to/to-mah-to between the two versions. The hollow one might, I suppose, weigh less than the solid, slightly thinner one. On the other hand, the hollow one has slightly more complex machining. I don’t know how the raw materials costs would compare.
Bob
Thankyou Bob, so l think l would be safe with new rudders sending 2 3/8 rod and the only machining would be the key way and threads for the nut? newrudders did mention l should send them the top nut as they can proper thread. overall length l have as 24 in to bottom hull and 32 in inside rudder blade. newrudders quote 2 3/8 inch solid stainless 316 steel 56 inch long not including machining 975 us plus crate and shipping. gary
Gary,
I think you’d be safe, in fact I’m pretty sure you’d be safe. But frankly I get a little nervous when you state it as a question. That makes me worry that you might proceed relying on my judgement alone.
My expertise consists of knowing how to read and interpret the drawings. I’m not a structural or mechanical engineer. I’ve laid out the information as I know and understand it. I consider myself qualified to lay out what the drawings say, and offer an opinion. But I would not want it to be treated as an expert recommendation.
With those disclaimers, I will say that it all sounds reasonable to me.
I’d hope others would weigh in. There are a number of people in this discussion group who’ve built and/or massively refurbished boats, and I’d hope they’d have something to say on this. Unless you’re under time pressure, I’d suggest waiting to see whether others agree rather than relying on only one person’s advice.
-- Bob
Do you have the old rudder? Maybe I’m missing something but the best source of specs will be the old rudder. You know it fits.
Will you be fabricating the non metal part yourself or does the supplier supply a drop in part? The keyway position is critical and as I remember it needs to be on the fwd side of the shaft exactly opposite the welded on blade root. I would have that done at the machine shop that does the rest.
Thanks for replies, the welder here asked for some precise numbers to ensure he can source
the rod material here or Trinidad. job will be done in Dec, rudder will be removed torn down
and old shaft will be used as template. Thanks for input very helpful…
gary
Contact Foss Rudders, they’re very reliable and do this for most any boat