Example implementations relate to media stacking mechanisms. In some examples, a printing device can include a stacking mechanism that includes a tamper to tamp print media positioned within the stacking mechanism, and a controller comprising instructions to: tamp a first sheet of print media received at the stacking mechanism a first distance based on a first size of the first sheet of print media, tamp a second sheet of print media received at the stacking mechanism a second distance based on the second size of the second sheet of print media, wherein the second sheet of print media is positioned over the first sheet of print media, and tamp a third sheet of print media received at the stacking mechanism the second distance when the third sheet of print media is the first size, wherein the third sheet of print media is positioned over the second sheet of print media.

A sheet post-processing device is connected to a punch processing unit. The punch processing unit includes a skew detection unit and a punch unit. The skew detection unit detects a skew amount of a sheet. The punch unit forms punch holes at positions of the sheet according to the skew amount. The sheet post-processing device includes a processing tray, a paddle, a driver, and a control unit. The sheet of which the skew amount is detected by the skew detection unit is mounted on the processing tray. The paddle conveys the sheet on the processing tray by a paddle operation. The driver drives the paddle to perform the paddle operation. The control unit is configured to operate the driver to control a number of times the paddle operation is performed by the paddle based on the skew amount.

An example sheet guide devices comprises a housing and a guide member coupled to the housing. The housing is to receive a stack of sheets to staple. The guide member includes a cylinder shaft, a counterbalance component, and guide arm. The cylinder shaft is rotatable and disposed within the housing. The counterbalance component is disposed with the cylinder shaft to shift a center of gravity of the guide member in a first direction. The guide arm is disposed off-center from a central axis of the cylinder shaft in a second direction.

A table for squaring metal sheets and metal plates by means of applying controlled pressure to the edges of such sheets or plates to bring them into symmetrical alignment for further processing.

A table for squaring metal sheets and metal plates by means of applying controlled pressure to the edges of such sheets or plates to bring them into symmetrical alignment for further processing.

A sheet post-processing apparatus that performs post-processing on a sheet on which an image is formed includes: a punch hole forming portion; and a sheet bundle forming portion that has a conveyance portion, stops a first sheet on a conveyance path, and conveys a second sheet after the first sheet to a position overlapping the first sheet to form a sheet bundle. The sheet post-processing apparatus includes a shift portion to make a shift so that a relative position between the first sheet and the second sheet in a direction orthogonal to a conveyance direction becomes a relative position at which the second sheet does not overlap a punch hole of the first sheet to make the second sheet overlap the first sheet, and forms a sheet bundle in which sheets overlapped with each other are deviated in a width direction.

A sheet post-processing apparatus that performs post-processing on a sheet on which an image is formed includes: a punch hole forming portion; and a sheet bundle forming portion that has a conveyance portion, stops a first sheet on a conveyance path, and conveys a second sheet after the first sheet to a position overlapping the first sheet to form a sheet bundle. The sheet post-processing apparatus includes a shift portion to make a shift so that a relative position between the first sheet and the second sheet in a direction orthogonal to a conveyance direction becomes a relative position at which the second sheet does not overlap a punch hole of the first sheet to make the second sheet overlap the first sheet, and forms a sheet bundle in which sheets overlapped with each other are deviated in a width direction.

A sheet stacker includes a sheet stacking portion, a pair of sheet restrictors, a sheet feeder, and a position detector. A bundle of sheets is stacked on the sheet stacking portion in a stacking direction, and the sheet stacking portion moves in the stacking direction. The pair of sheet restrictors move in a width direction to regulate a position of the bundle of sheets in the width direction. The sheet feeder feeds a top sheet of the bundle of sheets at a sheet feeding position in a sheet feeding direction. The sheet feeding position is disposed at a top of the bundle of sheets in the stacking direction. The position detector is disposed between the pair of sheet restrictors in the width direction and above the sheet feeding position in the stacking direction. The position detector detects a position of the pair of sheet restrictors in the width direction.

A sheet stacker includes a sheet stacking portion, a pair of sheet restrictors, a sheet feeder, and a position detector. A bundle of sheets is stacked on the sheet stacking portion in a stacking direction, and the sheet stacking portion moves in the stacking direction. The pair of sheet restrictors move in a width direction to regulate a position of the bundle of sheets in the width direction. The sheet feeder feeds a top sheet of the bundle of sheets at a sheet feeding position in a sheet feeding direction. The sheet feeding position is disposed at a top of the bundle of sheets in the stacking direction. The position detector is disposed between the pair of sheet restrictors in the width direction and above the sheet feeding position in the stacking direction. The position detector detects a position of the pair of sheet restrictors in the width direction.

A method moves a stack of products by a robot. The robot has an articulated arm and at least one gripper disposed on the articulated arm to grip the stack of printed products and the stack of products selectively being turned. The method includes pivoting the stack of products through an effective angle α1< >180° and subsequently pivoting the stack through an effective angle α2=180°−α1 or pivoting the stack back through an effective angle α2=−α1. This method of moving stacks of products is performed in an automated way and in particular of depositing them in a turned or unturned arrangement.