How to design a roller coaster book

Shameless self-promotion. I've wrote a book entitled Coasters 101: An Engineering Guide to Roller Coaster Design, available to purchase in paperback and ebook form. Below is an excerpt regarding Roller Coaster Design Software and Computer Technology:

3D CAD software, such as CATIA, Solidworks, or AutoDesk Inventor now allow designers to have every aspect of thrill ride design all within one software program including 3D modeling, 2D manufacturing drawings, kinematic simulations, finite element stress analysis (FEA), and high-resolution image renders for marketing and sales purposes. Standard parts like bolts, springs, nuts, screws, and washers can be taken from standard part libraries or catalogs and bills of material can be derived directly from the model and inserted into a drawing. Some companies are now using a practice called Model Based Definition (MBD) where all of the required manufacturing information is contained within the model as 3D annotation data. MBD is an environmentally friendly practice by reducing the amount of paper used due to having fewer 2D drawings.

Utilizing this type of software is an enormous improvement over methods that were employed even twenty five years ago. The time required to create a roller coaster from scratch would be quite lengthy without using a computer because of the enormous number of calculations required. Changes and iterations can be made much more rapidly using the computer. Multiple track variations for the same ride may be presented to the customer. Of course, some older roller coasters were designed and built much quicker than some recently built rides but that is due to the fact that safety standards were nowhere near as strict as they are today

Rides can also be built to higher standards, quality, and tolerances. Modern 3D CAD systems can help the engineers design the ride within the limits of biodynamic tolerances of the passengers. A simulation of the coaster can be done based on the CAD data so the forces and the dynamic behavior can be determined way before a prototype has been built. The roller coaster is virtually assembled early in the design phase to test functional relations and mechanisms as well as collision detection of components and the ride’s clearance envelope (the area within possible reach of the passengers in the vehicle). When the CAD work is complete the production data is electronically sent to the manufacturer or fabricator.

Even with this high powered computer technology, the translation from the CAD model to the real world is never accomplished without a few surprises. Stack-up of assembly tolerances and other dimensional differences can affect the actual ride. There are thousands of variables in a roller coaster and it is impossible to adequately address them all during the design phase. These unknown issues could delay the project and should be budgeted for in the project schedule.

Engineers design parts with a tolerance range, meaning as long as the manufactured part’s properties falls within the specified range it should not affect the function of the component. Tolerances are specified to allow for variability and imperfections within the manufacturing process as it is extremely difficult to manufacture parts exactly as they are designed. A piece of track may be 0.02 inches longer than it was designed. This may seem insignificant but over a 5,000 foot long layout all of those values can add up and suddenly you have a problem on your hands when you go to connect the last piece of track to the first piece because it won’t fit. This is called tolerance stack-up. Engineers must plan for the best and worst case scenarios by studying the dimensional relationships within an assembly. Generally, the more precise the tolerance, the harder it is to achieve, thus the higher the cost to maintain that quality.

Though 3D CAD software is a powerful tool, designers must be careful and thoroughly think through all aspects of their design so as not to fall into one of the many pitfalls when relying on computer software. For example, let’s say you are going to design a support column and a steel track segment that are going to bolt together with eight, half inch diameter steel bolts. In the 3D CAD model it is ridiculously easy to perfectly align the bolt holes on the support with the holes on the track. In reality, when that support column is manufactured the holes are potentially not going to be exactly where you modeled them. They could be off by a fraction of a millimeter or more. A designer must account for this in the design by making one of the sets of holes on the track or support slightly larger than the diameter of the hole on the other mating component. This way, if the holes were not drilled exactly to specification, and the holes are slightly off center to each other, the bolt can still be inserted through both holes. Parts must be designed with the manufacturing and installation processes in mind.

Purchase the paperback here and ebook here.

Stay tuned for my upcoming release of VB Scripting for CATIA V5 where I'll teach you how to learn macros. I've created a new page where you can view all of my publications.