Month: November 2013

Issues with MakerBot Replicator2X

I’m facing a strange issue with our Replicator2X, then I decide to make a video to show it:

Other guy faced an issue even worst on Replicator 2:

My conclusion is MakerBot Replicator has many issues that needs to be fixed in the new versions.

Our company bought a Makerbot Replicator 2X that damaged its X axis in the first working week. It was a very intensive usage, but it damaged in less than 100 hour of use. I suspect they didn’t validate it well.

I fixed that issue following the suggestion from this guy:

I *should* have bought an Ultimaker printer instead of a Makerbot. The Makerbot parasites the open-source and don’t contribute nothing back. The Ultimaker in the other hand contributes to open-source development and created Cura, the best and easy to use software to slice and control your printer.

Case you are looking for a 3D printer, please consider Ultimaker instead of Makerbot Replicator printer! This is my warning for you!

Overview of my experience with Makerbot Replicator 2X

Currently I’m working with the Makerbot Replicator 2X 3D printer and I want to share my experience with other people.

The initial configuration is easy. Just open the box, remove some plastic fixtures, connect the tubes where filament will pass thru and put the filament in the holder. Then turn on the machine and execute the start-up setup. This process will ask you to align the platform relative to two extruders. It is a little bit boring and need to be well done.

Then just use MakeWare to open your 3D object and print it. MakeWare is too easy to use, but there is not advanced features like Slic3r, Cura and other slicers softwares.

Bad things about Replicator 2X: after few hours printing (about 60h) the printer starts to print the objects in a messy way. This is strange because I oiled the gears after 50h printing. I noticed the horizontal belt (X axis) was a little bit loosened. The I tighten the motor connected to this belt and then it started to print again.

Conclusion: the printer and software are easy to use, but it needs some maintenance to stay working after few usage days. This printer was purchased by the company for which I am developing a product. Case you are planing to buy this printer, please consider Ultimaker 2 as an alternative, just my 2 cents.

Update: this above problem was already found and fixed by this guy: Bad news: you need to replace the cable which controls X axis.

Lendo sinal de um sensor LDR sem usar entrada analogica

Ao pesquisar sobre fotosensores LDR encontrei uma dica interessante que vale a pena compartilhar aqui no site. Este cara usou a própria característica dos sensores LDR (de variar a resistência com a variação da luminosidade) para descarregar um capacitor.

Ele usa um pino do microcontrolador para fazer a carga do capacitor, então coloca o pino em alta impedância (tri-state) e fica lendo para detectar quanto tempo o capacitor demorou para descarregar. Quanto maior a luminosidade menor será o tempo de descarga do capacitor.

A ideia original esta neste blog, use o google translator para traduzir de Polones:

How to detect if your system has high resolution timer?

High Resolution timer is a necessary resource for realtime applications, fortunately the software support is already integrated on Linux kernel, but your hardware need to have internal support. Also fortunately all “modern” computer has this internal support.

Case you’re in doubt if your computer has it, then just execute this C code to test:

#include <stdio.h>
#include <linux/time.h>

static int check_timer(void)
  struct timespec ts;

  if (clock_getres(CLOCK_MONOTONIC, &ts))
    return 1;

  return (ts.tv_sec != 0 || ts.tv_nsec != 1);

int main()

  int missing_hires;

  missing_hires = check_timer();

    printf("Your system has High Resolution timer!\n");
    printf("Sorry, your system doesn't have High Resolution timer!\n");

  return 0;


Replica do AGC

O computador usado no projeto Apollo era fascinante, mas comparado com a tecnologia atual ele é inferior a um microcontrolador de alguns centavos de dolares. Em termos comparativos ele seria equivalente a um microcontrolador com 2KB de RAM e 32KB de Flash (embora a ROM dele tivesse 36KB e as palavras fossem de 16bits).

É interessante ver que alguém criou uma réplica do computador AGC original:

Você também encontrará muita informação e um emulador do AGC neste site: