Matt Schmotzer’s Incredible 3D Printed Roller Coaster Model

We’ve covered our fair share of realistic roller coaster models over the years, but this is the first time we’ve seen a fully functional 3D printed roller coaster model – and it may just be the best model yet! 3D printing is a process of making three dimensional solid objects from a digital model on a computer. It’s also known as additive manufacturing because it uses an additive process where an object is created by laying down successive layers of material until the object is created (as opposed to extruding, molding, or stamping manufacturing processes).

We recently caught up with Matt Schmotzer, the creator of the Invertigo printed coaster, to learn more about what it takes to design and build a working 3D printed roller coaster. Thanks to Matt for taking the time to tell us all about his incredible creation.

First, check out this exclusive video to see the Invertigo recreation in action including a behind the scenes look at some of the amazing detail included in the model!

C101: For those who don’t know, please briefly introduce yourself: who are you and what do you do?

I’m Matt Schmotzer, currently employed at the Ford Motor Company. I work in engine systems on the 2.0L/2.3L GTDI engine programs. Outside of work I am enrolled as a graduate student at Purdue University studying to earn my Masters in Engineering.

3d printed roller coaster

C101: What made you want to take on this project of 3D printing a roller coaster model?

My interest in roller coasters goes as far back as I can remember. I had tried previously to make model roller coasters in high school but never had the correct tools available to create a model that would fully function. Over the past four years I had grown an interest in 3d printers so naturally with an interest in roller coasters and 3d printing, a 3d printed roller coaster was bound to happen.

C101: Out of every roller coaster out there, why choose Invertigo at Kings Island?

This is a great question, and probably the most popular. I wanted to create larger layout roller coasters but didn’t want to invest all my time into something that may not work so I decided:

1) The coaster needed to fit in my garage.

2) It needed to be a ride I have ridden.

3) It needed to be short.

So with those three requirements I fell on Invertigo.

C101: What was the biggest challenge you faced when designing and building the model?

Most people would assume having the scale model completing the circuit would be the hardest part. However, having the lift hills work correctly was the hardest part. I had trains uncouple from the lift, and getting jammed on the lift (hey, kinda like the real one ?!) all the time. It wasn’t until I dialed in the code and the mechanism that it finally worked without a hitch.

C101: What CAD software/design tools did you use?

The design of the layout starts in NoLimits Coaster Simulator 2. From there I export the track spine coordinates into Excel. Once in Excel, I scale the ride down to the proper size I want to construct the model at. After scaling I import the scaled coordinates into Solidworks 3D CAD system. Finally, once the layout is imported into Solidworks I design the track profile and support structure. The trains, mechanisms, and station are also modeled in Solidworks.

solidworks roller coaster model

C101: You could have just 3D printed the track and train and left it at that, but instead you’ve made it a fully functional model with amazing detail. What planning and work went into fully automating the model?

If you walk around IAAPA, coaster companies are always showing small models of future products, but you rarely see them in full, and scaled, operation. Most operational models are flat rides or other rides that don’t rely much on gravity to complete a circuit.  I wanted to bridge the gap of modern coaster art into coaster science.

Creating a static, non-functional, model was pretty straight forward and I had completed that phase of the project within a month. Originally I had the track entirely 3d-printed which came with drawbacks. First, with 3d printed track, no matter how much sanding and smoothing of the rails I did, the train would vibrate while running causing the train to stall and not complete the circuit. I went back to the drawing board, or my computer, and redesigned the ride without the rails and substituted plastic tubing in its place. I was then able to 3d print the track and then glue the tube to the 3d printed track. While gluing the tube for the rails to the track I 3d printed about 100 brackets to hold the tube in place after being glued. This 3d printed tool really helped speed up the gluing process.

C101: The track is printed in segments with just the spine and cross-ties, correct?

Yes, that is correct.

C101: So do use any automation/macros/tools when designing in Solidworks to speed up design time? Specifically I’m thinking about the cross-ties that hold the track to the center spine. Do you place them all by hand or use some tool? How is the spacing between each cross-tie determined?

Yes, I wanted the coaster to assemble like a real one so I printed off the track in sections and bolted each pieces together with M2 fasteners. In order to model the track cross ties I use a pattern feature with a designated spacing. This makes the entire cross tie generation automated. When patterning however you need to make sure to keep the cross ties perpendicular to the track spine, otherwise they will all be in the same orientation.

C101: What 3D printers do you use? 

These are the 3d printers I own that helped me complete the project:

Lulzbot Taz 5  – Used to print Track

Lulzbot Taz 5 (modified) – Used to print Track

Lulzbot Taz 6 – Used to print Track

Flashforge Finder – Used to print Support structure & trains

Flashforge Finder – Used to print Support structure & trains

MendleMax 1.5 – Used to print Support structure

One cool thing to note is that I purchased the first Taz 5 from lulzbot and used that printer to print out the parts to build the Taz 5 (mod) and Taz 6 for half the price of purchasing a new one. Machines making machines man haha.

C101: That’s awesome! How long does it take to print one track segment?

This model contains 33 unique track sections that take roughly 12 hours to print. An individual train car takes about 3 hours to print.

C101: Interesting you use so many printers, and different models too. Is there any particular  reason why you use different types of  3D printers to print the train versus the support versus the track? Could they all be made on the same printer or is there some limiting factor?

My main printers are the lulzbot Taz machines. They are big, robust, and work horses. In addition if I have any issue, the machines are open source so I can print new parts or find where to get parts easily off their website. In addition, two of the three machines I built from scratch to save money. The Flashforge machines I found “broken/used” off eBay and only spent a hundred on them. One had a bad PSU and the other had a wire-harness that needed to be replaced. Once I fixed them up I realized they were great for printing off small parts. So in the end the lulzbots were the main machines that printed the track and the finders printed the trains and supports just because the tracks were too big for the finders.

I would say the size of the part is the only limitation, however most slicing software out there allow the user to split the model in half. So if the track section is too big for your machine you can slice the track part in half and print it in sections.

C101: OK that makes sense. So how do the lifts work? How does the train engage and disengage with the chain at the right moments?

From my understanding the actual Invertigo Coaster has flaps on the lift that engage and disengage a lever arm on the train that engages the lift. At the scale I was working with that would have been way too complicated. In turn I just decided to use magnets. The magnet setup is a bit complicated but I will try my best to explain. The lead car has a metal plate and the second car has magnets. The lift hill in turn has a magnet that connects to the lead cars metal plate, and further down the chain there is a similar metal plate that attaches to the train magnets. Trial and error brought me to this setup. I needed to control the position of the train, but also make the lift able to catch and release the train, so the design became complicated quickly.

C101: How did you program the station gates/restraints/lifts/etc and what tools did you use? Any other details on the train, station, and control panel you would like to share?

The entire roller coaster is controlled by an Arduino Mega. The electrical system includes 13 button inputs (control board), 9 servo motors (6 on track, 3 in station), 2 dc motors (lift hill) and 12 LED lights (control board). In total, I use 40 pin outputs on the arduino. The dc motor H bridge requires 6 pins off the arduino to drive the two dc motors.

The program that runs all of the manual operation and automatic operation is only 658 lines of code. The controller has an automatic setting along with manual. Automatic was created when I travel and want the model running constantly, where Manual is set when I want to be the actual ride operator.

Honestly, thought it would be more than 600 lines of code. ? #arduino #programing

A post shared by Matt Schmotzer (@print_my_ride) on

C101: Where did you get the buttons for the control panel?

I purchased all the Allen Bradley buttons used off eBay. Normally, brand new buttons run about a hundred each but used you can find them for cheap. For example, here is a lot of 10 buttons that may actually sell for roughly $30.

C101: Have you ever operated a real roller coaster? From watching your video, it looks like you have experience operating a coaster.

I have never operated a real coaster.

C101: What’s next? Is the Invertigo model completely finished? Do you have any future projects?

I was all setup to build Valravn at Cedar Point. However, after starting the design work my Invertigo model started getting noticed online and I have since been approached by multiple organizations to build different rides. So right now we are in the works, but I hope everyone stays tuned to see whats next. I hope to create at least one model every 4 months (being optimistic).

C101: Where can people go to follow along with your project updates?

This is where you can follow the action as I post the most recent pictures of the project.

This is where you will be able to eventually get more information/pictures/ and CAD to build yourself! (it is a work in progress)

C101: We always have to ask: what’s your favorite roller coaster?

I have so many favorites for many different reasons, but if I had one I had to pick it would be Millennium Force at my home park Cedar Point.

Thanks again to Matt for taking the time to answer our questions and for even going above and beyond by showing us around his workshop via the video. It wouldn’t surprise me to see this or another model created by Matt at a future IAAPA expo as the quality is just that good.

What 3D printed roller coaster models would you like to see Matt build next? Let us know in the comments below or if you have any questions for him.