All the coolest gadgets are too darned expensive; especially when they’re brand new. 3D printers are no exception.
Even the dramatic reduction in price that the open source hardware movement has managed to produce only brings 3D printers down to just over $500. That’s amazing compared to the commercial options (which start at $10,000) but it’s just not good enough.
I think the goal should be $250. That’s right around the pro-sumer line so anything under it is legitimately obtainable for the average person. You don’t have to worry about how much profit you can generate with the thing when it’s cheap enough.
A printer that cheap could become a practical option for STEM education. It would be a good introduction even if it didn’t have impressive performance.
Based on some research it looks like that price point is obtainable, in theory, today.
The most expensive part is always the electronics. Well, eMAKERshop sells sanguinololu electronics, fully assembled (and flashed), with the pololu drivers, for $125. They also sell a mechanical endstop kit for $10. Nema 17 stepper motors are around $15 from Kysan (4 of those). A 12v 5a power supply goes for around $10 on Amazon. That’s the majority of the electronics right there for about $200.
Now we just need to build the frame and linear motion systems. A 1/4″ x 2′ x 4′ piece of pine plywood can be about $10. Home Depot lists 16″ keyboard sliders for about $15 (3 of those). Assuming you could make the printer out of cabinet supplies, that’s about $55. If the extruder could be made out of a bolt with some nichrome wire (old school I know) it wouldn’t add much to the total, which is now around $255.
There are some crucial assumptions in there like a dirt-simple extruder and no need for timing belts. At any rate I think this demonstrates that the idea isn’t as far fetched as it might at first appear. A big piece of the puzzle will be getting around the need for metal pieces, printed pieces, and laser-cut pieces.