What to expect from a CNC Marine buildOur comprehensive drawing set features 3D assembly instructions guiding you step by step through the construction sequence
Designed in 3D using the latest 3D CAD software, our DIY aluminium boat kits are built in the computer before they are physically built. This allows us to develop the most efficient construction methods which saves time and money. It also allows us to produce easy to understand 3D drawings.
Our comprehensive drawing set features 3D Assembly Instructions guiding you step by step through the construction sequence.
Our aluminium kit boats are designed to cope with the choppy waters encountered off the Australian coastline and many of them feature our exclusive “S” shaped inverted chine with variable deadrise hull. This combination was made possible using advanced Naval Architecture software and results in a unique hull shape that is both stable and soft riding.
We have tested in the open waters in a 2.5m swell. We tested into the swell, beam on to the swell and running with the swell. The boats stay dry, do not broach and maintain a comfortable 25 knots.
We have designed our hulls to stay in the water and cut through the waves – not jump over them.
Our unique hull shapes are each designed from scratch using advanced naval architecture software. With the exception of out ‘Punts’, Our design brief is generally to develop a hull shape that is best suited to the conditions off the Australaian coast. Our hulls feature a variable deadrise combined with an inverted forward chine. This combination was chosen to give a balance between stability at rest, smooth water planing and rough water comfort. The inverted chine allows for a finer entry to increase comfort levels when heading into choppy seas. Below the waterline the flatter deadrise aft promotes stability and easy planing. Using advanced naval architecture software allows us to test each hull on the computer and fine tune the shape before any plate is cut. Once we are satisfied with the hull shape we can then extract the individual plate shapes for computer controlled cutting. Our design development costs are kept to a minimum since all the trial and error is done on the computer.
DESIGNED BY A QUALIFIED ENGINEER
Aluminium is a great material for building boats since it is light weight and corrosion resistant. The down side is that it has a very poor fatigue resistance. That means that in areas of repeated vibrations, such as those caused by engines and sea chop, Aluminium is more prone to cracking than steel and other materials. This is why it is vital that your boat is designed by appropriately qualified & experienced people. When designed properly, the risk of cracking is significantly minimised. This is why we place so much importance on using CNC cutting to allow us to use stress relieving shapes. We can design the best shapes and cut them cost effectively.
DESIGNED BEYOND THE STANDARDS
We design our boats by referring to Australian Standard 1799, BV rules for High Speed Light Craft, DNV rules for High Speed Light Craft and the USL Code. In addition we then apply fundamental engineering principles in areas not covered by these rules such as stress relieving cutouts. We go beyond simply meeting the minimum requirements.
SOLID FRAME CONSTRUCTION
To maximise the strength and safety of your boat, our hull frames are full depth solid plate.
Unlike some manufacturers, we do not use floating frames. On CNC Marine boats each frame is welded to the bottom plate. The use of floating frames has no technical merit and is purely a cost saving measure.
BUILT IN CHINES
We design our boats with chines that are built in the same way that larger commercial boats are built.
That is inserted between the bottom and side plates and fully welded inside and outside.
The alternative is to join the side and bottom plates directly and then cap the join with an extruded angle section. We will not design this way due to the risk of crevice corrosion. If this capped section should ever leak, damp salt would build up inside.
The area would then become oxygen deficient and corrosion would be accelerated.
Some builders that use the capped method drill drainage holes in the ends of capped chines to let water out if it ever leaks. The problem is that this also lets the salt water in. While the water would drain out, the salt will build up.
By building the chines our way, this problem is eliminated. The use of computer controlled cutting allows us to build in this way without extra cost. We tend not to use reverse angled chines as we believe they increase running costs due to causing extra drag.
Some builders use lap joints when joining frame halves and brackets. While this is acceptable in steel applications it is not good practice for aluminium. Classification societies do not allow lap joints in commercial vessels. We do not use lap joints anywhere.
We include welding diagrams as part of our instructions to you. We also etch the weld pattern lines directly to the kit plates so there is minimal chance of you getting this wrong.