Auto Retracting Utility Knife

For safety purposes, I designed this utility knife with an automatic retraction system using a spring from a pens. I hope the springs all have the same dimensions.Spring Dimensions :Lo = 25 mm x 4.2 mm x 4.2 mm .Assembly stepsStep 1 :Insert the 3 blades in the printed part .Step 2 :step 3: step 4 : step 5:Step 6:Don’t slide the part. Clamp the two pieces together until you hear the click.“If there is a problem, try rotating the arm so the gearing can lock into place.<img src="https://makerworld.bblmw.com/makerworld/