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tutorials

clean the nozzle

how to clean the nozzle

The world of 3d printing, especially for those who deal with it at a hobby level, is unfortunately not free from problems. An unexpected event that can happen is that related to the obstruction of the nozzle of our hotend on the part of the filament. Fortunately, it does not happen often and in any case there are many ways to clean it, for example it is often sufficient to extrude a material with a higher operating temperature than the one causing the cork, or if the block was due to the abs, a bath of a few hours in acetone often solves the problem. In my specific case, the block was due to some plaque that I had neglected, causing it not only to deteriorate but also to dust. This caused, after a few minutes of printing, an obstruction of the nozzle which was not easy to remove with the most common methods. So I came up with a “soooo homemade” way to clean the nozzle.

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articles

warping

What is warping? warping is that defect that is sometimes created in our prints due to a characteristic of the materials we use for our 3d prints whether it is PLA, ABS, PTFE etc etc and which in practice consists in the enrichment of the ends of the bases of the our 3d prints.

warping
Let’s see better ….

Like most existing materials, plastic, of any kind, undergoes changes in volume due to thermal variations. When we go to heat the filament in our hotend, in addition to changing from a solid state to a fluid one, it undergoes a volume variation that can affect the result even in a quite evident way. This not only happens when it heats up but also when it gets cold, naturally with the opposite consequence and with different characteristics depending on the material used.

Now let’s think about a piece with a fairly wide base and see what happens at the time of the first layer. The heated filament, for example at 210 °, is deposited on a much colder surface undergoing a thermal alteration which varies its dimensions by decreasing them. The second layer built on the first will have a warmer base than the first and therefore will undergo a different thermal shock and so on the third and fourth layer.

PLA, ABS, PTFE …. all the same?
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tutorials

stepper motors

stepper motors

Why stepper motors are used in 3d printers?

motori passo passo
One of the main characteristics of stepper motors is that of being able to perform a complete rotation divided into small sections. A complete rotation means a movement of 360° from a starting point on a circumference.

To simplify the concept, let’s imagine that we can turn the shaft of our stepper motor by 1° at a time, to make a complete rotation we will have to “tell” the motor to operate 360 times always in the same direction.

motori passo passo

These small movements are the “steps” and we can easily understand that the level of precision that we’re going to get is defintely high. The stepper motors that are used for 3d printers generally have steps of 1.8° which means that to make a complete rotation we will have to operate our motor 200 times (200×1.8° = 360°), therefore we have an excellent level of accuracy.

This precision is used to make really small movements with the moving parts of the 3d printer, this allows a remarkable level of accuracy and detail in our prints.

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software

free stl

free stl, where to find them? 

In this page we report a list of sites from which it is possible to download free stl files ready to be printed in 3d both free and paid.

Thingiverse

thingiverse stl
thingiverse

Thingiverse is a community created by Makerbot, one of the largest manufacturers of 3D printers. Born with the rapid spread of 3d printers, it has become one of the largest 3D design communities in the world, allowing you to share and download over a million files for free.

 

grabcad

grabcad stl
grabcad

GrabCad belongs to  Stratasys, America’s leading professional 3D printer manufacturer. Made up of a community of mechanical engineers, it contains everything, over 1,000,000 free files ranging from various genres, from mechanics to household items to costume jewelery.

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tutorials

tuning of driver Vref

tuning of driver Vref 

Regolare la vref dei driver A4988 Regolare la vref dei driver DRV8825

A very important step to properly set up our 3d printer is tuning of driver’s Vref of the motor’s step by step. Very often a hasty calibration of these drivers leads to lose some steps or even to their break due to overheating…

tuning of driver Vref

I have used both the most current DRV8825 and the A4988 StepStick, both on different printers with different cards. The main difference between the two drivers concerns the capacity of current supplied and the number of managed steps: 2A and 16 microstep for the A4988, 2.5A and 32 microstep for the DRV8825. Obviously the cost varies and the A4988 are naturally cheaper.

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articles, printing problems

retraction what it is and how it works

retraction, what it is, what it is for and how it is regulated.


The retraction is the consequence of a series of precautions that we can adopt to avoid the phenomenon of “stringing” or … a spider web that forms especially in the case of small prints with cantilevered parts close together. This problem ruins the aesthetic aspect of our prints and produces an impressive amount of very small filaments that can also naturally detach from the piece and then fall into our 3d printer risking to end up on mechanical and / or electronic parts creating the related problems of the case.

Why are these little “hairs” created?


Suppose we have to print on a base two small solid cylinders at a short distance from each other. Our hotend, after having printed the base, will begin to create the two cylinders layer by layer, thus passing from a phase of extrusion of material to one of non-extrusion and again to one of extrusion. All in a relatively short time.

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