By DE Editors
Q: Do I really need to understand the concept of an STL file??
A: Absolutely! An STL file is what your RP model is generated from, therefore is it important to create a high quality file. An STL file is only a representation of the true CAD model. It is a digital file that can be compared to a fancy point cloud. Points are placed all over the true CAD surface and then connected to form a quilt made of small triangular plates, each with its own normal defining surface direction. Higher density on non-flat surfaces results in a more accurate representation of your CAD model. Most CAD packages allow you to enter a tolerance when exporting an STL file. This tolerance defines the maximum error in your STL file and unfortunately ‘0’ is not an option. You will have favorable results if you can export your file using a tolerance between 0.0001” and 0.001.” Keep in mind that better resolution will result in a larger file size. Complex CAD models can have the ir STL counterparts in excess of 100MB, so it is important to work with your service provider to find the right balance between file quality and manageable file size. Each CAD package has its own unique algorithm to creating STL files, so it’s always a good idea to refer to their specific instructions. In cases where your CAD package prohibits you from creating a quality STL file, you can export other formats such as Parasolid, STEP or IGES. Most service providers will possess handy software tools that will allow them to generate high quality STL files from those formats.
Q: What is the best way to get prototypes and low volumes of my plastic part design?
A: The answer to this question (and to most good questions) is “it depends.”
If speed and lowest cost are the only considerations, additive Rapid Prototyping (RP) technologies like 3D printing SLA, SLS, and FDM, are good options for getting concept models quickly.
If you also care about functionality, you’ll want better material properties than RP can provide. Suppliers like First Cut Prototype and Protomold have applied computer technology to traditional manufacturing techniques like CNC machining and injection molding, making them comparable to RP with respect to speed and cost, with the added benefit of providing the true material properties needed for meaningful functional testing. As one reads about rapid prototyping, the Holy Grail appears to be “thermoplastic like” materials. A close look at the specifications for these materials shows that, at best, a few of the mechanical parameters approach 80-90% of the same values for the true thermoplastic materials available via injection molding or CNC machining. The rest of the mechanical, thermal and electrical properties of these “thermoplastic like” materials fall short and render them ineffective for meaningful functi onal testing.
Q: Is now the right time to bring scanning technology in house?
A: Whether measured in time or in dollars, getting 3D scan data from physical objects has traditionally been expensive, limiting scanning technology to those who could afford it.
One of today’s most exciting developments within RP&M/RE is the explosion in scan data use to design and manufacture parts and products.
NextEngine offers high-performance 3D hardware and software solutions 1/10th the price of established scanning systems. Ease-of-use has improved in concert with dramatically lower prices and now more people than ever are enjoying the performance edge this time-saving technology can provide.
Scan data file outputs: Are you familiar with how to use Mesh, Surface and Solid files to speed your design and manufacturing workflow, expand capabilities and provide added value to customers?
With the barriers of cost and ease-of-use lowered businesses, both domestic and foreign, are becoming more efficient with in house scanning capabilities. Is yours?
Dimension 3D Printing Group
Q: According to the Wohlers Report 2007, 3D printers sold over the past four years (2003-2006) represent 68 percent of the total number of additive systems installed worldwide. Why has 3D printing become so popular?
A: First off, 3D printers are less expensive to purchase than other three-dimensional modeling systems. The entry point for 3D printers is under $20,000, tens of thousands of dollars less than most traditional entry-level rapid prototyping systems that commonly cost $60,000 and up.
Second, 3D printers increase productivity by speeding up the design cycle. Once installed, 3D printing can help an organization quickly fine tune designs and dramatically cut the product development schedule. With 3D printing form, fit and function can be tested and multiple design iterations can be explored – over the network, right from designer’s desktop.
Third, 3D printers are less expensive to house, run and maintain than other three-dimensional modeling systems. Traditional modeling systems generally have a much larger footprint than 3D printers and use consumable materials that are more expensive and more difficult to handle. In contrast, 3D printers can sit on a desktop, and it’s common for them to be centrally located in office environments.
Finally, 3D printers are easy to use. Unlike other forms of RP, 3D printing systems requires little or no training and can be incorporated as easily as a laser printer used for desktop publishing.
Q: Is rapid prototyping technology really ready for use in manufacturing?
A: Rapid prototyping technology is quickly taking on more of a manufacturing role. Advancements in technology and materials continuously improve the strength and appearance of parts. For example, RedEye™ recently introduced a new process called Ready Part™ that uses a process to produce a smooth surface finish and water-tight seal on parts and models built with ABS material. That enhancement to the Fused Deposition Modeling™ technology allows designers the ability to use rapidly manufactured parts in their end-use application. Today, organizations are using RP technology as a manufacturing tool. In fact, rapid – or digital – manufacturing is an ideal tool for start-up companies looking to get their new products to market faster on a tighter budget. Many start-up companies are using digital manufacturing to help them through the design validation process. Using RP technology allows them the flexibility to make multiple design iterations without cost penalty or interrupting production. Because of that, start-ups can ensure their product designs are just right before spending upward of $25,000 on a mold for mass production.