Updated May 11 2020
If you are interested in 3D printing molecular models, the workflow is quite straightforward and a complete guide is available at https://munfred.com/proteins.html
The Prusa i3 is the flagship RepRap printer, meaning it was designed by the community and meant to be as 3D printable as possible (so they could self-replicate). The current version is a rock solid 3D printer with a relatively large build volume, a high-quality hot end, and a solid metal construction. There are many different knockoffs which tend to cost around $300 and they're usually very good, for example the Monoprice Maker Select Plus 3D Printer below. The kits take about 8-10 hours to build, and the ones we had did not require soldering of any kind, so building the kit would be possible for middle schoolers! If you have the time to do it, building a kit will give you the full range of knowledge you need to run and service the printer. The best part about the official Prusa i3 is that the instruction manual is top notch.
This printer is very similar to the Prusa i3, though it's construction is a little lower quality. Of course, the price point more than makes up for it. It is very easy to start using and very reliable. A good choice if you’d like to spend less than $400 getting started with 3D printing.
The Creality 3D printers models and knock-off (particularly the CR-10 and Ender-3/Ender-3 pro models) have become very popular, due to price and reliability. Although I still think the Monoprice Maker Select Plus is more robust at the same price point, it is 20x20x20cm, and the creality printers are bigger, with models at 30x30x30cm, 40x40x40cm and 50x50x50cm. But for 90% of your desires, 20x20x20cm build volume is actually fine.
This is a cheap SLA printer that features some improvements over a common design offered by many sellers.
Wanhao model: https://all3dp.com/1/wanhao-duplicator-7-d7-3d-printer-review/
Monoprice model: https://www.monoprice.com/product?p_id=35435).
I got the Beam 3D prism on it’s kickstarter and have been happy with it, cannot complain. If you go with it or similar models, the easiest slicer to use is Chitubox: https://www.chitubox.com/
Formlabs is the high end of consumer SLA printers, it’s geared towards professionals and businesses that need it to work every time and not waste their time, so it costs more . Ten times more, in fact, the resin is 3-4x the price, at $150-200 per liter depending on type. But, it’s a good printer, with real customer support and all.
Slicers here refer only to FDM/FFF technologies. If you buy a printer using a different technology then the vendor will point you to the software to use. There are many, many slicers around and many more to come. The list of slicers below is not comprehensive but those are the most popular ones. Additionally, Simplify3D, my favorite slicer, provides very useful troubleshooting and material guides regardless of which slicers you use.
Simplify 3D troubleshooting guide:
Simplify 3D FFF materials guide:
I see no reason to use this
I think it's the best slicer, but costs moneys
The original slicer, very open source and customizable, also hard to get right.
Slic3r Prusa edition
Slic3r as modified by Prusa, open source. Maybe a good idea if you have a Prusa
Basic version is free, premium $62
Fusion 360 is my favorite CAD (Computer Aided Design) program, and what I would recommend for anyone with no prior experience but interested in serious design. Fusion is made by Autodesk, the company that makes AutoCAD, which together with Solidworks (mad by dassault systems) are the
This is the entry level CAD (Computer Aided Design) software, something that even elementary school students can learn. It's different from most others because it works by taking geometric shapes and adding or subtracting them. It's a basic, but powerful approach even though it's different from most other software out there. It's also cloud-based, so you can run it on a Chromebook no problem. Best of all it's free
Blender does a lot! It's a full game design studio, but for 3D modeling it's good for organic modeling (say, a basket of fruit) and character modeling and animation (like a video game character, for example). It's a very powerful program for modifying other people's 3D models. It's also very elaborate and will take you years to master. It's free and open source.
It's meant for architecture design, and so it's good for non-biological shapes (ie not a lot of curves). It's also fairly simple to learn. It's free, but has a pro version as well
MeshMixer is good for tweaking 3D models and creating organic shapes. It's free and fairly easy to use.
Netabb repairs broken 3D models. Sometimes what you design or what you download from the web won't print correctly without some tweaking. Netfabb does all of this with some math magic. It's owned now by Autodesk, so it's free for students. It's also super simple to use, just click the auto repair model button and you're good to go. The free educational licenses of the Netfabb Standard, which is capable of repairing anything, available at: www.autodesk.com/education/free-software/netfabb.
Obtaining models from the real world is generally done in 2 ways: structured-light 3D scanner, where the device used generates a point cloud which is then processed to make a 3D model, or photogrammetry, where many 2D images are processed to make a 3D model. All these processes use a camera in some way so you can only record 3D data captured from one perspective at a time. So if you want to scan features such as deep holes it can be challenging. Below is a list of photogrammetry software that was recommended to me by friends - I don’t have much first hand experience.
Recap by Autodesk (free for academics, not hard to use, I’ve done tests with it):
Agisoft Metashape - most commonly used
Pix4D - photogrammetry software suite for drone mapping of landscapes
Alice vision - free software (but very slow apparently)
Capturing Reality - Fastest software available (hours vs min difference) but license costs $90 for 3 months