3D Printer build – it’s a lot harder than you think…

Anyone thinking about building a 3D printer from scratch should come to their senses quickly and just buy a ready-built printer or a high-quality kit. The prices are falling like a heavy rain and you can get a high quality printer for the same money, and less frustration, than building one will accomplish.

The problem is in the general design of the current crop of “open source” 3D printers.  There are just too many nuts, bolts, wires, haphazard software settings, firmware settings, mix-matched hardware and electronics issues to make it a user friendly experience.

First off, the motors.  Most people wanting to build a printer will rush to Ebay and buy the cheapest lot of 5 NEMA 17 sized motors.  These are the same people who don’t even know what NEMA 17 means.  Here’s a hint:  It is a form factor, not an electrical specification.  This means that NEMA 17 specifies the physical form of the motor’s case.  It does not dictate anything about the electrical current requirements, stepping angle, steps per revolution, etc.  All of these are “parameters” that affect the overall system, and they must be “plugged into” the software that runs on the controller board (aka firmware).

20150410_210803

The same situation applies to heating elements, hot ends (the part the hot plastic comes out), temperature sensors, fans, end-stops (the little switches that tell the controller that your motor has moved the carriage into the 0 position).

Each and everyone of these are elements that must be hard coded into the device firmware.  There is no user-friendly machine-mounted menu option for these parameters.  In fact, depending on your other choices, you might not get an LCD screen at all (which is where the machine-mounted menu system is displayed).

I’m building this printer as a means to and end.  I need to experience it the “hard way” sothat I can design the “easy way”..

Here are some of my observations so far:

  • Nuts, Bolts, Screws – there are too many.
  • Settings buried in firmware – they should be easily accessible via software.
  • Wires – need to manage the vast pile of wires.  This means better end to end connectivity.  Perhaps using 4, 6 and 8 wire RJ-45 style connectors would make this a lot nicer to build.
  • There should be a “setup wizard” software that guides you through configuring the firmware for the first time. It should auto-detect that the printer has not been configured and guide the user through the process.  This could be a desktop application or available in the printer’s LCD controller (but not all have LCDs…)

 

 

RepRap 3D printer project is not for the faint at heart

So I launched my “RepRap” 3D printer project a few weeks ago.  I am building the Prusa i3 printer using 6mm acryllic for the front and side support wings.  A picture of it is shown below:

20150331_082300

Although I decided to scribe my nickname “Thetazzbot” in the printer’s frame, it should not be confused with “Taz” by lulzbot.  I’ve been using “thetazzzbot” since the 1990’s, and I’m not going to stop using the name now just because some company decides to use “Taz” as their product name.  Maybe I should trademark my name…

There are numerous “RepRap” printer designs available for the do it yourselfer.  The concept is theoretically good:  Build a bare bones printer, then use it to build the parts for a better printer.

The original design, aka Prusa Mendel, was built using threaded rods, a lot of washers and nuts, and even though I’ve never built this specific printer, I can tell you it will be a pain to build.  The critical part of the printer’s construction is alignment.  And all those threaded rods will be difficult to get the intersections aligned where the angles aligned and the whole thing squared up.

The other downside of the current generation of RepRap printers is the number of unique parts involved.  This includes threaded rods, screws, nuts, bolts and printed parts.  If you look at the bill of materials, it is quite staggering.  To picture it even better, take a look at this photo:

Mendel-reprap-entry-level-3d-printer-diy-kit

Let me reiterate, there are a LOT of parts that go into building your own RepRap Prusa Mendal or i3 printer.

Depending on the model you decide to build, you could also be facing “printed parts fatigue”:

Mendel90_plastic_parts01

Or, Nuts-And-Bolts-Hell:

800px-RepRapNutsBoltsWashers

There are even MORE if you decide to build a Makerbot or Ultimaker clone.

I also have a great deal of heartburn with the “wires hanging everywhere” approach that the DIY community seems to be in love with.  This haphazard appearance makes the machine seem unapproachable by non-techies.  Exactly the opposite of what we need for mass adoption of the technology.

Assembled-prusa-mendel

The DIY community needs to try to reverse this trend.  I vote for Less is More.  Not every printer needs to have an 8″x8″x8″ build volume.  What if we started building task-specific printers that didn’t need the height (simplifying the Z axis), or a heated build platform (negating the need for big beefy power supply), or maybe use smaller, cheaper stepper motors, DC motors.

My goal is to build a platform that doesn’t require screws, or tools.  It shall have a wide platform (12×12 inch or 12×14 inch), with lower vertical build space requirements for printing small, flat parts.  The goal of this project is to reduce parts count drastically, and reduce construction complexity such that anyone can assemble it.

My bare minimum design includes:

  • Single board controller + stepper drivers
  • Hotend for PLA, Nylon, etc.  Experimentation here..
  • X/Y Nema17 or smaller steppers
  • Z with 4″ or less of travel
  • Little or no bolts/nuts/hardware (expensive)
  • Utilize inexpensive aluminum square tubing
  • Stationary build platform
  • Bowden style extruder

I’ve just finished designing and printing the plastic parts and cut the frame and test fitted everything.  So far very good results.  Now I have to put together the wiring and controller and then run some motion tests.

The long term goal of the project is to build a low profile, highly stable platform that is inexpensive to reproduce and simple for the end user to assemble and get printing.