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Old 04-29-2014, 08:18 PM   #291
brian eiland
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City: St Augustine, FL
Vessel Name: RunningTide
Vessel Model: 37 Louisiane catamaran
Join Date: Jul 2013
Posts: 903
CNC-cut Metal Kits, ProBoat

There is an interesting affirmation article concerning CNC-cut metal kits in the latest issue (Apr/May) of Professional Boatbuilder:
Table of Contents 148 - Professional BoatBuilder Magazine

Precisely engineered CNC-cut metal kits simplify custom and production projects at aluminum sailing-yacht builder K&M and steel-motoryacht builder Jetten, ..both in the Netherlands

In case you are unable to access this article on-line, I will just hi-lite a few of the notable observations.

Today, at K&M Yachtbuilders, metal components delivered to the construction hall are far more refined: Precut stringers are the precise shape required to yield the finished hull, and they arrive from the computer numerically controlled (CNC) laser cutting facility with an intricate pattern of notches cut halfway through their depth to interlock with the transverse frames, which in turn have a corresponding pattern of narrow cuts around their outer curves. These pre-cut structure members with cutouts, coupled with precut hull plating, assure a stronger hull than conventional build, and require fewer highly skilled builders, and much shorter production time on the shop floor

Building with kits (alum and steel) saves much of the expert but time-consuming manual work, because parts come precut from CNC-laser, or CNC-plasma cutting machines and fit together only one way....

I like this new way of building boats. Nevertheless I must admit with the old method the welders on the shop floor had a very big part in making the hull what it should be. With the cleverly engineered metal parts that fit together to become a firm structure without the workers manipulating any part, construction follows the procedure planned by the engineers. Still it is a fascinating process to see a yacht take shape following the arrival of a pile of metal parts. And we can build much faster now.

When we build with metal kits, the hull comes out smooth, with a lot less finishing work.

A 50' boat can be finished within months. It allows welders and yard professionals with less experience to build a strong, lightweight hull exactly to specification in a predicatively short period of time.

We had a lot of demand for the kind of quality built steel motoryachts we build here. ...That is why the innovation program was started ( the government funded project mentioned earlier, Virpack's Smart Kit was one outcome).
At Jetten Yachting one of the first boats built by the Smart Kit method was a 40' steel-hulled cruising yacht. The yard had built hulls to this design previously, but always by traditional methods. The same boat built from a Smart Kit was finished in just eight months, cutting build time in half.

Building with kit-ed CNC-cut components is so efficient that just 2 weeks after construction began, the hull of this Bestevaer at K&M is ready for plating, which has started at the garboard.

Another savings of the Smart Kit for Jetten is that not all plates must be cut by laser. Laser metal cutting allows no more than 0.1mm deviation from computer drawings, but less expensive plasma cutting is now as precise as 0.5mm-0.8mm maximum deviation.
So we have the main construction of transverse frames and stringers laser cut, but the hull plating plasma cut.

The process of optimizing cost and build time for our yachts continues. The Smart Kit gets smarter all the time, while we also try to improve on yard logistics and cost efficiency. The lower the cost of our yachts, (and the shorter the build time, BE's edit), the bigger our market
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