Many people have asked me for K'nex roller coaster building help, here I'm going to walk you through the steps I took to create a recreation of Dragon Fire at Canada's Wonderland. I'll also point out some guidance and tips I use in creating a model roller coaster.
Step 1: Planning & Preparation
You may be anxious to start snapping pieces together right away, but any project requires a bit of preparation and planning before you begin.
If you're just starting out in your roller coaster building career, I recommend starting small and getting a feel for how K'nex works. Starting small also helps gauge how big you can build with your current K'nex collection. In my opinion you'll need at least 2-3 roller coaster sets before you can really start building.
First off I needed to decide the scale, to do this I used a google maps image of the real ride, as well as reference pictures found online. If I'm not recreating a real life roller coaster, I usually draw a couple aerial view sketches to get an idea of the layout. (this idea almost always changes, but it helps to start somewhere)
Step 2: Starting Construction - Lifthill
Typically, I find starting with the lift hill a good approach. This will determine the overall height, and will help me guage how much momentum (in the train) I have to work with.
Using real life pictures of the ride, I try and recreate everything from the supports and track into the K'nex equivalent. As a guideline I like to use 7-8 track ties (the black pieces in the pictures) per flexi rod length. Using this many will help keep the track smooth.
If you're having trouble with the mechanic's of a lift hill I recommend building the lift from the Screamin' Serpent roller coaster set first.
Step 3: Construction - Loops
Again using a reference picture I began piecing together the loops, each loop took me approximately 4 hours to get it shaped to my liking.
When I'm building I like to start with a solid base, in this case it was constructed using blue rod boxes, but it can be anything really. A solid base for your roller coaster to sit on is key to keeping the track from moving around while the train is running. If you can keep the track work sturdy, this will help maintain as much speed as possible.
After the base, I tend to construct a 1-2 foot long section of loose track. I then hold this track where I would like it, and build the supports to hold it. I find this way works the best to keep the track smooth as you go.
Step 4: Construction - Turn
Pretty much just like the loops, I found a reference picture and tried to recreate it to the best of my ability.
As you can see in the third picture, I started laying out where the base was going to sit for the next elements. I kept referencing the google map aerial view in this process.
Step 5: Construction - Corkscrews & Helix
Continuing onward with the corkscrews and brake run. Sadly I had to use a chain on the brake run as I was running out of speed.
Step 6: Construction - Station
The last little bit of construction. Stations always take a while for me to build as they consist of a lot of parts.
Step 7: Motor Mounts
Since the model was going on display, I wanted a stronger motor to power the lifthill. I did a CAD drawing for a motor mount, which then got CNC cut. The motor I purchased can be found here: http://www.mcmaster.com/#6142k46/=wrpy5c
I'm very happy with the performance of this set-up. It gives me a very sturdy system that works well with standard K'nex parts.
Step 8: Final Setup
Everything was taken apart into section's and transported to be put on display.
The base of the ride was made from 7 sheets of plywood, sonotube (tubes they use to make concrete posts out of) and some green carpet. It turned out well and was super sturdy. Overall dimensions were about 30 feet long x 6 feet wide x 4 feet high.
Having the train lubricated is crucial to keep your model running smoothly. I recommend silicone spray, use a little bit on each wheel axle. I tend to re-lubricate every month or so of continuous running.
Step 9: Notes
If you are looking to build roller coasters I highly recommend this website: http://www.sscoasters.net/ There are many tutorials for certain elements with helpful members who can guide you on the construction process.
Please leave a comment if you have any questions, I will do my best to try and answer them.