If you like this thing, please, please subscribe to the 3D Printing YouTube channel "Ethan Makes". The kid really needs your support, and his goal is to reach 500 subscribers:
Just in time for Christmas. Those magnetic construction toys that you've seen around.
Watch an entire make of these: https://youtu.be/1idFaioi5L8
I grew up playing with Lincoln Logs. I'd always run out of the regular sized pieces. Even after eminent domaining my brother's set, I'd still always run out. Well, what if your mom or dad could just print more of the pieces that you needed? That's what I'm talking about.
Maybe you don't need so many squares, but you need a ton of triangles. Print what you need. Reclaim the magnets from the ones that you don't use.
I'll slowly be adding other pieces, but if there are some pieces that you really can't wait for, please leave a message and let me know.
If you make these, please don't just share photos of your prints. Instead, share photos of the shapes that you "make" from them. Thank you.
While I figured out that I could print my own magnet toys at about half the cost of the retail ones from say, Target, I did end up finding out that you can buy the toys quite a bit cheaper directly from China via eBay and Ali Express. So, this didn't really end up being about the cost, but about the ability to print as you go and print what you need.
- I found that the printed pieces work better than the retail ones. The layer lines actually aid in lining up the pieces and make the structures a bit more sturdy.
- The retail toys are glued or riveted together. With the printed ones, the magnets are "permanently" embedded.
- You can store some of the magnet toys on the refrigerator when you're not playing with them. They make nice refrigerator magnets.
- Since they're enclosed, they also make nice bathtub toys, especially for cast iron tubs.
Preparing Your Printer:
You may need to modify your printer by replacing metal parts that might pull up the magnets.
For my Monoprice Maker Select (Wanhao i3 clone), I removed the metal fan duct and replaced it with this plastic one that I designed:
A typical brass nozzle does not attract the magnets, but if you have a stainless steel one, it might be a different matter.
Pausing the Printer:
You'll need a way to reliably pause the printer at the proper layer. You'll want to pause the print at the layer where it caps the magnet holes.
For my Monoprice Maker Select (Wanhao i3 clone), I use the plugin that I wrote for Cura:
Inserting the Magnets:
Insert the magnets in the holes and use additional magnets outside of the print to hold the inner magnets in place. Otherwise, the magnets might fly up and attach to each other when your printer jerks (changes directions quickly).
If you're printing these for anyone under 3, I recommend using ABS, which is very strong and will bend before it breaks. PLA is brittle and will crumble. If you use PLA, your toddler may be able to more easily remove the magnets and swallow them, which is VERY dangerous. If you're at all concerned, don't give these to toddlers. Warn your kids that swallowing magnets can KILL them.
Keep the magnets away from anything with a screen or magnetic based memory (like your printer's SD card), or phone. I lost the contents of one SD card already. I don't even know what I did because I obviously wasn't paying attention.
Printing in General:
I used 10% infill, but you may be able to get away with even less, depending on how well your printer bridges.
The holes are 0.8mm away from the walls, so these models are really designed for 0.4mm nozzles (two perimeters). However, your slicer should be able to make the adjustments if you're using a different sized nozzle. If not, let me know, and I can whip up some other files. I tried a single perimeter to get even stronger magnet action, but you could see the magnet through the plastic, which made it unattractive, and it didn't look all that safe.
For the larger pieces like the pentagon or hexagon, you may find that you need to use a heated bed to keep the part from warping up off the bed.
The triangle piece is rotated to best print for slicers that use 45 degree top layers like Cura. Keep it rotated unless you know what you're doing.
4x9mm Diametrically Magnetized NdFeb Magnets:
250 4.3mm * 8.9mm (AliExpress)
100 4.3mm * 8.9mm (Ali Express)
~50 3.9mm * 8.9mm (eBay)
The larger ones are theoretically more powerful since they have more volume, but I couldn't tell the difference by feel. The ones from AliExpress take about 40 days to receive in Ohio, whereas the ones from eBay take about 15 days.
Make sure that you're using Diametrically Magnetized magnets, where the poles are on the sides of the cylinder, not the ends, otherwise your toys will be weak and fall apart, and your kids will cry.
It's important to use cylindrical magnets that can rotate in the holes to automatically align themselves.
If you find a better deal on the magnets, or similarly priced but in the US, please let me know through a private message. Please do NOT spam the comments. Thank you.
3.9mm * 8.9mm = 425mm volume
4.3mm * 8.9mm = 517mm volume