gybing

[Martin Field 1Participant @martinfield1]

Hi all, just wondering…what takes the shock of the boom slamming across from one side to tother in a gybe?

Martin

[Martin Field 1Participant @martinfield1]

[Ian GardnerParticipant @iangardner62867]

It depends on how quickly you duck!

[Colin BishopModerator @colinbishop34627]

The mainsheet if you do duck. And it can be very painful if your hand is in the way.

Colin

[Martin Field 1Participant @martinfield1]

Not the servo? If so, how can that be lessened.

Martin

[Colin BishopModerator @colinbishop34627]

On a model it will be whatever the mainsheet is fixed to, probably the servo arm. When full size yachts are running downwind it is common to rig a 'preventer' stay which extends from the end of the boom to a point forward on the hull. This prevents the boom swinging across.

Colin

[Martin Field 1Participant @martinfield1]

I have given in and bought a winch servo, but was just considering the shock that a sudden gybe would put on the mechanism. Perhaps a length of elastic where the main sheet is attached to the loop system?

Martin

[Dodgy Geezer 1Participant @dodgygeezer1]

A length of elastic would make fine adjustment of the sheet difficult. And elastic is not very strong…

I would use a slightly stretchy cord, and attach it at both ends with something like an O ring – something that is fairly rigid but will deform with a very strong jerk. If the sheet is passed through a couple of pulleys that will also go some way to lessening the shock…

[Kev.WParticipant @kev-w]

Anglers 'pole elastic' might suit the job, it has to take the shock of a fighting fish making sudden pulls.

It is available in differing strengths.

Edited By Kip Woods on 29/05/2016 21:57:46

[Martin Field 1Participant @martinfield1]

Thanks, chaps. I suppose the knack is to be careful to draw the sails in before gybing and then let them out again as you turn, so no big slapping of boom. You'll guess from this that I've never sailed using controlled sails. Only rudder!

Martin

[Paul TParticipant @pault84577]

Hello Martin

Winch servos are designed to operate under the kind of shock loads that gybing creates.

Can I offer an alternative solution, instead of trying to compensate for the problem you could use a spring balance to measure the shock load that your sail rig creates and then either research a suitable servo or have a chat to a knowledgeable supplier.

Hope this is of some help

Paul

[Martin Field 1Participant @martinfield1]

Thanks, Paul. I'd need to go out and hold the boat in a wind with a spring balance. Considering it's not even rigged yet, that ain't gonna happen and it'll be a while before it is since my shed, big as it is, isn't high enough to take it all rigged!

This'll serve me right for thinking up scenarios long before they happen. I bought a sail servo and that's what has to be used as I can't justify any expensive ones.

But, no doubt I'll be back with more dumb questions later. Also having to deal with a forced house move currently.

Thanks again,

Martin

[Paul TParticipant @pault84577]

Hi Martin

There is no such thing as a dumb question as the only way to find the answers is to ask. No single person can know everything but in our close and friendly forum there is a good chance that one of us will have the answer.

Paul

[Martin Field 1Participant @martinfield1]

Well, that's good to know. It's sometimes difficult to realise that some have immense experience in a few things and none in others. Being a long term modelmaker, doesn't make anyone a model yachtsman, for instance and vicky vercky.

I will no doubt keep asking about the latter, while hoping others will ask me the former as I really can help there.

Martin

[Gareth JonesParticipant @garethjones79649]

Martin,

I don't think you need to worry about gybing loads unless you have, by chance, bought a really badly designed or manufactured servo. The mass of the boom will be quite small and there will be some compliance in the sheets and the servo loop if you are using a drum type winch. I have used Hitec HS785 BB drum sail winches in 5 different yachts, the largest being a 2m long 10 Rater. None of them have not failed (so far).

Gareth

[Bob Abell 2Participant @bobabell2]

Here`s a little poser?

Is some of the shock from Gybing, absorbed by the hull being in water?

Come in Paul

Bob

[Gareth JonesParticipant @garethjones79649]

I have just realised I made a silly typing error in my post above. The last sentence should have read:-

None of them have failed (so far).

Gareth

[Paul TParticipant @pault84577]

Hi Bob

No

[Martin Field 1Participant @martinfield1]

Thank you gents,

I have my own shock loads to worry about currently as I'm just back from hospital, having woke up with no balance! They think it could be wax build up affecting the inner ear, but we'll see.

Cheers,

Martin

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