Cutting a slot in a carbon mast

[Deep Purple 530]

We have an unacceptable amount of friction on gennaker hoists and drops cause by the mast base. I'm looking at taking as many blocks and turns out of the system as I can and looking at an exit slot in the mast direct to a pivoting block with cam. There's a slot already but on the wrong side where the jib halyard tensioner is and also the wrong side for starboard hoists.

Any tricks to cutting a slot in a carbon mast? I'm assuming 2 holes and a fine jigsaw but my experience with such things warns of feathering and cockups.

 

 

[harrytom 697]

old post on subject

 

https://crew.org.nz/forum/index.php?/forums/topic/10188-drilling-a-hole-in-a-carbon-fibre-mast

 

[Deep Purple 530]

Thanks HT, I think I'll try the existing slot before I stuff something up. 

[Cameron 96]

First comment from the photo… have you tried reducing diameter of the halyards? They look pretty big.

[mattm 106]

Different direction than your considering, but my previous boat, a sports boat, had all halyards out the bottom of the mast, just an open hole of ~1.5”, through a matching hole in the mast base, to turning blocks attached to the mast post. Main halyard stayed inside, other ran through exit sheave on the cabin top, and back to the cockpit. Could you remove all your mast foot sheaves and copy that? It also allowed for a fine tune on the jib halyard, and one for the kite halyard to tension code 0’s. 

[Deep Purple 530]

7 minutes ago, Cameron said:

First comment from the photo… have you tried reducing diameter of the halyards? They look pretty big.

Three halyards, main (black), headsail (blue) and snubber (orange) are small diameter although it doesn't look like it in the photo. The masthead (green) is bigger but even if the same as the others would rub plus the base sheaves are very small, non-rollers and collect all the grunge from the mast, so never turn all that well at the best of times.

[Deep Purple 530]

7 minutes ago, mattm said:

Different direction than your considering, but my previous boat, a sports boat, had all halyards out the bottom of the mast, just an open hole of ~1.5”, through a matching hole in the mast base, to turning blocks attached to the mast post. Main halyard stayed inside, other ran through exit sheave on the cabin top, and back to the cockpit. Could you remove all your mast foot sheaves and copy that? It also allowed for a fine tune on the jib halyard, and one for the kite halyard to tension code 0’s. 

be major surgery but I'll have a look

[Deep Purple 530]

Another consideration is that I'm looking at running a heavy weather jib on an inner fore-stay so the spare turning sheave won't be wasted. We struggle in the SSANZ races with a fore-triangle 3m of a 7.5m boat. Our small jib just blows the bow around and going smaller again way out there won't be much better. Advice from designer and sailmaker is to bring it aft.  There's the old topping lift exit which just needs a fore-stay tang above it and would be about right with a pad on the deck. 

[Jon 412]

Don’t you need a bigger mast Phil

[Jason128 6]

Replace the ropes.    Drop 1 size.    New rope flexes so much better and will have less friction.  Those all look well worn and will be as stiff as can be.    

[Deep Purple 530]

41 minutes ago, Jon said:

Don’t you need a bigger mast Phil

Not while you keep running races in 30knots

Seriously though the rig does look small but with the boat weighting 600hg all up including a 300kg bulb we've never begged for more sail. Although we are about to push the limit on mainsail size ...

[Deep Purple 530]

24 minutes ago, Jason128 said:

Replace the ropes.    Drop 1 size.    New rope flexes so much better and will have less friction.  Those all look well worn and will be as stiff as can be.    

Yeah there's a few dodgy areas too. Will be replacing all the halyards as soon as Mr Bondage goes back to work. The orange one is new anyway but is just a short tail on 4mm dyneema I made up last year for the 3/4 kite snubber. Kite halyard is a nice size according to my crew though. 

[Jon 412]

55 minutes ago, Deep Purple said:

Not while you keep running races in 30knots

Seriously though the rig does look small but with the boat weighting 600hg all up including a 300kg bulb we've never begged for more sail. Although we are about to push the limit on mainsail size ...

You always look like you’ve got a reef in off the start line, but never on the results sheet

Only 15 to max of 20 on the start line, wait until it’s really blowing 

[Deep Purple 530]

Better indication of sizes and dodgy bits time to replace

 

[Ex Machina 390]

I did a halyard hole mine . Just drilled a regular hole a bit oversize then got a chainsaw file and filed it at an extreme angle to make a slot . The file works a treat makes it smooth as with no fuzzy bits 

[mattm 106]

Not sure how much help this will be. But here is the setup I had. Blue halyard is the jib and its fine tune. Yellow with black in the clutch under the cabin top is the main halyard. The black halyard only visible at the bottom right of the mast post is the kite halyard, running back to come out of the cockpit floor, with the pole out line. This was before the fine tune for 0’s. There is also a wire and winch on the post for forestay tension.

Hope you sort your problem 👍

 

[Black Panther 1,767]

Those bunks are kinda narrow.

[Ex Machina 390]

That looks like a bi-turbo elder ? 

[Deep Purple 530]

That's very cool thanks Matt. New halyards are in process with a drop in size for the kite (sorry crew). Some good ideas there

Always amazes me how the NZTYS embrace the turbo elders despite their record of capsizes and sinkings but reject the north island designs of Shaw, Elliott and BBW (and probably others)

Then again if 2020 accounts and scarcity of published minutes are anything to go by it seems they do nought but spend more than they earn galavanting over the country.

Enabled by Yachting NZ to be sole arbitrator of the TY rules despite coming up with nothing in the latest regulation update, failing to address the void  between similar boats racing in the same fleet under different sections or a growing movement and opportunity to cater for exciting boats that people want to sail. Can you imagine the NZ Multihull Club being the sole arbitrator of multihull safety regs in NZ with no oversight by YNZ? No wonder progressive TY fleets are leaving the NZTYS. Yet member or not, in order to race as a TY you have to succumb to their 40 year old rules and thinking

ooos thread drift

 

[mattm 106]

4 hours ago, Black Panther said:

Those bunks are kinda narrow.

You need to really enjoy the after party to find them acceptable to sleep on.