Train V: Prototype
January 2022
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Train Specs:
1:35 scale Track Gauge: 26mm Length: 220mm Width: 43mm Height: 45mm Number of components: 476
Design Time: 45h Print Time: 10h Assembly Time: 20h Printer: Anycubic Photon M3 |
"Extreme Motorbike"
- Introduces an iteration on the Motorbike Coaster that allows riders to lay nearly prone throughout the layout
- Vehicle can navigate complex maneuvers including inversions, with tight corners and rapid transitions
- Utilizing the previous train's proven wheel and steering assemblies ensures consistent functionality
- Leveraging resin printing, more complex parts were able to be produced, in turn reducing the total number of components needed
*This vehicle was designed for riders who are ~35mm tall -- many adaptations would have to be made if this were to function at full scale*
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Resin:
Without FDM printing's downsides of unreliable supports and a minimum of ~0.2mm resolution, SLA allows much more complex geometry to be achieved at a miniature size. This train would not have been possible without the use of a resin printer. At a layer height of 0.05mm, even the smallest bolt details were able to be captured.
Although the results are stunning, the post processing and cleanup routine for resin printing can be lengthy and messy compared to FDM. Fumes during printing are noxious and toxic chemicals need to be washed and cured properly before handling the finished parts.
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Friction Elimination:
Bearings (marked in red) were introduced to replace sleeves that previously rotated solely about screws. This addition allowed the bogies and steering axle to pitch and yaw more smoothly and freely while still being fastened securely to the chassis spine. Cross section views visualize how the assembly fits together, with the hardware (in purple) sandwiching the bearing onto the axle and the bogie housing press fitting onto the outer race of the bearing with a few dots of Loctite.
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Bogie design was streamlined by printing the spine and guide wheel brackets all in one as opposed to the previous three pieces. This now ensures a consistent gap for each wheel to spin freely on its bearing.
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All bogie components were able to printed in two jobs totaling only 2 hours, 8 less than the 10 hours needed for a FDM printer to complete the same parts.
Chassis Assembly:
Each car's chassis is made up of 26 pieces and houses five ~4g tungsten cubes to add weight to the train. The steering axle assembly remains relatively similar to the previous train using a tie rod end as a pivot point as well as functioning as a hitch for the next car. Magnets hidden within the baseplate allow the seat assemblies to snap and hold onto the chassis when in the closed position.
Each car's chassis is made up of 26 pieces and houses five ~4g tungsten cubes to add weight to the train. The steering axle assembly remains relatively similar to the previous train using a tie rod end as a pivot point as well as functioning as a hitch for the next car. Magnets hidden within the baseplate allow the seat assemblies to snap and hold onto the chassis when in the closed position.
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A total of six 3mm OD magnets are positioned within each seat assembly to allow the stages of the loading/unloading procedure to be visualized reliably and consistently.
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The above version of the train remained white and unpainted as it was primarily used to verify tolerances and for initial testing.
Two additional trains for layout operation were printed and painted once the white prototype train was finalized.
Two additional trains for layout operation were printed and painted once the white prototype train was finalized.
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