We provide all the same rigid tap features as with the original Fadal controls, but add even more.  We examined the tapping process to see what we could do to make the rigid tap process easier to use and minimize part scrap tapping during the tapping process. Below is a list of some new improvements that take rigid tap from just another “check box” item to something that really makes the difference – something anyone experienced with rigid tapping will greatly appreciate.
Say goodbye to stripped threads.
Rigid Tap Retract
With other machines, when something interrupts the tapping operation, it’s up to the operator to figure out how to remove the tap that is stuck in the part. Now with our new Rigid Tap Retract (RTR) feature, if the tapping process is interrupted (i.e., from an ESTOP, Slide Hold Abort or Power Failure being performed while tapping) the tap can be easily retracted from the part by using simply using JOG.
While in JOG, pressing the R key begins the RT Retract Mode. While moving the Z axis up with the JOG button or the hand wheel, the spindle remains synchronized and the tap easily feeds out of the part. Even if the machine looses power during rigid tap – it’s simple to recover.
Rigid Tap During Jog
Now you can even tap holes while in the JOG mode. Simply move the axes to position and jog Z down/up as you like to thread a hole.  The tap automatically rotates to follow the Z axis as you Jog up and down.
Faster Setup
Normally, at the beginning of the G84.1 Rigid Tap cycle, the spindle rotates three times to calibrate.  Our new technique virtually eliminates the calibration time.  Now the tap rapids down to the hole and immediately begins tapping.
A Brief History: Fadal Rigid Tap

The original rigid tap feature was introduced on the Fadal machine back in 1979 with the first machine, the VMC45.  A very unique feature at the time, it was possible thanks to a large DC permanent magnet servo motor was used for the main spindle motor, programmable just like the XYZ axes.


In 1983, the VMC40 and VMC4020 models were first introduced without rigid tapping.  For higher RPM and as a cost reduction, a common AC induction motor was powered by a PWM Inverter.  Unfortunately, the inverters could not control the spindle rotation with the servo precision required for rigid tap.  Machines at the time used tapping heads to accommodate for the synchronized mismatch of the Z axis and the spindle during non-rigid tapping.


Then in 1991, the introduction of PWM Vector Technology made it possible to control an AC induction motor in ways the inverter never could. With the Vector Technology, it also made it possible for Fadal engineers to revive the old VMC45 code for Rigid Tapping and add the feature to all the 10,000 RPM machines.