Mag?CUBE : Magical Magnet-force Cube

mag?CUBEs are NOT simple building blocks, they can be built on its side or bottom face by magnetic force. BUT mag?CUBEs need NOT to be built on opposite polarity face of magnet, they can be chucked with each other on any faces.
Cube with magical magnetic-force, its the reason why named mag? to this 4cm square CUBE.

mag?CUBE can chuck only another one, though it inspires us much more than conventional blocks. How about making your mag?CUBEs for/with your family?
If you can use certain laser-cutter, you can make this 4cm-square mag?CUBE without magical techniques. Magnets can be gotten at one-coin shop (thanks such shops in Japan).

materials and parts for 27 cubes

1. MDF(Medium density fiberboard)
   • thickness 2.5mm
   • 730x436mm 1pc (maximum work size for the laser cutter which I used)
2. MDF(Medium density fiberboard)
   • thickness 5.5mm (used for jig, substituting 2.5mm for 5.5mm is available))
   • 200x150mm 1pc (2pcs if substituted 2.5mm)
3. magnet
   • 162pcs ( = 27cubes x 6 faces)
   • cylindrical form - dia 6.0mm x thickness 2.5mm. magnetized on one flat suface as N, and another as S.
   • according to the package printing, magnetic flux density=220 mTesla. Suppose to be a Neodymium magnet. This shall be minimum, stronger magnet is better. Ferrite magnet is too weak for this use.
   • 8 magnets a package is sold at one-coin shops in Japan, 100JPY in 2020. Thanks to this reasonable price.
4. adhesive
   • instantaneous adhesive: gel type; usable for binding MDF and MDF
5. cotton swab
6. toothpick

tools

1. laser cutter
   
   • I used Trotec Speedy 300. Attached drawings are layouted for this. You may need to modify them for the cutter you will use.
2. clump; 3pcs or more
3. hummer (rubber head is desirable)

IMPORTANT: Before cutting out all parts, confirm the press-fitting strength and engraving depth. I recommend you to assemble two cubes before cutting out all parts to confirm press-fitting and magnetic force.

For your reference, measured actual press-fit-margin and engraving depth data is attached (file: calculate kerf-loss and press-fit-margin.pdf). This press-fit-margin may be a little too hard to assemble, but I’ve never experienced broken-up without adhesive even if a cube is falling on wood floor.

1. Cutting out from MDF thickness 2.5mm
   • cube face: 3 kinds of shapes x 2pcs / one cube
     • To assemble faces securely without adhesive, they are press-fitted hardly. You may need adjust the size of fitting.
       IMPORTANT PROCESS: Before cutting out all parts, confirm the press-fitting strength and adjust size and/or laser-cutter parameters. Assembling with adhesive is available.
     • Mad black square of the cube-face.pdf file means engraving area. Adjust the power of laser cutter to engrave its depth between 1.2mm and 1.5mm.
       IMPORTANT PROCESS: Before cutting out all parts, confirm the depth of engraving and adjust laser-cutter parameters. Shallow engraving leads to week magnetic force, deep egraving may lead to fragile face. Too weak magnetic force to chuck another cube is not available.
   • magnet case: 2 kinds of shapes. magnet-case-with-hole:3pcs & magnet-case-without-hole:1pc / set * 6 sets / cube
2. Cutting out from MDF thickness 5.5mm
   
   • jig: 1pc (2pcs, if substituted 2.5mm for 5.5mm)

1. remove burnt residue on the engraved area using cotton swab.
2. make a jig for assembling magnet case
   
   1. cut three toothpick to length 13mm(= total thickness of assembling MDF 5.5 + 2.5*3)
   2. insert toothpicks into the holes of jig with adhesive.
      (if substituted 2.5mm, pile up 2 pcs and adhere before insert toothpicks.)
3. assemble magnet cases on the jig
   
   1. adhere magnet case parts on the jig. Pile up three magnet-case-with-hole and a magnet-case-without-hole on the jig.
   2. clump the case assy on the jig, and remove. clump the center of the magnet case assy for curing time.
4. adhere a magnet case to a face
   
   1. set a manget on the engrabed area center.
   2. adhere magnet case on the face
   3. take care not to contact magnet with adhesive

   4. clump for curing time.

5. assemble faces
   

   1. before assmbling, shake the faces with magnet case and hear the sound, to confirm magnet shaking freely.

   2. firstly, half press-fit (not press-fit completely) all faces.
   3. secondary, press-fit gradually on each press-fits by fingers.
   4. finaly, press-fit completely using a rubber hummer.
6. check
   1. shake and hear the sound to confirm magnet is shaking freely.

   2. confrim each faces can be chucked by another cube.

Please watch “playing Demo” video on the top of this document.

My mag?CUBE can chuck another one on its side or bottom face. Even only one but it inspires us something much more than conventional blocks.

Make your mag?CUBEs for/with your family and have a nice time!

(Just for your reference, chucking more cubes requires stronger magnetic force and/or lighter weight. Deeper engraving depth, smaller cube size, stronger maget may be considerable.)