Wanhao I3 Mini Review

So I purchased a Wanhao I3 Mini, this was because the frame of my main printer’s (Prusa i3 style clone) cracked and stopped printing reliably. So I got the I3 Mini as a bridge so I can print the necessary parts to put together a P3Steel, Though I do have a delta (Kossel I3 Mini), it’s still not printing very well and it too needs some parts printing before it would be up for the task.

The printer came well packaged, as all in one part with the exception of the spool mount (Just a case of screwing it on), It came with various little extras:

  • Scrapper
  • Glue (Pritt stick)
  • Allen Keys
  • SD Card (With test model on it)

Getting it setup and a first print out of it was a simple as plugging it in, following the levelling instructions and selecting the test file on the SD Card. The file started printing at very reasonable quality and made it about 80% way though the print before it came of the bed and failed.

So the biggest issue with the printer is the lack of a heated bed, I tried printing on the provided surface and though it sticks when using some glue, on longer prints the parts always come loose from the bed. My solution was to just use blue tape, it’s cheap and PLA sticks to very well. Because of the non-heated bed, it’s also necessary to print with either a brim or raft because on a lot of prints the corners will come up ever so slightly.

So there were a few things that were quite bad about this printer (I ended up taking the printer apart after my 5th print attempt):

    • The cooling fan stopped working after a couple of prints:
      • I found that the fan wires were just very thin and they had just broke where the printer was moving back and forth on the X axis.
      • The cooling fan was actually just plugged into a 24v port not the dedicated fan port, So I switched it over and brilliant it started working… However, I noticed that when I have prints longer than 20minutes the fan would just randomly turn off (I checked the gcode, it was not being instructed to do so), After searching and high and low for the problem, I believe it’s something to do with the printer’s firmware, I believe the firmware has some kind of auto off, which is why it was just plugged in to a 24v output port to begin with.
      • As a result of the cooling fan, the extruder kept clogging, there is only the one fan responsible for cooling the extruder (preventing malt plastic from getting stuck) and cooling the part.
    • Only 3/4 of the build plate can actually be used, the back 1/4 is unreachable without some modifications
    • The X and Y carriage have tensioning springs and are not very well tensioned, However the Y carriage hits the one of the GT2 pulleys making a metallic horiable sound.

So from the above you’d think this is a bad printer, Wrong! It is actually a very good printer, if all you want to do is print tiny models, this would be perfect, A novice would be able to get the printer up and running in no time, and as for my problems, it’s part of owning a printer, not everything is always going to be perfect. The printer is very sturdy, prints dimensional correct parts and prints them well. I would totally recommend this printer to a novice, especially at its price point.

For my current purposes, I’m going to leave the printer unmodified with the expectation of adding a Raspberry Pi for OctoPrint and maybe a few LEDS, until I’ve gotten the parts for the P3Steal printed at least. When I do get around to doing a couple of mods, here is what I have in mind:

  • Remove the internal power supply and the 240v connector, it only outputs 2amps at 24v and there is very little space. Instead I think I would build an external power unit that plugs into the back using a higher rated PSU.
  • Add a heated bed, probably just the silicon pad type heated bed and plugged it in to a Mosfet and wire it to the main control board.
  • Add an additional fan for the part cooling (will require designing a replacing X axis where I shall attempt to add more space) and plug it in to the FAN port
  • Flush the firmware and place the latest copy of Marlin on it. This will be needed to fix the fan port. Worse case I might just swap the whole control board out for a RAMPs board.
  • Place a Raspberry Pi inside the main the case and add a mount for acamera,
  • Add LED lights to the X axis so I can actually see things with out my phone torch!

I’ll probably write up a how-to for any modification I make, but it will be a while. For now, I’ll leave with you with a couple of pictures of the machine (inside and out)!

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