On the type plate at the rear side of the HT500.2 you find all information to precisely identify your 3D Printer:

• Serial number
• Date of manufacturing
• Hardware Revision¹

¹ You will also find the valid hardware revision in the [Setup] menu on the touchscreen.

• unintended usage of the HT500.2
• false setup, commissioning, operation repair or maintenance
• operating the apparatus with defective, missing, improperly installed and/or malfunctioning equipment.
• unauthorized or inadmissible alteration of the electrical or mechanical equipment or the operating parameters of the apparatus.
• use of other than the specified replacement parts, tools, and/or operating materials
• exceeding the specified maintenance intervals
• cases of disaster and force majeure

The HT500.2 has been designed for stationary application. It is not equipped with special transport devices such as lifting eyes or handles. The feet provide sufficient clearance to lift the apparatus and carry it to the installation site.
While the HT500.2 is packed and on its transport palette, use a lifting cart or pallet stacker for transportation. Make sure that the weight is evenly distributed and secure the HT500.2 against tilting.

The HT500.2 is recyclable due to its low-pollution equipment. Nonetheless, the European Guideline 2002/96/EG (Waste Electrical and Electronic Equipment - WEEE) and the German Elektro- und Elektronikgesetz (ElektroG) forbid the disposal of the apparatus via the household garbage. For environmental friendly recycling and disposal of the HT500.2 please contact a certified electronic waste management professional.

• Use the HT500.2 for its intended use only.
• The HT500.2 must be in goor working order and in a safe state at any time. Check the apparatus prior to every commissioning and at regular intervals for wear, damage and cleanliness.
• Ensure that nobody can be injured by parts of the 3D Printer.
• Fix any error condition or visible damage immediately. If prompt rectification is impossible, decommission the 3D Printer and do not put it back to use unless all problems have been solved.
• Regard the local accident prevention regulation.
• Provide access to the operating manual for anybody operating the machine.

When the emergency stop is triggered, the microcontroller board responsible for the stepper motors, heaters and sensors is reset immediately and returns to idle state afterwards. Now it is safe to resolve any problems or defects in the build chamber.

The build chamber can then be reactivated via the [Print] menue.
Detailed information are provided in the Operating manual.

The HT500.2 3D Printer uses the Fused Filament Fabrication (FFF) process to build up workpieces in subsequent layers of 0.10 to 0.60mm thickness. The plastic filament is heated in the nozzle to its melting temperature and continuously conveyed by a cogwheel. The molten plastic is pressed through the bore of the nozzle tip and onto the heated print bed. After each layer the print bed is lowered by the preset layer height and the next layer is applied. The heat of the newly applied plastic ensures an adequate binding of the layers.

All temperatures and movement commands are provided by the GCODE, a file format previously generated with a “slicing” software. This file contains all information for a single print job and is uploaded to the 3D Printer via the web interface. All Kühling&Kühling 3D Printers are built to operate best with Slic3r, an OpenSource Software designed for professional 3D printing.

After the workpiece has been finished the user can leave it in the heated build chamber to slowly cool down thus reducing shrinkage and internal tensions, or he can immediately remove it and start the next print job. The layered building process enables the user to create even complex forms that otherwise could not be realized.

The HT500.2 is built on an aluminum framework covered with acrylic panels. Its main functional sections are the upper build chamber and the lower electronic chamber. The build chamber is covered with translucent plates to provide insight during production. It contains all mechanical components, the air filter. At the back cover, the filament supply is installed.

The lower is covered with opaque sheets and contains the electronic components and the mains adapter. All connections and the power switches are located here and the touchscreen for operation is mounted at the front cover.

All covers are fixed to the frame with M4x20 hexagon socket screws and hammerhead nuts, thus being easy to remove and making all around access possible to all parts if required.

All references concerning directions are defined throughout this manual as follows:

All movement directions of the axes are defined throughout this manual as follows:

All movements of the extruder drives are defined throughout this manual as follows:

The build chamber is the main production area with the vertically moving print table and the two-directional horizontally moving extruder head inside.
All electrical motors are installed at their working point and equipped with a water cooling system. The extruder head moves on an H-frame, tooth-belt-driven by two separate stepper motors in X- and Y-direction. The print table is lifted and lowered in Z-direction by a spindle drive.
For regulating the temperature inside the build chamber two heating resistors in separate housings heat the air which then is circulated through the chamber by the fans.
Cables and hoses are installed in and guided by cable carriers.
To minimize air pollution from dissolved substances, an additional fan circulates the air through a filter element filled with granules of activated carbon.
The access to the build chamber is the magnetically closed double door at the front.

The filament spools that provide the necessary material are installed at the rear of the build chamber next to the filament feed unit.

The extruder head is mounted to the traverse of the H-frame and moves horizontally in X- and Y-direction with useful operating ranges of X = 200 mm and Y = 185 mm.
It contains the filament drive gears forwarding the filament strands and the hot ends which melt and dose the material onto the print table. The filament is supplied through a hose from the filament supply and is clamped between the idler lever and the filament drive gear. The filament drive gear is rotated by the filament feed motor and thereby forwarding the filament strand.
Each hot end is provided with its own filament strand, thus enabling bicolored prints, printing two materials or two objects simultaneously or printing with different extrusion thicknesses (e.g. for outer contours and inner filling structures).
The left (primary) hot end is configured for standard single-extruder prints and is the reference nozzle for leveling the print bed. The right hot end is only leveled passively after the print bed has been aligned correctly with the primary hot end.

Each hot-end is heated by a ceramic heating cartridge so that the filament is molten inside the nozzle. The integrated thermocouple provides direct alignment of set and actual temperature.
To improve the thermal control of the melting process the hot-end mount is connected to the cooling system, ensuring an even temperature distribution in a well defined area of the nozzles so that there is a preheating zone and a melting zone.

The nozzle is exchangeable to provide different bore diameters for different materials, layer thicknesses or print speed. Ex factory, the 0.35mm tip is preinstalled. Additionally, three nozzles with diameters of 0.25mm, 0.5mm and 0.75mm are included. The tips are distinguishable by the engraved markings.

The 0.35mm and the 0.5mm nozzles should be used for most purposes and can be operated at an extrusion speed of up to
60mm/s. The Slic3r profiles provided by Kühling&Kühling are optimized for the 0.35mm nozzle. Additional information can be found in the Service Guide and in the Slic3r manual.
Please try and find the settings best suited for your task. The Slic3r profiles will be constantly updated and extended.
The 0.75mm nozzle is primarily intended for experimental usage and should only be used with a max. extrusion speed of 20mm/s for a start. Adjust the extrusion speed stepwise until optimized for your needs.
The 0.25mm nozzle is for filigree, thin walled extrusions. Do not exceed an extrusion speed of 35mm/s since the material throughput will not suffice for higher speeds.

The print table is mounted on the crossbeams of the elevator assembly which is positioned accurate to the millimeter in Z-direction in its useful operating range of 280mm by a spindle drive.

The print table itself consists of an aluminum sandwich panel with a silicone rubber heating pad that provides temperatures of up to 130°C, providing an even temperature distribution and ensuring optimal adhesion throughout the printing process.

It rests on three springs lockable with set screws for an even and accurate leveling since a precisely adjusted distance between print bed and nozzle tip is vital for the print bed adhesion an the print results.

The semi-automated leveling process is described in the Operating Manual. Additional information on leveling can be found in the Knowledgebase.

Print jobs are executed on the removable print bed laid on the print table and fixed with four bulldog clamps at the corners. This fixation allows the use of print beds of different thicknesses.
The print bed can be exchanged for every print, thus minimizing interruption times during production.
The standard print bed included in the delivery is a 210x210x1.8mm polyetherimide (PEI) glass fabric plate that provides excellent adhesion for a large variety of materials, including ABS, Nylon, PET, PC, HIPS, TPU and other.

Five electrical stepper motors, one per direction of the extruder head, one for lifting and lowering the print table and one per extruder head nozzle for forwarding the filament, provide all necessary movement for printing. All motors are equipped with water cooling to prevent overheating due to workload and the heating of the build chamber.

Sensors for positioning and temperature control are installed inside the build chamber.

Every axis is equipped with a Hall effect sensor and a magnet for accurate home positioning. If the Hall effect sensor nears the magnet and measures the defined threshold value of the magnetic field strength, the sensor effects a “stop” signal via the microcontroller. After all sensors have given this signal the moving axes are in home position. The home position is the reference value for all relative movement of the extruder head and the print bed.

Thermistors measure the relevant temperatures for the printing process, i.e. the print bed temperature and the build chamber temperature. All thermistors deliver their input signal to the microcontroller and thus effect switching on and off the according heating resistor.

The print bed temperature is measured directly at the heating pad with which it is looped in a control circuit.
The build chamber sensor is installed at the elevator assembly and measures the air temperature inside the build chamber. Its measurements influence the control of the heating resistors inside the heating elements.

The extrusion temperature is measured directly at the heating cartridge by an integrated thermocouple.

The HT500.2 is designed for printing filament strands of a diameter of 2.85 mm with a tolerance of ±0.1 mm. More information about filament and materials can be found in the material section and the print preparation section of the Knowledgebase.
Two separate strands can be fed from the outside to the extruder head. One filament spool can be positioned on each spool carrier; a stop collar prevents them from falling down due to their rotation.
The end of the filament strand is manually inserted into the inlet of the feed unit and led through hoses to the two extruder nozzles. At the inlet the filament is put through a sponge that wipes dust off the strand to keep the material unsoiled before reaching the nozzle.
A limit switch registers the end of the filament strand when the spool is empty. The print process then is interrupted and the lack of material is signaled on the touchscreen. The printing process can be resumed after refilling the supply.

The HT500.2 3D Printer is equipped with a wiper to enable high-quality dual extruder printing.

During every tool change of a dual-extruder print, the nozzle to be used next will be primed and wiped to ensure pressure loss during its pause time is compensated and the nozzle starts well filled.

All control elements are installed in the electronic chamber together with the 12V(DC) mains adapter and the cooling unit.

The chamber is completely covered with white acrylic sheets fastened to the aluminum frame with hexagon socket screws and hammerhead nuts.

The RADDS 3D Printer Driver Shield in conjunction with the SAM3X microcontroller on the UDOO board controls all processes of the printing process, i.e. the drives, the heating resistors, heating fans and the temperature sensors. Exchangeable hardware components are the stepper motor drivers.

The UDOO Quad Single Board Mini PC provides the GUI of the touchscreen and the ethernet connection and processes the G-codes of the slicing software.
Slots in the bottom cover provide an air inlet for the cooling unit.

When the 3D Printer is switched off the internal real-time clock of the Mini PC is fed by two external batteries so that the system's time signal is not lost.

The solid state relays switch the four heating resistors of the build chamber heating and the heating resistor of the print table.

The cooling unit consists of a pump with water reservoir, a radiator and the closed loop coolant circuit filled with an electronic cooling liquid. It is automatically switched on and off when the build chamber is activated/deactivated.

The coolant is pumped in a circle past the motors and the extruder nozzles where it absorbs heat which is then emitted via the radiator.

Check the coolant level monthly and if required, refill as described in the Service Guide.

At the rear cover you find the mains plug and the main switch of the mains adapter and the RJ45 ethernet plug for the network connection.

The cooling systems' accumulated warmth is dissipated via the radiator grill to the outside.
The type plate is positioned next to the fixing screws of the cooling water pump.

The wake button at the front panel provides a wake-up function and indicates the general operating status of the 3D Printer. It is equipped with a light ring that is illuminated while operational and dims after the 3D Printer has been shut down. Press the button to restart the 3D Printer from standby.

All 3D Printer operation is carried out via the Graphical User Interface at the touchscreen.

Operating the HT500.2 is designed to be comfortable and intuitive. Therefore, a high-resolution 10” TFT touchscreen mounted at the front panel provides an easy-to-use Graphical User Interface (GUI).

All operation of the HT500.2 is carried out via the RepRapOnRails operating software which provides status messages and control functions that can be chosen by simply tapping the respective buttons. Find detailed explanations of functions and operating procedures in the Operating Manual.

In case you experience any trouble, please refer to the Service guide and Troubleshooting. If you cannot solve a problem with the information given there, you are always welcome to contact us personally. We are trying to improve these information constantly and will be grateful for your help when you encounter any previously undescribed faults or problems.

of the operating software is displayed on the right-hand side of Setup menu together with additional system information.

Set up the HT500.2 at a well aerated place with an all-season ambient temperature between 15 and 25°C and a relative humidity of 70%.
Position the HT500.2 on a flat, carrying and enduring surface with a load capacity of at least 75 kg.
To ensure unhindered aeration of the electronic chamber no soft, movable materials (e.g. table cloth, cardboard strips, paper etc.) may be placed underneath the apparatus to prevent clogging of the vent slots.
The required setup space must at least be 650 x 650mm and provide approximately 500mm free space to either side to enable unhindered access to the electronic chamber for service and maintenance work. At least 750mm free space must be left at the back of the HT500.2 to make changing the material easy and to ensure free air circulation at the ventilation grill in the back cover. At the front a free space of 1.250mm is recommended to allow easy operation with open chamber doors.
To easily access the touchscreen in a sitting or standing position the height of the setup table should not undercut 780mm.
A 230V power source must be within the range of the connection cable.

To unpack the machine, cut the tensioning straps of the wooden transport box, remove the lid and carefully lift the box over the printer.
Then cut the tensioning straps around the 3D Printer and remove the wooden cover plate and the air cushion foil.
Set aside and store all parts of the transport packaging for later use, e.g. moving or shipping the 3D Printer.

All moving components of the HT500.2 3D Printer are secured with blue tape against damage in transit.
Make sure all transport restraints named in the adjacent pictures have been removed before commissioning the 3D Printer.

• Take the HT500.2 out of operation as described above.
• Drain the cooling system and collect the coolant. Dispose of the coolant according to your local guidelines and the manufacturer's data sheet.
• Disassemble all components according to their recyclablility and dispose of them adequately and lawfully.

The HT500.2 3D Printer features a low-maintenance design, thus intensive maintenance time is not required during normal operation. Nonetheless regard the maintenance intervals stated in the Service Guide.

Apart from this, regular cleaning will mostly suffice to keep your 3D Printer running satisfactorily.

In case of faults, refer to the Troubleshooting Guide and the Service Guide where most problems known to us and according remedies are lodged.