Fully Customizable, 3D Printed Marble Track

THIS PROJECT IS A PROTOTYPE AND IS SUBJECT TO CHANGE.

These are the parts that i made for my 2nd itteration of a 3d printed, customizable marble track. Alot of work went into this, although some parts arent "finished" as they require modification in a 3d modeler to fit your size criteria. (like the crank shaft for example) Im posting this as mainly scaffolding for other people to play around with. I fully intend to continue working on this to refine it and make it easier to build and print, however it may take a while as life gets in the way.

Here is a video showcasing my finished prototype.

materials needed are, wooden dowels which can be found at lowes, some 6-32x1/2 machine screws and respective screw nuts, which can be found at mcmaster.com screw nut and some hot glue. I tried to minimize the ammount of hot glue needed as i see it as a cheap, quick and dirty solution, but i couldnt find a better way to attach the supports to the base so oh well.

The actual track that the marbles ride on is the printer filament (1.75mm) bent to shape and held in place with the spacing clips. the way the clips are made allows the track to be held in place without the marble hitting the clips, slowing down. This allows you to bend and shape the track to go in any direction or angle the way that rigid peices wouldnt allow for.

The build requires some hardware such as screws, wood dowels and a wood base, although the base could be any material. The screws hold the joints together allowing you to change the angle the track is supported from while being able to tighten it in place.

There are some parts that arent of my design, specifically the chain links and the crank handle, those are parts from one of JBV Creative's projects that I had the files for and didnt bother redesigning from scratch. I also intend to eventually redesign these parts to better fit my use for them, but thats for future me to worry about.

As for anyone deciding to make a track using these parts, there will some building skills that would help, as the support for the marble lift is 2 wooden square posts that were cut to height with several holes drilled through them to allow for the shaft that the gears sit on to be held in place.

The file "Chain Gear Top" are the top gears which can freely spin around one of the wooden dowels that act as a shaft. The "Chain Gear Bottom" parts have a square hole so that they rotate in unison and are mechanically atached to the shaft "Crank Shaft 1". Connecting the crank shaft to the handle will require some modification in a 3d modeler to allow you to specifically choose what length the crank shaft is. the long end of "Crank Shaft 1" will connect to the end of "Crank Shaft 2" that does not have the peg sticking out of the top. however you decide to connect them doesnt really matter as long as it can handle the torque required without breaking. its also possible to use a dowel rod as a shaft, as thats an idea im exploring in the future. the peg on "crank shaft 2" interfaces with a part in the "handle parts" file allowing the handle to interface with the crank shaft. a restriction of doing it this way is that you can only rotate the handle clockwise. i intend to work on this in the future.

The chain links can be printed in place already connected. These are one of the parts JBV made and are not mine. I did get permission to share them. Connecting them is easy as they just snap together with a ball joint. the chain link scoop ive modified to better handle the pick up and dropping of marbles. There are 2 marble "stations", one for the bottom and one for the top. the bottom acts as marble storage when the track is not in use, holding 6, 1.5cm marbles. it also has 2 slots that the arms of the marble scoop go through to pick up the marble. the top station also works the same, instead in reverse with the marble hitting the top and rolling away before the arms of the scoop go through the slots. The "marble collection clip" file is a clip that sits in the openings of the bottom collection to allow a marble to roll in without hiting the sides. this is an area im looking to improve in the future.

As the track itself. the marble "rails" are lengths of 1.75mm printing filament that are bent to shape. coming off of the spool, the filament is very unwieldy and already in a tight coil. trying to use it in this way was awful to do and needed way more clips to hold it in place than necessary. a good solution i found was to cut a length of filament that you can stretch out from arm to arm and hold tight, and put that in a pot with around an inch of boiling water for like 4 seconds and take it out with a fork. it will be like wet spaghetti and will cool quickly, so take it and hold it straight and tight allowing it to cool. coming out of boiling water, its suprisingly not hot and i was able to hold it with just my fingers with no issue. dont pull too hard though as that will cause it to stretch, getting thin in spots which wont connect to the clips. repeat a few times and you should have some straight lengths of filament that are much easier to manage. from there you can easily bend them to shape with your fingers. dont bend in one spot though, instead grip it with your thumb and slide it through your fingers over and over until it gets to the desired bend.

the final tip is welding the lengths of filament together. for this i got some extra ptfe tubing, simmaler to the kind found on some printers and cut a length of a few inches off. putting 2 ends of filament together inside the tubing, i held a lighter underneath for around 20 seconds allowing the plastic inside to melt. then i pushed the ends together allowing it to cool inside. when it was cool, i was able to remove the tubing by sliding it off the end of the filament. this worked great, however left a slightly thicker part of track behind where the clips are too small to hold on. just put 2 clips on either end of the thick part and your set. something i figured out the hard way, is that because your sliding the tubing off one end of the filament, you cant start building the track from the top and bottom and meet in the middle, as there would be nowhere to slide the tubing to. you have to start from the top or bottom then slide the tubing off at the very end.

and as of me writing this i think thats it. ive most likely forgot to write something so as i get questions ill update here at the bottom. remember, this project is a prototype and i will be making changes and updating it in the future. if you still want to give it a try, please do, as it was realy fun to build. also send a picture if you do make one. id love to see. Good luck!