Through out the year we at ProImage3D have realized that there are quite a few people who think all 3D printing is the same or have no idea what it is entirely . So, today we’ll talk about a few processes to help familiarize yourself with what 3D printing is capable of.
Hobbyist Type Printers
FDM- Fused depositional modeling or FFF-Fused filament fabrication
FDM/FFF are the most common type of 3D printing and is what most people think of when they hear 3D printing. We like to describe it as weed eater string going through a hot glue gun, they tend to be the most affordable for hobbyist and have the most open and strongest community base. This is one of the reasons it’s mistaken as the only type of 3D printing.
FDM works by pushing a line of filament (weed eater string analogy) through a heated nozzle(hot glue gun analogy). FDM parts tend to be some of the more durable plastic parts but have very visible build lines. A good choice if your part needs to handle some weight and doesn’t have to be very precise in its dimensions.
SLA printing is also common among hobbyist and has become almost as accessible as FDM in the last few years. SLA uses resin that is cured by a laser to create the parts. SLA has a very nice surface quality and can hold amazing detail, however, SLA printing supports attached to the print with very thin points that will leave nubs on the print that have to be sanded off and can ruin some detail.
It is best practice to put the supports on the back of the model or in areas that are easy to sand. SLA prints can also be painted easily and are ideal for models and board game pieces with details.
Industrial/ Service Bureau Type Printers
PolyJet is similar to a regular ink printer, PolyJet uses a liquid, called digital material, and shoots out a layer of material that gets cured by UV light. Each layer takes 3 passes to be fully cured the first pass cures it 70% and then the next pass it’ll cure it 95% and once it does the third and final pass it fully cures that layer. This process also has water soluble support, so it is easy to clean and keeps the part very accurate dimensionally.
PolyJet is good for checking dimensions, we at ProImage3D use it to print gears for our print shop guys to check our models and then have the model cut by a CNC to replace busted gears that you can’t buy individually. Getting the machines working again saving them time and money.
DMLS- Direct Metal Laser Sintering
Something that shocks a lot of people is that we can 3D print metal. DMLS uses a high powered laser to melt metal powder together (kind of like welding powder together). DMLS has a wiper that lays out a thin layer of metal powder on a build plate, the laser melts the pattern in the layer and the build plate lowers one layer height, and it repeats this process until it has made the part.
There are many alloys that are used in this process steel, titanium, aluminum, and cobalt chrome being just a few. Since the build plate lowers itself and gets filled with powder around the part there is no need for support structures (although you do have to go on an archeologist dig for your part afterwards) all that’s left is to sinter it in an over to the parts requirements for a solid metal part.
DMLS has been used a lot in architecture, unique pavilions and support beams, and in the medical field for titanium implants.
SLS- Selective Laser Sintering
SLS and DMLS are actually very similar with the only major difference being material. SLS melts a layer or plastic/ceramic/polyamide and then the build tray lowers, and a wiper adds another layer of material (see very similar). SLS parts tend to have a sanding texture and look to them but with one of the most common materials for it being Nylon it can have some pretty tough parts, and some material can withstand pretty high temperatures.
We’ve seen it mostly for automotive parts under the hood, and for a 95’ Buick AC unit in Arizona.