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Old 10-11-2023, 03:36   #826
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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I mean, you just brought this up. You just said that not having the mast make full contact around the perimeter will cause an accidental gybe. How does that happen? I need to know this. You canít just make a claim like that and then abandon it. That a big statement. One people need to know about. I can't see the mechanics of this.

So the shim allows it to connect around the entire perimeter. Where would the problem be after that?

No, I 'm sorry, maybe I have not explained it well, what I mean is that if the mast does not bite around the perimeter in the step, in an accidental gybe, if it happens, it can break, I've seen this before, I don't know how you're going to be able to raise the mast step those mm to accommodate a shim? anyway, if it's a few mm Chotu, believe me, loosen the uppers and lowers a little bit and let the mast sit well, you won't lose any rake.
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Old 10-11-2023, 04:48   #827
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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No, I 'm sorry, maybe I have not explained it well, what I mean is that if the mast does not bite around the perimeter in the step, in an accidental gybe, if it happens, it can break, I've seen this before, I don't know how you're going to be able to raise the mast step those mm to accommodate a shim? anyway, if it's a few mm Chotu, believe me, loosen the uppers and lowers a little bit and let the mast sit well, you won't lose any rake.
Oh ok. I was very confused. Now I understand. Sorry. that makes sense. A twisting motion while the spar is supported only at one point could lead to a lot of very strange forces around the circumference. I get that.

The thing is, the shrouds aren’t even that tight. they are just tight enough to prevent it from flopping around.

I can’t loosen the uppers and lowers more than they are. It will flop side to side. Everything is exactly right for the rake.

And you are wondering how I would do the shim? Picture a horseshoe. It goes under the mast itself. Not under the step.

Get the horseshoe perfect slowly with a grinder and tap it into place. Fasten with screws.

Edit: wait a minute. This type of complicated shim isn’t really necessary. The big thick plate at the bottom of the mast can distribute that load all around in a proper circle. All I have to do is make sure that plate is shimmed using a wide, but more traditional shim like a door stopper shape. The plate is very thick and the mast (by definition) already touches it perfectly all around. The plate is about 1/2" (12mm) thick. That's what touches the mast step. The mast itself does not.
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Old 10-11-2023, 08:02   #828
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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One more standing rigging thing.

itís not really tightened up like crazy. How much pretension should this have? I remember the technique to measure the stretch in the stainless
Mast base shims... depends on the mast base style, if it has a rocker in it, I'd leave it, but if it's point loading on the back on a flat edge, I'd want to shim it.

Also I'd want to go sailing and test for performance (weather helm) at that rake angle before doing anything permanent.

Pre-tension... depends on what your hull can take, but I'd be looking for 15% as a ballpark starting point, which would be 3mm stretch per 2m section - as per the Selden guide -

"All 1 x 19 stainless wire stretches under load, but returns to its
original length when the load is removed. 1 mm stretch per
2 m wire is equivalent to 5% of the breaking load, irrespective
of the diameter of the wire"

Page 31 at this link https://support.seldenmast.com/files/595-540-E.pdf

After that, I would go tune under sail.
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Old 10-11-2023, 08:40   #829
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

thanks for the advice. Makes sense to wait on the tuning and do it after or during some sailing.

Everything about the rig is dead on to plan. So hopefully the designer figured out the weather helm and Lee helm. I do know my sister ship has the exact same rake and there is no odd helm behavior.


What is that they say? A picture is worth 1000 words? Here’s a picture.

I think I need a shim.
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Old 10-11-2023, 09:11   #830
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

Oh yeah...now that I see a pic of the gap, that is a serious issue.

1/4" is a lot, way too much, w-a-a-a-y too much and the crack/opening seems to extend all the way to the rear, meaning the mast is basically supported only by a fraction of it's perimeter surface.

But you already know that.

As pointed out by myself, and several other posters, the mast should be flush with the mast plate.

I'm still of the opinion to raise the mast plate by loosening those four bolts, just loosen enough so you can jam a shim in there and then squirt epoxy in there so you'll have a solid " floor" under the plate.

I suppose the mast could be raked forward some, and then bent back is another option, though I'm not a big fan of bendy masts.

As you have alluded too, you've got everything dialed in to where you want it, so from my point of view, shimming the plate, as described above, is your best option.

Now, I know you are allergic to epoxy, so maybe someone can do the epoxy part for you.
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Old 10-11-2023, 09:50   #831
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

serious problem? I think a small inconvenience.

I will shim in between the metal plates.

there is no more hiring people for anything. I have had nothing but bad experiences and no one will ever work on this boat again except me.

The only exception is I may hire someone to go aloft on occasion. If I had a significant other I would send them up lol

other than that, it’s all me. So I’m shimming in between the plates

theoretically, I could jam a stack of quarters at the very forward edge where the gap is largest and it would do just fine. Because of the upper plate. That upper plate that extends into the mast is not bending or going anywhere.

So, a nice shim up there toward the front will do a good job
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Old 10-11-2023, 09:56   #832
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

Hugh, the crack had better extend all the way to the back. If it didn't, it means the upper plate is bent (impossible). So even a crack 1/16th of an inch would extend all the way back.
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Old 10-11-2023, 11:28   #833
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

Being as the mast has a mast plate on the bottom, yes, I can see where a nice BIG solid shim between the mast plate and the mast step will also work.

It will have to be fabricated to allow for the angle that the mast base is currently at.
I would still consider squirting some epoxy in there behind the shim plate for added safety factor.

Making a lot of assumptions here as I don't know if there is machine shop nearby or other fabrication shops, etc.

If you have a metal grinder handy you could try fashion a shim out of some 1/4" alum. plate.

Y'know, it's customary to place a silver dollar under the mast to appease King Neptune, don't forget to slip that under there.
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Old 10-11-2023, 11:43   #834
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

Oooh! I forgot about that silver dollar! Maybe it's not so bad I have a gap. Still possible to slip it in.

That's what I was planning. Aluminum shim. Get it right slowly with a grinder. Screws to hold in place.
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Old 10-11-2023, 11:52   #835
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

Yep, aluminum should be easy to grind with most any angle grinder.
You can also fit some industrial grade 200 grit sandpaper to an orbital sander to smooth out any imperfections to get that perfect fit for the shim plate.

One afternoon and a six pack of beer oughta do it
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Old 10-11-2023, 12:27   #836
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

i’ll probably use an angle grinder to get the rough dimension. Then I will use the best tool that was ever invented for the rest.

You can’t build a boat without one of these lol

I still have two of them. I have replaced brushes. They have hundreds and hundreds of hours on them.

My favorite tool in the shop or on the boat

They have speed settings so slow you can drag a part on the disc sitting on a bench with your bare hands and not get hurt if you drag your hand on it...

Or... Speeds where you can grind a boat away and it looks like you're running a small snowblower with all the waste shooting out one side of the disc.

I usually use 80 or 60 grit. Best for lots of shaping projects but still lets you tear a lot off something quickly if you need to.

and for anyone who thinks this is off-topic, it’s not. I ordered the bushings from The Yacht Rigger a little oversized. On purpose.

to get a perfect fit I put this thing on its back on the lowest setting and locked the throttle. then I slid the bushing onto a bolt and held it against that disc as everything spun. The bushing spins, the disc spins, and you change the angle so that it’s slowly but perfectly evenly wears away the outside of the bushing.
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Old 10-11-2023, 12:30   #837
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

What, you donít have a CNC machine aboard?
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Old 10-11-2023, 12:35   #838
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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What, you don’t have a CNC machine aboard?
Ha ha ha ha ha. yes. It is in the room with the lathe and drill press. Right behind the metal brake

Here is a pic. It's carbon fiber. I do have a catamaran, so it's important my CNC machine is carbon. Every pound counts.

Here, you can see me making a new door knob for my spice cabinet

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Old 10-11-2023, 12:52   #839
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

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Ha ha ha ha ha. yes. It is in the room with the lathe and drill press. Right behind the metal brake

Here is a pic. It's carbon fiber. I do have a catamaran, so it's important my CNC machine is carbon. Every pound counts.

Here, you can see me making a new door knob for my spice cabinet

You can even do it with a 3D printer in plastic, then use that to make a mold on the beach with sand, then melt the empty beer cans and cast it right in the required shape
Surely you have a 3D printer!?
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Old 10-11-2023, 13:28   #840
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Re: Chotuís Advanced Standing Rigging Thread (lots of pics)

You can even do it with a 3D printer in plastic, then use that to make a mold on the beach with sand, then melt the empty beer cans and cast it right in the required shape
Surely you have a 3D printer!


Too easy....how about this...

You can slide a thin piece of paper under the mast base plate....push it as far back as you can.
Slide the next piece of paper over that....slide it as back as you can, but slather it in epoxy first so it will stick to the first piece..
Repeat until the 100th sheet or so is fitted.

Voila....a one piece perfectly fitted shim.

Trim the edges with a sharp blade...

Sheeesh.....do I gotta learn y'all everything...
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