Hmm I can't see using a dremel to power a centrifuge working for non trivial lab uses. And as @jlgreco comments elsewhere chemistry labs have glass-working techs that make a lot of the kit - I recall being taught very basic glass-working at school.<p>A Lot of lab gear is very specialized when I worked at RnD organization lab they had 2 wood shops a metal shop and an electronics shop to build one off experimental kit. And we employed Very good guys some of the wood pieces they turned out where stunningly beautiful.<p>I could see 3d printing working for some labs but this would be the very high end ones that have decent resolution and accuracy and can work with a wider range of materials. Big question is would it be that much cheaper than cnc machining or sintering - given that labs have machine tools and technicians to run them.
I can see 3D printing really taking foot in areas where making your own assorted odds and ends is already commonplace. Plenty of universities have glassworking shops that chemistry departments make extensive use of <i>(for example: <a href="http://www.chem.vt.edu/facilities/glass-shop-index.html" rel="nofollow">http://www.chem.vt.edu/facilities/glass-shop-index.html</a> )</i>. 3D printing shops could find similar usefulness.