Fundamentals · Lesson 2

Lab Safety and Earning Tool Access

Nothing in this room is locked away from you. It is waiting for you to earn it.

Grades 7 to 12
Time 2 class periods
Difficulty Beginner

Most school labs work by keeping students away from the good equipment. This one does the opposite. There is a laser cutter, two 3D printers, robots and a shelf of kits, and every one of them is something you can earn the right to use on your own projects, during class and during academic time. The trade is simple. You learn how each machine hurts you, you prove you can shut it down safely, and then it is yours.

What you'll learn

The seven rules that apply to every tool in this room
How a safety check works and what it unlocks
The specific way each machine can hurt you or itself
The one material that must never go in the laser cutter
What to do when something goes wrong, and why reporting it protects you

What you need

Yourself, in the room, paying attention. This lesson happens at the machines.
Long hair tied back and loose sleeves pushed up before you touch anything

Day 1

The rules and the deal

Goal: by the end of today you know the seven rules without looking, you know how each machine can hurt you, and you know what you have to do to unlock each one.

Step 1: The deal

Straight from your syllabus, which you already signed:

"Every tool in this lab is something you earn access to, and once you have earned it, it is yours to use for your own projects, not only the assignment that introduced it. A safety check is short: I show you the tool, you show me you can use it and shut it down safely, and you answer a few questions."

Read that second sentence again. A safety check is not a test you can fail and be finished with. It is a short conversation at the machine, and you can take it again.

Safety checks are graded, under Informal Assessments. They are worth doing properly for that reason alone, and for the better reason that the Glowforge is genuinely more fun than anything else in this building.

Step 2: What each check unlocks

Tool	What you pass first	Then you may
3D printers MakerBot, Formlabs	Printer safety check	Slice and queue your own prints in class and during academic time
micro:bit and Raspberry Pi	Handling and power check	Sign out a kit for a project
RoboMaster	Driving and battery care check	Build, drive and program it for your own projects
Glowforge laser cutter	Independent learning certification	Cut your own designs, with an adult in the room

Checkpoint: you can name which tool you most want access to and what you have to pass to get it.

Step 3: The seven rules

These cover every tool in the room. They are quoted from your syllabus word for word.

Tie back long hair and push up loose sleeves before using anything that spins, cuts, or heats.
Eye protection when cutting or soldering.
Never leave a running machine unattended, never reach into a printer that is moving, and never override a lid switch or guard.
The laser cutter is only used with an adult in the room.
Charge batteries at the charging station, in view, not overnight.
Report damage, a burn smell, or an injury right away. You will not be in trouble for reporting something. You will be for hiding it.
Breaking a safety rule on purpose costs you tool access and earns a 0 for the day. Getting access back means retaking the check.

Rule 6 is the one that matters most. Nearly every serious workshop accident is a small problem that somebody decided not to mention. You will never be in trouble for telling Mr. Krigger something is wrong.

Step 4: How each machine hurts you

Not to frighten you. Knowing the specific hazard is what lets you work confidently instead of nervously.

Machine	The actual hazard	What you do about it
MakerBot	The nozzle runs around 200°C and the build plate is heated. The gantry moves without warning.	Hands out while it moves. Let the plate cool before removing a print. Use the scraper, away from your other hand.
Formlabs	Liquid resin irritates skin and can sensitize you to it permanently. The wash uses isopropyl alcohol, whose vapor is flammable.	Nitrile gloves for anything wet, every time. Keep the IPA bottle closed. Wash skin with soap and water immediately on contact.
Glowforge	A laser strong enough to burn wood, and a real fire risk. Some materials release poison gas.	Adult in the room. Lid stays shut. You stay and watch it. Approved materials only.
RoboMaster	Fires gel beads, and carries a battery that can vent or catch fire if damaged.	Eye protection during blaster events, never aim at a face, charge at the station, report a swollen or damaged battery.
micro:bit, Pi, CrowPi	Low risk. Mostly damage to the board from static or wrong power.	Hold boards by the edges. Power down before rewiring. Check voltage before plugging anything in.

Step 5: The material that must never go in the laser

Never cut or engrave vinyl or PVC. Glowforge states it plainly: cutting vinyl "can release hazardous gases that can hurt you and damage your Glowforge." The gas is chlorine based. It corrodes the machine from the inside and it is genuinely dangerous to breathe.

Two more on the never list, for different reasons.

Galvanized metal. Also releases hazardous gases when cut or engraved.
Shiny soft metals, meaning copper, chrome, gold, silver and brass. These reflect the beam instead of absorbing it, which Glowforge warns "can be hazardous to people and damage your Glowforge."

The rule you actually need: if you did not get the material from Mr. Krigger, it does not go in the laser until he has looked at it. Sticker sheets and vinyl wrap from home are exactly the thing this rule exists to stop, because they look completely harmless.

Checkpoint: you can say what happens if vinyl goes in the Glowforge, and why nobody would notice until it was too late.

Step 6: Now make the call

Eight situations. Carry on, or stop?

Checkpoint: all eight judged.

Before you leave today

A progress check, not the hand-in. The full submission list is at the end.

You can recite the seven rules without looking
All eight situations judged
You know which material must never go in the Glowforge, and why

Day 2

Earn your first check

Goal: by the end of today you have passed at least one safety check and unlocked a tool you can use on your own projects.

Step 1: What a check actually looks like

It takes about five minutes and it happens at the machine, not on paper.

Mr. Krigger shows you the tool and the parts that matter
You run it, with him watching
You shut it down safely and put it back the way you found it
He asks you a few questions, including at least one about what you would do if something went wrong

You can retake it. Nobody has ever been permanently locked out of a machine for not passing first time. The only thing that costs you access for real is breaking a rule on purpose.

Step 2: Track your own access

Tick these as you pass them. This page remembers on your own device, and Mr. Krigger keeps the real record.

Printer safety check, unlocks slicing and queueing your own prints
Handling and power check, unlocks signing out a micro:bit or Pi kit
Driving and battery care check, unlocks building and programming a RoboMaster
Glowforge certification, unlocks cutting your own designs with an adult in the room

Checkpoint: at least one box ticked for real today.

Step 3: Write the shutdown

Pick the tool you got checked out on and write the shutdown procedure from memory, in order, as if for somebody who has never touched it.

Base · everyone

The steps to safely finish and leave the machine, plus the one thing a person is most likely to get wrong.

Stretch · required for HS, bonus for MS

Add the emergency version. What you do if it starts smoking, jams, or a part comes loose mid-run. Say where the power is and who you tell.

Why writing it down matters: the good ones go on the wall next to the machine. If yours is the clearest, it becomes what the next group learns from.

Before you leave today

A progress check, not the hand-in. The full submission list is in the Turn in tab.

At least one safety check passed
Your shutdown procedure written from memory
High school: the emergency version too

What you turn in

The whole list. Every item comes out of an activity you already did.

The seven rules, written in your own words. Not copied. If you can only manage five from memory, hand in five and say so.
Screenshot of your situations score, plus one sentence on any you got wrong.
Which check you passed and which tool it unlocked.
Your shutdown procedure, written from memory. High school also submits the emergency version.
Reflection, 3 to 5 sentences: which machine do you most want access to, and what is the thing about it you are most careful of?

Tick the boxes as you go. This page remembers them on your own device. The next screen shows exactly how to hand it in.

Handing it in

Two things to hand in, not one

1 · The assignment

Everything on the previous screen goes here, as file uploads.

Open Lab Safety and Tool Access in Schoology
Click Submit Assignment
Click Upload
Select all your files at once, then Submit

Do not click "Create". Create is for typing text and will not let you attach a screenshot. Upload is the one you want.

2 · The exit ticket

A separate item in Schoology, taken in class. Short quiz on this lesson, graded on its own.

The safety check itself is graded separately again, when you pass it.

Vocabulary

Term	What it means
Safety check	A short demonstration at the machine that unlocks it for your own use. Graded, and retakeable.
Guard	A cover or switch that stops a machine when it is opened. Overriding one is the fastest way to lose access.
Build plate	The surface a 3D print is built on. Heated on the MakerBot, so it stays hot after the print ends.
Resin	The liquid a Formlabs printer builds from. Irritates skin, and repeated contact can sensitize you permanently.
IPA	Isopropyl alcohol, used to wash resin prints. Its vapor is flammable, so bottles stay closed.
PVC and vinyl	The plastic that must never go in the laser cutter. Releases chlorine based gas.
Sensitize	To develop a permanent allergic reaction to something after repeated exposure. Why gloves are not optional.
Venting	What a damaged lithium battery does before it burns. Swollen means damaged.

When it goes wrong

I think I broke something.

Tell Mr. Krigger now. Equipment gets replaced, and you are not in trouble for an accident you reported. Hiding it is the only version of this that goes badly for you.

Resin got on my skin.

Wash it with soap and water straight away, which is what Formlabs says to do. Then tell Mr. Krigger. Do not use IPA to clean your skin.

The print is stuck to the plate and will not come off.

Let the plate cool completely, which fixes it most of the time on its own. Then use the scraper with your other hand out of its path. If it still will not shift, stop and ask rather than applying more force.

Something is on fire in the laser cutter.

Small flare-ups happen and usually go out on their own, which is one reason you never leave it. Keep the lid closed, since opening it feeds the fire air. Stop the job and get Mr. Krigger immediately.

I failed my safety check.

Take it again. That is what it is for. Ask which part you got wrong and practice that bit specifically.

Can I use the lab during academic time?

Yes, once you are certified on the tool you need. That is the entire point of the checks. The Glowforge additionally needs an adult in the room.