Boaz: A DIY 3D Printer, Built Twice

3D Printing
Boaz is a CoreXY 3D printer I designed and built at home, then took apart and rebuilt the way a machine shop builds a fixture: dowel pins pressed into hand-reamed holes and checked with a dial indicator on granite, a cast tooling-plate bed on a three-ball kinematic mount, an eddy-current probe that made first layers hands-off, and a resonance sweep read as a report card on the build. The first build ran a charity toy drive and a thousand-part production contract and failed in nearly every subsystem; the rebuild met seven of eight criteria fixed in advance. See the machine print, watch a pin get indicated to a thousandth of an inch, and take home a checklist you can apply to any printer you own or build.

Schedule

Sat 3 Sat 3 October 2026
Cafeteria
11:00 am
2:00 pm
Full Schedule
Boaz: A DIY 3D Printer, Built Twice project image
Abhishal Kochhal Maker Picture

Abhishal Kochhal

Abhishal Kochhal is a senior at Leland High School in San Jose. He has designed and sold 3D-printed drone parts and printer components since 2022 as MRCAT-51 Drone Parts, builds competition robots with FRC team 604, flies as a certified drone pilot, and shows work at local maker faires. Boaz is his own machine, built twice: once the way the hobby builds printers, once the way a machine shop builds a fixture. He wrote up both builds, and the failures in between, in a 200-page book and a research paper. He is looking for an internship in 3D printing.

Categories: 3D Printing, Engineering, Fabrication, Tools & Tips, Young Makers

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https://www.linkedin.com/in/abhishal

What inspired you to make this project?
I built my first 3D printer the way the hobby builds them: printed brackets, idlers on M5 screws, rails lined up by eye. It looked like the CAD render and printed worse than a $300 machine from a factory. I did not want to accept that a year of building had to lose to a box off a shelf, so I went looking for how machine shops get precision on a budget. The answers were decades old: stiff frames, dowel pins in reamed holes, kinematic couplings, and measuring as you build instead of after. Boaz is what happened when I rebuilt the same printer using them.

What are some of the challenges you have encountered and how did you address them?
Most of them were things I did to myself. I reamed pin holes oversize, so pins that should have been press fits slid in by hand; the fix was a 4.95 mm reamer, a micrometer, and a dial indicator on granite to prove every idler ran true. The PCB heatbed warped 1.6 mm and no software mesh could hide it; a cast tooling plate on three balls fixed it, and an eddy probe made first layers hands-off. I tensioned belts one at a time and racked the gantry square out of true; now both go on together and a printed calibration part checks the result. The rebuild met seven of eight targets I set before starting. The eighth, acceleration on the Y axis, is still open, and I say so.