Self-Regulating Heat Bed for Ultimakers (and other 3D printers)

thingiverse

A heated build platform (HBP) improves printing quality by helping to prevent warping. As extruded plastic cools, it shrinks slightly. When this shrinking process does not occur throughout a printed part evenly, the result is a warped part. This warping is commonly seen as corners being lifted off of the build platform. Printing on a heated bed allows the printed part to stay warm during the printing process and allow more even shrinking of the plastic as it cools below melting point. Heated beds usually yield higher quality finished builds with materials such as ABS and PLA. A HBP can also allow users to print without rafts. (Source http://reprap.org/wiki/Heated_Bed) This self-regulating heat bed provide a temperature controlled build platform ideally suited for printing with PLA (green LED) or ABS (red LED). The original design of this heat bed was made by Scott Mayson (http://about.me/scottmayson), unfortunately it disappeared from Thingiverse. This Thing provide an updated version compatible with currently available parts, as well as detailed instructions guides suitable for all. You can learn more about this thing on our bloghttp://prototype.asia/blog/2013/01/30/self-regulating-heat-bed-ultimakers-and-other-3d-printers/ 2014/02/11 - I added "UM_HB_V2-2014.zip" to the file set, nothing has changed but some users have reported compilation issues, so this is an attempt to see if these files fix the issues. Instructions Bill of Material: To successfully build a heat bed for your Ultimaker you will need: 1x Arduino Uno 1x Arduino Uno Protoshield 1x MK2 Heat Bed http://tinyurl.com/bjqajpt 1x Beefcake Relay Control Kit https://www.sparkfun.com/products/11042 1x Thermocouple Amplifier MAX31855 breakout board http://www.adafruit.com/products/269 1x Thermocouple Type-K Glass Braid Insulated - K http://www.adafruit.com/products/270 1x 200x200x4 mm Tempered glass square or aluminium square 1x MeanWell SE-450-12 (12V 37.5 A) http://www.meanwell.com/search/se-450/default.htm 3 inch wide Kapton Tape About the wires, you will need Single core wire for PCB connections Multicore wire for connecting to the BeefCake Relay Large gauge wire (capable of handling 40 A) to power the Arduino and the Heat Bed Assembly and Configuration Instructions: Assemble the components according to the schema Fix the thermocouple to the underside of the heat bed using kapton tape, make sure the tip of the thermocouple is near the center, but not in the hole. Place the heat bed in the middle of the 10mm acrylic build platform and drill holes accordingly Use 3mm worth of washers to lift the heat bed from the 10mm acrylic build platform and secure in place using appropriate bolts Place the kapton tape covered tempered glass square in the middle of the heat bed and secure in place with kapton tape Calibrate the new build platform by adjusting the 4 level screws and the Z contact switch 7.1. Power up and preset the heat bed to PLA (green LED) and wait for it to reach its maximum pre-set temperature (when the relay switches off) 7.2. Using a laser thermometer, measure the temperature in the middle of the build platform. 7.3. Adjust threshold1 and threshold2 in the Arduino code until the heat bed self regulates to a temperature between 50-60°C 7.4. Repeat until the desired operating temperature is achieved Activate the ABS pre-set (red LED) and adjust threshold3 and threshold4 in the Arduino code until the heat bed self regulates to a temperature between 105-115°C Usage Instructions: Power up the heat bed and wait until the desired pre-set reach its maximum temperature Pre-heat the Ultimaker extruder using the Ulticontroller feature Thoroughly clean the build platform using 99% IPA and a micro-fibre cloth Lauch the print job Wait and wait.... until the job finishes Power down the Ultimaker and the heat bed Let the build platform cool until the part(s) pop up automatically (may take some time, do not pull on the parts as it will decalibrate the build platform level and deform your parts).