February 2015 – Vlad Petrescu

The last part of my build deals with electronics, which combines the mechanical movements with the software algorithm that analyse the 3D model. The electronic diagram looks easy:

This is the RAMPS 1.4 board which can be bought or made. It connects to an Arduino Mega board which has the USB interface for the computer. Except from the two boards, I also needed some powerful drivers. In my opinion, the most important parts of a printer that have to be qualitative are the hot end (I used E3D), the linear bearings (SKF) and the drivers, which are in this case the DRV8825. They have a 1/32 step which increase the resolution of movement, therefore a smoother part results out of the printer.

Because NEMA 17 weights about 300g, the printer head will have an induced momentum, meaning that it would have not handle the high accelerations that I will need in order to print fast. This is why, I decided to go for a bowden setup and replace the old configuration. This is how it looks now:

This is a lighter version that has one fan (in the front) for cooling the cold end and 2 smaller fans that will cool down the hot extruded filament. The latter comes through the white teflon pipe being pushed by a stepper motor:

The parts needed for this conversion can be found here:

In order to push the filament to the hot end, the NEMA motor needs a gear to have grip. I use the MK8 gear and here it is an easy and cheap way to make it.

Month: February 2015

Electronics

Change to bowden set-up