What are Hydro Printers

RepRap / de

RepRap is a free 3D printer that is able to print plastic objects. Since most of the components are made of the same plastic, it can be viewed as a self-reproducing machine that anyone can recreate with a little time and the materials.

Reprap.org is a community projectwhich means that you are welcome to improve the pages or create new ones. You can find more information on how to participate on our community portal.

Use the links below to explore the content of the website. Some of the content has been translated into other languages, but the primary documentation is in English.

About | RepRapable Objects | Community | Help and support

Usage instructions

For the time being, please primarily use and improve the English-speaking pages. This should only contain information that is of particular interest to reprappers from the German-speaking area. The wiki lives from participating! You can find information on how you can participate or get in contact with other RepRappers on the German-language portal page.

If you have a question that is not answered by the content in the wiki, but has been discussed and answered elsewhere, please be so kind and complete the corresponding wiki page. Others before you have done that too! You can also find ideas, hints and other half-baked topics under the tab discussion read up.


These two models, which are still very widespread, achieved the big breakthrough:

  • Prusa Mendel - Very similar to the classic Mendel in terms of functionality and based on its concept, but much simpler in terms of mechanical structure. This also makes it cheaper to manufacture. Due to continuous revision, the assembly instructions can differ a little, but mostly to the advantage.

The initial structure of triangles as it occurs in the Mendel or Prusa Mendel is often no longer used in new developments. A good example of this is the Prusa i3 or the Mendel90.

To start out in the RepRap world, of course, you need a 3D printer. Here you can start with a complete system that is ready for the first print or a kit that still has to be assembled. The kit not only saves you money, but you also get to know the printer much better and can quickly solve problems yourself.

Of course you can also use the instructions in the RapRap Wiki to buy the individual parts even cheaper and to assemble them with the help of the instructions. For the necessary printed (plastic) parts, you either know someone who will print them for you or you can take a look at the forum.

The RepStraps offer another starting option, with which it should be possible to "bootstrap" a RepRap, for example the FTIStrap made from Fischertechnik components.


Most of the RepRap electronics are based on the ATmega processors from Atmel. An ATmega168 is just enough, mostly the ATmega644 or ATmega644P is used. Larger ATmegas do no harm, but they are also not useful because they have more memory, but not more computing power.

The type of electronics is quite independent of the type of RepRap machine. Every common electronics fits on every common machine. Because all machines are operated by three to four (X, Y, (2x) Z) stepper motors and an extruder. There are deviations in support for heated build platforms and support for multiple extruders.

Common versions

Generation 3 Electronics - the classic. Modular design, tried and tested a thousand times, but rather too complex based on current knowledge.

Generation 6 Electronics - Electronics designed from the point of view of an industrial product. It is only sold fully soldered and does not support a heated construction platform or other extruders. Ideal for people who want “the main thing is that it prints”.

RAMPS - An Arduino as a base, on which the RepRap-specific parts are self-made. Now very common and a good compromise between generations 6 and 7. RAMPS 1.3 is very suitable for self-construction (also on a breadboard), very suitable for converting an existing CNC to 3D printing (step / dir). RAMPS 1.4 is optimized for industrial production with SMD components.

Generation 7 Electronics - Electronics with the aim of being as replicable as possible. The circuit board and the selection of components are designed in such a way that they can be produced using a RepRap or a do-it-yourself process. In terms of functionality, it is not inferior to the other electronics and also supports a heated construction platform.

Megatronics - is a mix of Arduino Mega 2560, RAMPS, SD Ramps and thus, like the others, a complete solution.

All electronics are connected to the USB interface of a PC, if necessary via an appropriate converter. A separate power supply unit to power the motors and heaters is also required.

An overview of all currently known electronics can be found under Alternative Electronics.

Stepper motors

A list of suitable stepper motors / drivers and the selection criteria can be found here: StepperMotor


Here you have to differentiate between several parts.


The firmware is uploaded to the electronics processor. It interprets the G-code that comes in via USB or the serial interface and converts it into corresponding electrical impulses for the heaters and stepper motors. The firmware is compiled for each individual case and must be adapted to the respective machine. For example, it must be specified how many pulses a stepper motor needs to move an axis 10 millimeters.

Most of the firmware can be adapted to all common electronics. The most commonly used are the following:

  • Teacup firmware - programmed with great attention to detail, it can move axes much faster. Also suitable for manual operation of the machine, e.g. if a milling motor is set up instead of an extruder.
  • Tonokip - The attempt to rewrite the FiveD and “better” it.
  • Sprinter - Rewrite from Kliment. Various other firmwares had an influence on this. Adapting the firmware to your own requirements is very easy. Supports printing from SD card.
  • Marlin - An improved version of the Sprinter firmware
  • Repetier Firmware - An almost complete rewrite of the Sprinter firmware with functional inspiration from other firmware versions.

Host software

The host's task is to send the existing G-code to the electronics. There is a certain amount of chaos, since most hosts are not very fault-tolerant and badly adapted to the firmware. You have to try what goes together.

Uploading the firmware with the Arduino IDE works with
  • Repetier-Host: Suitable for the Repetier firmware, but also works with other versions. Multi-platform (Linux, Mac OSX, Windows), integrates Slic3r and optionally integrates Skeinforge.
  • OctoPrint: Due to its structure as a web interface, this host software can also be used to control the printer remotely. Octoprint was specially developed for the Raspberry Pi.

G code generator

These "generators" calculate which movements of the extruder are necessary to produce a certain component. This function is often built into the hosts. Since this task is demanding, the G-Code generator is of decisive importance for the quality of the components produced.

A non-integrated G-code generator attracted attention with its good print results (but also with its complicated operation): Skeinforge. There is a user-friendly version of Skeinforge Sfact.

Not quite as good print results, but Slic3r allows a very fast slicing process.

The slicer Cura developed by Ultimaker is very user-friendly

More about software

A list of the known software parts with compatibility lists is available under CAM Toolchains.

The primary German-language source of information for RepRap is next to this wiki here the German-language sub-forum.

Here is a small excerpt from the latest posts in the FAQ sub-forum of the German forum area: