[protoserge]

We have a Lulzbot TAZ 4. It has been good oberall, but not without its issues though. We replaced the glass bed with 1/4" cast aluminum after I broke the glass while removing a part. We upgraded the hot end this season to an E3D v5 (it was bought with the printer and never installed). The nozzle works great and I look forward to making nylon parts next season. Just a few weeks ago, one of the z axis drive screws came off the stepper motor and had to be realigned. I had to print a replacement extruder herringbone drive gear last season. If I had a guess, we have 400 hours on the TAZ. It has a great build volume and overall I would recommend it. It is an overall great printer and a lot of the components are 3D printed, which annoys me on a printer of that cost, but is also easy to repair given access to a working printer. Print spare extruder parts right away if you get one.

My OpenBeam Kossel Pro has been a champ for the past 15 months and has over 200 print hours on it. I spent a lot of time in the build making sure things went together perfectly. Something with the latest MatterControl build has rendered it non-operational, but it appears to be code added to the print sequence and not a control board issue. It does need a 32 bit control board since I should be able to print about 4-5x faster. While I love the printer, I'm torn on whether to recommend it based on your requirements.

I have heard good things about the MarkForged printer. It is a very capable printer and can print kevlar reinforced parts.

Most all printers are going to require some level of hassle and fine tuning. Sticking with open source will get you back up quicker and will probably be less expensive. Not to mention your students amd mentors can become experts and create modifications to improve the machines.

I would avoid Makerbot. I "consult" with my state libraries and they have had nothing but issues with them. Their Ultimaker v1s have been more reliable than the v2s.