If you're looking for a how-to article on building a 3D printer for $300, you can find all sorts of them with a quick web search. This Instructable is definitely NOT for you.
If you're looking for a how-to on building a machine that prints at 1000 mm/sec, this Instructable is NOT for you. SoM, like MegaMax before him, was built with an emphasis on print quality, not speed. I haven't tested maximum print speed, but SoM was designed to print at about 50 mm/sec and does so beautifully.
If you need a complete bill of materials with prices and suppliers listed, and illustrated, step by step assembly instructions, this Instructable is NOT for you. There will be plenty of pictures showing how I built my machine, and I’ll describe some things in detail, but you’ll have to get a lot of info from the photos, by reading the references I’ll link, and by asking questions.
This Instructable IS for people who don't want “cheap” to be the only positive (?) thing they can say about their printer. It's about how to build a printer the right way. It definitely isn't the ONLY right way, and it definitely isn't the cheapest way. SoM cost me about $1100 to build, and included a lot of used and free parts.
Here’s how things usually go when I want to make a print: I put the gcode file on an SD card, plug it into the machine, wipe the bed with acetone, and print. There’s no bed leveling, zeroing, no tweaking settings or other baby-sitting during the print. I come back when it’s done and remove the finished print from the bed. I can do that over and over, and I can put the machine in my car, laying on its side, drive it across town, take it out, stand it up, and do it all again without making any adjustments.
If that sort of reliability sounds like what you want, and you're willing to pay a little more and expend some effort to get it, this Instructable IS for you. Almost reliable? Of course, there are still plenty of things that can and do go wrong, so I still have occasional print failures. That's why I call it an "almost reliable" printer.
I built my first 3D printer, MegaMax, using surplus machine parts over a period of about 2 years. I built it myself because when I started the project, the biggest build envelope you could get in a reasonably priced machine was about 5" x 5" x 5" or so and I wanted to make bigger prints- full sized human skulls using data extracted from CT scans, for example. I decided to build for a 12" x 12" x 12" print envelope. MegaMax produced high quality prints, but as I worked on him and solved many problems problems over a couple years I got some ideas for improvements and decided it was time for a rebuild using everything I had learned.
This Instructable is about the rebuild, and though you probably won't be able to duplicate my machine exactly, I hope it will provide some ideas you can use in your machine. I wanted the new machine to be self-contained, smaller, and the electronics isolated from the warm print chamber. I also wanted the print quality and reliability pushed to maximum. SoM is the result. I already had a large investment in time, effort, money, and materials in MegaMax, so SoM was built in the same configuration (bed moving in the Y-axis, X-axis lifted by Z-axis screws), reusing many of the parts. If I were building a machine with the same print envelope from scratch today, I would probably use a coreXY design so that the relatively heavy print bed moves only in the Z axis.
SoM is a cartesian printer with the print bed moving in the Y axis, but most of the ideas presented will apply to other architectures.
SoM basic specs:
- Size: 30" high x 22" wide x 39" long
- Weight: about 60 kg, I think.
- Build Envelope: 305 x 317 x 270 mm
- X axis: belt drive, fully supported linear guide, 100 oz-in stepper with DSP driver and 32V power supply
- Y axis: ball screw drive, fully supported linear guides, 425 oz-in stepper with DSP driver and 32V power supply
- Z axis: dual 1/2" lead acme screws with 5/8" fully supported round guide rails, belt driven by a 150 oz-in stepper
- Extruder: BullDog XL
- Hot-end: E3D v6
- Print bed: 1/4" x 12" x 12.5" cast aluminum tooling plate covered with 5mil kapton tape, 450W heater
- Controller: SmoothieBoard with graphic LCD interface
- Typical print settings: Acceleration 1000 mm/sec^2, junction deviation 0.03, speed 50 mm/sec, layer thickness 200 um