How To Remove Tap Using EDM Machine

Breaking a tap is incredibly frustrating, especially when the part it's broken in took a lot of time to make or is expensive. The broken taps are often incredibly difficult to remove and if it is successfully removed, wasted a lot of time.

It's not only taps, this also applies to broken drill bits, screws, sheared pins (that can't be pressed out).

Existing EDM broken tap removal machines are expensive enough that only a large machine shop might invest in one. Although making use of it only a few times would pay back for it.

Homemade Small Hole EDM for Under $20 (but does it work? The are using a solenoid which makes it retract automatically) - https://youtu.be/fRPmSgfIJqY?si=vXhnNk29SSmi_EAn

Poor Man's EDM - Simplest design that I have seen. Electrode is attached to DIY solenoid. When the electrode discharges, the power energizes the solenoid and retracts it.

• https://www.shopfloortalk.com/forums/showthread.php?t=32279

• http://www.youtube.com/watch?v=d9w-P8QAseg&feature=related

• http://www.youtube.com/watch?v=KjBjxWWh82E&feature=related

Jon Elson's Machining Page

• A Mini-EDM System

The Home Built EDM Machine

• https://homebuiltedm.tripod.com/

EDM Power Supplies

• https://rackrobo.io/products/PCV2

  • Has outputs for current that can be used to control the motor drive speed.

  • Only 180W

Commercially Available Tap/Drill Remover EDM

• This is a very cheap, simple, low power EDM machine. 180W, manual drive

  • "The diameter of the hole is 1-6mm. If the hole is more than 6mm, you can try to use a hollow brass tube. The depth of the hole is 8mm. If it exceeds 6mm, it is relatively slow. Because the impurities punched by the hole depth are not easy to discharge, it will cause discontinuous sparks. , thus slow."

  • The linear slide can be motorized using a stepper motor. Can the current be sensed to automatically control the motor speed or retract?

  • A water pump is needed.

  • Only 180W

• Least expensive EDM broken tap remover ~$500

  • Parameter:

  • Portable Broken Tap Remover

  • Model: EDM-400C EDM-500C

  • Voltage: AC220V 50/60HZ

  • Input Power: 400W

  • Output Voltage 80V

  • Electrode Range 0.8-10MM

  • Automatic travel 70MM

  • Processing speed ≈1MM/MIN

  • Features:

  • 1, With Φ1-Φ5 brass electrode

  • 2, It is suitable for taking M2-M12 broken taps, drills, screws, etc. with a

  • breaking depth within 40mm.