3D Printing

Time for something different – no I’m not starting a Podcast, or creating a You Tube Channel* – I’ve treated myself to a 3D printer for my birthday. If there is anything I am good at it is finding distractions from current projects, and this has gotta be the mother of all distractions – or at least the rapid prototyper of all distractions. 

*(audio/video editing is too much hard work for my liking)

I backed a Kickstarter – its seems that kickstarters are to blame for a lot of things lol – because I really liked the model(s) and well it was the perfect excuse to get a 3D printer. I even put up some shelves in the spare room with the intention of putting the printer there, large height and depth to accommodate something big, running an extension cable there for power, and putting small strip light on the underside of the shelf above. So this has been on the cards since March, so between then and now I have been researching which printer to buy. Oh My God, this is a mine field!

This is the criteria I was looking for:

  • Small enough to fit the space on my shelf.
  • Cheapish printer, preferably less than £200.
  • Capable of a decent quality print.
  • Easy to set up i.e. either ready to go out of the box or a simple to build kit.

Big ask? Well I have to admit I got a bit annoyed looking at the choice, considering I know very little about the technology. So my choice was actually more informed by seeing what other miniature hobbyists had produced on their 3D printers. That is pretty much how I ended up with the Creality Ender-3. Sadly, I am struggling to find the forum post to reference that pointed me towards the Ender-3 in the first place – it had some excellent looking models.

I bought the Ender-3 from Amazon, although I’m seeing it cheaper now at many other retailers – its “like to be” as the wife says. But being Amazon it did get delivered pretty quickly.

 

As you can see this whole 3D printer thing caught my 4 year old son’s attention. He did “help” me build it. All credit to him, he was very eager and I was being the old ‘fuddy duddy’ reading instructions and other stupid slow things. Although I can’t help but think I would have been twice as quick without *cough* “help“.

 

Speaking of instructions, they are pretty good. Very Ikea like, barely any textual description at all.

 

In true ‘fuddy duddy’ style, all the bits laid out (yes its comes with tools) and my favourite part is the labelled zip lock bags telling you the contents (actually I really like the Ender dragon logo – the former is the engineer in me, the latter must be the arty side of me).

 

Don’t worry this isn’t a step by step how to build the Ender-3, I’ll just highlight some issues I had with the build. My first issue was with Step 7, and how the two screws mounted the Bowden extruder bracket to the V-slot bar. In my defence I was still being “helped” by my 4 year old, but at the time I was struggling to orientate the bracket as per the diagram and work out how to attach it. The eureka moment, pictured below, when I realised the holes on both plates that form the bracket line up allowing the long shaft of the allen key to tighten the bolts.

 

It wasn’t long before I reached this stage, and was thinking of switching the machine on. When I realised it had developed a wobble. All the way through the build the four feet were flat on the table. Second issue: the front right foot was now ~3mm off the table.

 

Backtracking through the instructions Step 10 fitted the cross bar to the top of the uprights. I almost loosened off these bolts a little, however my guilty conscience started nagging at me, because… Way back at Step 1, I really graunched up the bolts attaching the uprights in the first place. I turned the printer on its side and loosened those bolts off – there was no need to apply as much torque as I had done in the first place – and tightened them to a more reasonable level. Putting the printer back on its feet I found that all 4 were back touching the table.

 

The time has now come to switch it on. At this point I realise there are no instructions in front of me on how to actually use the printer. The inner 4 year old says “you don’t need instructions, its only got a single push button twiddly knob” (they were on the supplied micro SD card). So I power it up, and scroll through the menu system. I find the ‘Auto Home’ selection and press the knob. The x-axis motor whirrs to life whizzing the nozzle assembly into the x-axis end stop switch, turning off the motor. Then the y-axis does the same. The z-axis motor powers up, turning the threaded bar bringing the x-axis bar down towards the end stop switch. Just as it touches the switch the bar stops moving and there is an horrendous noise as the motor continues to try and turn the threaded bar. I quickly switch off the power, and start taking a closer look at the z-axis mechanism.

This is what I found… The x-axis assembly is just touching the switch, but not enough to activate it. So even though the x-axis assembly had reached the stop switch the motor was still trying to turn the threaded bar but was unable to for some reason. Looking at the z-axis motor I noticed it was at a slight angle to the frame. With the motor off vertical by a small amount the threaded bar must be too. Assuming the motor is a rigid anchor point for the threaded bar, with the x-axis assembly near the top the angle the threaded bar is off vertical is small. As the x-axis assembly descends the angle off vertical increases to the point where the threaded bar jams in the x-axis assembly. It just so happens this occurred just as the switch was contacted. I loosened the z-axis motor bolts off slightly (instructions Step 4), which immediately allowed the motor to be parallel with the frame. Powering on again, the Auto Home worked as intended.

That’s it everything ready to go…. except the PC side of things. But I’m not going to bore you with that. Here are my first prints…

In the above picture on the left, a messy blob because I forgot to level the bed. Centre, the provided test file of a dog. Right, the first print of the Chicharra aircraft from the Kickstarter (ran out of the supplied filament part way).

Close up of the test dog model supplied on the micro SD card. I felt a bit let down with the quality of this print if I am honest.

 

Close up of the Chicharra incomplete aft fuselage. I had adjusted print settings before printing this, because of how i felt about the dog. Compared to the dog this came out amazing quality.

 

All in all I am really happy with how my experiment in the world of 3D printing has turned out. It has been a much less trouble free experience than I expected. I think I may have got lucky in some aspects, the sheer quantity of settings to experiment with is staggering. I’m glad my partial Chicharra print turned out as it did, I don’t think i would really have had a clue where to start changing settings to improve quality.

You’ll see a complete Chicharra model in my next post.

One response to “3D Printing

  1. Pingback: Chicharra – 3D Print and Assemble | Splayed Paint Brush

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