White Board Magnetic Marble Track by bamoore01

Last crawled date: 4 years, 1 month ago

The grand kids are getting bored during these CV-19 restrictions so we decided to do something fun. This is a work in progress and will be changing as time goes on as I add things or modify things. right now, I a pretty happy with the V4 that I have out here. I doubt that that will change much or even at all. If I do modify, it will probably be cosmetic changes where any new version will work well with the old versions.
What I've made are tracks that magneticly stick to white boards (that can be used with magnets), refrigerators (flat), or any other magnetic panel for marbes to run down. There are different lengths and shapes of track. You or the kids can rearange all you want. It is all made for a 14mm marble which seem to be a common size, and availlable on amazon (Amazon link below). The magnets that I am using are 15mm x 2mm fridge magnets (Amazon link below). I think the idea is pretty simple and straight forward so I won't spend any time on explanations of how to use it. Instead I'll just use a build notes section below to try to explain the how and why I did things the way I did and my results in different printing methods.
Build notes:
Materials. (The links work today. I can't make any claims that they will work tomorrow and if I will be able to update them or verify replacement parts)
Marbles: 14mm dia., https://www.amazon.com/gp/product/B07WP8JZSK/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1
Magnets: 15mm x 2 mm, https://www.amazon.com/gp/product/B07G48647D/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1
Design.
Joining holes in the end. There are 3 holes in the end of each piece to aid in joining multiple pieces together. I just use a short length of the PLA filament for that. Depending on your printer and settings you may have to ream them out with a drill bit.
Number of magnets required to make for good sticking power. I think I have extra holes in each section. For instance, the 100 mm straight piece has holes for three sets of magnets. I actually only use two holes with one magnet in each hole and it seems to work well but..... it has not been thoroughly kid tested at this point. In those three holes you can use up to 6 magnets total (maybe even 9) to increase the sticking power.
The spiral piece(s), front and back will have to be glued together.
Printing.
I tried printing on end and with the backs of the tracks to the plate. Printing with the backs to the plate worked the best for me and I optimized the design for that. Printing on end makes for a little bumpier track and the supports you need for the magnet holes can be a little messy.
Supports. Supports are not needed for most parts. Printing these pieces on their backs as they are oriented works well for the track pieces. The buckets do require supports when printing on their back.
I use PLA at 210 degrees for the print head and 60 degrees for the bed.
Post Print:
To put the magnets in, I just made a little ring of CA in the bottom of the magnet holes around the edges, dropped the magnet in, put it up against a piece of metal to pull the magnets tight let it sit till the CA cured. Seems to work well. If you decide to use a second magnet, it will hold quite well against the first one without any additional glue. Glue if you want.
One problem I ran into was the PLA slides easily against a white board. This can be helped a lot by putting a layer of electrical tape on the back of each piece. I found that Scotch 33+ worked well. Some electrical tape is fairly thick. The thicker the tape, the farther the magnets will be from the board resulting in a weaker grab. The 33+ is 7 mils. If you want more grab, a second magnet can be dropped into each hole. That helps a little.