ACU: Inventor practice

Speed-scored Inventor practice for the whole class period.

CAD Clash is a timed quiz arena for high-school engineering students getting ready for the Autodesk Certified User: Inventor exam. Five questions, one per official domain, the same set for every period, scored to the hundredth of a second.

See how a round works Play onlinecoming soon

Today the arena runs on the classroom network. The hosted version is planned. Where that stands.

Sketch · difficulty 1 · 20 s 0.00 s

You just created a new part file and want to draw the profile for a phone stand. Which command do you use first?

600 pts on the table

Same formula as the app. In class the server keeps the clock, not the browser.

  • Domains5, the official Certiport objective domains
  • Timingserver-side, shown to 0.01 s
  • Identityclass code and a handle
  • Student emailsnone, no column for one

A class round

What happens between the bell and the leaderboard

  1. 01

    Join with a class code

    Students enter the join code for their period and pick a handle like TorqueOtter42. The dice button rolls one for anyone who is stuck. That handle is the only name the app ever knows.

  2. 02

    Five questions, one per domain

    The Daily Challenge is pinned per date. Workspace and Navigation, Sketch, Model, Assemble, Document. Period 1 and period 6 see the same five, so the cross-period board is fair.

  3. 03

    Answer against the clock

    Points start at 600, 800 or 1000 by difficulty and drain to 40 percent at the buzzer. Streaks add a bonus. Wrong or late is zero. The server stamps the time, so a fast laptop is not an advantage.

  4. 04

    The wall shows the top, never the bottom

    A projector page cycles the podium, positive-only spotlights and participation bars. Answers stay sealed until the school day ends. Losing is private.

Scoring, from shared/scoring.ts
DifficultyTime limitInstant answerAt the buzzer
120 s600240
230 s800320
345 s1000400

Streak bonus adds 40 per consecutive correct answer, capped at 200. Build challenges pay three times these numbers.

Dimensioned engineering drawing of an L-bracket in steel, with front and end views and all dimensions in millimeters
One of the ten bundled drawings. The numbers on it change every attempt.

Build Arena

Model it in Inventor. Type the volume.

A build challenge hands the student a dimensioned drawing and a five to eight minute clock. They model the part in Inventor or Fusion, read the volume or mass from the physical properties, and enter the number. CAD Clash checks it against the answer generated for that exact set of dimensions.

Retries get fresh dimensions, and the app refuses to reuse the last eight answers a student has seen. Memorizing one number does not work. Building the part does.

  • Ten drawings: stepped block, drilled plate, bored cylinder, hex standoff, L-bracket, spacer tube, slotted rail, counterbore block, wedge block, bearing flange.
  • Personal bests and a class top five, timed by the server.
  • Teachers can attach their own part files for open-and-modify tasks.
  • It grades the number a student enters. It does not yet inspect the CAD file itself. That is on the roadmap.

Privacy

Handles, not students

CAD Clash stores a made-up handle for each student and nothing else that identifies them. There is no name column and no email column. Both validators reject anything shaped like an address or a student ID, and a teacher rename goes through the same rule.

The mapping from handle to teenager lives in the teacher's own private roster, outside the app. The bridge between the two is a four-column export.

roster-export.csv
handle,external_ref,join_code,class
TorqueOtter42,S-0417,CAD-3P,Period 3
GearFalcon07,S-0522,CAD-3P,Period 3

Four columns on purpose. No names, no emails, no scores. The teacher matches on the reference token in a gradebook the app never sees.

For teachers

Built by a teacher who runs it in his own periods

The admin side is where the class actually lives. It is small on purpose.

Question bank and review queue

Students can write questions. Numeric ones must pass an answer-your-own-question proof before they reach you. Approve, edit or reject with a note from the keyboard.

Bulk import

Paste from Sheets or a CSV. Every row goes through the same validator as a student submission, and errors come back per row.

AI drafts, gated

Ask for variations on a question or a fresh batch in a domain. Every draft lands in your queue. Nothing generated reaches a student without your approval.

Reports and the Period Cup

Filter by period, year or grade and export a gradebook-ready CSV keyed on handle and reference token. The weekly cup rewards participation over one grinder.

Status

Playing online is not open yet

CAD Clash runs today on one teacher's machine, and students reach it over the classroom network. That works, and it costs nothing. It also means nobody can play from home.

The move to a hosted version is planned and written down. Pseudonymous handles were the first requirement and they are done. Rate limiting, backups, a deletion path and a written answer for the school come before a public URL takes real classes.

When it opens, this page is where the class code goes.

  • doneHandles only, no name or email column
  • doneBuild Arena with per-attempt dimensions
  • doneServer-side timing and sealed daily answers
  • plannedHosted database and deployment
  • plannedRate limiting, backups, deletion path
  • laterLive Clash rooms, projector and phones
  • laterGrading the CAD file itself