Roller Train!

Hey there, wonderful people! 

I really enjoyed putting the Roller Van together, but the obvious question was: how can we join a bunch of these together.  And so, the Roller Train was  born!  However, from a design perspective, it has a few differences.  Read on!

Most obviously, the wheels on this one are different.  The van had huge exaggerated buggy wheels, but that didn't really work so well for a train, so I went back to the (virtual) drawing board, and made small wheels with proper axles, rather than the hourglass shape of its predecessor.  Now, initially, the base of the engine and carriage extended down far enough that the axles were entirely enclosed, and that looked nice and neat!  What it added, though, was friction.

So, version two was an exercise in trimming away as much material as possible around the axle.  The base was raised, and void channels were added to reduce the contact area between the axle and body.  The wheel arches were also raised so that the wheels wouldn't end up rubbing against those, either!  See, the smaller wheels also mean less contact area with the ground, so they are at a natural disadvantage compared to larger wheels, so the friction aspects get really important.

The other obvious difference is that there are linking components to join the carriages together!  The front of each carriage overlaps the rear of the one before it, and a bolt slips through the top and fastens to the bottom, fixing the two carriages together but allowing them to turn freely against each other.

There are actually two differen bolt designs, one with a larger head, and one with a slotted head that could be used with some kind of bladed tool, like a screwdriver.  Just use the one you like best :)

Printing Tips

This thing is designed for straightforward printing - no supports required and no crazy angles.  However, as usual with articulated models you'll want to make sure your bottom layer is nice and neat, and that there aren't any print issues like stringing or overextrusion that might bind moving parts together!

The Engine and Carriage print on their sides, and the bolts sit head-down, like so:

File Locations

You'll find this one on Dropbox under 788 Roller Train

(Dropbox link post: https://www.patreon.com/posts/dropbox-and-are-31697592 )

Final Thoughts

I'm really resisting the urge to make the longest train I can, but it really does make me wonder what other kinds of designs would lend themselves to endless extension in the same way.  Marble runs?  Much, much larger geometric assemblies?  Tiny drawers?... 

Happy train-ing!

xoxo

Sven.