Safety Box Opener (Uses Bambu Scraper Blade) 

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Minor Updates 13-Sept-2024 (Be sure to use Print Profiles ending ‘v1.1’ and thanks to everyone for the suggestions & such positive feedback!)

• Added a hole at the tail end to enable you to hook onto whatever you like :)
• Improved spring tension by thickening it slightly in areas
• Optional location for a metal spring from a pen (aprx. 4mm Diam. x 22-25mm Long) should you wish to use instead
• Improved tolerances by adding small chamfers to edges of pivot hole & slot (combats first layer squish variations)

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Note: A second variant of this model that accepts standard Utility Kinfe Blades, can be found here.

This uses the scraper blade and screws that are supplied with all Bambu Lab printers…. so the chances are you already have the hardware required for this print. But links to the items can be found at the bottom of this page if you want to source them.

Frustrated with other options, I really wanted a truly ‘fit for purpose’ tool to open parcels & boxes with. Too often I will just grab a pair of scissors and use with the blades opened (and grasped in hand!)… so safety was also a key consideration here.

The Bambu Scraper blade seemed the perfect fit as while it is pretty darn sharp, its not quite as deadly as a craft / Stanley knife blade. I also figured most of us Makerworld folks would already have one (or more) of these kicking around now, and rarely use them to actually remove prints given how good the sprung build plates are these days…. so, this model aims to put these blades to good use while solving a universal problem….. opening those pesky taped up boxes!!!

Key Features:

• Blade always returns inside the handle courtesy of a printed ‘flexure’ trigger return spring. So no need for a metal one (tested many versions to get one that won't deform… even when using PLA).
• Handle cover plates simply snap fit into place, and can be removed (if needed) using the flat screwdriver slots provided around the perimeter.
• All items print with zero support, and no additional hardware is needed other then the Bambu Scraper items. 

Makes for very satisfying assembly and use!!! Will also fit on any BambuLab printer including the A1 Mini… enjoy :)

Assembly: 

1. Insert the 2x Bambu Screws (2.6x8mm) through the right hand trigger retainer (this is the one with counterbored holes to accept the screw heads and so they end up sitting flush). The screws should pass through unhindered, but a few turns with a hex screwdriver may help to ease things in.
2. Add the Bambu Scraper Blade with its tapered edge facing the trigger retainer and by locating the holes onto the screws. Again the screws should just pass through.
3. Attach the left hand trigger retainer by locating the screws into the untapped holes and slowly doing them up…. best to do this a few turns each at a time to keep everything square as it tightens.
4. Add the Trigger return spring onto the assembly by sliding it in from the front, and so that it ends up sitting against the front face of the scraper blade. Please note: orientation of the spring….. there is an offset slot that should only allow this to be done one way. 
5. Insert the above trigger assembly into the right hand cover plate by locating the two screw bosses into the corresponding slot & hole in the plate. Be careful to also place the spring in its correct position between the two locating lugs. 

6. Attach the left hand cover plate, which should index together (sandwiching the trigger & blade assembly) and then snap fit into place around the permitter.

   ***See also the animated GIF (above) & exploded assembly BOM below***