Alternative Electronics

From RepRap
Revision as of 08:12, 2 December 2010 by Casainho (talk | contribs) (Listed HBox electronics)
Jump to: navigation, search
This page has been flagged as containing duplicate material that Electronics Variations also attempts to cover.
These pages should be merged such that both pages do not attempt to cover the duplicate topics.

The page RepRapElectronics has a good high-level description of what the electronics do and how they connect to the rest of the system. The standard, well-tested RepRap electronics are described at circuit board construction. Various ways of mounting and cooling RepRap electronics (whether standard or nonstandard) are described at Electronics Improvements.

Many people have come up with ideas for improving on those electronics. We list and compare and contrast some of those ideas here.

Feel free to download the current version of the RepRap electronics on SourceForge and make improvements, rather than starting from scratch.

If you want to know about the weird naming convention/s being used here, including the strange ( and broken) "Gen X" nomenclature, please see Electronics_Variations.


Deprecated, Experimental, and New RepRap-related electronics that have been built

general techniques for making circuit boards

  • According to some estimates, the vast majority of RepRap and RepStrap machines use one of the above custom PCBs specifically designed for RepRap and fabbed by a commercial PCB fabricator. Mendel Buyers Guide and PartsSupplies lists some of the places selling such PCBs, either the empty PCB or the assembled PCBA with all the parts already soldered on.
  • Many developers assemble extremely experimental electronic prototypes on bits of stripboard.

ideas that are still theoretical

Various pie-in-the-sky ideas ...

  • One of the more fascinating ideas is to use the RepRap itself to help manufacture the next generation of electronics. We talk more about that idea on the Automated Circuitry Making page.
  • Is it possible to build a RepRap that, instead of using the standard Stepper Motor Driver 2.3 boards, instead used some other stepper motor driver boards? perhaps the open-source OpenStepper boards ( from ) or the open-source Linistepper ( from )?
  • Is it possible to build a RepRap that, instead of using stepper motors, instead used slower, smaller, cheaper hobby R/C servo motors?
    • perhaps driven by the servo motor driver board plus magnetic encoder board combination -- MagServo or OpenEncoder )?
    • perhaps driven by the servo motor board plus a sub-$2 mechanical encoder?[1]
  • Is it possible to build a RepRap that, instead of using stepper motors, uses faster, bigger, more expensive DC motors?
  • Is it possible to build a RepRap that, instead of using stepper motors, uses faster, bigger, more expensive AC motors?
  • Is it possible to build a RepRap that, instead of using stepper motors, uses nitinol shape-memory wire?
  • Is it possible to build a RepRap that can print photovoltaic cells?
  • Is it possible to build a RepRap that, instead of using 8-bit Atmel AVR microcontrollers, instead uses 32-bit ARM microcontrollers -- perhaps one of the ones listed at Vaporware Electronics ?


There are a variety of ways of "improving" the RepRap electronics -- but, alas, several of these ways conflict with each other:

  • reduce the net cost of all the motors and electronics and connectors, when fabricated and assembled at commercial PCB fab and board assembly house in high volumes. This seems to imply putting everything on one board, eliminating the cost of connectors between boards; eliminating parts that are not absolutely essential to run a single RepRap with a single extruder; and using tiny narrow-pitch surface-mount components packed tightly together, to reduce the size and therefore cost of the PCB.
  • add one or more features that early RepRap electronics doesn't have
    • SD card reader and LCD screen so that it can run "stand-alone" disconnected from any PC host.
    • high-power stepper drivers to drive bigger, faster RepRaps
    • 7 stepper drivers so it can run 3 axis plus 4 extruder heads -- a Mendel Multiple Extruder -- or a Stewart platform plus 1 extruder head, etc.
    • lots of thermistors so it can occasionally pause and wait for motors and motor drivers to cool off if necessary, rather than covering them with enough heavy heat sinks to cover the worst case.
    • all the stuff necessary to interface with magnetic linear encoders or optical linear encoders to directly measure the position of the tool head. This lets the firmware immediately detect and correct "skipped steps" ... and also enables microstepping with optical feedback that may give higher positioning precision.
  • make it possible for people to fab the boards with a relatively crude homebrew process -- perhaps one of the Automated Circuitry Making techniques. This implies spacing parts relatively far apart to leave more room for the relatively wide isolation gaps and wide traces these techniques produce.
  • As far as possible, use only widely-available parts that are unlikely to go obsolete soon -- available from multiple manufacturers, etc.
  • Lots of flexibility to allow a variety of "functional units" to be substituted. Then the assembler can use whatever is cheapest at the time and location. Easy to switch to alternate parts if the original parts are unavailable. Easy to experiment by temporarily swapping in a new functional unit to test if it is really better than the old unit. Easy to upgrade just one functional unit if a better unit becomes available -- less buggy, more fault-tolerant, faster, more power-efficient, etc.
  • Each motor driver on a separate board, for the reasons listed at PMinMO: "Why Modular Designs?".
  • make it possible for people to assemble all the parts on the boards with relatively crude soldering tools -- this implies easy-to-solder parts, either through-hole parts or large wide-pitch surface-mount parts.


  • Does it work at all ? Testing RepRap Electronics
  • How do I use the RepRap Stepper Tester ?
  • How do I use the OpenCircuits Stepper Tester ?
  • Does it shut off properly when it overheats or slams into an end-stop?
  • What is the cost compared to the standard RepRap electronics?
  • Does it print things faster than the standard RepRap electronics?
  • Does it print things more accurately than the standard RepRap electronics?

The process of releasing improved electronic designs in a way that makes it easy for other people to use and make further improvements is described at ElectronicsReleaseProcess.

Further reading