More filament cleaners!
This project has seen a lot of trial and error over several months but has been good practice in designing parts for glue-less assembly and ease of use. Hopefully it's useful and interesting to others.
Modifications / improvements made:
- Opening tabs moved to the longer edge for even easier opening
- Push-fit magnet pits with though-holes added for adjustment or removal
- Gripping and retaining ribs added into compartment to help keep foam in place
- Magnet depths of 6x3, 6x2 / 5x1, 5x2 (mm)
- Shorter “mini" versions of each size
Predictable safety message
Do not let young children be unattended around items with strong magnets that may come loose if played with, as they are harmful and potentially deadly if swallowed.
Printing Notes
- 0.2mm layer height, 2 perimeters work for all types.
- Use a decent amount of infill (such as 30% grid.)
- PLA or PETG are fine. (Not tested others.)
- Using a 0.6mm nozzle should work okay but keep the perimeter widths low or small details may not be resolved so well.
Assembly
- Press one magnet in firmly. A flat-bladed screwdriver can help with this, or pressing the corner down onto a flat hard surface.
- Stack another magnet on top of the seated one and press together with the other half. Repeat this for the last two corners.
- Cut some 3mm polyurethane foam to fit the cavities and press in.
Fit issues:
- If the halves don't meet flush when closed, then check for retraction blobs on the top layers and inside the magnet pits and clean up.
- Choice of filament can make a difference to magnet fit - it's possible that the magnets may not seat tightly, or even be difficult to press in. If so, then try altering the flow rate of the print to make the extrusion a little thicker or thinner to compensate. Or try a different filament.
- There are tiny variations in diameter and depth between makes of magnets that can cause fit problems. Cheaper ones are more likely to be less accurate.
- Deeper magnets have a better chance of staying in place when push-fitted.
- It's not necessary to use a very strong grade of magnet (such as N52) as they may stick so tightly that they pull out of one side when opening. Lower strengths can work just fine on a certain print where a stronger type will cause a failure.
- In any case, there is the option of using glue. Two-part epoxy is fine.
Geoff
