This video presents my 3d printer enclosure and shows the first part of my project - implement chamber temperature control, remote Start / Stop of the printer and Auto Shutdown after the print job is finished. I relay on OctoPi with its Enclosure Plugin - a great tool for monitoring and total control over the print job, the 3d printer and its enclosure.
Download OctoPrint: octoprint.org/
Structure of the heated 3d printer enclosure:
Sides from 10 mm thick polycarbonate sheet, with edges cut at 45 degrees, attached with cheap brackets used in furniture manufacturing. This material has excellent thermal properties - no physical deformation up to 130°C and low thermal conductivity that helps keeping heat inside longer (less power consumption). Compared to other solutions it is more expensive and heavier.
Control and electrical system:
The controlling device is Raspberry Pi 3 or 4 with OctoPrint and Enclosure Plugin. If you don’t need video processing and timelapse functionality Raspberry Pi 2 will also do.
Get it on Amazon: amzn.to/2RvanxW (affiliate link)
The temperature sensor:
I use DS18B20 - cheap and reliable 1-wire sensor, supported natively by RPi on pin 4.
It has 3 pins - Ground, 3.3 V and Data (the data pin is connected to pin 4). It needs 4.7 kOhms pull-up resistor connected between the 3.3V (Vcc) and the Data pins. You also need to write in the RPi’s configuration file located at /boot/config.txt the following line: dtoverlay=w1-gpio
For more information and setting-up other temperature probes check the plugin github page at github.com/vit...
Get it on Amazon: amzn.to/2uEn549 (affiliate link)
For the power switching devices, there are several options, depending on how silent you want your enclosure to be:
Option 1 (my current setup):
- Interface (intermediary) small SSR relays (2A) for switching AC loads. These can be controlled directly by the Raspberry pins and are used to command more powerful switching devices (that can not be run directly by the Raspberry).
Amazon: ex. amzn.to/38Lnyka (affiliate link), but many other options are possible
- Industrial 3-phase contactors. These are robust devices, mainly used to control motors. Their rating (nominal current) is normally given for AC-3 operation (motor control), however when used for resistive loads (AC-1 operation mode), they can switch much higher current. For example, 9 A contactor for AC-3 can switch 20 A in AC-1. They have life expectancy of about 100000 switching operations before one contact fails and I have connected all 3 contacts to switch just one phase.
Amazon: amzn.to/2U1LviO (for US - 120V coil) or amzn.to/2O5pyvE (220V coil)
Pros: cheap, reliable, no heating issues like with power SSRs.
Cons: Noisy switching
Option 2 (noiseless setup with solid state power relays):
- The same interface relays are used;
- The heater and the printer are switched On/Off by 10A or 25A (recommended) SSRs with AC control.
Amazon: ex. amzn.to/30Wzgpf (affiliate link), but many other brands are possible.
Pros: cheap (if chineese), noiseless
Cons: need radiators to dissipate heat
I think the best option is a mix - standard industrial contactor for the printer (toggles only once per print) and AC controlled SSR for the heater. That is what I will implement next, in order to have silent operation.
28 авг 2024