# Printer/Material/Setup recommendation for printing mechanical parts [closed]

I'm interested in printing small machine parts (gears, linkages, structural components) so I'm looking for accuracy and mechanical strength over speed and volume.

I'm also somewhat concerned about harmful emissions so would like a solution with some sort of filtration, whether it's built into the machine or something added. I'm thinking I will run the machine in an unventilated garage, which is quite warm and humid during the summer in Texas.

My price range is \$1500-\$2000 USD. I've looked at several options but I didn't really come across any scenarios like I've described and would like some advice from the experts before committing.

Anyone in a similar boat have any suggestions?

• Hi! I unfortunately have to close your question for being primarily opinion based. Please have a look at out help center for more information on how to ask questions for the Stack Exchange sites. Good luck! :-) – Tormod Haugene Sep 6 '17 at 7:27

Your environmental conditions will preclude finding a machine suitable for your purposes in the budget specified.

Humidity is a problem with many material types, especially nylon, but also with PLA and ABS, the more common filaments used in 3D printing.

You can likely reject PLA for your mechanical needs, as it is brittle and weak compared to ABS. PLA releases virtually no gases of concern, while some find ABS fumes to be offensive and dangerous.

The humidity issue is forefront in your search. You may have to construct within the garage a chamber in which you would operate a portable or window air conditioner unit, to keep the humidity in check. If you can assign a different budget to such a construction, that will leave your printer funding intact and better able to address your goal.

Selective Laser Sintering using nylon powder, also susceptible to humidity, which is sintered by a laser, hence the name, making very detailed and strong parts. The process is also self-supporting, allowing for fairly intricate parts. Once the machine is calibrated, the part accuracy can be quite good. Unfortunately, SLS machines are also out of the budget range you've noted.

You can use an external service to print the parts you design, at least at first, to get a better indication of how the various materials will work for you. Start with PLA, then move to ABS for a set of test parts, and even perhaps have some printed using SLS.

If you find, for example, that ABS will be strong enough, you might find an affordable 3D printer which will generate parts on your budget and timeline. For printing ABS, the warmer temperatures are to your advantage, but the humidity has to be properly addressed in any home/shop/garage installation.

• Hi, thank you for your thoughtful response. The main reason I was considering running the printer in the garage is due to the emissions, as I figured ABS would be the material of choice. I could run it in the house if I could contain emissions. My initial thoughts were to enclose the printer in an acrylic box and install a circulation fan with activated charcoal filter and let it run for a length of time prior to opening the enclosure after a print. Is this feasible? I could also consider exhaust to outside after print is complete. Does anyone print ABS indoors safely at home, and how? – Pat Aug 23 '17 at 11:20
• I print ABS at home in my non-enclosed Sigma 2016 printer. I can't address the "safely" part, as the odors are minimal. If you plan to enclose your printer, consider that a fan will increase problems with ABS due to thermal irregularities. I'd suggest leaving a fan off until the print has completed and cooled fully before exhausting the chamber into a filter or outside. – fred_dot_u Aug 23 '17 at 14:30
• I think the optimal solution would be exhausting the enclosure outdoors after print is complete. Closable louver in the front and flexible duct with fan out the back I can seal to the window an shut off while in use. I guess the final thing I would ask is for a printer recommendation. The ones I was thinking about were MakerGear M2, Prusa I3 MK2S, and the Robo R2. Any thoughts? – Pat Aug 24 '17 at 2:45
• I've assembled a Prusa i3MK2s kit in the recent past, for the public library and it was an excellent experience. The Prusa was easy to build and creates quite good models. As a kit, you would also have the ability to modify it to move the power supply and "brain box" outside the enclosure, assisting in cooling. You can find the assembly instructions on Prusa's web site. The project was incredible fun and the printer is cranking out models for the library patrons. Your ducting and fan idea would likely work well, and may need only a minute or two of exhausting to clear the air. – fred_dot_u Aug 24 '17 at 9:59

There is more than one question here. Which touches three topics: the choice of appropriate 3D printing technique, the choice of materials, and control of any hazardous, noxious, or annoying out-gassing.

It is important to understand the limits of the 3D printing process you will choose. Each process has its own limits on repeatability and resolution of small features, such as gear teeth. A 10 pitch (teeth-per-inch) gear could print acceptably well with a low-cost printer, but the size of a 10-tooth gear would be 1/2" diameter. This could be a small part, or a huge part, depending on the use. To print an 1/8" diameter 10-tooth gear would require a 100 pitch gear likely would not, and would call for an optical process (laser sintering (SLS) or photo-polymerization (like the FormLabs Form 2)) or a dot-jetting process (such as the StrataSys Objet Connex machines). These are not in the budget you've suggested, but are available through service bureaus.

Answers here another community question give some hints for using a plastic-extrusion machine, and information about SLS.

Each process has different environmental requirements, and impacts, but first should be to understand the requirements of the parts, based on those choose a process and material, and then mitigate the environmental factors.