Smoothie Aq CEVO

This is part #? in a list of postings on the electronics of my CEVO. The full list can be found  here . The topic of this post is how to wire the stepper motor to the RAMPS. I am pretty sure most newer motors are the same, and yet I had difficulties to find a simple guide on how to do the wiring. The most referenced guide is  https://reprap.org/wiki/Stepper_wiring , and that was indeed the generic guide I used as reference. I am however quite sure you can just follow my guide below. Most DIY 3D printer uses Nema17 stepper motors like the one on the right. The one in the picture uses a 6-pin connector, a JST 2.0 PH 6-pin male connector, and that seems to be pretty much standard. This connector is generally not that common, but you can order it for example at  Aliexpress . Even though it has 6 pins, it is actually a bipolar motor with only 4 connectors, as shown in the diagram on the right. To wire the motor we need to know the wires for the A coil and for the B c...

Traditionally, all movement is supported and constrained by bearings running on linear shafts. While alternatives are getting more common, this is also what I am going for on my CEVO. In this post I will compare a few different shafts. Traditionally most 3D printers have used solid stainless steel shafts. They are available cheaply from China in quite good, but sometimes varying, quality. The major disadvantage of these steel shaft is that they are quite heavy, but they are also quite stiff and smooth. Quality suppliers like Igus and Misumi have alternatives in aluminium and as tubes instead of solid, but these tends to be quite expensive. In later years quite cheap Carbon tubes have been available from China. Here and there people are experimenting with using these carbon tubes as an alternative to stainless steel shafts. They should be 3K roll wrapped carbon tubes. Their main advantage is that they are a lot lighter, and personally I think they also just look a lot cooler - for...

The aluminium bed will expand when heated, and I will have to take that into account when designing the mount for my bed. But how much does it expand? I googled a number of thermal expansion calculators, and somewhat to my surprise they don’t give the same result, although they do give results in the same ballpark. The calculator https://www.omnicalculator.com/physics/thermal-expansion seems well done and well documented. Using that, I get that a 300x300mm plate will expand 0.4mm in width when the temperature rises from 22 degree C to 80 degree C. The change in thickness is so small that it will not matter. Another issue is that the bed may warp. Obviously a thinner bed will warp more easily, and as I understand it, a rolled aluminum sheet will warp more than a cast sheet. The very best is therefor a thick cast aluminum sheet. I will have to take this into account when designing my bed mount. However, it also makes me think that it might not be so good an idea to print first lay...

The HEVO uses lead screws and steel rods for Z-movement and steel rods and belts for X- and Y-movement. A lot of experimentation are going on of using flat linear rails with bearing blocks and also some on using V-slots and wheels. This in some ways seems the way to go, but it does not (yet) seem clear to me which parts to choose in that direction, and I will stick with screws, rods and belts for the first iteration of my CEVO printer. I will however look into using carbon tubes instead of steel rods, and will also try a somewhat different configuration of both Z and X/Y.

I’ve been bitten by the bug. It all started early 2018 on a totally different hobby project, where I needed some project boxes and other parts. That caused me to look into 3D printers, and I quickly became fascinated. This blog is about building a 3D printer pretty much from scratch. My first go was an Anet A6 printer kit. I got it for USD 200 inclusive shipping. This is really a great printer with a great community. It comes as a box of parts, but prints great after assembly. There a lots of modifications you can do to improve it in various ways. I don’t really need a 3D printer, and for sure I don’t need two, nor anything more advanced that my A6. But building and improving a 3D printer is immensely satisfying; it is a bug that have bitten a large number of hobbyist and makers around the world. Being part of that community is satisfying as well. My second printer is just for the fun of it, but I am going to be more ambitious this time than just buying a kit or even than just ...