It’s been said there’s more than one way to skin a cat, and although I don’t really feel like making sure that’s true, there’s definitely more than one way to make a reprap mendel. You can build one out of wood, metal, or load up your Makerbot with these production sleds and start printing.
Mark Ganter over at Open3DP has been interested in 3D Printing for a lot longer than most of us. He’s a professor at the UW Mechanical Engineering Department, and a friend of the shop since we met at dorkbot. Being at a University has it’s perks. They’ve got half a dozen commercial 3D printers, and have been experimenting mostly with materials and alternative recipes for powder based printers
This is very interesting, because for us, 3D printing means thermoplastics. For them, it means plaster, glass and ceramics.
As an experiment, Mark has printed up some mendel pieces for us to check out. They’re printed with plaster, and infused with epoxy, making them high resolution rock hard purple parts. They look a bit like they’re carved out of stone, and because the recipe for them is plaster based, they’re incredibly incredibly cheap to make. They’re not very flexible, but they’re extremely accurate. I am already positive the bed spring isn’t going to work, but that’s probably OK.
Alternatively, Mark has also started a full Mendel build using his commercial FDM printer, with which he has calculated out runtime to be about $30/hr. Estimated time of build is somewhere around 60-70 hours. To me it sounds like a pretty good way to break the bank, but on the other hand, it will be a standard (albeit high resolution) ABS build.
Once that Mendel is printed however, the ability to produce more drops down to more reasonable levels. ABS plastic for open source printers costs a little over $10 a pound, and you have a growing pool of materials to pick from. For a rights managed cartridge, it’s $12 per square inch. There is a resolution difference, but there is a huge cost difference in the machines as well. For under $1000, you can have an open source printer, a growing community and access to cheap materials. If you spend $30,000, you get a little bit more resolution and digital rights managed plastics. It all depends on what you’re doing of course, but for almost all of us, the choice is pretty obvious.