New folding pins installed on No. 80 cruising

including Amas (Floats), Akas (Beams) , Swing Wing system and all other hull related issues.
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peterwarm
Posts: 1
Joined: Wed 19 Jan 11, 13:56
Your Country: UK,Plymouth

New folding pins installed on No. 80 cruising

Post by peterwarm »

I would like to share our experience with this job, particually since it ended up going quite well.

For some time the pin looseness has been apparent and started to cause the g/f from the arm to abrade the hull g/f adjacent to the pins. movement was estimated at around 5mm horizontal on the front arms.

Last year one of the pins snapped , luckily whilst out in Plymouth sound a mile from home. So we knew we had to do a complete refit. We had read on this forum that the approved method was to fit larger diameter pin, but felt the increase from 16 to 18mm might not be enough to take out all our wear.

So we had her lifted ashore and borrows the excellent Cradle that Mel from Swansea has designed (Thanks Mel) to hold her securely whilst we stripped off the Amas and Arms. These amas are heavy, recommended that three people are needed, one for each end and one to play with bolts, packing etc. The arms were also heavier than expected, although one person was OK. The slack in the front arms at their widest point, measured vertically with no Amas on, was 50 and 45mm, 25 and 20mm at the back.

We had made contact with a local stainless steel fabricator and he had agreed to make up new pins - stronger than the old ones as we did not want an internal thread as the Quorning ones had - this is where they snapped, so we had a solid pin with a thread cut on the end and installed it with a nylock nut on the bottom. He said standard sizes for him to fabricate from were 16, 18, 19 ( old 3/4") 20 and 22mm.

In order to pick the size of the pins we took the worst hole - upper front hull plate and worked on turning it back into a circle. Quite hard work. We used long files to keep the holes in alignment, first a bastard or rough cut file 400mm long, then a second cut file again 400mm long to smooth the hole. Both files were tapering and by chance the largest diameter on the second cut file was just under 18mm - 17.45mm, which made it easy to keep the hole relatively round. Finally we used an adjustable reamer, 17-22mm to take the hole out to exactly round. This was hard on the reamer, as it is really designed for softer material, but it allowed us to get a perfect round hole. ( see pictures) In the end we finished the hole to 17.55mm and decided 18mm pins. sounded much less work than 19mm ones!

Whilst the fabricator was making these up we looked at the holes in the plates across the arms and decided to simply unbolt them and give them to the fabricator and ask him to drill these out to suit the pins.

A week later was reassemble time. Glad to have kept the reamer around because of course the fabricator drilled the holes square in the plates, but the arm plates do not sit square to the pin: so a little more filing with the long second cut file and out with the reamer to finish the fit. the results: Very tight fit of the pins in the hull plate, somewhat looser in the arm plates - probably about right to keep the pin solid in the hull plate and let the wear take place in the arm plate and pin, both relatively easy to replace in another 10 years...

Other jobs we did whilst about it:

Replaced the 10mm out/inhaul with 8mm racing dynema. We have had a lot of problems with winching the arms in and out over the years. We were clear that the problem was not the stiffness of the folding mechanism, but the mechanism itself - trying all the pulleys by hand in stripped down form we found the culprit - its the stationary pulley set in the inner end of the arm. When the load goes onto the dyneema, the dyneema spreads and jambs the pulley on its short side. Thanks again to Mel for a quick bit of encouragement to do this swap, and although as I write we haven't been back onto the water but I'm feeling encouraged as it seems very easy now.

We checked the waterstays. We have StaLok versions so we can change the stays every 3 rather than the recommended 5 years, and at minimum cost, so checking was OK. If we had the crimped type we would have replaced them, after such a structural rebuild. We spent a long time getting the pretension just right, using Arne's reported method of having someone sit on the ama and just being able to push the waterstay pin through. (easy with no mast up, although we have done this with mast up beached before.

Checked outer end of arms 6mm hex countersunk screws and dome nuts - wish wed found a job lot now as the chanderly ran out and we had to use a mixture if hex and slot drive. In future I'd definitely get all these before hand as they are not accessible once the Amas are back on. Beware the lengths are different - and quite a few had failed, which is not surprising given the differerent lengths to fit the dome nuts. We dumped the dome nuts and fitted nylocks - at least you can see if youve got enough thread gripping now.


We replaced the tramps. Probably a bit over the top really, but OK as part of the whole job. Out existing tramps were OK but had been
resewn quite a few times so I guess worth it.

Costs:
fabricate 18mm pins drill plate etc: £300
Files, reamer £100
Nuts and bolts £40
30m 8mm racing dynema for both side of in/outhaul rope £130
Checking water stays ??
New trampolines £1800

Anyone else want more info happy to help.

Please click on any of the photos to see them enlarged!

Image Image Image Image Image
peter warm
Wideawake No 80 920 touring
parkhouse
Posts: 32
Joined: Sun 20 Jul 08, 17:56
Your Country: U.K./Inverkeithing

Post by parkhouse »

You have certainly been busy.
One comment about the swing wing pins - I lost one, probably due to swell in a poorly protected marina while tied up and Jens Quorning commented that the geometry was such that the pressure on each pin is in an upward direction. He was puzzled how it managed to fall out. That being the case, it might have been marginally safer if you had put your pins in the other way round, with the nylock nuts on the top.
Mike Paterson, Df1000/34 Champus
Mal
Posts: 83
Joined: Thu 02 Nov 06, 16:48
Your Country: Wales

Swing Wing Pin Change.,

Post by Mal »

Peter;- Thanks for the detailed report. Will be useful info for those like me who might have the job ahead of them. Regards, Mal
DF920 Pelican, Swansea
sjschweitzer815
Posts: 25
Joined: Wed 10 Nov 10, 2:36
Your Country: USA, Racine, WI

Swing wing pin change

Post by sjschweitzer815 »

I am considering doing the same work, but: 1). Don't want to do it prematurely, because of the amount of work, and: 2). Have a concern for the room for the 18mm pins you describe.

Item 1: I have some vertical and horizontal movement at the hinge, although not much. The gap between the area and the hull may open and close by o.125" when I have the rig fairly loose. (Sorry, damn Yankee doesn't get the who metric thing). At high wind, and tight back stays, The movement is reduces. At what point is the movement excessive?

Item 2: it seems to me that there isn't enough space between the edge of the existing pin, and the vertical wall of the plate to increase the pin by 2mm.

Your thoughts, please.
rgsson
Posts: 8
Joined: Mon 12 Aug 13, 9:57
Your Country: Sweden, Stockholm

Post by rgsson »

I have a question related to this: How much shall the front arms flex when sailing? I have noticed that my starboard amas arm is flexing a bit in the front when going through waves. The back arm is solid. I have tried to check the pin and attachment, but can not find any faults (will do a closer look this winter when the boat is on the trailer).
When in port and no load on the backstays, the waterstays are tight.
I have been sailing in quite rough weather and the flex is not getting bigger.

regards
Robert Gustavsson
Stockholm, Sweden
920 #86 Greyhound
Claude Dulait
Posts: 2
Joined: Mon 11 Sep 17, 15:50
Your Country: Belgium, Brussels

Contact inquiry

Post by Claude Dulait »

Hi.I am in negotiation to buy Wideawake and would like to enter into PM's contact with you.Can you help? Thanks in advance.Sincerely,
C.Dulait
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