How To Guide 3D Printer Guide

[strongst]

This little guide should help newcomers to find some practical tips and the right technique for 3d printing projects.​

3D printing isn't expensive or hard to learn when you are able to operate a PC(no, not a playstation or xbox) and repair it by replacing a motherboard or it's components.

It is very useful to produce something that does not exist on this planet and you can't buy for money, like clip for your tablecloth(yeah, I've printed some for my table).

Also it can be cheaper to print spare parts rather to buy new producrs. I've printed a steering lever for my sons RC car for example whcih was broken and wasn't able to drive stright on anymore. So it sost me ~less than 1$ at all to fix this rather to throw the car away and buy a new one - safes the planet!

So here we go with a little overview:

1. 3D printing technologies​

2. Materials​

3. Software​

4. Firmware​

5. Tuning/repairing your printer​

6. Common problems​

For questions or discussion please head over here​

 

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1. 3D printing technologies​

I'll describe the most common technologies of 3d printers for private usage, as there are a lot way more 3d printing technologies used in industrial environments (Selective Laser Sintering (SLS) for example)
but they have prices of several thosand $ so no the scope we want to deal with at home

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Spoiler: Stereolithography (SLA) Printers

Those printers are using liquid plastic and UV light. The liquid plastic, called resin, changes his properties from liquid to solid when it get's exposed to light. Similar like dentists filling your teeth and exposing the infill to an UV light. The resin is inside a tank and the UV light is controlled with a LCD mask to light up only specific parts of the resin to produce a picture, like on a a LCD monitor. The resin will get hard on the print surface which will be pulled out a little bit an then the next layer will be exposed to UV light and with the LSC mask.

The resin needs to be handled with care and cured after printing too. It smells and should only be handled with gloves and goggles.

So using those type of printers is only for seperate rooms without kinds around.

The good thing is, you can print very small detailed things(resolution of down to .035mm on the XY axes) depending on the resolution of the printer compared to FDM for example. A printer costs several hundred $ or more depending on the resolution and size plus the curing machine and the resin. More information, see wikipedia.

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Spoiler: Fused deposition modeling (FDM) Printers

The most common, cheapest and secure printing technology for private usage.

The printer melts thermoplastic, called filament, from a spool and adding layer after layer to build an 3d object. Same procedure as a glue gun with glue sticks. but a print head moved on the x and y axis to melt down the filament on the built surface. The head will be lifted up a little bit on z axis until one layer is printed.

No curing afterwards, no smell(except for ABS or some specific thermoplastics), and safe to operate since the filament is not dangerous. Personally this type of printers is the best way for everyday objects and also mechanical designs where you can have issues with SLA due to the weak strength.

Also cool: You can print colored models either by switching the filament to another color at a specific point or using dual print heads or multi filament system. That's not possible with SLA printers.

Resolutions(layer high on z axis) of 0.1mm and 0.1-1.0mm in y and x direction are common and they are really cheap. For 160$ or less you can buy new printers + filament. Better ones are twice the price but are bigger or have smarter features. More information, see wikipedia.

 

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2. Materials​

Coming to materials we need to check whether it's for a FDM or a SLA printer, sure, that's easy cause all resin bottles are not for FDM printers and vice versa with filament.

Spoiler: Resin for SLA Printers

Most SLA printers are using a photopolymer which cures by around 405 nm of light which makes things easy when changing the printer or the material.
No temperature ranges or environment temperatures to take care of(not so crucial like FDM printing) but also each material needs it's own settings, especially the cure time.

You also have to wash your finnished print with IPA to get rid of resin(which is hazardous) wearing gloves, goggles and even a mask is useful. Then it needs to be cured again with UV light some minutes.

An overview of different resin types can be found here.

Spoiler: Filament for FDM Printers

Thermoplastic that melt at s specific temperature range(180-280°C) is needed for those machines, typically 1,75mm diameter is the common one. You'll find ABS and PETG(which is the same as a PET bottle, just optimized) in the tables below which are thermoplastics you find in everyday objects you can buy hence you know how stable they can be or how good the properties to form them are.

PLA is a specific Polymer which is made from natural substances and the most common, easy to print thermoplastic for FDM printers. But it's not really biologic and you cannot throw it into the nature

There are a lot of guides, overviews and tables out there where you can gather information which filament fits best for you, so I'll link you 3 guides which are my source for information when it comes to check the properties of filament for my project needs:

One
Two
Three --> great for comparison!

There are things to know for newcomers:

• One material, PETG for example, can have different properties within a specific range
• The same material from a different manufacturer can have different properties
• Different properties are printing temperature, bed temperature, strength and the look
• This is why all manufacturers give only ranges for the latter one cause printers are also not unique across all manufacturers.
• You need to make test prints with your unique setup to find the best settings for your project
• This is not a lot of work, but worth to do once you're changing to new material, especially from a different manufacturer

 

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3. Software​

When it comes to software for 3D printing there are 3 specific categories:

3D Modeling software(create virtual objects)​

Sure, printing out existing models from thingiverse.com or cults3d is fun, but why not starting to build something unique on your own? You need something that isn't available anywhere, a spare part for example? A toilet brush holder that looks like a heart?

This needs to be done with a drawing program, but, in the 3rd dimension, so paint or photoshop isn't here the key(but you can start with a 2D model for sure)

There a plenty of 3D modeling softwares out there, but I'll just show you some common ones which I'm using too and they are all free!!!

Spoiler: Tinkercad

Well this might be the starting point as a beginner. When you are able to build with wooden blocks when you were a child, you can simply operate this free online tool on tinkercad.com(registration needed)

Drag objects with the left mouse button from the side panel to the build surface in the middle, that's it!
You can stack, move, substract or merge them into groups. Resize them or give them exact measures.
Then siply click on export in the upper right corner and save as .stl whcih is the common format of a 3D printable object. You can also import the same file type or SVG images created with 2D programs like photoshop and make them 3D!

Easy to operate program!

Spoiler: Freecad

For more advanced modeling(not like minecraft) you'll need a program where you can make 2D sketches and extrude them into a 3D object(like you can do in tinkercad with .svg).
FreeCad is a good choice and...free. I like it but it's not as easy to learn like Fusion360 with many help and explanation buttons

nevertheless, you can find everything you probably need to make complex objects or easy ones like the nozze above which I've designed from a 2D sketch and then using the revolution function to rotate the sketch around the X axis to become an 3D object

Spoiler: Fusion360

As already mentioned, Fusion360 is similar but a little easier to operate. But you can also start with a 2D sketch, then extrude, add other 2D sketches and extrude them again to combine different objects

I like the history funtion on the lower left where you can jumt to any point and change them and also the cut view is nice to show what wall thickness you have

Slicer (Prepare the virtual objects for your printer, like translating them into machine language)​

Spoiler

Since FDM and SLA are additive technologies for 3D printing someone must tell the printer how a ball should be printed for example.

Imagine you want to print a ball of 5cm diameter with a glue gun, so you have to add several molten lines of glue above each other in a round circle until it becomes a ball, right?

This is what a slicher(to slice) software does for you. You load an .stl file into the program, hit slice and the model get's devided into slices(like when you slice an apple). This machine readyble code file can be safed and transfered to the printer. That's it.

There a a lot of slicers out there like Ultimaker Cura or Simplify3D or PrusaSlicer. All are operating the same way in general but have here and there better views or knobs and features where you can modify your print speed, setting for quality or look and also reduce the material to waste as little as possible.

Most of them can handle both SLA and FDM printers when you select the machine hence you have the same .stl model bu you can generate a different machine readable file either for SLS or FDM printers.

Ultimaker Cura for example has some cool and free addons in a marketplace like post processing, custom supports or calibration shapes. Also a extended settings guide is very useful to install!

In fact when you design a model you have to tinker about how your slicer can be translate this. If you create 3mm walls in tinkercad but your FDM printer has only a 0.5mm nozzle it might be cumbersome to print a smaller wall with a large nozzle.

Ultimaker Cura looks like this when opening a .stl 3D object file:

After hitting the Slice button in the lower left corner you'll see the "slices" and lines which your 3D printer(FDM) will understand:

Furthermore, near the lower left blue botton you'll see the estimated print time as well as the material amount in gramm or meter and, if set, the cost of the print(here 0,74€).
So you see it is not expensive at all(adding the power consumption of the printer).

Tools (to make it easier to operate your printer or create your objects)​

Those are optional and mostly for convenient reasons, but can help a lot to organize your day. Especialy a camera to watch your printer in the basement while you're in your garden.
You can tranfer your objects to a print server when you running OctoPrint on a RaspberryPi for timelapses or automated printing and surveillance.

 

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4. Firmware​

A 3D printer is a machine like your smartphone and has hardware like motors and sensors(or light source and LCD screen on SLA) which are controlled by a mainboard and it's firmware.

The most common firmware, especially for FDM printers is Marlin which was found in 2011 for the RepRap project and used by dozens of different printers today. There are also forked projects like jyers which have nice additions or UI menues.

The firmware is open source and specific configuration files can be found here. You can easily modify it for your own printer, for example when you replace or modify parts or add sensors, replacing the motherboard etc., compile it using platform.io and flashing the firmware to your printer.

More advanced firmware for 3D printers is klipper. You need an external PC(like a Raspberry Pi) where you run it, but the advantage is, that the calculations for speed, accelerations and hotend pressure are faster and more reliable than on your slow 8bit printers mainboard.

 

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5. Tuning/repairing your printer​

FDM printers offer more mods or tuning capabilities than SLA due to the various settings and mechanics.
So I'll focus on FDM mainly.

If you buy a Pruse i3 MK3s for 1000$ you probaly won't need any mod at all, but if you start with a 160$ i3 style clone printer there must be some space for the price range and this is the quality and the features you can buy or not.

That said, low price = low print quality, less or no support, slow printing, less features.
In general this is the same as with a cheap drill driver but it depends on your needs espeacially the quality you want to have or how long you want to wait of your print to be finished.

Also watch out for printers for which you can buy spare parts(or print them at your own like for Prusa printers, they offering open source models of them) or not. Common Creality Ender 3 or 5 printers have a huge community and you can buy plenty of spare parts for really cheap prices.

Not so common, high price printers can have not a big community and replacing a motherborad can be expensive for example!

When you want to tune your printer you need to understand why you have to do so.
Replacing a print bed when you have bad bed adhesion can have other reasons too(temperature, nozzle distance, speed). So just replacing somthing when you read this is necessary is the wrong way.

Every printer comes pre assembled(except SLA. Prusa or high price printers can be sold pretested and assembled, like a multimeter) and not tested from the factory. So you have to finish the printer and start to calibrate it, like you do on a inkjet printer for example.

That means, you are most likely the reason why the printer isn't printing like expected. But also why they are so cheap, ok?



tbd

 

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6. Common problems (FDM printers)​

As already mentiond in part 5, most likely your are the reason for most problems that occur during the printers life.

Whether it's out of the box during assembling or later when using wrong settings. Only a few printers can calibrate or troubleshoot on it's own.

Some low price printers have a bad reputation due to missing quality control which can have impact on the print quality(layer shifting, z axis binding) but most problems can be fixed on your own

By printing test prints like a xyz test cube for example, you can check whether your printer has dimensional accuracy or not or other mechanical issues like shifted layers. Fixing those issues one after one is not that hard but needs some time and preparation.

In general, setting up a 3D FDM printer should follow this scheme:

1. Bed leveling and nozzle distance to the bed(depending on step 2)
2. Steps of the extruder motor per mm (I'm using one-wall tests and one layer tests)
3. Steps of the x, y, z motors by using defined test shapes for accuracy
4. Stringing/retraction test and settings to improve the quality

More to check are flow rates and compensations, but in my opinion this is not necessary when you have checked the 4 steps before.

Most of the settings have relations to each other.
Example:

When your hotend melts less material than expected cause your extruder does not transport as much as he should, then less material have a chance to stick to the bed hence you need to lower the distance between your bed and your nozzle.


tbd

 

[svetius]

Awesome guide @strongst -- great info.