SLS, FDM, SLA, LOM… What 3D printer meets your needs?

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3D printers are making their way into homes and businesses around the world. As more people shop for 3D printers, they are different type of 3d printer with a wide range of options.
All 3D printers work by laying down a layer of material at a time to build a 3D object. The difference in the machines is in how the materials are placed down. For this


I’ll look at the types of 3D printers that are currently used in the desktop printer market.
I’ll look at examples of different types of 3D printers, comparing the following.

  1. Cost: The high and low-end of this type of printers is considered here.
  2. Cost of consumables: Like inkjet printers, the cost of the materials you 3D print with will be the major expense.
  3. Technical skills: Can you set them up out of the box, or do they require extensive technical skills?
  4. Resolution: How fine or coarse can you 3D print with these printers?
  5. Space / auxiliary requirements: What else does this type of 3D printer require to operate

Fused Deposition Modeling (FDM) – type of 3d printer

Also known as fused filament fabrication (FFF), this process is the most common one used in desktop 3D printers. FDM is by far the most flexible method to 3D print anything.
In FDM a thermoplastic filament is melted and extruded onto a build plate to build an object. FDM printers can also be modified with a syringe extruder to extrude food, clay, or bio printing. Other types of FDM printers have been developed that use cement for building construction, or bio printing.

Commercial brands of FDM type of printers include Makerbot, Ultimaker, and Lulzbot. RepRap, the open source 3D printer that kicked off the desktop 3D printer revolution, is also a FFF type printer.
Most FDM printers will only print in one or two colors at a time. Future innovations will develop a process for multi-colored prints.
Cost: RepRap kits sell online for as little as $200, and high-end 3D printers like the Makerbot Z18 sell for $6,499.
Cost of Consumables: Part of the RepRap project was to develop a filament extruder that could use recycled plastic bottles to make new filament. Such extruders are suited for businesses or serious home users.

Carbon Fiber filament from Colorfabb - type of 3d printer

Carbon Fiber filament from Colorfabb

For a 1 kg spool of PLA, you can spend about $40.00 and up depending on the filament brand. A 1 kg spool will be enough to produce about 40-50 hand sized objects. You can find a wide variety of colors available.
Other types of plastic cost more. ABS is a popular filament, but it requires ventilation to use comfortably.
Technical skills: Most FDM printers are easy to assemble from kits, or come ready to print out of the box. Commercial brand FDM printers have great technical support, and easy set-up procedures.
Resolution: With FDM printers you will see and feel the layers involved in 3D printing. Generally you’ll see 0.1 mm to 0.3 mm resolution with most desktop 3D printers. Check the specs of your particular FDM printer. With FDM printing you will have laminated layers, with weaknesses along the laminated layers.

Taz 5 y-arm tool tray - type of 3d printer

Taz 5 y-arm tool tray made by the author. Features the tools used for finishing a FDM print.

Space / auxiliary requirements: FDM desktop printers are designed to work in the home, and are great for general purpose use. If you are interested in starting 3D printing, or just want a general purpose 3D printer, FDM type printers are the way to go. They require a simple set of hand tools for finishing which you can find at any hardware store. If you want to polish ABS you will need a work space with plenty of ventilation to use acetone.

Stereolithography (SLA) / Digital Light Processing (DLP) – type of 3d printer

This type of 3D printer uses a digital light projector to form the object from a vat of liquid resin. The main advantage of this process is speed and resolution. By projecting a layer at once, the object can be 3D printed in minutes instead of hours compared to a FDM printer.
As companies develop new photo polymers to go with this type of 3D printer, the range of products that can be produced will expand. (CLIP) These are on the larger size of the desktop range, with the build space limited by the projection area of the digital projector.

SLS printers produce high-resolution and high quality prints. SLS printers are better suited for industrial uses then home use. The liquid resin is expensive, and messy to process. SLA / DLP printers can only print in one color.
Cost: SLA / DLP printers have been made for as little as $20.  Commercial SLA printers like the Formlabs Form 2 run $3499.00.

SLA printer - type of 3d printer

$20 3D SLA type printer made by students, using powerpoint to slice and build the object.

Cost of Consumables: Many SLA printers use proprietary cartridges for their resin. FormLabs carriages cost $149.00 and up depending on the material.
Technical skills: Calibrating SLS printers can be difficult. You also have to clean the resin tank and build platform after every print, and you have to be careful in choosing your resins. SLA / DLP printers are more for industrial printing than home use.
Resolution: At 25 microns and up, SLA / DLP 3D printers produce smooth seamless objects. They can print transparent prints, which help in many designs.
Space / auxiliary requirements: These printers do fit on a desktop, but need a separate work space with ventilation for solvents. They use rubbing alcohol or other solvents to treat the parts. The resin itself is messy, and requires gloves to work with from the 3D printer.

Laminated Object Manufacturing (LOM) – type of 3d printer

LOM type printers are unique in 3D printing. Instead of using powers, liquids or filament, they use sheet goods to produce solid objects.

LOM type printers are actually the precursor to 3D printing. Before RepRap, LOM type printers were the first rapid prototyping machines on the market.

Currently LOM printers are used for niesh materials and applications.
They work by cutting a slice of material and fusing or gluing it to the previous layer. This technology can be used with fabric, paper, or other sheet goods. Disney Research is using a LOM type printer to develop new stuffed animals for production.

While this is not a common type of 3D printer, the ability to use different materials will appeal to artist and craftsman. In the future this type of printer may find more acceptances in the desktop 3D market, as well as nesh industrial markets.
With LOM printers using paper as a material, it is possible to print in full color.

Cost: Mcor LOM printers recently debuted at CES, but the cost has not been released.

Cost of Consumables: Proprietary color ink cartridges will be the most expensive consumable for this printer. The glue used to bind the layers will also be expensive.

Technical skills: Once aligned, LOM printers will not require the technical skills to calibrate as other printers.

Resolution: LOM printers are limited to the resolution of the material.

Space / auxiliary requirements: LOM printers can easily be desktop models. Depending on the material used, you may need secondary equipment to finish.

SLS (Selective Laser Sintering) – type of 3d printer

SLS printers are the industrial powerhouses of 3D printing. Laser sintering is a process where a laser or glue is used to form the object from a bed of powdered material.

A cousin of SLS is Direct Metal Laser Sintering (DMLS) which uses plasma or high – powered chemical lasers to directly fuse metal powder.

SLS printers are the machines that can print in ceramics, metals, and plastics.

  1. Cost: The chemical laser system is the most expensive component of a SLS System. Recent start up companies and kickstarters have tried to push the prince under $5,000 for desktop SLS models. However, SLS / DMLS are industrial machines that run six – seven figures.
  2. Cost of consumables: The powders used have to be uniform and very fine, and few companies specialize in their production. The market price for metals can also factor into the cost, especially for titanium and cobalt. SLS also use industrial quantities of electricity and industrial gas.
  3. Technical skills: Companies will need to hire skilled CNC lathe operators or trained technicians.
  4. Resolution: Resolution can be to the width of a laser beam.
  5. Space / auxiliary requirements: SLS / DMLS machines can require a decent sized footprint in a factory.