It isn’t news to most that 3D printing exists, but it is rapidly evolving and becoming more affordable to the point where they are being sold in retail stores. The market has been flooded with various models ranging from $300 to around $5,000 for consumer-oriented desktop printers and upwards of $750k for commercial use to aid in rapid prototyping and manufacturing.
Left: Makerbot (owned by Stratasys) Replicator 2x Desktop FDM printer $2799 Right: Stratasys Objet 1000 Industrial grade FDM printer $40,000
The most popular form of 3D printers available is FDM (Fused Deposition Modeling) which works by melting a plastic filament that is fed through a heated nozzle and layering it on a variable height platform all controlled by a software that divides a 3d object into many thin 2D cross-sections so it can print layer by layer into a 3D part. It is basically like taking a hot glue gun and layering the glue on a sheet of paper to make something 3-dimentional. The main materials it can print are PLA (a biodegradable plastic derived from corn starch) ABS (a strong plastic that’s in most common household items) Nylon and even elastic materials like FilaFlex. FDM was invented in the late 80’s by S. Scott Crump mainly in order to prototype CAD/CAM designs. This form of 3D printing was commercialized and trademarked in 1990 by Stratasys, one of the big names in the 3D printing world to date, the patent expired about five years ago and blew the doors open to open source communities , thus the Makerbot was born and provided an extremely affordable 3D printing platform as well as inspiration for DIYers. This is why FDM printing is very common in the hobbyist to low-end manufacturing market.
All parts necessary to build your own FDM 3D printer are available from many sources and there are communities involved in the open-source development of DIY 3d printers like the RepRap or PrintrBot. I plan on making my own FDM printer in the next couple months (I need a new welder first) so check out the projects page soon as I will be grabbing some parts for the build very soon.
Another form of 3D printing that is about to blow up is SLS (Selective Laser Sintering) which may be a big one. It works by firing a high powered laser in a preset pattern, layer by layer into a preheated powder resin that is on a height controlled platform. The laser heats the resin up just enough to sinter it, which is somewhat like welding but there is no melting involved. with every layer that is printed, a roller pushes a thin layer of the powdered resin over the last layer and repeats the process until the part is complete. There is a large range of materials that can be used with this process such as; nylon (glass filled) ABS, ceramic, glass, rubber-like, acrylic-like and a few other plastic substrates. With DMLS (Direct Metal Laser Sintering) there are the options like; titanium, gold, silver, brass, bronze, aluminum and stainless steel. The beauty of SLS printing is that the part being printed is always contained in a medium ( the resin ) therefore has more flexibility with what you can and can’t print with it, ex. parts with overhang such as a tree, or or even parts contained within a part that are freely moveable like the thumbscrew on an adjustable wrench.
Left: an FDM printed part needs support to print with overhang
Right: an SLS printed part (which is suspended in resin during printing) is removed from the printer as is
SLS printing provides an extremely accurate form of 3d printing. DMLS provides the same results to the next level by being able to produce precision machined parts in metal. The video below from Solid Concepts of Austin, TX shows the process of SLS, particularly DMLS. They were the first company to 3D print a fully functional 1911 handgun as a testament to the strength and accuracy of DMLS.
The original patent for SLS US Patent 5597589 expired on January 28, 2014 which somewhat opens the doors for open source SLS printers. I say somewhat because although this patent contains the majority of the details involved with making an SLS printer it doesn’t contain them all and there have been a handful of other supplemental patents in addition to 5597589. Sure that doesn’t really matter much to Chinese manufacturers but within our country there will be a risk involved with stepping up to the plate and building a more consumer-friendly SLS printer. Currently SLS printers are in the hundreds of thousands of dollars, making them far out of reach of small businesses and the general public. While FDM is a great option for prototyping, SLS is clearly the better option for production of a finalized product.We’ll see what the future hold for consumer SLS and DMLS printers, you may see some unexpected companies figure out a loophole to jump on the 3D printing bandwagon using SLS, especially since within the next few years the rest of the patents are set to expire, which will really open the doors to cheaper SLS technology.
I am closely watching the progression of 3D printing Tech, from toys, to car parts, to firearms, even food and living organs so keep posted because I’m bound to get back to this again, especially when they successfully produce a fully functional cylinder head (custom ported heads anyone?). 3D Printing is advancing every day and holds some great changes for our future and even our economy, I’m excited about it and can’t wait for what’s next. In the meantime, take a look at the info I have provided and start digging in yourself!