Tevo’s Turn – Taming The Tarantula 3D Printer

This is the tevo tarantula. I’ve only just unbricked the last 3d printer gearbest sent me (which happen to be an Anet a8) but I thought why the hell not – lets build another one. This is a first, there’s a assembly manual.

Off the bat – the box came well packaged and the inclusion of a manual lulled me into a sense of false security. The instructions were riddled with mistakes and was incomplete, so the build quickly became more difficult than it should have been.

It didn’t help that I was recovering from a cold and my brain felt like the foggy windshields of a doggers car at midnight – thick with evaporated human sweat.

Wow this actually has some sort of heat shield on the base. These stepper motors look a little bit bigger than the ones that came with the Anet  A8. Just generally everything looks a little better packaged and slightly better quality, but I’ll only know when I start assembling it. Ok I’m going to pause for a second and have a read of this, and then I’ll come back and start to put it together.

The machine is clearly robust – or can be upgraded to a robust machine but the design and similarity of many of the parts meant I quickly built the machine incorrectly. And had to backtrack once I’d noticed.

Wait I’ve already made a mistake. So these sections here are meant to go this way around. Damn-nations, this is going to be a long morning. One of the slide-in angle brackets also came without a thread drilled into the opening – so I had to tap and fix that. I found an angle bracket without a thread cut into it. You can see there’s no thread in there.

There were some upgrade components also supplied such as two rigid brackets, but because I didn’t have that information in the manual I didn’t use those parts until later in the build. And it also meant I had to partly dismantle the machine again – taking more time.

Ok that’s what it should look like. I’m going to assume that this ideler here is meant to line up with the aluminium extrusion with the centre. At the moment when the able spacers in, it’s about 2mm to one side. What I noticed was I can’t put the machine screw all the way in unless I have both, and that’s really to one side. And they’ve also got one ABS spacer in the diagram and I’ve been sent two. And that’s a bit confusing. When I attach both of them (ABS spacers) on this doesn’t turn. so what I think I need to do is get rid of one, and replace it with some smaller washers which sit onto tiny bearing on the idler and allow it to move.

There’s also a technique for installing the t-nuts into the aluminium extrusion. They are small enough to put in without having to slide them from the end of the extrusion. This might have made missing steps in the instructions a little easier – but you can if you are not careful miss the aluminium extrusions lip and tighten them directly to the plastic plates.

The only thing I can’t tell from the manual so far is where the terminal goes on the stepper motor. Which direction I should point that out too. My instinct is to have that going in this way and the label to be on top. If I’m going to have to change it, I’m going to have to take this plate off, so I can take this idler out. And now I’m left with one extra ABS spacer. I’ll put that over there. Next page.

All that said the machine has it’s advantages. The electronics and LCD display are a lot better than the anet A8 and there are two extruders mechanisms included – depending on which you prefer to use. The heat bed is also insulated underneath – probably a good idea considering the closest part is acrylic. V wheels – which I have coincidently use with my self-built CNC machine (link in the card) are great and also quite. Although you don’t notice that with routers. But the mounting openings for the eccentric spacers could have been to a higher tolerance. I eventually got things lined up and without noticeable wobble but again the design of this machine made everything feel a lot harder to complete. I have to say the hole here is really badly cut, and the eccentric spacer wobbles around like anything in there.

Ok they provided these spring washers to go between eccentric and spacers, and the wheels. And I can tell just looking at them they are completely on the piss. Luckily when I built my CNC machine I bought a very big bag on precision shims, so I’m going to replace these spring washers with normal ones. I’ve been trying to align the eccentric spacers so the hole is closer to the opposite side. I’ve been struggling a little bit as it doesn’t seem to hold that well. so I undone it so I could look at it visually. The eccentric spacers I bought for my CNC machine has a little notch in them so you could tell when you were turning them which bit was closest to the edge. I don’t particularly want to swap over to my ones – I mean the whole point is to use as much of the stuff that’s been sent with the machine.

Ok that’s feels alright. I’m going to put some extra nuts on these in case it loosens. Ideally this should really be out of metal. WTF, so you’re meant to put this on here to laminate it and in theory strengthen the part. To strengthen the part choose to overlay. It’s not really clear. Is that at the top or the bottom? I don’t know what to do now.

Ok I’ve just put a board down because I don’t feel like the table is flat enough, and I will reattach these while pressing it down flat. I’m using an engineers square to help me keep everything square.

Ok I’ve jumped ahead a little bit and made these two sections up. The motor the idler and the opposite end with all the v-wheels. That one goes on that side and that goes on that side there. This will go across and now I am going to assemble the gantry. I’m left with 4 machine screws which I can’t tell where they go.

I should mention here that I didn’t notice that I should have put the limit switches on the gantry before sliding it onto the extrusion. In fairness it was on the drawing but there was no explanation on the relevant pages. I later had to rely on one machine screw instead of two to keep it in place.

This piece here was out towards the camera, so I’ve loosened all the machine screws with the t-nuts along the gantry bar, and I’ve also loosen the top a little bit. This has shifted a little bit now so I’m hoping that I can actually square it up, as it didn’t feel like it was square at first. There’s definitely better brackets than the ones being used to square the machine up at the moment. They are slightly twisting the aluminium at the moment.

The manual also missed the steps for installing the timing belts. So you put them on a bit like when you realise you’ve lost a bit of weight and your trousers are about to fall off.

I went with the bouden extruder but the flimsier feeling one was the upgraded version – I didn’t realise.

There is a hole at the top, and I’m making sure that the teeth line up with it.

So I think I’ve found the next parts. This piece here. This wasn’t even in the manual as far as I can tell.

I’ll take that off.

I think I’m going to tidy up now. I found a bag with another extrude. It looks a little bit different. I prefer the one I’ve put on but there is a few extra things which I don’t quite understand what they are for, or where they’ve come from. Clearly there’s alternative setup for this particular type of machine. I think what I should do i stop, tidy up and do a little more research online to check whether there are some alternative build instructions and just compare them with what I’ve been doing.

Do you remember earlier I said I found two corner brackets that I only later realised I had to swap with the flimsy ones that were supplied and listed in the manual – well here I am doing it.

After the machine was assembled the problems didn’t stop there. Some of the parts can be installed ack to front for example, which I did with the controller boards mounting plastic. I only noticed I had done that when I ended up driving the y stepper motor into it. Luckily I didn’t break the plastic but it sounded like I had.

Wow the design of this is just ridiculous. I mean the stepper motor, I was drawing it down and I didn’t notice it catches onto the plastic here and I have a really bad feeling I snapped the plastic a little  bit.

A goose?

Two of the four limit switches also came broken and I had to solder new ends onto the original wires. Here are the broke ones. You can here there’s no clicking. That wasn’t too difficult but obviously you need a soldering iron and replacement limit switches.

Ok I’m going to put the limit for the Z… Here we go again, the limit is on the inside… This doesn’t fit now because I’ve got the bracket there. I’ve definitly seen a video telling me to put this here… Ok it’s this way around. So the limit switch is facing outwards… Ahh this is ridiculous. The clip actually slips out from underneath the plastic… I’ve stuck it this way around. It feel like it’s got the best position. It can still slip out but there’s not much I can do about it. I’ve had ot take one of the machine screws out just so I could fit this in place. That’s on the minimum z, I’ve stuck all of them on the minimum and left the max empty. I had to swap the polarity of x stepper motor so it moved towards the limit switch. This isn’t difficult but if you are expecting a machine that works once assembled – this one as with many in this price range require more user input than you might be use too.

I had to swap the polarity of x stepper motor so it moved towards the limit switch. This isn’t difficult but if you are expecting a machine that works once assembled – this one as with many in this price range require more user input than you might be use too.

So I swapped the blue and red around. You just have to be careful you don’t pull the crimp out, so you use a very small screw driver and lift the plastic up while you pull the wire out and that’s what it should look like.

When I built the Anet A8’s it’s wires were labelled and came in varying lengths depending on where they were meant to go. However with the Tevo tarantula, all similar wires came the same length – another features which adds confusion. The wiring does feel really messy and tidying all of that up will add hours to the build.

I do like this though as a controller. It’s a lot easier to use. The z axis was also making an odd noise once everything started to move, but I manged to realign the acme threaded rod by slightly loosening the top motor plate, and sliding it around while moving the z axis up and down until the noise had stopped – and then re-tightening everything.

All the problems with this machine can be overcome and once you upgrade some of the parts – which you can do with the printer itself, you’ll probably find you’ve forgotten about all the initial problems.

Oh-o, oh-o, I can see smoke.

Ok I made another mistake. I put the fan and the fan over here into the terminal labelled cooler fan.  Obviously I assumed that’s how you’re meant to do it but actually these fans need to stay on whenever the machine is on, especially when the extrude is heating up, and have to be daisy changed onto the power input. In fairness there’s a couple extra wires coming into the terminal there but as with everything else in this manual it does not mention it at all… well sort of. It says square fan but you have two square fans. Which square fan are you meant to put on? what I am going to do is connect the fans directly to the power supply unit, coz things are a bit tight in here to daisy chain them all together.

Instead of shoving these wires into the power terminal on the controller I decided to soldered them together, adding an extended wired which ended with forked crimps which I placed directly on the power supply unit. It’s safer and there’s less chance they will fall out unlike the control board terminals if you were to stuff it with several wires.

I think it’s the little things which annoy me with this design. They could have easily left some holes there so you could put an allen key in to reach the machine screw which hold the insert t-nuts against the aluminium extrusion. They could have also spaced the holes out a little bit wider so when you were tightening that piece up against the machine itself, you weren’t rubbing that piece up the edge of the allen key against the circuit board itself. There are all good things to notice about a machine because I think I will try and build my own one.

Ok that doesn’t look good. There’s also no… oh god.  Ok the answer was staring me at the face. The temperature needs to be 210C and I had that set to 190C. I was lifting it up a moment ago.

I then had to toggle the potentiometers on the controller to provide enough power to the steppers – in particular the extruder filament feeder. That motor was clicking because it didn’t have enough torque. This wasn’t something I had to do with the Anet A8. I have a sneaky suspicion that the PTFD tube is not going all the way into the hot end – and there were a few moment where the extruder seemed to be blocked and I had to pull the filament out and snip the mangled end. I then had trouble offsetting the z axis – which is the final stage to levelling any 3d printer bed. I initially tired to this on  the controller itself using the LCD display panel. It didn’t matter what I had set within the on-board controls, as the gcode would override it – so I set this in the slicer within in repetier host. I also can’t tell why the centre of the heatbed is offset. I thought I put the dimensions in repetire host but clearly I have to re-look at these.

Ok after 50 attempts it looks like it’s printing correctly but it is really offset. The positioning must be off.

Ok that looks really impressive for the first print. I think I’m just very lucky. There’s a little bit of a curvature on this side here, but this bit here looks really flat. This PLA is quite weird. It looks like snot. It’s come out really well.

So do I recommend this 3D printer. If you’re planning to buy one at this price range and you don’t happen to have one, then yes – but you are buying the potential for a good 3D printer and ignore the fancy packaging – it needs the work to get it there.

Ahhh no. So that was a major noob error. I didn’t let the head-bed cool down enough, or maybe I had it too hot while printing the PLA? Whatever I did, it returned the first print with a major haemorrhaging of the buildtak. 19.95mm

The print came out more or less ok though. I think I need to shore up a few places on the machine, but the quality seemed a lot better, off the bat than the Anet A8. I think it’s because of the bowden extruder which is not mounted on the gantry and results in printer head not having to move such a heavy stepper motor as well.

So this is how I replaced it.

To cleaned the adhesive off the aluminium I  used mentholated spirit, and a scraper.

I think I’m going to have to level the bed again once I’m done. I then carefully stuck the new buildtak on from one end to another pushing it down to avoid air bubbles. Ok I’ve got a spare one which I bought for the Anet A8 and what I’m going to do is just clip the corners so I can access the screws. Just for record this is 3m9080a double coated tissue paper.

I then put a piece of borosilicate glass with PEI plastic stuck to it, to print on. I’ll link to the video when I put those together in the card. I prefer printing PLA in PEI as it bonds well and easy to remove.

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