FA 5 - 3D Printing and Scanning

Fab Academy 5

3D Printing

INDEX:

Here you will find an Index with links to easily navigate through the section content.

1

Intro:

The process for creating a website.

2

3D Printing:

A little explanation about what is GitLab and version control.

- 3D printing Methods.
- 3D printing materials.

Based on the methods used for 3D printing, we have seen that different materials can be used. And it is that a printer cannot use any material to print but has to use some compatible with the type of printer and technologies used. Some materials also need different bed or noozle temperature.

There is a wide variety of materials used for printing objects in three dimensions, from liquid, solid, flexible, transparent, opaque, colored materials, etc. And also there is a lot of experimentation with new materials like cells for printing body parts, chocolate, clay for printing buildings, mycelium, casein an other natural materials.

Polylactic acid (PLA)
It is a polymer made up of elements similar to lactic acid and with properties similar to those of polyethylene terephthalate (PET) that is commonly used to make packaging. A thermoplastic made from cornstarch, cassava, cassava, or sugar cane.

Laywoo-D3
Material formed by the mixture of a polymer, similar to PLA, and wood powder in different percentages and that offer a result with a similar appearance to wood and that can be easily painted and sanded.

Acrylonitrile butadiene styrene (ABS
On this occasion, it is a very resistant plastic that withstands high temperatures. It offers some flexibility and is easy to paint.

High impact polystyrene (HIPS)
It is a variety of polystyrenes, a polymer that is quite brittle at room temperature and that it modifies by adding polybutadiene to improve its resistance.

Polyethylene Terephthalate (PET)
It is a type of plastic widely used for beverage containers. Chemically it is a polymer that is obtained from the polycondensation reaction between terephthalic acid and ethylene glycol. It belongs to the group of synthetic materials called polyesters.

Thermoplastic elastomer (TPE)
They are a type of polymers or mixture of polymers that form thermoplastic and elastomeric materials. That is, they combine the advantages of elastic materials such as rubbers and plastic materials.

Filaflex
It is an elastic filament with a polyurethane base and other additives that together offer great elasticity. Printing with this type of material is slower but it is very useful for certain objects.

Laybrick
It is a material that results from the mixture of various plastics and plaster. This makes objects look like stone and can be easily painted and sanded.

Nylon
Synthetic polymer from the group of polyamides. An elastic and resistant textile fiber widely used for the manufacture and manufacture of fabrics and fabrics.

Amorphous Metals (BGM)
Amorphous metals with those that have a disordered atomic level structure, which allow various forms for their solidification.

One of the most important things I learned was hot to properly calibrate it, which I thing is one of the most important settings in order to get a good quality printing, plus having your printer bed pretty clean.

CALIBRATION:
In the beginning I started calibrating it with some calibration printed tests, but this process takes to long because you will have to wait for the print to finish, calibrate and test it again a lot of times, so I prefer to do the paper test:

1 - I move the noozle to automatic home and then disable the stepper motors so I can easily move it in any direction.

2 - I move the noozle so that it is right on top of one of the calibration springs and knots in the corners.

3 - You pass a piece of paper between the noozle and the bed, and star adjusting the knob until the paper slightly pases between them with a little bit of force.

4 - You repeat the same process in the four corners many times, because when you calibrate one, the others will decalibrate, so you have to repeat it many times.

CLEANING:
Some people add hair spray to the bed so that the object sticks better to it, I personally have never used it outside of the lab, but I discovered in some tutorials that cleaning the bed with a cloth and a little bit of alcohol works very good, since it removes the dust that might be over the bed and that would interfere in the sticking process.

The noozle might also get stuck or dirt, for what I would recommend to first heat it up so that it is easier to remove the resting parts of the last used material so that it does not contaminates your new print.

NOOZLES:
My printer comes with 0.3, 0.4, 0.5 and 0.6 noozles. I mainly have printed in PLA of 1.7mm, for what I usually use my 0.4 noozle, which I thing gives me a good balance of quality and speed. I could go to a higher speed with a 0.6 noozle or even force the machine speed a bit bi turning the control knob, but that will give me a not that good detail, so it also depends on what you are printing.

The opposite happens with the 0.3 noozle which will give you more details with less speed, but it is pretty good when you have to print small details that might not be printed using the 0.4. You can check this when you do the slicing in cura and check that in every layer, every part is printed correctly, because sometimes parts might appear in red and not in yellow, what might indicate that the printer can't print it with that size of noozle.

MACHINE UPGRADES:
I've found a lot of upgrades for my 3D printer on Thingiverse and have already printed some like knobs for the extruder, pulling handles for the heating plate, cases for tools and others. For doing this I recommend to look for a file that has a lot of downloads or reviews, and personally I choose the same color for every tool so that it combines with my printer (RED).

I also changed the mainboard for a silent one, which reduced a lot the noise of the printing. Now only the ventilators make noise, which they told me you can also upgrade with silent ones. The only problem in changing the board was that the connections where glued with hot glue.

One of the upgrades I want to add is the BLTouch sensor for auto leveling the bed, which I find kind of expensive but really useful for the leveling process. The other one is the new WiFi connection that will connect the printer wireless to the slicer and send it directly.

Slicing is "the conversion from a model in STL format to printer commands in g-code format in fused filament fabrication and other similar processes. The slicer first divides the object as a stack of flat layers, followed by describing these layers as linear movements of the 3D printer extruder, fixation laser or equivalent. All these movements, together with some specific printer commands like the ones to control the extruder temperature or bed temperature, are finally written in the g-code file, that can afterwards be transferred to the printer."

This process basically divides the object in a stack of layers that are later transformed intro printing information for the machine. In this process is where you also define most of the printing configurations like the infill, the profile, the support, wall thickness, movement speed, extruding speed, fan speed, layer height, etc. There are more complicate adjustments that will help you better results depending of what you want, but the three most common ones to adjust are:

Infill:
Solid objects need a large amount of valuable material (filament, ...) and print time. The slicer can automatically convert solid volumes to hollow ones, saving costs and time. The hollow object can be partially filled by internal structures, as internal walls, to provide additional robustness. The amount of these structures is called infill density, this parameter being one of the adjustments to be provided to the slicer.

More Infill requires more time but also gives the 3D printed part more rigidness.
Less Infill requires less time and gives less structure.

In the infill you can also select different kind of designs for the structures, which also affect the structure of the whole piece, but personally I haven't experimented much with it yet.

Supports:
Most of the 3D printing processes create the object layer by layer, down to up, with the layer under construction being deposited over the previous one. As a consequence, all object parts must overlie, at least in some part, over another one. In the case of an object layer that is floating (by example, the flat roof of a house or an horizontally extended arm in a figure), the slicer automatically can add supports for it. The support touches the object in a way that is easily detachable from it at the finish stage of the object production.

You can generate normal supports or tree supports. I personally like more the trees because they waste less material and seem to be easier to detach from the object. Also they can get into inner, more complicate parts without having to print the whole structure to get there.

Rafts, skirts and brims:
The slicer can automatically add some detachable structures to minimize problems related to the initial surface sticking to a bed. Usual types of these base structures are a skirt (a single band around the base of the object without touching it), a brim (several lines of filament around the base of the object, touching it but not under it, and radiating outwards) and rafts (several layers of material that form a detachable base, with the object printed over it).

I usually go with brims, but if it is for a very high part or with little support, I would prefer using rafts than skirts. The problem with rafts is that they take a lot of time and material, but they are easily removed. Actually I love the flexibility that the raft removable pieces have, since they are thick but flexible. Would love to print in the future something like that on purpose.

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Voltio