Hewlett-packard Development Company, L.p.

Michael Ewe

Eric Collins

Keith Jariabka

Wesley R Schalk

Arthur H Barnes

Duane A Koehler

Brent Ewald

Juan D Ramos

Peter J Boucher

Donnell D Daniels

Samuel Jeong

According to examples, an apparatus may include a processor and a memory on which are stored computer-readable instructions that, when executed by the processor, may cause the processor to access a characteristic of a motor coupled to a carriage in a printer. In this regard, an ink cartridge may be mounted on the carriage and the characteristic may be of the motor during movement by the motor of the carriage. The processor may calculate an amount of ink in the ink cartridge based on the characteristic of the motor and may determine whether the calculated amount of ink differs from an estimated amount of ink in the ink cartridge. In some examples, based on the amount of ink in the ink cartridge differing from the estimated amount of ink in the ink cartridge, the processor may disable the printer and/or generate a notification.

Ink cartridge ink amount calculations based on motor characteristics

Example implementations relate to print media rollers. For example, implementations can include a device that includes a first roller to receive print media, a first sensor to determine when a leading edge of the print media is at a first location, a second roller to be activated based on a type of the print media and when the leading edge of the print media interacts with the first sensor, a second sensor to determine when the leading edge of the print media is at a second location, wherein the first roller is deactivated based on when the leading edge of the print media interacts with the second sensor.

Print media rollers

An electronic device includes a carriage to move along an axis relative to a platform. In addition, the electronic device includes a print head disposed within the carriage to move with the carriage and to deliver a print agent to the platform. Further, the electronic device includes a cooling system. The cooling system includes an air source to deliver air to the print head within the carriage to cool the print head. The cooling system also includes a pressure sensor to measure a pressure of a first zone within the carriage. Moreover, the cooling system includes a controller to control a flow rate of the air into the first zone or from the first zone in response to the measured pressure to maintain the first zone at a positive pressure with respect to a second zone outside the carriage.

Controlled cooling for print heads

In an example implementation, a method of fusing layers of 3D parts includes forming a layer of build material, and selectively applying a liquid agent onto the layer of build material to define a part layer of a 3D part and a sacrificial layer of a sacrificial part. The method includes, in a single pass of a thermal energy source over the layer of build material, applying fusing energy to the sacrificial layer, sensing a temperature of the sacrificial layer, adjusting a power level of the thermal energy source based on the sensed temperature, and applying fusing energy to the part layer with the adjusted power level of the thermal energy source.

Fusing three dimensional (3D) parts

Example systems relate to recoater movement. A non-transitory machine readable medium may contain instructions executable by a processor. The instructions may include instructions to change an action of a recoater in response to a determination that the recoater has reached a first location of a build area comprising build material. Instructions may further include instructions to lift the recoater in response to a determination that the recoater has reached a second location of the build area. Instructions may additionally include instructions to move the recoater over the second location at the lifted position, wherein the second location includes a build-up of the build material.

Recoater movement

An example three-dimensional printing system includes a first carriage, a second carriage, and a synchronization controller. The synchronization controller is coupled to the first carriage and the second carriage to synchronize movements of the first carriage and the second carriage. The synchronization controller is to avoid interference between the first carriage and the second carriage.

Carriage synchronization of a multi-carriage three-dimensional printer

Described herein are techniques that facilitate the prediction of the end-of-life of a direct current (DC) motor of an apparatus. The described techniques include tracking end-of-life indicative motor-response values of a DC motor based on an applied-voltage value at its corresponding specified speed of the DC motor when the motor is engaged, in response to the determination that the tracked values exceed a range of acceptable operational values, a health-status notification regarding that DC motor is generated. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Prediction of end-of-life of a direct current (DC) motor

In an implementation, an example method of indexing a media feed shaft in a media feed device includes rotating a media feed shaft and transmitting the rotation to an output gear that is remote from the media feed shaft. The method also includes sensing a feature of the rotating output gear and indexing the media feed shaft to the feature.

Indexing a media feed shaft

An example method for controlling a carriage of a printing device is described. In one implementation, a target velocity value that satisfies a sharpness threshold is filtered by a processor resource of the printing device, a feed forward term is generated using a continuous model applied to the filtered velocity input using a plurality of electromechanical parameters, a feedback term is generated based on a difference between an expected pulse-width modulation (PWM) profile and an actual PWM profile, and a voltage to be provided to a motor of the carriage is adjusted based on the feed forward term and the feedback term.

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Vancouver, WA, United States of America

Michael Ewe