When you start working on electronics projects, one of the most important item is power supply. There are many ways to follow on this subject:

  • Purchase a power supply for each of the necessary voltage (12V and 5V are pretty easy to find, 3.3V not so much)
  • Use the computer USB outlet (it’s almost a standard on Arduino projects)
  • User batteries

For simple and infrequent projects, you can move forward with one of the options above, but when you get serious projects, these options are not very good (they are not practical, the lack power, …). So, the choice is to purchase a professional bench power supply, which, in general, can cost a lot or, being a DIYer, you can use an old  AT/ATX computer power supply and make your own bench power supply, adding the features you like most.

This post is about the making of a my bench power supply. The second part of this post is on Bench Power Supply Part II  – Assembly.
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Some FDM printers (like the Prusa i3, and others), whether purchased assembled or as a kit, are already equiped with some auto-leveling feature, that means an automatic leveling of the nozzle relative to the printbed, in a way that the distance between both are always the same – and as little as possible. On the other hand, there are other 3D printers / kits that doesn’t have such feature. In this cases, it’s necessary to use the endstops (micro-switches that limit the axis movement) and, for fine-adjustment, screws / springs that change the height of the printbed.
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The Graber i3 is a 3D Printer Prusa i3 clone, but with a laser cut MDF structure. There are lots of Graber i3 kits, a little bit different from each other, but the majority is based on the same MDF structure, provided on this GitHub project. It’s a good project, to be honest, it’s ver stiff and easy to assemble.

A problem that had not occurred to me though – in fact, I didn’t notice it for months – is that MDF wood expands/shrinks depending on the heat difference. For the most part of the MDF structure, this is not a big deal. But the printing bed, for ABS printing is heated up to 100C and it is bolted to the MDF base, thin and almost fragile. After some time, I noticed that the heat from the printbed made the MDF base to curve down. The consequence is that the base was colliding against the zipties that hold the Y axis rods and endstops. This collision was enough to make a difference on the printber height (relative to the nozzle) and propagate as object imperfections.
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I tested a lot of table smartphone stands (and some tablet stands) but, so far, none of them were much of mi interest. They were fragile, didn’t grip the device well, didn’t allow to use the device on both vertical / horizontal orientation, or I couldn’t use them connected to a USB cable, or even worked well on some particular smartphone models.

That’s when I found a stand I consider great in many aspects:

  • It allows the device to be used on both vertical / horizontal orientations
  • It’s firm and string on both orientation and grips the devices well
  • It can be used with the device connected to a USB cable
  • It accepts virtually any smartphone on the market (even the older / thicker ones)
  • And, it looks and feels good

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Since I started 3D printing my projects and posting them on Thingiverse (after sometime, also here), I had the need to take pictures from the objects I had printed, the assembly and even recording them. I purchased a Cutting Mat, gree, with dimension markings painted all over it, which helps a lot on the picture contrast and also to give an idea of the objects size. But the biggest problem, when taking pictures is always lighting.
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