A heated build platform is an essential component of a production Makerbot Cupcake or other Reprap-based printer using ABS media. Large prints often "warp" because the bottom of the print cools while the top of the print is still being created. The solution is simple -- keep the base of the part relatively warm until the entire print is finished and can cool at the same rate.
These instructions will show you how I made my platform, if you make an improvement please share it with the rest of the Reprap/Makerbot community so they can give it a try.
Note that there are actually two sets of instructions here. The first set requires you to have access to metalworking tools and some basic metalworking skills. If you have a friend who can help you with this (like maybe someone in Robotics Club or who is a welder), that's just as good. The second set gives suggestions on how you can work around not having fancy/expensive tools.
This project requires a number of tools that can seriously injure you or a bystander. Wear your safety glasses and be careful.
A heated build platform uses Nichrome wire and can easily reach 220F/105C without any change in physical appearance.
Never leave a Makerbot unattended while the build platform or extruder are at temperature.
Step 1: Collect Materials and Tools
- Piece of aluminum plate approximately 100mm x 100mm x 5mm. If it's only 4mm or 6mm thick, or 105 x 105, that's not the end of the world. There are a number of online metal suppliers who deal in small lots/sizes, look around before you go to your default Big Online Superstore, you might be able to save some money.
- Approximately 35 cm of insulated nichrome wire. I use the same wire that people use for the extruder, 31 gauge double-glass silicone nichrome wire.
- a thermistor, I used the 100K ohm EPCOS thermistor available from online resellers like Mouser electronics.
- a 4.7k resistor
- a 10uF capacitor
- a 3 pin, .100 header socket
- Kapton (equiv) tape, the roll that comes with a Makerbot kit works just fine.
- 3mm round magnets
- cyanoacrylate glue
- 2 different colors of 18ga stranded wire for connecting everything together
- a 4-pin connector pair to make a quick-release attachment for the platform
- high-temperature epoxy for gluing things to the platform
- heat-shrink tubing
First you'll need most of the stuff you needed for making a Makerbot or Reprap: soldering iron, solder, wire cutters, wire strippers, etc. Then you'll need one of two sets of tools:
Machine shop tools:
- basic metalworking tools like a drill press, transfer punches, clamps, etc and know how to use them safetly.
Hacker: you're making it up as you go :-)
- masking tape
- a sharp pencil or mechanical pencil with a long lead
- metric ruler
- small t-square
- electric drill and appropriately sized drill bits (we'll figure it out later)
- center punch and small hammer. if you don't have a center punch, buy one to keep with your drill, you won't be sorry
- flat metal file
- round metal file (not the end of the world if you don't have this)
If you can borrow/use any of the following for free, it will make this project much easier:
- Good multimeter (ex: Fluke) with a temperature probe
- Metal mill with drill chuck or a x/y table and drill press
- Band saw: buy a longer piece of aluminum plate than you need, cut it into sections, then have a group building party with other Makerbot owners!