3D printing FED3
FED3 was designed to be printed on FDM printers, in fact, most of the FED3 devices we have made were printed on relative cheap printers in PLA. That said, if you have access (or funds) to use professional 3D printers you will get nicer parts. This page will give some tips and overviews of different printers we and others have used to print FED3.
The information on this page is not an endorsement of specific products or companies. Specific products and company names are mentioned solely to provide information, we get no compensation from any of them.
The most common printer we have used to design and print FED3 is the Sindoh 3DWox1. We have successfully printed and used entire FED3 devices with this printer in PLA. To get the highest quality prints we recommend slowing the print speed down to 20mm/s and printing all parts in the orientation in the STL files. The housing will require supports, but no other parts will. When you generate supports for the housing make sure there are none inside the pellet chute! We estimate it to cost ~$5 in PLA filament to print all of the parts.
Matthew Buczynski's lab at Virginia Tech bought the Prusa i3 MK3S
because it has a large user base on the internet. This makes it pretty easy for students to get quick access to troubleshooting tips when the printer is not operating properly. We currently print parts using PLA at the settings (20mm/s). We’ve started using brass pellet trays (via Shapeways) and getting them to stay in place with a small dab of epoxy. Note that this photo is an older version of FED3.
Matthew Buczynski's lab at Virginia Tech also bought a FormLabs Form2 resin printer to print high quality parts. There are a number of advantages resin printing, and if the optimal resin were identified it might be a great approach to building FED3 housing. These parts are damn near perfect, felt smooth to touch, and I couldn’t identify any layer lines at 50 micron resolution. Interestingly, these prints still produce about 1-4% error rate (similar to PLA filament prints). Additionally, resin printers are substantially easier to use than filament printers, and by comparison require substantially less day to day maintenance. Moreover, we estimated that each faceplate only costs ~$15 to print and you can print two per day.
However, resin printing introduces a couple of new problems separate from standard filament printers. First, the parts were so perfect that we had a hard time disassembling them for cleaning. For this reason, we still print all non-essential parts (back housing, doors, lids) with PLA filament. Second, the standard resin (Black Resin, RS-F2-GPBK-04) did not hold up as well as filament under experimental use and the mice chewed at them more effectively (see picture). Additionally, the standard resin was susceptible to shear stress and occasionally cracked when mishandled by experimenters (or professors who start playing with them). We haven’t had the opportunity to test out other resins yet, but if an appropriate one that solved these problems could be identified I would wholeheartedly endorse using the FormLabs printers for FED construction. Note that this photo is an older version of FED3.
We really like the [HP Multijet Fusion] (https://www8.hp.com/us/en/printers/3d-printers/products/multi-jet-fusion-5200.html) prints in Nylon PA12. This printer is out of our price range to own, but we use Shapeways to print these parts. These prints are expensive (~$150 to print all parts) but the parts come out perfect. They do offer an education discount for students and educators.
Amy Sutton at the NIH printed FED3 with the Markforged Mark II and they are working well! From Amy: "We then bought the Markforged Mark II due to its capability to do a few things: 1) reliably print VERY SMOOTH pieces, 2) print MUCH stronger pieces using a combination of composites and fiberglass, and 3) easier support removal. After using it for more than one month, I highly recommend it. The smoothness of the Onyx Pro is great, especially since the disk is moving alongside a smooth interior. Just as important, the disk is extremely strong due to printing w. stronger materials. Lastly, removing supports is a breeze compared to PLA, and takes around 5-10 minutes for the entire new front. We even are able to put supports in the pellet chute and remove it with the new holes that Lex has inserted into the chute for easier support removal, and the chute is thus very smooth. 
To reduce damage to the front of FED from the mice chewing on it, we have the pellet well or "nose" 3D printed in steel with Shapeways. We use their "Black Steel" because it looks awesome but any color or even aluminum should work just as well for this. Shapeways charges $15 for each metal part. If you print this in PLA or a plastic material you can glue it into the FED3 housing and if it gets damaged you can replace it. In our experience the nosepieces can last a couple months even when printed in plastic, but they will need replacing at some point.
It's nice to have the lid printed in a clear resin so you can see when its low on pellets without opening the lid. The best commercial printer for clear resin we've found is wenext.com in China (they ship worldwide). They print in Somos WaterShed XC 11122 which comes out beautiful and looks like clear acrylic. These lids are ~$7.50 each.