SC 20 tuning

Technical discussion of ARC products
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nestes106
Novice
Posts: 5
Joined: November 6th, 2015, 7:59 am
Boat Make/Model: SuperCat 20
Location: Dartmouth, MA
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SC 20 tuning

Post by nestes106 » November 6th, 2015, 5:14 pm

Recently got a SuperCat 20 with custom outrigger seats. This boat has not been sailed in a while and the rig tuning needs to be touched up. I have not really sailed cats like this much at all. I don't know what to tune and what to look for in tuning the boat. Everything right now is at its most slack position. Im not looking to race this but a base setting or general tune of the rig would be appreciated. Is there a guide or is this more of a trial and error deal? Thanks guys.

Mac M
Professional
Posts: 227
Joined: June 13th, 2012, 2:05 am
Boat Make/Model: SC20 & 17
Location: Lugoff, SC

Re: SC 20 tuning

Post by Mac M » November 6th, 2015, 5:50 pm

I'd sure like to see a picture of your boat with the seats! Where are you located?

To help with the tuning what mast do you have? Standard or Tall Rig. When you say everything is at its most slack position, what are you referring to? I'm assuming you are taking about the diamond wires although if you have the floating Dolphin striker it needs to be tensioned too.

havliii
Professional
Posts: 258
Joined: March 27th, 2011, 5:12 pm
Boat Make/Model: SuperCat 19, Modded SC20
Location: Fredericksburg Virginia

Re: SC 20 tuning

Post by havliii » November 7th, 2015, 7:49 pm

Start with mast rake, I use about 2 degrees, 3-5 is suggested. Do you have the Hyfield levers for the sidestays? If so, the palm of your hand should be sufficient to close the lever, if it takes more pressure than your hand can muster, you are to tight on the rig. Adjust using the holes in the forestay adjuster and the holes on the Hyfield levers. Diamond wire tension is tricky, I use more than recommended, try to keep them equal by sighting the mast as you tighten them, don't count on the numbers on the turnbuckle to be equal tension. I cannot press my diamonds in till they touch the mast.

Downhaul until you pull all the wrinkles out of the luff, then a bit more, the battens should 'pop' into a camber. Attach the boom choosing a location in the clew plate for the expected conditions. Further out on the clew plate = a flatter sail. Play with mast rotation control line, upwind mast rotation should be nearly 90 degrees.

nestes106
Novice
Posts: 5
Joined: November 6th, 2015, 7:59 am
Boat Make/Model: SuperCat 20
Location: Dartmouth, MA
Contact:

Re: SC 20 tuning

Post by nestes106 » November 12th, 2015, 5:19 pm

I am located in the south coast of Massachusetts. I am talking about the diamond wires, but i also took a look at the side stays and forestay and they were also at their slackest position. In terms of tall rig versus the normal, Im not sure I'll have to check with the previous owner. I will happily post a picture of the seats, however she is wrapped up for the winter and the seats are getting touched up. I have normal turnbuckles for the sidestays. But thank you for the advice it is very helpful. A couple questions. What do the diamond wires control? And whats a dolphin striker and what does it do?

havliii
Professional
Posts: 258
Joined: March 27th, 2011, 5:12 pm
Boat Make/Model: SuperCat 19, Modded SC20
Location: Fredericksburg Virginia

Re: SC 20 tuning

Post by havliii » November 13th, 2015, 7:37 pm

Your questions indicate that an introductory book might be a good first purchase. 'Catamaran Sailing' by Phil Berman can be found on Amazon. His book and several other similar books explain the basic systems, rigging and parts of a catamaran. Boat design and rigging is all about handling loads in compression and loads in tension. In short, the mast is in compression and will break if the diamond wires are not there, the diamond wires hold the mast in column and keep it from collapsing under the load of the sails. The dolphin striker is anther (albeit shorter) mast in reverse, it keeps the front beam from collapsing under the loads from the mast.

Read every post on this forum from Bill Roberts. An search on authors name will generate a list.

PLEASE NOTE: If the Supercat 20 is your first catamaran, it (the Supercat 20) is a VERY VERY POWERFUL BOAT and NOT considered a beginners boat. At the very least get some coaching or a mentor before trying to sail your new boat. Your first sail could be your last sail if you do not respect the power of this boat.

nestes106
Novice
Posts: 5
Joined: November 6th, 2015, 7:59 am
Boat Make/Model: SuperCat 20
Location: Dartmouth, MA
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Re: SC 20 tuning

Post by nestes106 » November 17th, 2015, 6:07 pm

I am a very experienced monohull sailor. However, you are correct in the assumption that it is my first Multihull. Thank you for the advice.

havliii
Professional
Posts: 258
Joined: March 27th, 2011, 5:12 pm
Boat Make/Model: SuperCat 19, Modded SC20
Location: Fredericksburg Virginia

Re: SC 20 tuning

Post by havliii » November 19th, 2015, 5:02 am

Keep us posted, add some pics in the spring when you begin assembling.

Trinisailer
Novice
Posts: 7
Joined: August 11th, 2017, 7:31 pm
Boat Make/Model: SC 20
Location: Trinidad & Tobago

Re: SC 20 tuning

Post by Trinisailer » February 11th, 2018, 5:27 pm

nestes106 wrote:
November 6th, 2015, 5:14 pm
Recently got a SuperCat 20 with custom outrigger seats.
I know this is an old thread but it would be nice if we can see some pics with the seats.
Anyone else has any pics of other SC's with these seats on?
Thanks

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