FAQ – 3DPrinting

What is 3D printing? How does 3D printing work? 

1 – What is 3D printing?

3D printing is a way to prototype parts rapidly in which a real object is created from a 3D design.
The digital 3D model can be saved in a variety of standard formats including STL and OBJ and then uploaded to a 3D printer for processing. The 3D printer then prints the design layer by layer and forms a real object. More info about the history of 3D printing can be found here.

2 – What is the difference between SLA and FDM?

SLA -> Stereolithography
SLA is a form of additive manufacturing technology used for creating models, prototypes and production parts in a layer by layer fashion using photopolymerization, a process by which light causes chains of molecules to link together forming polymers.
FDM -> Fused Deposition Modelling
This is the type of printer that is most common as it is cheap and can be readily made with a few simple parts.
It works by heating up a piece of plastic and forcing it out of a small hole in the same manner as toothpaste.
Imagine drawing a picture with just a tube of toothpaste by squeezing a line out and going forwards, backwards, left and right only.
Let that first picture harden and then do the same again slightly higher with the next layer of the part you wish to build.
The plastic mentioned above is referred to as filament and can come in a variety of materials, textures and colours.
Different materials can be used for different applications.
Wood, plastic, metal and rubber type materials are all used by 3D printers.

3- What material is used in FDM 3D Printing?

Plastic filament is unwound from a spool and is pushed into an extrusion nozzle which can turn the flow on and off. The most common materials are ABS and PLA.

4 – What is the material used when SLA 3D printing?

In this type of 3D printing a photopolymer resin is used.  Wherever the ultraviolet(UV) light hits the resin it cures (hardens), creating the object layer by layer.

5 – What is the RepRap project?

RepRap is about making self-replicating machines, and making them freely available for the benefit of everyone. We are using 3D printing to do this, but if you have other technologies that can copy themselves and that can be made freely available to all, then this is the place for you too.”

On the RepRap site, you can find the blueprints on how to build a 3D printer using another 3d printer and a lot of wikis (a many-user generated help site) to help you in the 3D world.
You can find more info here.

6 – How long does a 3D print take?

That depends on several factors:
The size of your model
The material you are using
The layer height (smaller layers mean more layers to print)
The complexity of your model
Whether the object needs supports
The most common slicers give to you the estimated time of print the model, but since external factors affect the job the print could use more time or less.

7 – How much should you charge for a 3D print?

Almost every maker gets stuck on this question: How much to charge? There are a lot of factors that need to be included in the price. Like the cost of the material used, the energy used, the time that the 3D Printer will take to printer the model. In this post, you can find a tutorial explaining how much to charge for a 3D print.

8 – Where do I find 3D models to print?

There are many CAD (Computer Aided Design) solutions that are used for designing parts, they all have their own advantages and disadvantages in their area of design. 123D Design is free and is good for most parts while Blender, which is also free,  is better for character modelling. You have to find CAD software that you find the best to use.  In this post you can find 10 sites to download 3D models to 3d print.

9 – How do I build a 3D printer?

Due to the open source ideology around 3D printing, you can find various kinds of tutorials on how to build your 3D printer from scratch without needing too much experience to build one, or spend a lot of money. On the RepRap site you can find the most common models of 3D printers, like the Prusa or Graber I3 printers.

Since here at 3DPrinterChat we don’t have a tutorial (yet), to build a prusa I3 3d printer from scratch, I will leave this link to a tutorial on how to build a Prusa.

10 – Where can I buy a DIY 3D printer kit?

There is a lot of sites that sell 3D printer kits:
and many more.
You may consider finding your nearest Maker Space where like-minded people get together to make projects and they usually have a 3D printer and if you are lucky tools like laser cutters. Check out for a list.

11 – Where can I buy filament?

Amazon or local suppliers in your country.

12 – Are 3D printers noisy?

In all printers are stepper motors and drive belts moving around, so you will hear some series of whirrs and chirrups. But these aren’t noises that will drive you crazy (especially if you tune your stepper drivers to make your printer quiet) unlike the alarm of a car ringing.
Some printers are completely enclosed which massively reduces any noise from them.

13 – How do you control a 3D printer?

You can control a 3D printer from the SD-Card slot or with a printer host. For beginners, the use of a printer host will be easier, some of the advanced users prefer to use the SDCard. Here you can find an article about this kind of controls, explaining the pros and cons about each one.

14 – Can I control my 3D printer remotely?

Yes. You can control your 3D printer over the internet or via your local network. Here you have a post explaining about OctoPrint, a printer host to control your printer from distance. Be aware that

15- How to build a simple 3D model to print?

Well, you can start making key chains for example, in this tutorial you can find how to make a key chain in Blender, the free program to make 3d models. here you can find on how to get 2d images and turn into 3d models.

16 – What is G-Code?

G-code (gcode) is the code that the printer will use to print your 3D model. gcode can be in a file as commands instructing where the printer needs to move and extrude (X, Y, and Z) that the printer uses to build your model.
Here you can find a guide explaining gcode in more detail.

17 – How can 3D printing be used for military purposes?

3D printing has brought forward many advancements in the military – from making prototype parts to making undetectable plastic weapons. Here you can find more info about the military uses for 3D printing.

18 – What types of Filaments are there?

You can find all about the different types of Filaments on this post.

19 – How to finish your 3D prints?

The acetone bath is the common way to finish a 3d print object.
Here you can find a tutorial on how to finish your print.

20 – How to Print in Multiple Materials with a Single Extruder?

That is a little tricky, but here you can find a tutorial about it.

21 – How to 3D Print Using FilaFlex ?

FilaFlex is a newer filament that allows you to print models that are flexible using a material similar to rubber. Here you can find a tutorial about it.

22 – Which slicer to use?

A slicer tool is an indispensable tool to work with 3D printers. You need this tool, to literally slice your 3D model, generating a Gcode file that the printer will use. There are a lot of slicers available in the market, and here you can see a video review of the most common of them.

23 – Whose 3D model is it?

Around the internet you can find a lot of 3d models to print, mostly these files are under a license, like GPL or Creative Commons, that protect the file from commercial use-for example, here you can find more info about the bad business practice that is happening in 3D printing world.

24 – What is bed auto-leveling?

Auto bed-leveling is the love of a lot of makers. Here you can find more info about it.

25 – Can I 3D print food?

Yes. A specially designed RepRap printer can print in chocolate or you can go for one that would work out the box. They are mainly used in top-class restaurants for desert making. There are also pancake 3D printers which can print (unsurprisingly) pancakes with pictures or text on them.

26 – Which filament thickness is better: 1.75mm filament or 3mm?

Neither. You often don’t get the choice – some printers use the thinner filament, some the thicker. It’s all down to the design of the print head. Check which thickness is appropriate for your printer, and stick with it.
1.75mm filament is a lot more flexible and needs less pressure to print with. This filament is quite easy to break however.
3mm filament is not flexible and can snap if bent too far. It also requires more torque on motors to push it into the extruder.

27 – Why are there so many extruder nozzle sizes? Which should I choose?

0.1mm, 0.2mm, 0.3mm, 0.35mm, 0.4mm, 0.5mm, 1mm. So many choices, only one extruder. Which one should I go for?
Consider the type of prints you are doing. is it something with lots of detail such as a face or something flat like a box?
A box won’t need much detail so you can get away with bigger size nozzles. This will also mean the print will finish much faster.
Something intricate will benefit from a smaller nozzle size but take much longer to print.
As an example of the length of time different nozzle diameters take time to print here is a table:
1mm 1 minute per layer. 1 layer. Total time 1 minute. Very poor quality – like gluing string to paper.
0.5mm 2 minutes per layer, 2 layers to get to the same layer height as 1mm. Total time 4 minutes. Poor quality but acceptable for low resolution prints.
0.4mm 2.5 minutes per layer, 2.5 layers to get to the same layer height as 1mm. Total time 5 minutes. Fair quality, fair resolution.
0.35mm 3 minutes per layer, 3 layers to get to the same layer height as 1mm. Total time 9 minutes. Good quality, good resolution.
0.3mm 3.3 minutes per layer, 3.3 layers to get to the same layer height as 1mm. Total time 11 minutes. Very good quality, high resolution.
0.2mm 5 minutes per layer, 5 layers to get to the same layer height as 1mm. Total time 25 minutes. Extremely good quality, very high resolution.
0.1mm 10 minutes per layer, 10 layers to get to the same layer height as 1mm. Total time 100 minutes. Stunning quality, difficult to see the individual layers.

As you can see the smaller nozzle sizes cause a massive difference to print times but the detail increases.

Which one should you choose? For a beginner .4mm would be a good choice because of the speed vs quality.
Consider getting an extruder with replaceable heads so you would not be tied down with this initial choice later on.

One thought on “FAQ – 3DPrinting

  1. Section 15 should be amended to include software such as Autodesk 123D, for those who are more comfortable or experienced with 2D mechanical CAD software and dimensional drafting, and for those who are programmers and adept with parametric statements, a software such as Openscad. I’m an old draftsman, and as such, could never get the hang of Blender, which is more attuned to artists, or Openscad, because I was never into programming. For me, 123D, and then Fusion 360 were natural progressions for one with 2D drafting experience. Sketchup would also be one for those with a mechanical bent as opposed to an artistic one.

    There should also be a section regarding proper storage of filament between prints, which filament types are hygroscopic, and how to recover wet filament. there are 2 types of dryers currently in use for that. One is a 5 gal vacuum chamber and pump, the other is a heated dryer such as the PrintDry unit from Canada. Living in Florida USA, I run a constant battle with humidity contaminated filament, and use both a vacuum chamber and a PrintDry unit for recovery, both to good effect.

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