EDM 101 Tap Removal Guide

Removing a Broken Tap Using an EDM 101 Machine

Electrical Discharge Machining (EDM) is an effective method for removing a broken tap without damaging the surrounding material. This guide outlines the process and precautions for safely using EDM 101 to remove a broken tap.

Step 1: Prepare the EDM Machine

Before you start, ensure the EDM machine is ready and set up correctly.

1. Plan the job with a setup sheet Look at the setup sheet we use for all jobs here at TAPOUT TEXAS

2. Power off the machine and inspect it for any mechanical issues.

3. Install the appropriate electrode usually an electrode slightly smaller than the diameter of the broken tap.

4. Check the machine’s dielectric tank - dielectric fluid (we use distilled water).

5. Clamp your workpiece firmly to the machine’s bed or work surface, ensuring it’s stable during the process.

Step 2: Align the Electrode with the Tap

Precise alignment is crucial for the success of the process.

1. Position the electrode directly above the broken tap.

   • Use the machine’s visual aid (if available) or manually align the electrode with the center of the broken tap. Use the touch off feature to get your zero.

2. Ensure the machine is set to the job settings - allowing the electrode to slowly feed toward and through the broken tap during the machining process.

Step 3: Begin the EDM Process

1. Start the EDM machining process by engaging the machine's controls and flushing system (side flush, through flush or both) to initiate sparking between the electrode and the tap.

2. The EDM machine uses electrical discharges to slowly erode the tap material, starting at the highest point and working its way down through the tap.

3. Monitor the process—the machine will continuously cycle, with sparks eroding the broken tap into fine particles, to fine to see but as you get further down you may see larger parts of the tap break off. You can stop and remove them or just let the EDM 101 sense it, reposition its height and continue to burn through it.

Step 4: Flush Away the Debris

The EDM process produces microscopic debris that needs to be removed to ensure smooth machining.

1. Use the dielectric fluid (side flush or through flush) to flush away eroded particles from the gap between the electrode and the broken tap. You can set intervals or use the pre-programed methods to maximize the flush. 

2. The dielectric fluid will also act as a cooling agent, preventing the electrode and workpiece from overheating.

Step 5: Inspect the Hole and Repeat if Necessary

Once the EDM 101 program has completed:

1. The machine will stop and raise the electrode to inspect the hole where the tap was.

2. Check if the broken tap has been completely removed. If any part remains, realign the electrode and repeat the process until the tap is fully removed.

3. Clean the hole using compressed air or additional dielectric fluid to ensure all debris is cleared.

Step 6: Finish and Post-Processing

After successful removal of the broken tap:

1. Ensure the hole is clean and free of debris.

2. Check for damage to the threads or surrounding material. If necessary, re-tap the hole using the correct tap size.

3. Inspect the workpiece and dry.

Safety Tips:

• Wear protective gear: Always use safety glasses and appropriate gloves when working with EDM machines.

• Maintain proper dielectric fluid levels to avoid overheating or fire hazards.

• Ensure the machine is well-ventilated to prevent the buildup of fumes from dielectric fluid.

• Regularly check the electrode condition to ensure it hasn’t worn down during the process. A simple sanding to reface the electrode is all that's needed.

This method is highly effective for removing broken taps in hard materials where traditional extraction methods may fail. The EDM 101 machine ensures precision and minimizes damage to the surrounding material, making it a preferred solution for many machinists.

For a free quote, email us: info@tapouttexas.com or Call 832-240-6312