MacGregorSailors.com

Okay, when i get the specs on the aluminum pole from West marine i will post it and see what your math says about the strength of the different sizes. i still do not know the wall thickness of the West marine aluminum stock they carry - it's appears to be similar to the stuff we use on the factory table leg. I know you need a length to calculate deflection - I am working on that parameter right now.

A 6061 T6 tube, 1.5" OD x .125 W x 8 ft long is about $55 from several online metal suppliers. Same stuff the MRS is made of.

I need to make is a sliding affair. I will be using two different sizes. I am still looking for the right stuff. If i can't get what I need I might need to cannible one of those whisker pole sliding jobs (that's sort of what I was planning in the first place with my limited skills) but if i can find two sizes of stock that are compatible I would prefer that.

Any suggestions on the end caps? Know of a source for fitting for the ends? (I am really out of my element on this stuff) but eventually I figure it out.

It just might take me a long long time and a lot of errors to learn. I am going to Google 6061 T6 - thanks for that tip

https://www.onlinemetals.com/

https://www.metalsdepot.com/?msclkid=81 ... tm_content

I,d say if u r going to use a alum pole to brace side forces of the mast while raising it on the water u want to go as high strength say at least double the breaking points of suggested that the support pole will b subjected too but it can,t b more than what the mast can handle stress wise , so if the support pole collapses & the mast comes down sideways the mast is likely gonna bend if the bracing pole is too strong the mast is likely going too bend or snap from excessive side forces especially on the water with excess winds or gusts or wave forces ?
Tom , I know u know what I,m talking about , if u ever watch the Mac vids of raising the mast,s it,s always on dead calm glass lookin water !

J

It's not really the strength of the pole that is the feature of this but it's LENGTH. The problem with the baby stays is that they are too short - they connect to the mast at a point that is too low - too close to the deck - so there is not enough there to keep the mast from swaying back and forth when the mast is raised about two feet up out of the crutch.

that is the vulnerable place - when the mast is only raised about two or three feet from horizontal - it swings wildly from port to starboard almost two feet in either directions as the boat roles from side to side.

A LONG pole that attached higher up on the mast (like way over what you can reach with your hand) would hold the mast from moving in that precarious place when it's three feet above the crutch. The baby stays have a hard time in that position because they are too short - most of the mast is still way out beyond where the stays can hold it - the mass of the whole setup is too far away from the stays to stop the wobbling.

I think an X owner, with tight mast-connected baby stays, might argue that it's not baby stays that are the problem. It's the fact that they are connected to the MRS line and not the mast. That connection will allow about 8" of travel at the mast connection, discounting mast rotation/swing on the lifting connection. 8" of travel at 6 ft is a little more dramatic at the 30 ft end.

I agree that a rigid system needs to be implemented for mast control. I just think it can be done with wire rope or a pole as you propose. Your idea of using a multi purpose pole is attractive if you can work out a way to lift the mast with on board equipment. Then, you don't have the MRS pole and winch to stow or leave in the tow beast. Tight stays, connected to the mast, even at 6 ft, should adequately control mast movement, although longer stays would Reduce mast swing given the same "slack" in the baby stays.

Now that I have the stay attachment point properly located, I'm not opposed to putting longer baby stays on - if raising the mast on the water still scares me.

Have you got the universal lifting support, spinnaker pole, boat hook and bow sprit designed yet?

Jimmyt wrote: ↑Tue Feb 25, 2020 5:46 pmTight stays, connected to the mast, even at 6 ft, should adequately control mast movement, although longer stays would Reduce mast swing given the same "slack" in the baby stays.

Taking that idea further, true as it is, using a quick-release shroud lever on one side would allow you to take out the slack with the flip of a lever. The baby stays have the same shroud adjusters as the side and back stays, so they're not really adjustable on the fly, but the lever style would allow you to tighten them like a turnbuckle, but flip the lever to put a bunch of slack into the stay so you can unhook it.

You'd have to leave the mast a bit back from vertical in order to undo the other one (unless you put one on each side), then raise the rest of the way, but taking the slack out would by itself be the biggest improvement in mast control and reducing dynamic effects, shock load in particular.

That all assumes the top of those flat 'hooks' at the deck, where the stays actually pivot, are on or very close to the centerline of the mast hinge.

Great idea Tomfoolery! That would definitely get the raising stays tight during raising or lowering AND make them easy to install and remove.

BOAT: I know that there is a possibility of mast flex due to grabbing it at the 6 ft mark, but what I was seeing was simply sway due to slop in the raising stay arrangement. In violent seas, the dynamic loading would probably produce mast flex, when grabbing at the 6 ft mark.

I don't think my loops welded to the stanchions are strong enough for that situation. I'm looking to use it on out of level parking areas, in a bit of cross-wind, or on the water in fairly calm seas. Anything more than that, I'd want a higher connection point on the mast and more of a chain plate arrangement to connect at the deck.

Jimmyt wrote: ↑Wed Feb 26, 2020 5:33 amAnything more than that, I'd want a higher connection point on the mast and more of a chain plate arrangement to connect at the deck.

I was going to bring that up a couple of times, but didn't want to add more variables. But you're quite right; those stay attachments seem to be adequate, but I wouldn't want to test that on rough water. The consequences of a failure are catastrophic.

A chain plate attachment, bolted through the hull, with a proper pivot for a rigid tube strut would probably be ideal, but wire rope on either side with no slack would be about as good, too. IMO, of course.

Tomfoolery: I apologize if I missed it, but would you remember how high your baby stays connect to the mast of your X?

Thanks, Jim

Jimmyt wrote: ↑Wed Feb 26, 2020 6:25 amTomfoolery: I apologize if I missed it, but would you remember how high your baby stays connect to the mast of your X?

You didn't miss it because I never said it. Because I don't know. But the boat is down the street, and I'm happy to go measure them later if you like. But they are somewhere around 6 ft off the deck - I use the tang at the top to tie off my spreader flag halyard, which is around head height or so.

No need. I was wondering if it was dramatically different. Sounds like roughly the same height. That’s good enough to satisfy my curiosity. Thanks!

Here u go guys mast raising using two spinnaker poles
http://klackospars.com/about/mast-raising-magic.html

Knew I seen this before so did some searching now this would b very easy to implement & make urself

hope this makes u all happy now let me know if u want me to find other systems
J

https://www.windrider.com/products/wind ... ing-system

J