DIY Mini Open Source 3D Printer built from scratch (in progress)

NOTE: The design files are not yet released – they require a bit of tidying up before going public, but once I’m done, they will be open source.

So, it’s been eight months since I got into 3D printing with my Anet A8 printer.
I learned so much, and got so hooked, that three months ago I decided I should build a second 3D printer from scratch. I did not want to buy a kit – I didn’t really need a second printer, I needed the EXPERIENCE gained while building it, and the satisfaction when you first power it on 🙂
And while most people go bigger – scaling the design for bigger build volume and (usually) more complex build, I decided I want a smaller and simpler printer. I didn’t even want it to have heated bed, because I was not planing to use it with something different than PLA, and PLA does not really require a heated bed – there are still ways to get good first layer adhesion.
So, after a couple of days of “research”, I chose the Printrbot Original design – it was small, simple, and didn’t even require cutting some kind of a support frame:

I started ordering the parts off aliexpress – motors, mainboard, rods, mainboard (RAMPS 1.4)… almost everything. All parts were the cheapest ones I could find.

Meanwhile, I imported the Printrbot Original design files in Blender, and started tweaking them to suit my requirements.
Soon, I realized this design was obviously going to be crap – unstable and not easy to carry around, albeit small. Add a couple of meters of wiring to it, and it gets even worse.
So, I decided I need something more “mainstream” – similar to the Prusa i3 design, with 2020 aluminum profiles for the frame, and place all electronics inside a wooden box below the frame.
I scrapped the old design, and started from scratch. And I mean FROM SCRATCH – not using existing open source parts, but designing my own in Blender.
Because why not?

About 10 days after everything started I had this:

One of the reasons for the decision to design everything from scratch, was that I wanted to actually learn something, and I liked the challenge. At that time I had just a few weeks of VERY limited experience with Blender (and no experience with serious CAD), so it was a pretty bold plan 🙂
But this was the perfect way to master Blender, wasn’t it?
Another reason was, that I wanted to have the biggest possible build volume within the constraints of the relatively short smooth rods I had already ordered, and most of the existing open source parts were not optimized for that.
The rods were 240mm, 220mm and 250mm in length – pretty short, compared to the ones on my Anet A8, but I managed to get 129x147x127mm build volume from them in the final design – which is pretty good, considering the overall printer size

Anyway, while I was waiting for the parts to arrive from Aliexpress, I had plenty of time to think and design everything.
At times it was harder, at times it was easier. I had to redesign some parts, because some flaws were not obvious while I was designing them, but after I printed them, it was obvious.
Maybe about 25% of the filament I used was for parts I had to redesign.

So, here are the final specs of the printer:

  • Build volume (XYZ): 129x147x127mm
  • Heated Bed: NO
  • Nozzle: 0.4mm
  • Extruder: Cheap E3D V6 Clone, direct drive
  • Filament: 1.75mm (most likely only PLA)
  • Mainboard: RAMPS 1.4 with 20×4 alphanumeric display
  • Power Supply: old ATX PSU (without its case)
  • Weight: not sure, maybe 3-4kg
  • Firmware: Repetier 0.92.9
  • Frame: Standard 2020 aluminum profiles

A couple more facts:

  • I am NOT using real lead screws on the Z axis. Rather, I use cheap M6 screws from the local hardware store, which work fine, btw. Initially I tried with M8, but they had a bit more slack, so I tried M6, and it was better.
  • All printed parts, except the E3D V6 mount are printed from PLA on my Anet A8
  • I haven’t yet calculated the final price for everything, but it’s around $140 or something like this.

Some photos taken during various stages of the build process:

And finally, some photos of the finished printer:

UPDATE (2017-08-28): I made some improvements on the design:

  • Made the top frame more stable by using better (printed) corner brackets, which are both corner brackets, and z rod holders.
  • Replaced the bed’s supporting frame with a fully printed lightweight H frame. The old one was built from M8 threaded rods (due to the lack of something better at hand at the moment), and was HEAVY.
  • Added additional brackets (or whatever) to hold the Z motors better, eliminating some vibrations on the X axis.
  • Replaced the direct drive system with bowden
  • Better wiring – the wires going to the extruder and the bowden tube are held together with a spiral cable wrap – it’s all tidy now; no loose wires.
  • Designed a new extruder fan duct. Works better and looks cool.
  • Replaced the M6 screws I was using for the Z axis with real T8 lead screws. This eliminated the Z wobble which was clearly visible to the trained eye before.

All this resulted in good prints at speeds above 100mm/s with accelerations 1600-3600mm/s^2!
Some photos of the current set up:

Print quality examples to follow shortly…

// END of status update

I realize it’s not “the best design in the universe”. But it’s mine, and it works, so I like it 🙂

What about the print quality? Well, it’s pretty decent actually – using similar settings to the ones I use on my Anet A8:

I would call that a WIN, and I am pretty satisfied with the result!
Now I will be working on making the design files ready for public release, and once I am ready, I will release everything I have under open source license, and of course I will make a BOM with links & prices!

In the mean time – happy 3D printing!

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