Macca,

Thank you for sharing ideas and valuable experience!

Are these systems heavy?
You need a stronger boom tube (than systems attached directly to the clew) plus the bolts going through the sheaves looks like heavy-duty.

Do use a similar system on your super-Taipan?

Stein

The internal system is ligther overall (including the boom) than a normal external system.

The boom is a normal section in weight, you could go smaller and lighter but then you would be forced to use an external system and thus be heavier overall.

Super Taipan is currently an external system until I make an all carbon internal boom <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

Here's the diagram, redrawn. There is a higher resolution version attached.



Please critique.

The major things I like about the design are:

• Costs about US$100, assuming you have a boom, a 3/8" mainsheet, and hexa-cat base already.
• No overloaded blocks, assuming 1250 lb total load.
• Balanced loads (no twist).
• Relatively simple construction.

My only [minor] concern about the sketch is the block at the front of the boom. When the mainsheet is eased to the limit, the load from the primary to this block will be imperfectly aligned. This could be fixed by replacing the cheek block with a single on a very short pigtail (but still installed touching the wall of the boom extrusion to minimize wear that the pass-thru hole).

Enjoy,

Macca,

The weight of our Taipan 5.7 external 10:1 mainsheet system is 3.3 kg (excluding the mainsheet line itself).

This includes the aluminium boom + all 10:1 system mainsheet blocks (including centre-sheeting).

How much do you gain by changing to an internal system?

By the way, do you contruct your new super-Taipan boom from off-the shelf carbon tube?

I will weigh the systems that i have and post over the weekend. the internal sheeting system on the Tornado is a little bit lighter then the external (carbon boom) system on the Taipan.

The new internal boom for the Taipan will be from std carbon section, looks like it will be an eliptical section from CST.

Another gain of the internal system is windage, it is much more streamlined.