GUCOCO A8 DIY Printer Assembly

So now I’m the proud owner of a 3D Printer. To be specific, its a GUCOCO A8 Prusa i3 DIY 3D Printer and according to the the Amazon listing it looks like this:

On delivery, however, it looks like this:

Still, it did say DIY on the tin, and I enjoy a bit of a challenge, so I’m hoping this will be fun. I’m sure it will be, as the instructions are in Chinglish. I’ll be referencing these instructions as I go (where needed), so I’ve uploaded the manual as a PDF for your perusal. Open that rather than the included .DOC file, as I’ve had to reboot every machine I’ve tried to read it on. So…

Before we go any futher, please note: I am not an engineer, technician, 3d printing expert, experienced kit builder (well, apart from model railway building kits), or in any way a competant person. If you’ve read the progress of my Raspberry Pi Dalek, then you’ll know not to expect miracles here.

I did once build a 2D plotter from scratch, but that was nearly 30 years ago, back when I was young, clever, optimistic, and able to see properly.

Firstly, go and find/buy a small amount of Blu-Tac (or smilar). You will find it useful for temporarily holding the M3 nuts in place in the various frames while the screws go in. Later you might want to use Milliput to secure the nuts in place., as they do tend to rotate if over tightened.


Step 1 A1 Main Frame Installation

Parts (as it doesn’t relist them in each stage – we are not in Ikea territory here):

  • 3 – M3 Washer
  • 4 – M3 Nut
  • 6 – M£x16mm Screw
  • A1 – XZ Frame
  • A2 – Left Side Frame
  • A3 – Right Side Frame

There are 6 screw/washer/bolt sets to put in, and their locations are fairly obvious.

The photos in the manual are ok, and there are no major pitfalls, apart from over tightening. Don’t worry if it looks like the frame is slightly on the wonk, as it will straighten up later.

Step 2 A2 Main Frame Installation


  • 5 – M3x8mm Screw
  • 21 – Dupont Cable
  • 23 – Power Supply

What isn’t clearly shown is that the PSU should be mounted OUTSIDE the frame. And you’d best check that the 110/220v switch is set to the correct voltage. Get it wrong and there will be a loud bang, and possibly a fire. It annoys me that the frame has a swirly cut-out that suggests a fan output, yet the PSU has a blank flat face adjoining it. And no, I didn’t put the PSU on backwards.

Don’t connect the mains power cable yet, as it will just get in the way.

Step 3 A3 Module Installation

  • 28 – Control Board
  • 5 – M3x8mm Screw (4)
  • 9 – Fan Column Support (4)

These go in the bottom 4 holes on the Left plate. With the PCU facing OUTWARD and the right way up!

Step 4 Wire Connection

  • 21 – Dupont Cable (again).

It goes off the rails here and goes on about parts used in the next few steps.

In English… Take the power cable from the PSU and connect it to the Red circuit board. Remember Red is Positive and Black is Negative. But if I have to remind you of that, then you should have given up just before the ordering stage. It also suggests connecting the mains cable (again), but it just gets in the way.

Step 5 Assembly of P Module

  • 6 – M3x16mm Screw (6)
  • 4 – M3 Nut (6)
  • 3 – M3 Washer (6)
  • 22 – Short motor cable Y
  • P Module

This is an arse-pain.  As this is a vital step, you can’t just mung it and hope for the best.  You WILL end up hanging the frame off your knees and swearing at the cat in a whole new variety of permutations of curse words if you get the wooden grommits on the wrong side of the frame. And you’ll need an M3 spanner or some pliers to help tighten the nuts on the wooden grommits. Only after that ordeal can you look at plugging the wires in. Oh boy.

Aside from the Blue wires, it doesn’t really explain which is which.  Which is nice.  So here we go…

So after this step:

Step 6 Assembly of A4 Module

  • 6 M3x16mm Screw (3)
  • 4 M3 Nut (3)
  • 3 M3 Washer (3)
  • 22 Short motor cable Z1
  • A4 module

Straight forward, but fiddly. On mine, the Z-axis limit switch was not bolted on, so I had to fix that.

By now the board should look like this:

Steps 7 and 8 are messed up

Steps 7 and 8 have the same instructions, so I did this instead.

Step 7 LED Display Assembly Method

  • 6 M3x16mm Screw (3)
  • 4 M3 Nut (3)
  • 3 M3 Washer (3)
  • 13 LED Module Cable
  • LED Module

No real issues here, so…

Step 8 Assembly of A5 Module

Basically, you’ll need to fit the A5 motor to the Right side of the fram, much like the A4 motor. This one doesn’t have the Z-axis switch though…

  • 6 M3x16mm Screw (3)
  • 4 M3 Nut (3)
  • 3 M3 Washer (3)
  • 22 Short motor cable Z2
  • A5 module

See photo:

And the circuit board now:

Now we should be back on track

Step 9 Q Module Assembly Method

  • 2 Threaded rods (2)
  • A4 Left and Right top plates
  • 6 M3x16mm screw (4)
  • 4 M3 nut (4)
  • 3 M3 washer (4)
  • 1 Smooth rods (2)
  • 22 motor cable (X)
  • Q Module

Oh deary deary me.

Take the Q module and stick the smooth rods through the outside holes. Then thread the threaded rods through  the threaded holes.  About half way for now. Then line up the L&R top plates with the rods and bolt them in. The motor should be on the Left side hanging backwards on the frame.


“Adjust the distance between the left and right bearing of Q module, and move the screw locking ring NO8 to the connected area of screw rod NO8 and A4 plate and fix the scre locking ring.”

I have no idea what this is refering to and there were no parts.  This bothers me.

“Align and insert the the flexible coupling M5 and A4 module with extrude side of the motor on A5 module. As ashown in picture 25, adjust the difference between left and right side of Q module. to prepare for the next correct assembled. Adjust the outer fringe’s horizon distance or both screw rod NO2 at nearly 320mm which is described as picture 27. The fastenin screws of the coupling of the fixed motor above are shown as picture 26.”


So picture 25 (and 26):

Pic 27:

I measured the distance and it was “nearly 320mm”.  And I think it means “push the flexible couplings onto the motor stubs as far as you can and then carefully and tighten them up then make them level”.

Then connect the red cable to the circuit board and use the short motor cable (X) to plug in to the board.

So now the board looks like this:

Step 10 Print Head Assembly Method

  • 6 M3x16mm screw (2)
  • 3 M3 washer (2)
  • 4 M3 nut (2)
  • Print head (L1 L2 L3)

Ok, so… Unbolt the 2 long bolts throught the cooling fan, and the assembly will come apart.

There are 3 bits:

L1 (The bracket, and extruder)

L2 (motor unit)

L3 (heatsink and cooling fan)

So now take the L1 unit and bolt it to the cross-peice of the Q Module. Of course the instructions don’t say which of the mounting holes to bolt into, but from the photo provided it looks like the bottom ones.  Plus if you used the top holes, the printhead would be able to smack straight in to the hotbed!

Now put it back together just how it came apart.

There is a veritable Rat King of wires coming off this assembly, which you’ll need to tie up with the handy cable tidy.

The end of this unholy tangle needs to be plugged into the circuit board.

But, Houston, we have a problem! There are two fan sockets to plug in to, and only one fan!

Above, we see the connector plugged into the socket suggested by the supplied pic of the board:

Luckily this is confirmed in the 29 minute build video:

That connection signifies almost the end of the build. There is only one thing left to do, and that is to connect up the highly dodgy and unsafe mains power lead.

How can that power cable be legal in a country where we aren’t even allowed to wire up our own plugs anymore? Thinking about it, the device doesn’t have a power switch, or CE approval, so plugging it in will invalidate my house insurance. But, I’ve welded stuff in the kitchen without burning the place down, and I’ve got a fire extinuisher somewhere, so what is the worse that can happen? Death, that’s what.

So, given the choice  twixt Death and the chance to print my own Daleks, the power lead gets wired in.

Before that, just a quick aside on UK wiring colours.

  • Live is Brown, but used to be Red.
  • Neutral is Blue, but used to be Black.
  • Earth is Green/Yellow.

So given these terminals and the colours of the wires,

it should be, from left to right, Red, Blue, Yellow. And it is.

So close the laughable safety flap…

… and get ready for POWER UP!

Almost. Manually crank the left and right screwed rods down so that the head is just above the plate, and move the plate around to level level it using the 4 wingnuts in the corners.  Then adjust this bolt sothat it maked contact with the Z-axis limit switch:

You’ll be fine tuning this later.



Slightly worried that there isn’t actually a card inserted, but it changed to “Card removed” after a short while.

And don’t peel of the blue tape like I did. Oops. But it was crumpled anway, and I’ve got loads of making tape laying around.

Assembly done! Shakedown and test printing to follow.


Going Straight: On the Wrong Track

The pilot episode of “Going Straight” (sequel to “Porridge“) was the  show that started me off on finding errors in TV shows when it came to their depiction of railways and trains, and Stafford.

According to Wikipedia, the plot of this episode is: “Fletch, having been paroled, makes his way home from prison. On the train, he bumps into Mr Mackay and an old friend.”

This is going to be a brief one, as I have no intention of identifying the coaches used, just highlighting errors.

I apologise in advance for the blurry nature of these screen-grabs. Things weren’t exactly HD back in 1978.

07:48 That’s a Deltic!

Yes, the blurry yet unmistakeable front end of a BR Class 55 Deltic, undisputed Kings of the East Coast Main Line in the late ’70s. Here we have the slight problem that anyone travelling from the fictional Slade Prison in Cumbria to London would be on the West Coast Main Line, which at the time used different locos.

07:55 That carriage looks fake

Ok, so I said I wasn’t going to start carriage spotting. I lied. Anyway, those seats look like school chairs, and the camera position would be about a foot outside the the carriage. Otherwise it doesn’t look too bad. It is a bit short though, and the windows are too far apart.

(aside: “26p for a beer!” Tartan Bitter!)

12:52 “This is Stafford, this is Stafford”

Indeed it is! And it looks as grotty today as it did then. Thirty years, and the main change is that those signs have been replaced. Multi-million pound refurbishment my arse!

As far as I can make out, the loco is BR Class 86 86221 , but someone will point out my error if I’m wrong. Clearly not a Deltic though, and certainly WCML not ECML!

13:03 Running though the tunnel.

Hold your horses! A tunnel? At Stafford Station? Such a thing has never existed! The main reason for this is that the station lies too close to the flood level that about 10 minutes of rain will bring.  On a good day, the park (opposite the station) becomes a boating lake (important note: do not take an inflatable dinghy out on the flooded park – the police will get involved and it will not end well).

And the Manchester Evening News advert? Not ’round here mate.

13:48 This is what a real carriage looks like!

Filmed on filmstock, not the video tape used for the fake carriage above.

Fast forward to…

22:42 “Watford Junction”

First thing to notice is that the loco has changed. I *think* this is BR Class 86  86208, but that loco doesn’t seem to have gone into service until 1979 (same for 86221 above).

Anyway, the mismatched locos weren’t the point of this. The point is, Stafford Station doesn’t have a tunnel, didn’t have one in the ’70s, and TV producers still don’t pay enough attention to detail.

(See posts about Doctor Who and Railways for more guff).

Doctor Who: Trains on the Flatline

“Flatline”, S08E09, is an episode of the new Doctor Who which has bothered me for a while. I’m not on about the plot, which I quite like, but I always wanted to know where the railways scenes were filmed, and what the stock was.

I’m not going to dissect the whole episode, just the bits that refer to railways. So, obviously we’re going to be ignoring a hell of a lot of the episode.

03:00 – 04:06  and we already know where we are: Barry Island. Specifically,  on the former trackbed of the original Vale of Glamorgan line which would have run though Barry Island Tunnel. The building is the Plymouth Road Shed, just to the east of Barry Island Station.

Which, by the Magic of Television, has now moved to become part of  Bristol Sidings 344 (confirmed in the dialogue).

Note that Clara walks off in the direction of the tunnel. She’d get about 200 yards before hitting the fence. All civilisation lieth the other way…

06:16 – 0814 Same location (minus the TARDIS interiors). Nothing new to learn here.

20:15 – 25:11 And we’re in one of the Barry sheds (when we aren’t in the TARDIS). Note the presence of BR Class 08 Shunter 08503, one car of a DMU set (probably BR Class 101 DCTL 56356) and parts of a steam loco with a GW partly restored tender. There also seems to be a Road-Rail Vehicle and some more carriages in BR Yellow, but they’re not clear enough to identify.

And then they run into a storeroom, which allegedly leads to the tunnel (really, it doesn’t).

25:23 – 27:47 The tunnel. Note immediately the lack of tracks. Barry Tunnel is a shooting range.

To be fair, the do say that this is the “old tunnel” and set off to the junction with the “new tunnel”.  Good luck finding that one on Barry though.

A big hand snatches someone away, some running happens, and they need to open a door. But wait, suddenly they have track! As Barry does not have any track within a tunnel, we are clearly somewhere else now. Let us see how this unfolds.

27:47 – 29:42 Another tunnel. Cue running, and the TARDIS getting dropped a few floors. On to the running line. Specifically on to a Barrow Crossing over a running line.

Now forgive me if I’m wrong, but the TARDIS shouldn’t actually be in danger at this point. The train should just pass over it.

29:42 – 29:44 Cue a CGI/SFX  representation what looks like a 3-car DMU (likely a Class 117)in BR Green with an A113 headcode thundering down the tunnel. BR Green. Headcode. In 2014? And A113? Well its not a valid code anyway, and is just an in-joke with animators.

30:08 – 30:21  And The Doctor is doing his best to actually get the TARDIS directly under a wheel.

30:35 – 30:47 TARDIS falls back on to the rail, and The Doctor pulls a lever. Yeah, maybe that should have been done earlier.

30:48 – 31:41 In the tunnel, and a train is coming. The same CGI’d one that is now 2M65.

32:01 – 32:25 Stationary in the tunnel. It looks to me like a BR Class 117.

32:32 A BR Logo

That Logo is the “Ferret and Dartboard” one used from 1956 to 1965.

32:37 Hang on… Red seat moquette? Cubic grab-handles? Modern arrow signage? Drop window slam doors? Wales? Could this be the Gatwick Express Mark 2F/Class 488 set again? Possibly, but the colours are wrong.

  32:39 (approx) Even working this frame-by-frame doesn’t help. Best I can get is W5???3 or something.

32:40 – 33:19 Back in the cab. Nothing helpful here really.

Scenes from 32:32 onwards doesn’t show any tunnel parts, so could well just be filmed in the dark at Barry.  Sadly Barry doesn’t have the right rolling stock, so we have to look elsewhere… maybe somewhere with a tunnel to film in that isn’t too far from Wales.

Step forward the Gloucestershire Warwickshire Railway, which conveniently has a Class 117 set (W51360, W59510, W51363) and Greet Tunnel. W51363 could be the blurry number above.

So far we’ve got:

  • BR Class 08 Shunter 08503
  • BR Class 101 DCTL 56356
  • BR Class 117 (W51360, W59510, W51363)
  • Unknown Mark 2F/3 Possibly from the Class 288 Gatwick Express set at Barry.

And with that, I think my work is done.

A lot of moaning old shite