Individuals with limited dexterity due either to problems with muscle control or to joint pain can have difficulty lacing and tying their shoes. These magnetic shoelaces, originally designed by the Ruiz brothers at Adafruit, make it possible to easily put on, tighten, and, later, take off lace-up shoes.
This design improves on their design by supporting bar magnets of any size (much less expensive and much stronger than the disk magnets of the Ruiz design), sealing the magnets in a protective shell, and supporting shoes of various sizes (distance between lace holes vertically and horizontally). All of that is possible because the design has been implemented in OpenSCAD which is a programming language for 3-dimensional objects.
First Things, First:
Before you begin, you’ll need to go to the Printables page for the magnetic shoelaces designer. If, instead, you want to use OpenSCAD to do your design, you’ll need to download “magnetic_shoelaces.scad” from the “Files” tab. Follow these instructions to download OpenSCAD and open the magnetic_shoelaces.scad file for customization.
Customizing the Magnetic Shoelaces:
The customization options are organized into categories.
You’ll want to go through the customizations from top to bottom. Here are the customization categories that are available:
- The Shoelaces category contains options that describe how far the lacing holes are from one another on your shoes and how big a hole will be needed to pass the laces through.
- The Block Width category contains contains a single option that describes how wide you would like the block to be.
- The Magnets category contains options for describing the magnets you will be using and how you want to incorporate them into the block.
Next, we’ll describe each section. Remember, the best way to go through these options is from top to bottom. If you’re using OpenSCAD on your computer and you’re lucky enough to have a newer computer with OpenGL 2.0 or above, you’ll see the changes as you specify them. If not, you may want to wait until you’re done to “Render” your design since it can take a while.
Describing your Shoes and Shoelaces:
The Shoelaces category of options looks like this:
The “inter lace distance” is measured in millimeters and is the distance from the center of one eyelet to the next. In the picture below, the distance is approximately 20 mm.
The “lace hole diameter” is also measured in millimeters and you can use the eyelets on your shoes as a good starting point. In the above picture, the hole is about 5 millimeters in diameter. Remember that we’re looking for the size of the hole in the eyelet not the outside of the metal grommet.
Setting a Preferred Block Width:
The Block Width category has a single option:
The magnetic shoelaces are made up of two blocks. This option allows you to set what you’d prefer the width of each block to be. In the end, the size of the magnets you choose and the size of the lace holes will play a significant role in determining just how thin each block can be but you can make the blocks wider using this option.
To get an idea of what an ideal block width should be measure the distance between the two flaps with your foot (and sock) in each shoe. In the picture below the distance between the two flaps is about 28 mm.
An optimal block width for this distance would be 14 mm (one-half of 28 mm). That might not be achievable based on the size of the magnets you choose and the size of the lace holes but you can state that as your preference.
Describing Your Magnets:
Note that you don’t have to wait to purchase the magnets before you use the program. You can use the program to trial some magnet sizes before you actually purchase them. If a magnet produces a block that is too long or too wide you might want to look for something that is more compact and equally strong.
The Magnets category of options looks like this:
There’s only one type of magnet that is small enough and yet strong enough for use in this design. They’re called “rare earth” or “neodymium” magnets. For the example shown in the picture, we used bar magnets that are 20 mm long, 5 mm wide, and 3 mm thick. You can obtain neodymium magnets in cylinder or disk form as well but they will not perform as well as bar versions and they will, likely, cost more as well.
Note that you can place two bar magnets back-to-back and produce a magnetic force almost as strong as with a single magnet that is twice as thick:
We use paired magnets, back-to-back, in the example here but you may find a deal that makes a thicker magnet worth the money. The folks a K&J Magnetics have a magnetic strength calculator to help you choose magnets of appropriate size and strength based on the force that you need. When using the calculator choose the widest side (of the width vs. thickness) of the magnet as the width, and use 2 mm as the distance between the magnets. [When inserting magnets into our design always face the widest side out for the best results.] Press the “Calculate” button and look at the “magnet to magnet” pull force (case 3). That’s roughly how strongly the two blocks will attract each other when the blocks are assembled.
Depending on the length and strength of the magnets you choose and the distance between lace holes (there will be three lace holes in the block), you may want to go with one or two magnet slots.
The default choices for all options produces a block that looks like this:
It’s made up of a block that will hold the magnets and is drilled for the shoelaces to go through. The other part is the cap that fits on top and holds the magnets in place.
Note that the STL file contains both the base and the cap. If you need to print them separately (as we did when we created the multi-color version of the block pictured above), use your slicer software to “split” the two objects and then delete one of them before producing the gcode.
The cap also prevents the magnets from coming into contact with each other. Neodymium magnets are very brittle and can shatter or chip very easily if you allow them to come together with all the force that they are capable of – so handle them carefully:
Assembling Your Magnetic Laces:
Once you’ve printed the base and caps (you’ll need four of each), get the magnets ready for insertion into the base. You’ll need one or two magnets for each slot depending on the configuration you’ve chosen. In our example, we are putting two magnets back-to-back in each slot of the four bases. Two magnets in two slots in each of four bases requires a total of sixteen magnets.
To ensure that the magnets would attract each other properly when the blocks were finished we first arranged them into stacks of four.
The best way to separate a set of magnets from a larger block is to twist them before pulling them apart:
Now take a “Sharpie” and draw a line along the sides of the block of four magnets:
This will help you keep them in a proper orientation when inserting them into the two blocks. If they get out of alignment, you may end up with blocks that are repelled by each other with significant force…
Now bring all the parts together for assembly along with some superglue or epoxy (keep the blocks of magnets apart to avoid collisions and broken magnets):
Insert one set of magnets into one of the slots of one of the blocks:
Using the same twisting motion, remove the exposed magnets and insert them into the comparable slot in the other block – keeping the Sharpie line aligned with the magnets you’ve already inserted.
Repeat for the other set of magnets and the remaining two slots:
The bases should be kept apart so that the magnets don’t try to escape their slots until you’ve fitted the caps. Apply super glue or epoxy to the top of the base including the holes and the magnet faces:
Insert the posts on the caps into the holes on the bases. Hold or clamp the two together until the glue has set:
Once set, you can bring the two blocks together. If you’ve got the magnets properly aligned – which can be tough to do when they’re constantly trying to squirm out of your grasp – the two blocks will attach tightly to one another:
Give the glue sufficient time to cure before putting them on your shoes. The magnets are still trying to escape so don’t give them an opportunity.
Lacing the Blocks:
There are probably a thousand clever ways to lace the blocks to your shoes. This is just one of them (and not all that clever).
Unlace the shoes about 3 eyelet’s worth:
Run the laces up through the block and down through the shoe eyelet (you may want to do this while the blocks are stuck together to ensure that they’re in the proper orientation to each other):
Run the remainder of the lace down through the loops on the underside of the block:
Repeat with the other block.
When you insert your foot the blocks will separate to make room:
Give a swipe of your hand or stomp of your foot. The two blocks will snap together and hold your shoe on securely until you need to take your foot out again:
