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18 September
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 Trapeze tweakersGo to page [1] 2 3 |
| Author | Post |
| Opscannell |
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  Joined: Tue Feb 27 2007, 10:24PM Posts: 28 | I'm updating my rig by installing high trap points and tweakers. How do people generally have their trapeze tweaker system? Is it just a simple line that comes to a cleat for the helm that he uncleats at the weather mark and hauls on at the bottom mark? Has anyone seen a more complicated system that uncleats automatically when the kite goes out? this must surely be a fairly easy thing to devise? Any photos out there? Also, Are there ever exceptions to the rule of tweaker off completely for downwind and on tight for upwind?? Thanks. Peter S. IRL 8514 | ||
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| SJLake |
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   Joined: Mon Nov 06 2006, 11:28PM Posts: 254 | Here goes: Trapeze lines need to be long enough to go to the new higher position. A Y shaped peice of rope with loops at the end of each arm is threaded inside the mast with the arms coming out of the old trapeze holes. The new trap lines pass through the loops. The bottom of the Y rope comes out of the bottom of the mast and fed back to helm's position. This needs at least 2:1 purchase so helm can pull on really tight !. Never seen an auto release system, but this might be possible but tension needs to be very tight so I don't think auto on would be possible No exceptions that I am aware of ... mast looks pretty horrible going up wind with tweakers off ! [ Edited Thu Nov 08 2007, 04:21PM ] Simon GBR8955 | ||
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| Opscannell |
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Joined: Tue Feb 27 2007, 10:24PM Posts: 28 | Do you think 2:1 is really needed? I'm thinking that the crew is off the wire at the bottom mark when the helm pulls it on. It also means that there is twice as much tail slopping around the cockpit. Peter S. IRL 8514 | ||
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| ross |
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Joined: Mon Nov 20 2006, 04:46PM Posts: 149 | I think a 2 to 1 system is needed as there is a lot of rope and stretch needs sorting etc.... One issue you have forget to consider is that there is usually a lot happening when you come into the bottom mark and guess what, the treakers are often forgotten. I wouldn't be without them, but get your crew to look up the mast early on the beat to check they are on......hope this helps. We have already decided to return to Monkstown next year. How many of you guys will be attending out Nationals at Lymington. Any idea? Also, what about a trip to the East Midlands. Get the boats there and the flying is dead easy and cheap. Cheers Ross GBR 8945 | ||
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| Opscannell |
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Joined: Tue Feb 27 2007, 10:24PM Posts: 28 | Great to hear you're planning on coming back in June, I think we gained a few new regulars this year. For Lymmington, we'll hopefully have the same six that made it to Abersoch, maybe plus one or two more. I think work commitments will decide whether we can get to any other British events, especially if we're going to take two weeks for the worlds. I think I'll go for 1:1 with the tweakers with the option of changing to 2:1 if necessary. Is there anyone out there with 1:1?? I'm determined to make it automatic as well... ..watch this space... Peter S. IRL 8514 | ||
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| Norman |
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 Joined: Fri Nov 10 2006, 04:09PM Posts: 124 | I really wouldn't go for 1:1... Alternative is cap shrouds locked off at spreaders and no tweakers. Tweaker system pretty simple though but you must inspect the tweakers frequently for chafe. We splice some outer onto the vectran where it rubs on the exit points. Try not to pull the tweakers on with the crew on the wire (but you wouldn't be able to with a 1:1 anyway). | ||
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| Charlie W |
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Joined: Mon Nov 20 2006, 07:40PM Posts: 174 | I used to have 3:1 in 8555. Now have 2:1 in 8835, and actually preferred the 3:1..! Wouldn't go for 1:1. You will knacker the cleat. Chas Charlie W | ||
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| SJLake |
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Joined: Mon Nov 06 2006, 11:28PM Posts: 254 | I think 2:1 is an absolute minimum, with 3:1 preferred as Charlie suggested. The trap line had to be very tight on the mast so it doesn't pull away under load as this bends the mast. Don't forget you also need low/zero stretch rope for this .... Simon GBR8955 | ||
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| Smith |
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 Joined: Fri Nov 10 2006, 11:25PM Posts: 26 | What is the ideal height above where the old trapeze fixing point was for re attaching to mast? | ||
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| Norman |
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Joined: Fri Nov 10 2006, 04:09PM Posts: 124 | usually abut 4 inches below the kite halliard sheave | ||
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| Mits8269 |
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  Joined: Fri Aug 03 2007, 01:30PM Posts: 34 | Would have thought that if you have the load of the kite pulling forward above the load of the trapeze pulling aft, that the load from the halyard is still above the load that's supposed to balance it and would still pull the top of the mast forward while the load from the trapeze would still be adding to the tendency to invert it? Shouldn't the trapeze attachment be above the halyard sheave in order to pull the top of the mast aft and bend the mast back into shape? [ Edited Mon Nov 12 2007, 01:52PM ] | ||
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| Opscannell |
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Joined: Tue Feb 27 2007, 10:24PM Posts: 28 | For the non-Monkstown viewers out there..... What Mits is trying to say is, it was then that he realised he was very, very drunk..... Peter S. IRL 8514 | ||
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| Mits8269 |
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Joined: Fri Aug 03 2007, 01:30PM Posts: 34 | Best traditions of the Bar, m'dear boy... | ||
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| Russ |
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Joined: Wed Nov 22 2006, 04:50PM Posts: 16 | Cap shrouds locked off at spreaders. Andy and I are considering trying this. Saugman & Ramsbacks boat at the Europeans had this system, but that was the only boat we saw with this system. The idea sounds appealing as we can eliminate a rope end out of the back of the boat whilst the helm does not have to remember to pull them on and let them off - bonus. Suspect it may stiffen the mast up slightly upwind as the crews weight on the wire is coming from the hounds where it should do, and not from the tapered un-supported section above the hounds, albeit with the load being deflected by the tweeker rope. Any thoughts, apart from the obvious “Don’t break the mast”!! | ||
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| Mike Holt |
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 Joined: Fri Dec 01 2006, 01:02PM Posts: 62 | There is another way. After breaking tweakers twice I switched to a two trapeze line set up. One line comes down from the high point one from the normal position. The 2nd new line meets the hardware at the bottom with a 2:1 purchase above the original hardware. Very simple, can't fail and best of all it's the crews job to remember! Mike | ||
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| Mits8269 |
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Joined: Fri Aug 03 2007, 01:30PM Posts: 34 | Must be a lot of windage with it though? On the cap shrouds - makes sense, but I'd love to see a proper force diagram done for the tweaker system. The load must be going up to the high point, but since it's running vertically to it from the tweaker point, it would presumably be just compressing that part of the mast on the loaded face, possibly stiffening it up to windward (preventing it flexing to leeward in gusts? Or even, dread thought, inverting it there? Would need some shots from dead astern to see...). Thing is, on the fore-and-aft bit, which is what the tweakers are there to control, on that part of the forces exerted by the trapeze loads, that component of the force is only at or below the tweaker point. From there, it makes no difference to that component of the force whether it's actually at that point or above it; it's all acting at the same point regardless. Just thinking as I type - with the tweaker system on full, there's a virtually zero-stretch rope effectively dead-ended onto the hull running down through the mast, which is taking a the fore-and-aft and athwartships components of the load of the crew on the wire. Surely that must have some effect on the mast itself? Compression, stiffening it in those directions...? [ Edited Sat Nov 17 2007, 02:22PM ] | ||
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| Opscannell |
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Joined: Tue Feb 27 2007, 10:24PM Posts: 28 | Good God, what have I started......... Peter S. IRL 8514 | ||
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| Smith |
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Joined: Fri Nov 10 2006, 11:25PM Posts: 26 | Ok guys. I have fitted these tweaker things. (higher fixing point for trapeze wire 3 to 4 inches under moster kite pully position on mast) Done a 1 to 1 pull on / off system (works fine) But what's suposed to happen? I was hoping to take off and race across the lake. No differance at all was felt! What am I doing wrong? | ||
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| Jack Hayhurst |
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 Joined: Fri Nov 24 2006, 09:49PM Posts: 7 | I saw that John Webster had taken his tweaker strings into the mast via the shroudplate holes. So we ordered a mast from those helpful lads in Northampton without tweakholes, filed a smooth little groove around the top of the T terminal and Bob's your avuncular relation. Twice forgot to pull them on today; well, fingers were cold. | ||
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| Mike Holt |
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Joined: Fri Dec 01 2006, 01:02PM Posts: 62 | The twin trapeze set up may be slightly more windage, but I keep what hair I have left very short to compensate. For me the simple fact is tweakers fail too reguarly, trapeze lines don't. Mike | ||
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