A focus on two strategic functions of eTensil screwdrivers with torque/angle control system based on current absorption: PRE-Auto untightening and POST-Auto untightening

Smart Pro EVO programming

These two very useful functions provided by Smart Pro EVO programming in eTensil screwdrivers can be enabled/disabled and offer the following technical capabilities:

- Adjusting the number of untightening turns

- Adjusting the untightening angle

- Adjusting the pause time between tightening/untightening phases

Let's look at some practical examples to better understand the field of application of these two features

Field of application of PRE-Auto untightening

• The simplest case is when the screw recess (e.g. hexagonal, torx, etc.) can cause the bit to disengage initially at high screwdriver speeds. In such cases, low-speed PRE-Auto untightening with left rotation can be set to ensure that the bit always engages with the screw head and allow the operator to work continuously and safely; the operator places the bit and starts the screwdriver, which turns left very slowly to engage the bit in the screw head, and then proceeds with tightening at the set speed.

• Other applications arise when operators must insert the screws by hand in preparation for the tightening phases, and where thread integrity must be controlled through the tightening angle. This function makes it possible to perform a sort of start from “0”. How? The operator slowly unscrews the screws inserted by hand and starts tightening from an angle of “0” until the set angle is reached.

• Finally, when wiring components in electrical panels, if the terminal screws have not been unscrewed, the operator needs to loosen the screw to open the terminal, insert the cable and then tighten it again. With a normal screwdriver, the operator must select the untightening function, untighten, insert the cable, select the tightening function and tighten: 5 steps. With an eTensil screwdriver, on the other hand, the PRE-Auto untightening function does this automatically: the system performs the above steps automatically when the lever is held down. This significantly speeds up the whole cycle and increases productivity.

Field of application of POST-Auto untightening

• There are cases of assembly in which the component must be prepared with the screws pre-unscrewed to a very precise height to facilitate subsequent coupling with other elements. In this case, the operator tightens the screw in torque mode, and only when the screwdriver has stopped, performs the controlled partial untightening by the set angle. Similar situations occur, for example, when assembling heat sinks on LED headlights in the automotive components sector.

• Another application case is related to the preparation of electrical components that are supplied by the manufacturers with the terminal screws loosened, but not fully, so that they are ready for wiring. To achieve this, the screws must be tightened to a set torque during production to ensure that the connector is installed correctly, and then untightened by a few turns. With a normal screwdriver, the operator needs to repeatedly set the screwdriver (or control unit in the case of electric screwdrivers) to untighten and then tighten. With an eTensil electric screwdriver, on the other hand, the Post-Auto untightening function automatically sets the tightening and untightening by the set angle, considerably reducing the assembly cycle times because the system performs the above steps automatically when the lever is held down.