How to print non-PLA large-format objects on the gMax 1.5 XT+ (not for the faint of heart!)

Out of the box, the gMax might be able to print large-format PLA objects, but printing with production-quality materials requires nothing less than a complete overhaul of the gMax. We'll start with the overview, and add specifics in follow-up replies as time permits.

1. Replace all of the gMax's plastic parts (yes, all of them, every. single. one.) with ABS parts, printed using 100% infill.

2. Replace the electronics box cooling fan with a reliable ball-bearing fan. I recommend the Orion OD5010-12MB.

3. Add the dual-zone heated build plate, with additional bed retaining clips. Modify the ones on the sides to allow clearance for the Z-axis screws, and modify the ones on the front edge to allow clearance for the hot-end at extreme Y positions.

4. Build a heated enclosure. The enclosure must allow the electronics box fan to pull outside (cool) air into the box. Otherwise your stepper motor drivers will overheat, screw up your prints, and cause the hot-end to tear itself up. This will probably happen anyway, if you don't replace the fan (see #2). The enclosure should leave the control panel and the power supply on the outside, so they can stay cool.

5. Set up an OctoPrint server, with a relay board to control power relays for the heated enclosure and bed. Build or buy a filament sensor (two, if you have a dual extruder) and a temp/humidity sensor. Add Vitor Henrique's outstanding Enclosure Plugin to pull it all together.

6. Routinely, consistently, fastidiously check the X-axis arm level, X & Y belt tension, hot-end screw/bolt tightness, frame bolt tightness, and anything else that might work its way loose over time. Loctite may be your friend.

7. Buy Simplify3D.

8. Use a brim. I am still amazed at how effectively a brim can reduce warping.

I didn't have to do any of that except number 3. Print with carbon fiber for just about everything.
I did add Octoprint but that isn't necessary to print, I use it because it's better.


New Member
I assume you mean carbon fiber PLA, which is still just PLA...not an industrial-grade plastic. To print large-format parts in industrial materials like ABS, nGen, or other copolyesters, number 3 alone won't get you there.
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