Metal Torsion Spring Maker

DISCLAIMER: BENDING AND CUTTING SPRING STEEL POSES RISKS OF BODILY HARM. WEAR APPROPRIATE FACE AND HANDS PROTECTION. PROCEED AT YOUR OWN RISK.

Hi, I made this tool to prototype springs for my Spinal Hair Clip product. I was able to consistently create metal torsion springs that look and perform like factory-made springs. This tool allows you to prototype the diameter of spring steel, number of coils, length and direction of arms, direction of wound, overall size, and overall “feel” of the springs for your project. 

The following stl file, materials, and steps are what I personally used that was able to cover a wide number of applications such that I have never needed another variation, your use may vary. Other variations are very easy to make as the stl print is pretty much just a handle.

VIDEO TUTORIAL:

HOW TO MAKE METAL TORSION SPRINGS (IN 1 MINUTE)

https://www.instagram.com/p/C_3zaHtSZz4/

MATERIALS:

• PLA (or other rigid printing material)
• Dremel w/ Metal Cutting Disc (or other tool able to cut spring steel)
• 2.5mm Stainless Steel Rod
  • Rod 1 = 6cm
  • Rods 2/3 = 2cm each
• Eye Protection Glasses/Facemask
• Cut Resistant Gloves
• Glue (optional)

• Stainless Spring Steel Wire
  • I generally use between 0.8mm and 1.6mm
  • A variety pack is good for testing

TOOL ASSEMBLY STEPS:

1. Print two “Torsion Spring Makers”.
   • I used an Ender 3 V3-SE, Overture PLA, standard PLA settings in Cura, 20% infill, holes facing up orientation
2. Cut 2.5mm steel rod into one 6cm rod and two 2cm rods.
3. Insert 6cm steel rod into the centre hole of one of the Torsion Spring Makers (TSMs).
4. Insert 2cm steel rods into the outer holes of the TSMs.
   • Rods should stick up about 1.5mm above top
   • Shorter protrusion from the top will be easier for the initial turns but higher gives you more flexibility of spring steel diameter
   • Hammer into place and secure with glue if necessary

TOOL APPLICATION STEPS:

1. With the male TSM in your left hand, insert spring steel wire at its middle between the inner and outer rods.
2. Insert the female TSM with your right hand and make contact with the TSMs outer rods.
   • Left Hand Wound
     • Position the female outer rod slightly clockwise to the male outer rod
   • Right Hand Wound
     • Position the female outer rod slightly counter-clockwise to the male outer rod
3. Continue turning the female TSM with your right right in your desired direction while maintaining constant squishing pressure on the coil to keep the coils tight.
   • While turning just the first coil, use your left hand to apply pressure towards the left on the rod length that first makes contact with the male outer rod
   • This keeps the first spring arm out of the way until you make clearance space from the coils
4. Remove the spring after turning the desired number of coils, leaving some time for the spring to cool on the inner rod to prevent warping.
5. Cut the spring arms to desired length.

TOOL TIPS:

• With smaller diameter spring steel (around 1.0mm), you may be able to start bending from one end of the rod (instead of the middle) or are able to flip the rod to bend the other unused straight side of the rod. Larger diameters tend to only let you turn the shorter side of the rod. With some testing, these can help reduce waste.

APPLICATION TIPS:

• I generally insert a 1.6mm Stainless Steel Rod to secure my spring. You can use various diameters but it must fit inside the coils of your spring with room to spare as the amount of angular deflection changes how much the spring compresses towards the rod.
• Leave a bit of space above and below your spring as torsion springs lengthen when undergoing angular deflection.
• Ensure the free position angle of your spring allows for “pre-tension” so you have continuous tension and no “dead spots” for your application.