Ever wanted to run your 3D printer directly from SD card? This hack enables you to print from an SD card without the need of a PC.
Basically all you need to do is a cable to connect a SD module to your printer, but in this post I’m also going to show you how to create/adapt a SD module in case you don’t already have one.
You can use any SD module you like. MicroSD, SD, or even build your own! I’ll show you how
Despite I’m working on a control panel with some innovative features (look here), I’ve been asked to publish a super-cheap solution that can make you print without the need of a pc (or like in my case a Mac).
Printing without the need of a PC has many benefits, the first one of course it’s that… well… you don’t need a PC.
It could seem a stupid thing to say, but when you have to print a big file and you want to use your pc, you realize it’s not that banal after all 😉
Notice that Marlin firmware already supports a feature called “autostart” to automatically print a file from a SD card, but in my opinion it needs some improvments to make it more reliable for the scope we want.
This first post (of 3) will illustrate the “hardware” part of the solution: the SD card reader and how to build the cable to connect it to your printer.
Part two will be about the changes of the firmware, and part three will be about how to provide an enclosure and some improvements for a even better experience.
SKILL: not for a rookie if you want to build your own SD board, otherwise: not difficult at all
TIME: from 1 to 3 hours, depending on the options
TOOLS: a soldering iron, hot glue (optional)
COMPONENTS: 1 SD card module (or components to build it), 30cm of 10 wire ribbon cable, 1 2×5 female Molex connector, 10 female plugs
OPTIONAL COMPONENTS: 1 LED, 1 resistor, 1 push button (see part 3)
Categories: 3D Printer, Improvements
Tags: 3D printer, Control Panel, hack, marlin, Powerwasp, Print without a PC, RepRap, SIMPLEREADER, Ultimaker, Upgrade
Using a fan to cool the extruded plastic helps a lot to get better prints, but having it at a fixed speed it’s not the best way at all.
A variable speed fan can be used more efficiently during different moments of the printing process: first layers, bridges, small layers…
My variable speed printing fan at work 🙂
THE PROBLEM: on my board the pin dedicated to regulate the fan speed (via pwm) gets its current from an unregulated source. The Ultimaker board uses pin 7 to control the fan speed, but this pin has not a 12v maximum tension, instead it gets it power directly from the power supply (in my case a 18v transformator).
If I had used this feature out of the box my fan would have received a voltage of 0/18V not suitable for the popular 12v fan commonly used for this task.
POSSIBLE SOLUTION 1: Use a 24v fan, but this would also have been impractical since at 18v (maximun voltage of my transformer) the fan would have worked at a very low speed.
In fact, computer fans have a working range that’s not 0 to 100% volts since you need to kick in some power to make it turn first, for instance my fan can effectively operate in the range of 5 to 12v. Under 5v my fan doesn’t even start turning. But once it does you can lower it a little more, I will discuss it later on this post about this.
POSSIBLE SOLUTION 2: in your slicer program limit the maximum fan speed to a value safe for your fan. It works, but it’s not really practical nor intuitive and if you are using a controller (like the utilpanel, ultimaker controller ecc.) it’s not safe at all since you coul easily burn your fan using some functionality these controller provide.
Testing the pwv tension before attaching the fan.. safety first 😉
MY SOLUTION: I modified the firmware and set a parameter to define the maximum voltage suitable for my fan. Now I can safely use any slicer/controller in their full range of 0/100% fan speed. The firmware will then handle all the conversions for me.