Refillable Safe (Balloon) Cutter Knife

**** Hook-Blades are not standardized - brands/modells differ in sizes.

 Currenly follwing brand/modell are supported

• wolfcraft 4189000 I (e.g. Germany)
• STANLEY 1996 (e.g. France, GB, USA)

Choose the available model file according to the blades you are intending to use ****

I'm a balloon twister and decorator and I've used safety box cutters for a long time. Those knifes provide a good amount of safety for myself and for the balloon sculptures and decorations . 
Downside of those knifes had been the limited availability where I live and when the blades went blunt, you have to throw it away. 

So I was looking for a more sustainable refillable blade carrier which uses widely available cutter blades - this is what I came up with….

To build this you need following items:

Items which you can print:

• 1x Safe(Balloon)Cutter Base
• 1x Safe(Balloon)Cutter Flap (normal or countersunk)

Items you have to buy:

• 2x chopping blades 0,65x51mm (Hackenklingen) - https://www.amazon.de/dp/B002OHKI4K?ref=ppx_yo2ov_dt_b_product_details&th=1
• 2x nut M3 - DIN EN ISO 4032 -  https://www.amazon.de/Sechskantmuttern-Standard-Ausf%C3%BChrung-Edelstahl-SC-Normteile/dp/B01H8XRSXI?ref_=ast_sto_dp&th=1
• using the ‘normal’ flap: 2x  button head screw (Linsenkopfschraube) M3x4  DIN EN ISO 7380-2 - https://www.amazon.de/dp/B0793NYQCT?ref=ppx_yo2ov_dt_b_product_details&th=1
• using the countersunk flap: 2x  countersunk screw M3x5 or M3x6 (https://www.rst-versand.de/Senkkopf-Schraube-Kreuzschlitz-M3-x-5-mm-A2-ISO-7046 or https://www.rst-versand.de/Senkkopf-Schraube-Kreuzschlitz-M3-x-6-mm-A2-ISO-7046 )

For printing I used a 0,4mm nozzle, 0.2mm layer height, no brim, no supports. I printed this design in PLA as well as in PETG on a Prusa MK3 and it worked.

Here is, how I did the assembling of the cutter:

If you shake the assembled cutter and you hear some ratteling noise, you can squeeze some paper or a piece of ballon between the upper blade and the flip as it is shown here:

The design can easily be altered (different colors) or personlized (text with the “TEXT” feature of PrusaSlicer):

I would be happy if you can leave me a like, post a make or give me any comment on your experiences with this piece… there is always a thing to improve.

Happy Printing!

Intended use:
This knife was designed to support ballon artists while doing twist and decoration work (cutting ballons, nylon, balloon packages..). This design was never intended to use in a hard working area - please be aware of this. 

DISCLAIMER:
Be aware that you are handling very sharp cutters blades. Please take care and use personal protection where ever this is needed. Always check the SafeBalloonKnife before use -  if the base or the flap is damaged, the screws are loose or anything else is wrong DO NOT USE IT.

Differences between wolfcraft and STANLEY version:

update 2025-09-29:

• new cutter base for stanley with a better tollerance → sbc_stanley-1996_prusesclicer_251029_optimized

update 2024-03-15:

• new cutter base for stanley with a better tollerance → sbc_stanley-1996_prusesclicer_240310