Tag Archives: 3D printer

3D Printed Models

It’s been a couple of years now since KiwiMill started making 3D printed parts for our models. It took some experimentation to get this model making tool working for us, but we have settled into a nice rhythm in terms of its use.

About 70% of our jobs now involve some degree of 3D printed parts. At the beginning of a project, our model makers decide what materials they will use to build each part of a custom model. Several factors are considered when deciding what pieces will be fabricated on the 3D printer. The complexity of the part, its use on the model, it’s size and how quickly it needs to be produced are some of the considerations.

The 3D printer is an excellent choice for complex, intricate parts. Once the time is taken to draw up the part in CAD, the printer can effortlessly build a detailed object with great accuracy. Even when factoring in the time it takes to clean support material from a finely detailed piece, it’s often worth the prep work to get a final product that has all of the desired cosmetic effects intact.

Depending on the over all model’s purpose, 3D printed parts may be too delicate for use in a project. They aren’t the best choice for moving parts, or places that need to endure a high degree of impact. However, they may still work well alongside more durable materials such as ABS, metal and tooling board, adding detail to an over all sturdy model.

Not that 3D printed parts can’t be strong. Large, solid parts, with less intricate detail, can be quite durable in nature. However, they are often cost prohibitive. The resin used to create objects on the 3D printer, is relatively expensive material. It doesn’t make sense to 3D print large pieces that can otherwise be hand-built, CNC milled or routed out of another material.

The exception to this would be if timing is a factor. If the item being fabricated can be drawn in CAD, printed, cleaned up and finished quicker than a hand build, it may be chosen in a situation where a deadline is looming.

KiwiMill has yet to completely print a model. Even in cases where the final product was made up mostly of 3D printed parts, it still involved other materials and fasteners holding the various parts together. The 3D printer has not replaced a model maker, either, though we joked about that happening when it first arrived. It is simply another successful tool of the trade that we have fully integrated into our repertoire.

 

 

 

3D Printed Mold for Casting

KiwiMill has an Objet 3D printer to make scale model parts efficiently, accurately and with greater detail.

When the printer is not in use for model parts, it’s available to customers for rapid prototyping services. Not only can the printer create parts with very quick turn around and accuracy, but it can be used to create a tool for molding and casting multiple pieces.

Here is a 3D printed mold created by our designer, Mike, that will be used to cast multiple parts. It incorporates gating and venting in the design.

Creating a mold using a 3D printer saves time. Traditional molds require a Master to first be created, and then the mold is made from this initial part. 3D printing the mold means there is no need for a Master. The mold is created with a 3D drawing, then “grown” in the 3D printer. It comes out ready to cast its first part. In this sense, 3D printing the mold eliminates entirely the molding step as it is traditionally known.

Once you have your 3D printed mold, different materials can be cast in it – from very rigid, to soft and flexible.

Yet another technology tool for Model Makers to make use of, and for our customers to take advantage of.

Intricate Build of Manifold Trailer Industrial Model

This industrial model of a Manifold Trailer for Forum Energy Technologies involved extensive use of our 3D printer. The result was stunning detail, accuracy, and with the addition of brass structure, great strength.

KiwiMill model makers were very pleased with this attempt to create a model primarily of 3D printed parts that were then assembled into the finished product.

 

 

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Is a 3D Printer Like Having an Extra Model Maker?

3D printer for model making shop

The model maker team here at KiwiMill is definitely pleased with the addition of our newest Objet 3D printer. While we jokingly refer to it as our extra employee – it is quite a miraculous technology – it’s worth noting the support systems needed to make it run, as well as its inherent limitations.

First comes the training necessary to operate, clean and maintain the printer itself. An initial inservice with the sales tech after purchase is a good starting point. Ongoing tech support provided by the manufacturer keeps things running smoothly in the long-term.

Material to run the 3D printer is a regular investment as well. The resin itself  is expensive, and to a lesser degree, the support material used to print each item. The resin is the actual plastic that a part is made out of, the support material is what fills in the empty spaces in the design as it prints layer by layer on the tray.

The human labor involved in 3D printing is perhaps the most interesting aspect of this particular fabrication technique. Three dimensional printers can give the impression that they take the place of  a model maker. After all, they are touted as machines capable of  growing parts overnight, sometimes even whole models. How true is this exactly?

Traditionally model makers have sat at work benches, or run machinery, cutting, carving and shaping materials to the specifications needed for a model part. This method is considered subtractive – the model maker must extract from a whole piece of material the parts necessary to assemble the model. This certainly takes time and a considerable amount of skill, rightfully earning the model maker’s status of master crafts person.

Innovations in the field of model making have introduced automated machines that will do the extracting for you. CNC (computer numerical control) machines guide a router, lathe or mill to carve out parts automatically. Three dimensional drawings have been programmed into the machine by a computer, to provide coordinates for the subtracting device. X and Y coordinates guide the machine back and forth and the Z coordinate tells the machine what up and down motions to make, thus creating a 3 dimensional part.

The 3D printer works a bit differently;  it takes a 3D drawing and prints it out in 2D layers. What the model maker must first do is take a CAD engineered drawing from the client and make it “water tight”. This means that all lines in the drawing need to be connected, or closed off. If only a 2D drawing is available, the mode maker must be able to draw it up in 3D. If only the original object exists, with no drawing, it can be scanned and made into a 3D drawing.

3D drawing scale model part3D printed part for scale model

Why does the printer need a 3D drawings when ultimately it will be printing it in 2D? How the 3D printer works is that it takes a 3D drawing from any drafting program and slices it into 2D cross-sections, printing each slice out, layer by layer and stacking them up into a three-dimensional object. The unique aspect of this method is that it is additive, not subtractive. The part is built up out of nothing, not extracted from an existing piece of material.

3D printed scale model part

Afer the original 3D draft has been prepared by the model maker and sent to the printer, it is true that the machine then grows the parts itself. This is the magical aspect of the process. A model maker can go home for the night while a part is being created. However, once the part is removed from the printer, it is not exactly ready to use. This is where additional labor is necessary to clean the part.

3D printed model part

Support material is the substance that takes the place of empty space in a 3D object, where it is needed to hold up the design as it builds upward. It acts as scaffolding for the object being printed. A layer of support material is laid down on the print tray as well, as a foundation, before any part of the actual object starts printing.

When an object is removed from the 3D printer, it is this support material that needs to be cleaned off the part. Depending on the shape or design of a part, it is the removal of support material that takes the majority of labor in the 3D printing process. Water jet spraying, chemical soaking, scraping and digging out support material from intricate pieces takes time and effort.  Sometimes there is so much support material covering a part, that it needs to be extracted out of it as if it were a piece of gold embedded in rock. Thus making 3D printing a bit of a subtractive method as well!

3D printed part for model maker

Once the part is cleaned, it needs to be primed, painted, and usually assembled with other parts to make a whole model.  We don’t often – if ever – print a model in its entirety.  The over all complexity and sophistication of most of our scale models demands greater levels of detail. They are nice supplemental parts to have, and free our model makers up to add the human artistry that gives our models their custom look.

3D printed parts for model maker

A 3D printer does not replace a model maker, as fun as it is to joke around with the notion.  The added technology requires our model makers to be better trained in 3D drafting: drawing, reading and fixing 3D computer files. It ‘s another fabrication choice, and hones the critical thinking skills that determine what parts will be printed, CNC machined, hand-built or crafted in yet another method. This blend of artistry, engineering and technology is making the model making field such an exciting place to be right now.

3D Printed Part Transformed

At KiwiMill we use 3D printed parts to make some of our models, depending on the design and purpose of the project.

3D printed part for model

For a recently made MATV military vehicle, the doors were 3D printed out of plastic with handle,  hinge and window details. The part was grown over night in the 3D printer, taken out and cleaned up.

3D printed  scale model part

The part was then primed, painted and given additional details.

military model

Here is the door on the completed MATV vehicle. The printed part blends in with all the other materials that were used to complete this model. Our model maker chose soldered and braised brass for most of the model for the strength and endurance necessary in a trade show piece.

New Fabrication Choices for Model Makers

scale model parts

With the addition of  3D printer technology, new in-house model fabrication options are available to model makers. Decisions need to be made about what fabrication method is best for building each model part. What parts should be printed, molded, CNC milled/laser cut, or created by hand? The use of all available technologies in the correct circumstances makes for an efficient, bustling shop, and quality model production. That’s the goal. Not to replace craftsmanship with machines, or to unnecessarily complicate the model building process with flashy new equipment.

Factors that need to be considered when determining fabrication method include; time, cost, accuracy of part, material being used, model type/usage,and the information available on the item being built.

The time constraints of any given project are a major consideration when determining what fabrication method to use to create a model, or its parts. Deadlines are often very tight and sometimes the initial decision to bid on a project will be influenced by how quickly it is needed and whether or not available fabrication methods (and resources) will get the model done on time. An automated machine like a CNC mill or laser may actually take longer to produce a part than hand building, but will use up less human resources in the process. How much available time needs to be balanced with the number of model makers assigned to the project and the length of time each part will take to be made using a particular method of construction.

Costs are often closely tied into time when determining what fabrication methods will be chosen. Time means money, and the amount of labour put into the job is a large part of any model price. Machines can make up for some of the costs in human labour, provided the money is there to buy and run the machine in the first place. Material costs for particular machines, such as the resin needed in a 3D printer, need to be taken into consideration as well.

Model makers need to determine how accurate a part needs to be on the model when deciding fabrication methods. Computer-programmed machining is more consistent and precise than hand building a part. This may or may not be a consideration in a given project. Sometimes a model is an artistic representation of an object, and extreme fidelity to the original design is unnecessary and unwanted.

The kind of material being used in the model will help drive the fabrication method. A 3D printer uses resin. A CNC mill can carve plastic, foam, steel, brass, wood or machinist board. A hand-made part can be rendered out of just about any material available to the model maker. Usually the type of model determines the material being used, and is determined by the model maker,  but occasionally the client will have a particular material request as well.

The type of model needed is one of the overriding factors when deciding on fabrication methods. What shape, size and quantity the model will be, as well as its purpose – display, trade show, instruction, sales or prototyping – influence the type of material used to create the model, as well as fabrication choices.

Depending on its shape, a model might be made through a subtractive method of taking away material such as a CNC mill,  while other shapes are more suited for an additive method of “growing” a part on a 3D printer. A milled part on the CNC machine needs to be flat on the bottom, no shape can be created underneath the part. This is not a problem with the 3D printer.  A completely flat part with an intricate design can be  cut on a CNC laser.

The over all scale, or size, of the model may rule out certain fabrication methods. Large parts need to be able to fit on the particular machine being utilized. The quantity of models required influences the construction. Multiple models of the same object can be well suited for mold making. A master model part is made and molded, then multiples are cast from the mold. Automated (CNC) machines in general are helpful for multiples due to their consistency over a hand-built part.

Intended model use will help establish what construction methods are used as well. If a model is going to be moved around frequently, such as trade show use,  durability and strength become important factors. This will affect materials used, fabrication, and even assembly methods to ensure a model that will stand up to repeated transport and handling. While a display model permanently housed in a protective glass case can be made of more delicate materials and finer fabrication methods, such as hand-building.

Finally, the information available to build the model will help ascertain the best fabrication method to use. If 3D files are available of the item to be built, that will lend itself better to CNC or 3D printing processes. If the model maker has only a picture or photograph to go by, it will likely be more efficient to build the model by hand, using a well-trained eye, than to try to draw the parts first in a computer program.

A well equipped model shop with a full complement of fabrication methods makes a model maker’s job more effective. Multiple factors are taken into consideration when determining which construction methods to use on any given project. Time constraints, costs, accuracy required, materials used, type of model, and information available about the item to be built all can influence this decision. Many of these factors are intertwined. Ultimately it is a model maker’s job to assess these options early on in the project and plan fabrication methods accordingly.

3D Printer in the Model Shop

We’re getting ready at the model shop for a new 3D printer. This machine will introduce additive processes for model making designed to increase flexibility and productivity.

Model making has traditionally been associated with a subtractive method of fabrication. Meaning, model parts are formed by taking something away from a material through carving, sculpting, cutting, sanding or  chopping.  These extracted parts are then glued together to form the whole model.

Additive methods of model fabrication do the opposite. Instead of sculpting a model out of material by taking away, an object is built up layer by layer. This additive process creates a 3D object from seemingly nothing.  A computer image of the desired part is programmed into the 3D printer.  The machine then creates a solid object by adding successive layers of material in the desired shape and form.

The additive method is fast and efficient, vastly reducing the amount of hand’s on work needed to create a model part. The subtractive method can be sped up as well with the addition of computer numerically controlled (CNC) machines, making rote shaping and carving tasks more autonomous.

These technological advancements  are welcome additions to the model making shop. They cannot replace craftsmanship, experience and artistry. They’re meant to enhance the fabrication process, freeing up our model makers to put their energy and talents toward more essential and complex tasks.