by Jay Ducharme
(All text and images copyright Jay Ducharme 2018.)
Using the powerful and open-source 3D modeling tool Blender, I created my first model specific to Mountain Park -- the decorative rocket that sat to the right of the Satellite entrance. It was a really simple model to make, just three progressively smaller cylinders combined with three cones. My first print was so tiny it resembled a thumb tack. The second print was the right scale, but suffered from severe distortion near the top. So I needed to keep tweaking the printer's numerous settings.
After that test I dove right in and created one of the Satellite cars in Blender. I printed out a copy and realized the wings were too wide and the tail was too short, so I modified it in Blender and exported a new file. I tried printing it at different sizes and discovered that at the correct scale for the Mountain Park model, I couldn't get the tail to print; it was just too small. But at the larger scale, I was impressed with the amount of detail.
Next I created the car supports, which were attached to the tower. They were simple cylinders with flattened cubes at the ends. They ended up being smaller than toothpicks, but they printed fine. Then I created the ride's tower, complete with the air tanks that lifted the cars. There were twelve cars in all, and I found it a challenge to fit everything in. I printed it out and discovered that the tiny bottom supports were warped. So I lowered the print temperature and tried again, and that version came out much better, except for the globe at the top which was distorted. It was a series of compromises; I preferred a stable base to a perfectly spherical topper. Next I printed twelve cars at the correct scale, one after the other. Detaching the tiny objects from their plastic bases was a challenge. But after about a day's work, I had all the parts I needed.
I considered painting the parts with the acrylic paint I used on the model base, but acrylic on plastic would easily peel off. So instead I used the new set of Testor's enamel model paints I had purchased. The fumes were nasty, but the paint adhered like glue to the plastic pieces. I first consulted some color photos of the Satellite to make sure I was rendering it accurately. I started by laying down a sheet of wax paper and placing all the parts on it so they wouldn't stick to the surface. The first color I mixed was the sort of light yellow that was on the bulk of the cars. I had to hold the cars with tweezers and use a tiny brush while looking through a magnifying glass. It was difficult to keep my hands steady enough. (I guess next I'll have to invest in a 3D painter!) The wings and tail on each car had the same color as its arm and air tank (three separate colors). There were nice colored accents on each car, but those were too tiny to paint. It was challenging enough to get the wings painted.
The tower was easier to hold while I painted. I started with pale yellow on one of the air tanks, and when I got to the final tank it was only one away from where I started; it should have been two. I counted them and discovered I had created only eleven tanks. So it was back to the old drawing board. I had to modify the original model in Blender, shrinking and shifting each tank to make them all fit. I also lowered the tower's height a bit and then re-printed it. I was then able to finish painting it, one color at a time. The sphere at the top of the tower was actually a mesh globe. But there was no way I could make that in such a tiny scale. So I just painted the globe yellow. The last color I added was silver to the interior seat of each car. Then the painting was finished and I had to wait for it all to dry.
The paint remained a bit sticky, even days after. I did some research on PLA, the plastic filament used by the printer. I was surprised to learn that it basically was made of corn and sugar; it was completely bio-degradable. I had used model paint designed for styrene (oil-based) plastics. So for the next model I decided to try acrylic paint instead and see if that worked better. I attempted to glue the arms to the cars, something I really should have done before I painted them. I assumed wood glue wouldn't work, especially over the paint. So I tried Loctite cement for plastics and fabric, which was sort of like rubber cement. All it did was create a flexible rubbery film over the parts. And in my haste, I glued them all on backwards. So I pulled them all apart and moved on until I figured out a better solution.
Instead I started working on the ride opposite the Satellite: the Tilt-a-Whirl. I first building it in Blender. After a few hours of work that produced only half the ride platform, I hunted around online. I figured someone must have already built a digital model. And I was right; there was one available at TurboSquid -- for $50! It was a tug of war between my money or my time, and time won. I shelled out the money and downloaded the model. It was an absolutely beautiful rendering. I prepped it for my TEVO and set it to print at the correct scale. After about an hour, the printer had produced a pile of exploded plastic. There was simply too much detail to replicate at that tiny scale. I attempted a second print with different settings. The platform came out perfectly, but everything above it was a mess. So I created my own cabs, center, sign posts and railings in Blender and printed them individually. Then I cleaned up the platform. I did some research into gluing PLA, and the consensus was to use Locktite Super Glue Gel. So I bought a bottle and sure enough it worked perfectly. I glued the cabs on in random orientations to make it look like they were spinning. I printed out the actual Tilt-a-Whirl sign in scale and glued it to the sign posts. Then all it needed was paint. I continued to experiment with the Tevo. While I was waiting for it to finish a job, I turned my attention back to the Satellite. This time, I brought out my hot glue gun. I squeezed as small a blob as I could onto one of the tiny jets and then placed the arm on it. The blob was too large. I tried trimming off the excess glue when it dried, but that was tedious. I assembled four that way, then I tried a different method. Instead, I placed a blob of hot glue onto my aluminum drip pan, then dipped the arm into the blob and immediately affixed it to the bottom of the jet. That worked really well, melting the end of the arm and basically welding it onto the jet. So I used that method for the remainder and was happy with the result.
Once again, I found myself getting side-tracked. I had found a Ferris wheel model online like the one at Mountain Park, just smaller. The park's was a 16-cab Big Eli model made by Eli Bridge back in the 1960s. The model had eight cabs. It also had a different support structure. So I gave a try to printing it out, and got nothing. The printer would initialize and then stop. I tried chopping up the model in Blender and printing out just pieces, but that didn't work either. So I hunkered down and designed my own Big Eli Ferris wheel. I first printed out each side, with the sweeps already attached to the hub. Then I made a strut (a simple triangle) and printed two large and four small for the side braces. I made my own simplified cabs in Blender. I tried putting more detail into them, with the curved guards like on the original wheel, but once again they wouldn't print at such a tiny scale. So I printed 16 tiny versions and then began gluing them to one of the sides.
My micro drill set arrived and I wasted no time setting it up. I drilled indentations just above the air canisters on the Satellite tower, each one at a slightly different angle. I started by attaching the red jets. Sometimes the glue would hold and sometimes it wouldn't. When I got all four of the red to stick, I left them alone to dry. I kept them low because those were my first attempts with the hot glue gun, and they had large blobs of glue underneath them. The next day I finished attaching the rest of the jets, and the Satellite was finished.
I turned my attention back to the Ferris wheel. When one side of the wheel was dry, I began painting the cabs. Instead of the enamel paint, I switched back to acrylic. The original cabs had alternating colors: red on the back, blue on the bottom; then blue on the back and red on the bottom. There were other graphic details on them, particularly the numbers. But those details would be impossible to see, so I didn't bother trying. The acrylic was easier to work with, but didn't adhere very well. Once I finished painting the cabs, I glued the other side in place. When that dried, I glued on one of the struts and once again waited for it to dry. Then I stood up the ride and glued on the other one.
Next I finally began painting the Tilt-a-Whirl, working from the inside out. As with the Ferris wheel, there were painted details on the cabs. I put little dots of yellow on their backs, and that was as much detail as I included. I didn't paint the sides of the ride so that I could glue the railings in place. Once the paint dried (which was much quicker than with enamel), I glued on the railings. I wasn't very happy with the look of the acrylic, so for the bottom section of the ride I switched back to the enamel paint. It had a much richer and more saturated appearance. The last paint I applied was silver to the railing supports. The difference between the color of the enamel and acrylic was obvious. It would be the last time I used acrylic on plastic.
Painting models was never my strong suit. I always enjoyed assembling them, but I was never any good at painting them. My hand was never steady enough. The Satellite wasn't too difficult because it was all separate pieces that were simple shapes. The Ferris wheel and Tilt-a-Whirl were pretty much assembled when I painted them, and they had more complex shapes. In any case, I considered them finished. There were still a couple details I wanted to add to the Tilt: an awning above the entrance and railings around the operator's station. And the railings around the Tilt actually followed the rolling contour of the ride platform, yet mine were straight. But in two days the National Carousel Association was having a big convention at the Holyoke Merry-Go-Round, and I wanted to get the rides installed for that event. I wasn't yet sure how I was going to affix the plastic to the Homosote. I decided to do a test with the clear Elmer's to see if that would work, taking a spare plastic piece and gluing it to a Homosote scrap. The next day, it popped right off. So I tried the Loctite cement (not the Super Glue), and that actually seemed to hold really well. So I decided to try that on the model.
As it turned out, I didn't get a chance. I went to Heritage Park for the National Carousel Association's visit to the Merry-Go-Round on September 15. Over 200 enthusiasts were there in the morning, and I got a rare chance to turn on the Artizan Band Organ. I had brought the three model rides along, figuring I could get into the Visitor's Center to install them. But no one showed up to open the building. So I took them back home.
Over the next week, I tackled the Tempest, the ride we lovingly referred to at the park as the Puke Machine. When I broke it down into its component parts, I discovered that it was pretty easy to construct in Blender. The deck was a simple slanted cube with another cube at the thin end. The octagonal cabs had sides were made of a steel mesh, but I knew that would never print at such a tiny scale. So I made the sides solid. I created bench seats inside. The umbrella-like tops were the most complex to make and took the longest. I even created the signposts that stood between the cabs.
I printed out all the pieces, along with a couple more Satellite arms to use as the umbrella posts in the cabs. I couldn't get the cabs to print properly; at that scale, the printer filled in the interior. And the arches over each section didn't print. So I left it that way. The micro-drill set came in handy to poke a hole in the center of the cabs for the umbrella posts. I glued the pieces together and let them dry. Later on that same day I painted them. I found that using a bamboo skewer as a brush worked really well on the tiny parts. Once they were painted, I had to again wait until they were dry to continue. The next day I was able to glue everything together. That gave me a total of four rides completed, with just 24 more to go.
On September 19, I brought the four models to Heritage Park. This time it was open. So I glued the rides in place with the Loctite cement. Charlie was really impressed with them. I once again urged him to get a cover on it so nothing would get damaged.
And with classes in full swing, my progress on the model would slow down. I was thinking of next making the tunnel entrance and bridge for the miniature train. And maybe I could make the train as well. If I did that, along with the Sky Ride mechanism and the Mountain Flyer station, that would complete the north end of the park. With the 3D printer, I now had a lot of interesting options.