Guide to 3D printing with support from the Tevo Facebook group - many thanks! Definitely join even if you don't own a Tarantula. In this situation we won't tell you to check the manual, as there may as well not be one! And of course the folk on Thingiverse. Great community with great designs! Return the favor and share designs if you can, like I have.

If you find this guide useful, perhaps share it and give it a like.

This is a guide for people who either are thinking of getting into 3d printing or just started. This document is still being worked on (like everything else, sigh). Anyway, it's not written in stone, more like napkin notes!

 

 

BEGINNERS GUIDE

PT1 - GETTING STARTED

- General assembly
- Y axis & Bed
- Z axis
- Endstop Switches
- Hotend assembly;
- Heater cartridges & Thermistors
- Fans
- Extruders/motors
- Mainboard & Wiring; PSU, cables, SDcard, LCD, safety etc
- Mosfets
- Powering up
- Flashing
- Configurations/calibrations; EPPROM, PID autotune, Esteps,
- Slicing; (first get hold of a file to actually print – Thingiverse). Put it onto SD card. Now Gcode is ready.

- Upgrades; things to print. Stuff you don’t need. Stuff which might help.
- Maintenance list
- Troubleshooting

PT2 -PRINT SETUP GUIDE

General Assembly

Here we go, good luck, take your time, put on some music….

Ensure you start with a flat base. Can't emphasize this enough. If something isn't fitting right, don't then just continue assembling hoping it won't matter. Shine a light under the frame to make sure it is flat. If in doubt, get a Flat-Earther to check.

Get rid of split washers, they're crap. The only additional hardware you may need are regular washers, nuts and bolts, and electrical bits. Here's a good starting point for what you may need; M4 T-nuts, M4*10mm, M3*12mm, M5 Nylon lock nuts, M4 & M5 washers. For electrics; fans for cooling parts (5015), ferrules/ crimps (with tool), heat shrink, solder, maybe cabling, a power switch, and don't forget RGB lights!

 

Along with general tools:

Tweezers, Blade - to pick at things, and the blade to clean the bed surface
Feeler blades - good for Z height
Bendy mirror - can be handy for looking behind the printer
Cigar lighter - handy for work on the Hotend
Small brush - just to keep things tidy
Multimeter - so you check for a pulse

 

Belts

Stock are GT2 6mm, on a 16 tooth pulley. They need to be tight, so get either tension springs, or print out a tensioner.
An upgrade could be to change the wheels for 20 teeth. More torque = better resolution. But Esteps in firmware will need adjusting. You'll need to use the Prusa calculator and punch in the relevant numbers. Then you'll need to adjust the firmware.

[LINK]

Wheels

They're ok, not sure what all the fuse is about. Just mark them so that it's easier to see if one isn't turning.

wheels1wheels2

Spool Holder

There are quite a few cool designs out there. But avoid anything that mounts to the frame of the printer. Just because it won't be doing the frame any good with rolls being plonked on and off.

Enclosure

Plan it out before doing anything and give yourself allowance. Consider things like lighting, ventilation, cabling, spool location etc.
People like getting 2x Ikea lack tables. It works, but a slightly larger option is the METOD cabinet. But even that can get a bit cramped trying to duck your head in and out.
[PIC]

 

Upgrade Warning

There are some folk who immediately print upgrades and turn their printers into Frankenstein's aborted lovechild.

Yes, upgrades are good, but don't rush into doing them! Firstly you're not learning valuable insight for when the time comes that things go wrong. you won't know where the error is. Also the upgrades themselves are probably not going to be very accurate or reliable, so using iffy parts to 'upgrade' don't go hand-in-hand.
You might not even need them. It'll waste time and material. Don't go throwing parts at it!

If your printer isn't at the stage where it's ready to be printing quality items, don't go printing upgrades! Instead master the basic techniques (bed leveling, temps, speed) so that you have a firm platform to be working from.

Upgrade slowly, bit by bit so that you an see the effects. And you'll appreciate them more (winks at metal bed).

 

Y Axis (Bed Carriage)

*For large beds, move the endstop to 205mm from front of printer instead of 190mm.

*Metal bed upgrade is great. Firm, lighter in weight (145g compared to 194.5g), easier to access bed knobs, shiny.

*I'd recommend using a glass/mirror sheet as a surface for your prints. Don't print directly on the nice new bed!

*For adhesion people like to have their methods like glue stick, hair spray, scuffing glass, painters tape etc….you don't need that stuff, just clean glass. Seriously! The glass itself doesn't need to be special. Picture frame or mirror 2-3mm is fine. Note, the thicker the sheet, the heavier it'll be and will need more heating required to get it to temperature (more mass).

*If clips aren't for you, you can try double sided tape, works great for me. I'd go far as recommend grinding the glass to fit the bed perfectly, allowing the screws to be removed if need be.

glassbed
 

*You might want to print some kind of cable strain relief. Make sure the cable is securely attached; glue gun or duct tape. Give it some life by flexing it around (bend so it's not so rigid) a bit so it can flex easily as the bed moves.

*As the Y carriage has no tensioner, get a spring or some kind of tensioner on the belt.

*Over time, the connection may fail. Bad connection will result in higher resistance = things start burning. A solution is to solder directly to the board. But strain relief is even more important. Otherwise, fix a new connector or get a new cable.
In the example below, you can see the burnt connector. After hacking it off, and inspecting further I found it very loose. You could check these before this situation happens and it might be enough to stop things burning. But really, they're shoody connectors.

burntbed1  burntbed2

I decided to utilize the remaining fitting and solder directly to that. It seems to be pretty sturdy so it can act as my strain relief. Using this, it won't brea kthe board. The worst that can happen is that the pins get bent or the whole connection breaks off. But that would have to be quite an impact.
It was then double-insulated and has been working again just fine. 

burntbed3 burntbed4

Leveling bed tips

*Firstly note about glass if you use it. Is it on flat? No trapped dirt underneath right?

*Is the carriage assembled correctly? Sounds stupid, but seems like a common problem.

*You might find replacing the split washers for regular washers may help balance the 4 wheels holding the y carriage better. Split washers are no good!

bedlevel washers 

*Use a front facing Z endstop. So much better. F**k reaching round the back blind and f**king around with T-nuts. Adjustments are much easier with this.

[LINK]

Bed spring tightness/Bed knobs

You want to have the nuts threaded at least a bit in order to make sure the bed is attached firmly. The tighter it is, the more compressed the springs are which result in a firm bed. The advantage is that nuts won't loosen so quick, thus needing to re-level the bed. Also you don't run the risk of the nut just popping off mid-print. It will also stiffen the bed, which will help vibrations to a degree (it will transmit better into the springs/fame and resonate a little less.

The disadvantage is that (if really tight) there is less suspension in the sense that the springs will have less give. If the print head collides with the bed, it will transfer more to the acrylic. If it hits the print, it'll take more of the brunt and probably get knocked off. But really, you shouldn't have to worry about hitting the bed unless the endstop isn't working or you've forgotten something - doh!

*If you find one end lower/higher than the other, check the Z frame is square and X carriage is properly attached.

Check the Y belt isn't being yanked upwards. You want both ends pulling horizontally. Likewise check there isn't sideways motion. And make sure to get that belt tight!

 

Z Axis

The stock layout is pretty puny looking but works pretty well considering. Tarantula is single leadscrew. Check straightness by rolling on a flat surface and shine a flashlight under it. Make sure grub screws are tight! Bad noises is a sign of binding/grinding = not good amigo.

Many choose to invert the axis by putting the motor at the bottom. Firmware settings will need to be updated.

*Get some White lithium grease for the leadscrew. Also get a cap or something to catch oil drips from the leadscrew.

*I'd recommend the Front facing Z as mentioned before.

*BACKLASH NUT (UPGRADE) is good at relieving some jerkiness from things like the Z axis bouncing, doing bunny hops (Z hop).


Dual Z (Upgrade)

Decisions decisions....do you get 2 rods, 2 motors? Or single motor? To Z or not 2 Z, that is the question!

Another option is adding a second leadscrew. This is something I'm considering doing. There's also the option to have a single motor running both leadscrews or get a second motor for the second leadscrew. However as I have dual extruders, I wouldn't easily be able to plug it into the spare E1 port on the mainboard. It could be spliced into the first motors cables, but the motors will run at half their current or something (wired in Parallel). So if I go with dual Z, I'll probably just have a single motor running both screws.

The problem with 2 motors is that they need to be synced up. It's also a good idea to get 2 matching motors rather than adding an extra one from some random source.

*Also the firmware will need to be updated. To me it sounds like hassle. So for me, a single motor. Yeah it'll have to work more and kaput quicker, but then I'll just replace it. No biggie matching, coding etc.

 

Endstop Switches

You could go mechanical, optical, or use any number of other switching thing that'll give a signal to the mainboard.

It's worth resoldering even if they're working just to be sure. Then glob on some gluegun to stop the connections moving. If you wet your fingers a bit, you can shape the hot glue a little to get it smoother. Be careful as it is hot!

[PIC]

A common problem people seem to find is that the printer is hitting the endstop but not stopping, then it starts making a recurring bang /click noise as the motor is continually trying to turn, waiting for the signal to stop. It's easy to check if endstop switches work.

- Are they actually being triggered? If, not, why are you puzzled with the problem? reposition them so that they do.

- Are they actually connected? Check wiring. Check it's plugged into the correct socket on the mainboard.

- Can they be triggered when homing axis? No?, then stop the printer before it crashes into the frame/bed - CUT POWER. Find the problem. Don't just let it hump the frame and stare in shock, STOP IT!


BL-Touch

It replaces the Z endstop switch. There's genuine and clones. Avoid clones, but I hear they can still work fine.

I don't use one as I don't particularly need it. It's more stuff that could cause problems and it's added weight I don't want on the X carriage.

 

Hotend Assembly

All metal Hotend not good for PLA - melts and cause clog. quieter & prints faster

There are several parts here which confuse people greatly (including myself). This is the cake-layering part of the machine, where machine meets material and in a short space prepares it and lays it down whilst doing other things to get you the perfect line. Put on your baker's hat and prepare to dive into the business end of the machine.

It's probably best to follow the path the filament goes from the extruder to the nozzle. The Tarantula is setup Bowden style which is a PTFE tube going from extruder to assembly. It makes the X carriage lighter and guides the filament into the assembly properly.

Once inside the assembly, it passes through a heat-sink (aluminum block) which has a fan mounted and keeps the filament cool.

Further down the path there's an area known as the heat-break which is the divide between the cold zone and soon to be hot zone.

Then we enter the actual Hotend. This is where the heater cartridge lives and also a thermistor which monitors the temperature. This is where the cold filament gets heated, melts and starts to flow.

Then lastly we face the nozzle which is kept warm by the heat-block but not directly in the heat. It's the goldilocks zone where you want the filament to be ready to squirt when desired and on time.

*Most of the parts here are maintenance items, and having spares is handy for replacing things quickly.

The Tarantula comes with a 0.4mm brass nozzle. Other sizes are available. Generally hardened/steel nozzles are better and will last longer. However, I'm having no problems with the stock so far. Wear will come from the type of filament being run through it. Carbon/metal filament will abrade the nozzle quicker.

People seem to suffer with clogs. I wouldn't recommend jamming drill bits up the hole to try and unjam it. More likely you'll damage the nozzle. I'd suggest keeping temp on the higher side until you're confident you have good flow.

Otherwise if you have a clog, I'd recommend the cold pull technique. You might also want to check on the quality of filament being used. Don't be surprised if using cheap stuff you get problems.

Small Nozzles

* Good for detail, letter work, perhaps top layers. Could be used in dual combo!
* Take longer to print. clogs/under extruders. harder work on extruder, skips. use more torque. print gregg's weight extruder.
* Folks use silicone sleeve to prevent black dots and failed prints. I haven't had that issue yet.
* tougher to bridge gaps. increase extrusion te,p tp avoid bottlenecking
* Turn up temp to get it to flow easily.
* Setting correct Z height is more tricky, only slight.
* Turn retractions down
* Adjust alicer settings/Gcode
, more layers, extruder slow (20mmps)or it might grind filament/clog.

Dual Nozzles

Ah twin cannons. Recently I found a second extruder handy when the main one crapped out.

Pro's:

Can be a backup a Hotend.
Supports can be printed in other materials.
Can have different colours (although you could change filament during print)
Can have different size nozzles/setups, say a 0.2mm and a 0.4mm

Downsides;

Collisions, However, you could be having a leveling issue.
uneven fan distances.
Requires more calculating in the sense of offsets, calibrations, coding.
More parts/weight

TIP - Nozzle Height

I like to use a feeler blade (0.013?), and with the fan ON, reduce height until I feel the vibration (buzz) from the fan. It's such a good method, I don't need additional sensors/BL-Touch.

Leveling Dual Nozzles

Your gantry could be slightly sloped due to single Z leadscrew, so you might wanna adjust the nozzle heights.

Lower gantry until it touches bed, then loosen the set screws on the sides of the aluminum block which hold the nozzles and heat blocks. They can now freely be moved up or down. Adjust how you see fit and then tighten the set screws.

 

Heater Cartridge & Thermistors

You can use heat shrink to stop the cables fraying on the heater cartridges.

If you get error heating message, could be the Thermistors. Before jumping to replace, first inspect and do some checks. Look at the LCD and see what the temps say. If you got temp below zero, then most likely there's issue with the thermistor.
If you got a normal resting temp andit won't heat up (by looking at the temp on the LCD), then issue more likely with the heater cartridge.

 

To replace, just unbolt the heat sink from the carriage so it drops down. No need to dismantle lots of things. If the Thermistor itself won't come out easily, try heating up the block before removing.

When replacing, don't over tighten screws otherwise the lcd will say the temp has reached max (up into 600c) or you may damage the heater cartridge. Should be snug so they won't come out.

It's worth having a few spares as they can be a bit fragile. Also wrap with kapton tape if you have some.

TIP: heating up usually works, but you could add copper grease (automotive) to threads. Just a schmige over the hole before inserting screw. Or just avoid gunking up the heatblock.


Fans

Airflow is an important aspect of printing and electronics in general. There are 2 main areas of focus which seems to confuse people greatly; which fan is which, and how to wire them.

The fan that's bolted to the heatsink is the cooling fan. It's wired (in parallel) straight into the PSU or 12V main supply. It has to be constantly 'ON' when the printer is on otherwise you might get hot melted plastic goo traveling back up into the PTFE tube (known as heat-creep).

The fan/s pointing towards the nozzle/bed is the part cooling fan. Unfortunately the Tarantula doesn't come with part cooling fans, however they're cheap to buy. It's a critical upgrade and will need some kind of holder to mount to the Hotend assembly. It's wired into the fan terminal on the mainboard which will control the switching on/off and speed. Don't connect directly into a 12V rail otherwise it'll be constantly on.

Due to them being cheap, they can breakdown easily, so if you hear bad noises, it could be a sign things are beginning to go bad. It might be worth having spare fans, but they can be quite easily salvaged from old machines.

I've noticed that twin fan setups can help show if one of the fans isn't spinning as quick as it should. *TIP - It's easy to tell if you paint dots on them! Fans are a maintenance item, so worth keeping an eye on them.

 

 

..........Well done for getting this far. I need to go voer and spellcheck etc. It ain't over yet. More to follow after I sort out pics.