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Re: Pole end fitting

Posted: Thu Jul 14, 2016 1:36 pm
by Bruce
Aside from friction, the ex-800 sailors also said they used to go through tack lines at a rapid rate. I don't think I have ever had the line go under the pole while racing. Possibly because I tie the shockcord that holds that daggerboard in, about 120mm along the tack line. When the kite is down, it pulls the slack out of the tack line (and pulls the pole in - which was my main reason for doing it). The current system works well so I see no reason to change it. Time might be better spent on re-looking at the mast head crane design.

Re: Pole end fitting

Posted: Thu Jul 14, 2016 5:20 pm
by Daniel Henderson
the main reason i would have for the new design is that when you capsize with the kite up the tack line can twist around the pole and you are then like it for the rest of the race. It happened to me at the worlds on the last day while i was saying hello to the fish's. if you have the proposed new fitting this can never happen. I would rather replace the tack line every year than sail a race with a tack line twisted around the pole. Its probably no more than £3 worth of rope.

Re: Pole end fitting

Posted: Fri Jul 15, 2016 3:11 pm
by paul manning
Hi Bruce

I did raise the mast crane with Selden when I popped in to follow up on the new tracked mast.

They appreciate the input on the crane and have it on a 'to do' list, but they also said it wouldn't get looked at for some time.

Proposed new spinnaker pole outer end fitting

Posted: Thu Aug 31, 2017 7:07 pm
by paul manning
Report from Andy Tarboton

I have put the new pole end fitting on for testing. Fitting it to the boat is really easy and I think it would work well in general.

I have done some comparison hoists and drops and received the following results:
Current setup 85 sec
New pole end 78 sec
This test was carried out on dry land, standing next to the boat and hoisting and dropping the kite 10 consecutive times to get and average as well as an idea of fatigue factors influencing hoisting and dropping from halyard friction. From this it is my conclusion that the new pole end has about 5% less friction in the system.

I then went sailing with the setup and noted that if the tack of the kite travels all the way to the opening in the pole end, then the tack of the kite is slightly below the top of the pole and gets pinned to one side of the pole. The solution is very simple - leave a 50mm length of tack line from the rack to the pole end when the pole is fully extended and this will allow the tack to just float above the pole end.

The new system is a proven one for preventing wraps around the pole so I don't believe we will have a problem with that if we move to the new fitting as a class.

I am hoping to get some pictures to go with my report back in the next week or 2 but hope this helps with the discussion.

I am always happy to chat ideas over with you with regard to trim etc if I can be helpful in any way.

Re: Proposed new spinnaker pole outer end fitting

Posted: Mon Sep 04, 2017 12:46 pm
by paul manning
Note,

The proposed new end fitting is a solid turned delrin part. It is proposed that the existing sheave is simply removed and the new end fitting installed.

Re: Proposed new spinnaker pole outer end fitting

Posted: Fri Oct 06, 2017 12:31 am
by Bruce
Hi Paul,

So in effect you get a longer pole, as the tack line will be taken from the very end of the pole rather than though the sheave ~50mm back?

Re: Proposed new spinnaker pole outer end fitting

Posted: Fri Oct 06, 2017 12:20 pm
by paul manning
Bruce, yes that is the proposal

Re: Proposed new spinnaker pole outer end fitting

Posted: Sat Oct 07, 2017 11:13 am
by Bruce
Hi Paul,

My preference would be to match what we have as closely as possible, as I suspect this will make quite a big difference to downwind speed. Tying the tack line or halyard slightly differently, has a massive impact on speed, so I suspect this would be even more significant. You don't want to end up with one style being much quicker than the other. Presumably all you need is a hacksaw to get the exit point of the tack line to be similar?

Re: Proposed new spinnaker pole outer end fitting

Posted: Sat Oct 07, 2017 11:27 am
by Rick
If you want to match the position of the tack of the sail it gets messy due to the cut out in the pole for the block.

You'd have to cut through that which I guess would compromise the security of the new plug in the end of the pole.

The new plug will give I suspect about 30mm more extension than the block.

Many people don't tie tight to the block and seem to go ok.

I'd expect everyone would move over to the new plug as it seems a better solution and is not expensive.

Re: Proposed new spinnaker pole outer end fitting

Posted: Sat Oct 07, 2017 12:03 pm
by paul manning
As ever, it's up to the class to vote upon :D

It was a point raised by the class and the builder has provided a proposed solution.

Re: Proposed new spinnaker pole outer end fitting

Posted: Sat Oct 07, 2017 7:26 pm
by Bruce
OK think this needs to made very clear, as others I have spoken to also assumed the pole would be cut to give the same exit point for the tack line as the current solution.

Personally never had any issues with the current system, so don't want to be effectively forced to change in order to make sure I get the advantage of a longer pole.

Re: Proposed new spinnaker pole outer end fitting

Posted: Sat Oct 07, 2017 7:48 pm
by paul manning
Agreed

Re: Proposed new spinnaker pole outer end fitting

Posted: Sat Oct 07, 2017 10:39 pm
by Rick
Bruce wrote:OK think this needs to made very clear, as others I have spoken to also assumed the pole would be cut to give the same exit point for the tack line as the current solution.


The design has now been done so the pole needs to be cut which will give the same bearing point.

Last time we voted on this the vote went against but there seems more interest this time. We will see.

Re: Proposed new spinnaker pole outer end fitting

Posted: Sat Oct 21, 2017 7:58 pm
by Dennis_W
Would a potential solution be that all new boats and poles are supplied with the proposed new end fitting but the poles are shorter to maintain the same point the tack line comes out and not allow existing poles to be modified?

It would remove any benefits from a longer pole and any issues arising from retrofitting old poles. I think the cost of a current new pole is £325, so the cost of changing pole significantly higher than a retrofit modification but it would be more inline with the one design principles of the class and lower risk for preventing equipment failures.

I’m for the proposed change as it removes one thing that can go wrong and be an absolute pain.

Re: Proposed new spinnaker pole outer end fitting

Posted: Sun Oct 22, 2017 9:36 am
by paul manning
Hi Dennis

If the proposed bowsprit solution is adopted, all new boats would be supplied with the same end fitting and same total length.