Abhishal Kochhal

Maker · Engineer · Author

AbhishalKochhal

A high-school senior in San Jose who designs and builds precision machines. His CoreXY 3D printer, Boaz, was built twice: once the way the hobby builds them, and once the way a machine shop would. Then he wrote the book on the difference.

Explore Boaz Résumé The book on Amazon
boaz_cad_v7 · final assembly
CAD render of the Boaz CoreXY 3D printer: an aluminum extrusion frame with gusset plates, a belted Z axis and an enclosure.
Boaz, the final CAD assembly after the rebuild.

Accepted exhibit · October 2026

Boaz at Maker Faire Rocklin 2026

“Boaz: A DIY 3D Printer, Built Twice” was accepted as an exhibit at Maker Faire Rocklin, held at Sierra College in Rocklin, California on October 3, 2026. Abhishal shows the machine running, with a poster on how it was built and measured.

Maker Faire Rocklin The poster

Boaz in numbers

Measured, including the parts that fell short

Eight criteria were fixed before the build. The rebuilt machine met seven.

16:00
Speed Benchy, first attempt

A standard test boat, printed in 16 minutes against a 20-minute target.

7 of 8
Preset criteria met

Y-axis acceleration fell short of its target.

1,000
Part PETG contract

About 50 boxes a day. A $300 store-bought machine beside it made 60.

< 0.001 in
Pressed-idler runout

Wobble on every pulley kept: about 25 thousandths of a millimeter.

The story

He had a working printer, and rebuilt it anyway

The short version of a project that began in 2023, for readers who do not build machines.

2023 · Start

A machine nobody sold

He wanted a fast printer he could customize, for less than the established kits cost. He designed his own and paid for it at about $100 a month.

2024 · First build

It worked, with flaws

The first machine printed about 200 toys for a charity drive. It also needed a person to adjust every first layer, and it could not print a threaded lid that fit.

Diagnosis

A measurement problem

He traced each flaw to a cause: a pin 0.04 mm too small, a bed warped by 1.6 mm, rails set with printed jigs. Machine shops solved these a century ago.

2026 · Rebuild

Same design, built properly

He rebuilt it with a dial indicator and a granite block, tested it against eight targets set in advance, and published the results, including the two that went against him.

Portrait of Abhishal Kochhal

About

Builds the machine, then measures it

Abhishal Kochhal is a twelfth-grade student at Leland High School in San Jose, California, and expects to graduate in 2027. He has designed and sold 3D-printed drone parts and printer components since 2022, trading as MRCAT-51 Drone Parts on eBay and Etsy, and he draws in Onshape and Fusion 360.

He built competition robots with Leland's FRC Team 604 from 2023 to 2025, where he led design of the loading subsystem, and with a FIRST LEGO League team at Bret Harte before that. He is a certified drone pilot, belongs to Leland's RC plane club, and shows work at local maker faires.

Boaz is his own machine, built twice. Building Boaz is his account of both builds.

  • BasedSan Jose, California
  • SchoolLeland High School, class of 2027
  • Focus3D printing, motion systems, precision assembly, metrology
  • ToolsOnshape, Fusion 360, Klipper, dial indicator and granite
  • InterestsMechanical design, precision manufacturing, robotics
bed_mesh · 100 × 100 · 70 °C
A 100 by 100 point eddy-probe mesh of the rebuilt bed, almost uniformly flat.
The rebuilt bed: 0 to 0.2 mm across ten thousand points. The first build's bed spanned 1.6 mm.

Featured project

Boaz: one machine, built twice

Hobby printers inherit their construction habits from RepRap, which set out to build a machine that could copy itself, not one that could hold a tolerance. Boaz tests whether five practices from machine-tool building carry over. Both builds share one design and most of their parts, so the first build is the control.

  • Design began in October 2023; the first print came off the machine in 2024.
  • The first build failed at least four of its eight criteria. The failures were specific enough to diagnose.
  • The rebuild met seven, and lost a production race to a $300 machine. Both results are reported.
Read the project Papers, poster and slides

Library

Five ways into the same project

From a 29-chapter book down to a nine-slide deck. Every number in the shorter pieces comes from the book.

01 · Book

Building Boaz

An engineering guide to the effective DIY 3D printer: theory, failures, and the fixes that worked.

On Amazon → 02 · Research paper

Machine-tool practice on a DIY printer

A 13-page preprint, submitted for review to IEEE ISEC ’27: design, failure analysis and rebuild, measured against eight preset criteria.

Read the preprint → 03 · Article

A DIY printer built like a machine tool

A magazine-style feature for makers, in four-page and two-page cuts.

Open the PDFs → 04 · Poster

Conference poster

Motivation, method, results and the eleven rules on one A0 sheet.

View the poster → 05 · Slides

Nine-slide deck

The short version: why, what broke, what changed, and the numbers.

View the deck → 06 · Résumé

Experience and skills

Education, activities, robotics and technical skills on one printable page.

Open the résumé →

Achievements

What he has made, led and earned

Author

Published a book

Building Boaz: An Engineering Guide to the Effective DIY 3D Printer, 29 chapters, available on Amazon.

Engineering

Designed and rebuilt Boaz

A CoreXY printer of his own design. The rebuild met seven of the eight criteria set before construction.

Production

Printed for real customers

About 1,000 PETG pet-medicine boxes for a medical organization in Iraq, and roughly 200 toys for a charity drive.

Robotics

Design lead, FRC Team 604

Led the loading subsystem at Leland from 2023 to 2025. Multiple awards at regional and national competitions, and a competitive run leading up to the world championships (5th place).

Sponsorship

Backed by Duet3D

Received $150 of electronics from Duet3D in sponsorship of the Boaz project.

Business

MRCAT-51 Drone Parts

Has designed and sold custom 3D-printed drone parts and printer components on eBay and Etsy since February 2022.

Certification

Certified drone pilot

Certified through Pilot Institute. Member of Leland's RC Plane Club and Habitable World Club.

Academics

3.8 GPA

Honorable Mention on the National Spanish Exam. Above grade-level CAASPP and NWEA scores.

Exhibitor

Maker Faire Rocklin 2026

“Boaz: A DIY 3D Printer, Built Twice” was accepted as an exhibit, with a poster and a live demonstration, at Maker Faire Rocklin, October 2026.

Path so far

Six years of building things

  1. FIRST LEGO League, Bret Harte

    Designed and built competition robots with a middle-school team.

  2. MRCAT-51 Drone Parts

    Started selling his own 3D-printed parts online.

  3. FRC Team 604, Leland High School

    Design lead for the loading subsystem; laser-cut sheet metal and CNC-milled parts.

  4. Boaz design begins

    The first print came off the machine in 2024.

  5. Computer technology intern

    St. Basil the Great Greek Orthodox Church, San Jose: digitized and organized records, and worked on the website.

  6. Rebuild, measurement and the book

    Boaz rebuilt and measured against its criteria; Building Boaz published.

  7. Maker Faire Rocklin

    Boaz accepted as an exhibit, with a poster and a live demonstration, at Sierra College.

“Precision is not a part you buy. It is a procedure you follow.” From the Boaz slide deck
runout_check · granite
A dial indicator reading the face of a pressed idler, with the assembly squared between granite blocks.
Checking a pressed idler for runout against granite.

Contact

Questions about the work?

About Boaz, the book, the paper, or anything else on this site, write to amkochhal@gmail.com.

Email LinkedIn Résumé