This is a ratcheting device that replaces traditional shoelaces, saving the time and effort of tying your shoes. In addition to the 3D printed parts you will need some steel 0.5mm fishing line (I am using SurfStrand brand 0.5mm 7-wire braided fishing line), a few sewing pins, and two small springs (diameter < 5mm) for this project.
For your first go round I would recommend printing the pieces individually, starting with the following order:
This will let you check the fit of the pieces as they are made. The gaps between the pieces are quite small so if your printer isn't extremely well calibrated you might need to play with their scale using your slicer (or the parametric Fusion360 model) to nest all the pieces so they rotate freely without wobble.
Each unit requires one of each printed part.
Pictures to clarify assembly steps coming soon!!
Matterhackers Build PETG
You will need to have a well-calibrated machine to print this model properly, the tolerances between many of the moving parts are around 0.1mm. The Fusion360 model that is downloadable is parametric though and the tolerances between many of the major parts are adjustable in the parameter table under "user parameters."
The only very complex parts are the Release Mechanism & the Spool due to their sets of ratcheting teeth, so I would recommend favoring quality over speed in these two prints.
I have been using PETG for all of these parts but I'm sure PLA is probably find too.
Use a 0.1mm layer height (or smaller) for the following
- Release Mechanism (Use supports, Orient so hexagon points up)
- Spool ( Use supports, Orient so spool opens upwards)
Use either 0.1 or 0.2mm layer height for the following
- Pawl (Play around with the infill to determine ratcheting "drag")
- Spool Holder
Remove Elephant's Feet
The diameter of these parts is very important, so you will have to remove any of the squished first layer so that they can fit properly. If your printer is calibrated against this skip this step. Don't worry about taking off a little extra material, it won't matter with this design.
Take the laces out of your shoes and cut a piece of your fishing line to roughly the same length, no need to be precise here.
Thread it into your shoes so that an even amount is leftover on each side. Don't tighten the new laces, if they are already tight loosen them to the point where you could easily slide your foot into the shoe without pulling the laces.
Measure about 5" of line from the last eyelet in your shoe & cut off the remainder (do this on both sides)
Fold over the last 3/4" of the line & twist it tightly to create a tight closed loop. Cut off excess wire.
Measure the height of the spool you've printed. Now cut two small pins out of a sewing pin that have the same dimension. If you can't be very precise it's better to have a slightly shorter pin.
Using a new sewing pin, locate the small holes that run through the spool. Force the pin through the holes to enlarge them so that the smaller pins will fit snugly.
Set the pins aside in a small dish so you don't lose them.
Run the looped ends of the fishing wire laces through the holes in the Spool Holder part.
Grab the spool & one of the pins. Insert the pin halfway, then slide the loop of one end of the laces over the pin. Finish pushing the pin through the spool so that the shoelace is attached to the spool. Repeat this with the other side of the lace.
Using synthetic Silicone grease, lightly lubricate the inside of the spool holder, the release mechanism, & the top of the spool.
Push the pawl into place on the hexagonal post inside the spool holder. Make sure that it's orientation is right based on the direction the Release Mechanism will rotate (check the internal teeth). This should be a nice tight push fit so it stays in place.
Insert the spring into the central hole of the Spool Holder.
Insert the Release Mechanism into the spool holder so that the spring goes into it's central hole.
Place the spool over the Release Mechanism to hold it in place. You will have to do some shimmying to get the metal line to clear the bottom lip of the spool. It helps to rotate the spool 90 degrees so the lace anchor pins don't line up with the holes the laces pass through.
Place the Dial over the top of the spool so that the nubs face outwards. Snap the Cap into place over the Spool Holder, ensuring that the slots in the Cap line up with where the laces exit the assembly.
Testing & Usage
You should be all set at this point! Turn the dial clockwise to see if the laces winch in. Then press the center button & pull the assembly away from the shoes to release.
The 3D printed parts aren't strong enough to tighten the shoes by spinning the dial. Pull up on the entire assembly to cinch shoes, then retract the laces to keep them tight. To release just pull up on the assembly while pushing the button, then redistribute lace slack along shoe so you can slip it on/off easily.