Spar form/size

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Colin Helliwell
Posts: 24
Joined: 18 Jun 2014, 18:44
Location: UK

Spar form/size

Post by Colin Helliwell » 23 Mar 2015, 16:37

I'm wondering about the choices on spar sections (round/groovy) and diameters. Can anyone give me pros and cons of the various options?
Thanks.

Edit: I do realise that a larger diameter is likely to be (subject to wall thickness) stiffer than smaller and that, in any case, the sail cut should be appropriate for that stiffness - I expect to buy complete rig from one supplier.

Dave Pickett
Posts: 107
Joined: 18 Oct 2010, 19:33
Sail number: GBR3845
Club: Eastbourne
Design: TS2 and Shiraz

Re: Spar form/size

Post by Dave Pickett » 23 Mar 2015, 22:53

Hi Colin,

My Shiraz uses 11mm mast and it seems strong enough, I think as ever its not just size or even wall thickness, there are endless grades of Ali which confuse things.

Most folk only seem to like grooved masts on no2 and 3 rigs, no doubt an expert will be along at some point to explain why!

Moving on from masts to booms, I will add my limited experience and state that I am going over to Sailsetc rectangular section that I had on my TS2. They are slightly heavier (No3 main boom is 7grams more than the round section) but I find them much easier to adjust the sails and once set they dont move. Nothing wrong with the round spars, just not as user friendly IMHO, and the easier is is to adjust the sails the more likely you are to tune the boat at the water's edge.

Colin Helliwell
Posts: 24
Joined: 18 Jun 2014, 18:44
Location: UK

Re: Spar form/size

Post by Colin Helliwell » 24 Mar 2015, 19:18

Thanks Dave.
I've done some more trawling around, and am reading about 'jacklines'/'luff-lines' on round/sleeved masts.
For others looking into the topic like me:
http://www.onemetre.net/Build/Jackline/Jackline.htm
http://modelyacht.blogspot.co.uk/2014/0 ... w-rig.html [I think this guy refers to leech in places where he means luff?]

So I can see the benefit over a luff slot (groovy) arrangement. Akin to the rotating mast I had on my Moth (back in my youth, when I was fit and nimble....). And perhaps bears out Dave's input of groovy not being popular on No1 rig - on 2 & 3 the added turbulence is probably less of an issue?

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