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Old 10-07-2020, 09:59   #1
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At the masthead

How does one ad a crane to a masthead unit that's welded to the spar?
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Old 10-07-2020, 10:12   #2
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Re: At the masthead

Drill and tap, mine unscrews but you still need to drill and tap to add the crane.
https://www.rigrite.com/Spars/SparPa...aker_bails.php
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Old 10-07-2020, 10:25   #3
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Re: At the masthead

Crane is for backstay to clear roach of main.
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Old 10-07-2020, 10:32   #4
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Re: At the masthead

Assumed you meant a spinnaker crane, a backstay flicker is the term I've heard used most often, and still drill and tap.
https://www.seldenmast.com/files/142.../595-993-E.pdf
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Old 10-07-2020, 10:39   #5
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Re: At the masthead

Sounds like a bad idea
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Old 10-07-2020, 20:04   #6
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Re: At the masthead

Why?

It's not a frac rig so flicker not applicable. Just need to move the backstay out about 4"-6".

It is a masthead rig so a mod would have to be very strong. Better to fab entire new unit but how to mount.

Surgically cut out old unit except for vertical plates that are actually welded to the spar, fab a new one that drops in from above, bolt in place?
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Old 11-07-2020, 04:39   #7
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Re: At the masthead

Back stay is critical and heavily loaded. Forces increase substantially as the cantilever lever arm is lengthened. Proper engineering and fabrication will be essential.
I assume the mast is down?
Welding I expect will be the best way to achieve needed strength. Side plates may need to be beefed up. Welding will need to be done on site rather than in a more controlled shop environment. Don't know if this is much of an issue or not.

How about trimming the roach a bit?
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Old 11-07-2020, 05:25   #8
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Re: At the masthead

Quote:
Originally Posted by Drinky Crow View Post
How does one ad a crane to a masthead unit that's welded to the spar?
Is your mast a fractional rig or masthead ?
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Old 11-07-2020, 15:58   #9
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Re: At the masthead

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Originally Posted by slug View Post
Is your mast a fractional rig or masthead ?
You could try reading post #6 above where the OP says:

"It's not a frac rig so flicker not applicable. Just need to move the backstay out about 4"-6".

It is a masthead rig so a mod would have to be very strong. Better to fab entire new unit but how to mount."

Jim
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Old 11-07-2020, 16:28   #10
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Re: At the masthead

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Originally Posted by Jim Cate View Post
You could try reading post #6 above where the OP says:

"It's not a frac rig so flicker not applicable. Just need to move the backstay out about 4"-6".

It is a masthead rig so a mod would have to be very strong. Better to fab entire new unit but how to mount."

Jim
Oh, sorry about that

And you sound angry , frustrated

Concerning the OP

To accommodate large roach mainsails itís common to eliminate the aft mast crane completely and move the backstay down

The stainless insert and compression tube in the photo

Two running back stays

For a cruisers This setup works best with aft swept spreaders

You might run this setup by a rigger who can examine and comment on the engineering of your present masthead

You might ask the rigger to use the main halyard sheeve axel as the runner dead end
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Old 11-07-2020, 22:01   #11
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Re: At the masthead

Yeah that's cool but I ain't going with 2 runners keeping it simple I just wanted to code 6 the main maybe have to settle for PHRF max also don't want to add any more weight at the msthd than necessary.

Maybe cut the old one out and get someone to 3D print one for me out of carbon.
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Old 12-07-2020, 04:29   #12
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Re: At the masthead

I thought the strength of carbon was in the fibers. I thought that 3D printing was tiny blobs that then stick together. Can they do carbon fiber 3D printing?
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Old 12-07-2020, 10:22   #13
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Re: At the masthead

Sorry, that last comment was meant tongue in cheek..........
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