At MarsKeel™ we offer the production of struts for larger motor yachts. This is complete production, from receipt of the drawings to the shipping of the finished products.

We can offer the customer a range of production methods. We offer the ability to cast, fabricate or fully CNC machine the requested struts.

Once there is acceptance of the offered quote for the project and production method the production process will begin.

In the case of cast parts the process begins with the pattern maker. We will generate the required pattern or patterns, (if there are separate Port and Starboard castings.) based on the following considerations.

Prior to pattern construction we take into account the number of castings that are required now or in the future, the material being cast and the style of casting being used.

The number of castings will define whether we can use a medium density foam pattern material, a hard particle board, or for the longest lasting a solid wood pattern. We offer the customer a range of pattern materials to suit their production needs.

The material being cast defines the amount of shrinkage that has to be built into the pattern. Each material will shrink at different amount during cooling. 
Please see the included chart of shrinkages below.

Therefore the pattern has to be made larger then the required finished part. The range of materials that are offered include such metals as ductile iron to high strength Stainless Steel. 
A list of the common materials is shown below.

The last consideration is the style of molding or casting being used. Do we require a pattern on matched parting plates or a free pattern? This decision is also determined by the shape of the casting. Some patterns will have to be in removable sections, to allow their removal from the mold. The part can always be removed from a sand mold, it simply breaks away.

All of these considerations will also go into determining whether we can offer the customer a CNC milled pattern or a hand built pattern.

In the casting process itself we have some limitations to part size. This is caused by the size of the furnace used. 
See weight Limitations Chart. 
Please remember that the rough cast weight will include the rough part, the required gating as well as any required coupons for material testing. We offer the customer complete material testing, discussed in the Certification section. For common materials this is not a concern but for exotic materials the customer would buy not the part weight but the weight required for the entire heat. The gating, remainder in the furnace would then be inventoried for the customer, to be used a t a later date.

In the case of a fabricated part the project will move directly to the fabrication shop. For this method the drawing must offer all required dimensions and tolerances and welding specifications for fabrication. The material can be virtually any weld able material.

In the final case of the fully CNC milled part the project moves to the fabrication shop for cutting, fitting and pre-assembly and welding of the blank part, then directly to the machine shop for surfacing. This surfacing is programmed and checked from the complete IGES file from the customer. With a fully machined strut all of the machining processes including those that the cast and the fabricated parts go through are all included in the machining process.

Let us move through the production base on the casting process, which is the most common.

Once the casting or fabrication is complete the part would then be sent to the machine shop. Such things as the main bore, mounting holes, counter-sinks and any surfacing would be done. For these simple machining jobs we would require dimensional and tolerance information only, no IGES file is required. Any tolerance certification can be done with the part on the mill.

After the cast or fabricated part has had all the machining completed we also offer the custom different levels of finishing. The fully machined part is finished as well, but it required very little work. The different finishes that can be offered in the other two production methods include varying levels of surface blasting, and grinding, polishing. The Stainless Steels are usually lightly surface blasted, while the Bronzes are polished. All machined surfaces are protected throughout the finishing process.

Once the parts are completed they are sent to the shipping department where they are packaged for shipment to the customer.