I Bought a Gravotech IS400 CNC Station Blind. Here's What I Learned the Hard Way.

Can you laser cut polyethylene foam?

Yes, but it’s not as simple as setting the machine to “cut” and walking away. I learned this the expensive way when I was in a hurry to fulfill an order for custom foam inserts back in September 2023. A client needed 500 pieces for a trade show. I had a Gravotech LS series at the time, but I got cocky.

What I mean is, PE foam loves to melt rather than vaporize. The laser beam doesn’t just cut—it transfers heat, and with PE, the melting point is dangerously close to the vaporization point. I set the power too high and the speed too slow. The result? Every single piece had a melted, glazed edge that looked terrible. $3,200 worth of materials and machine time, straight into the dumpster.

Here’s the trick I eventually learned: you need a high-speed pass with moderate power, not a slow burn. For a CO2 laser like the Gravotech LS100, I now use 80% power, 100% speed on a 60W tube. (Note to self: always test the scrap piece first.) The edge is clean, no melting. For the IS400 fiber laser? You don’t cut foam with fiber typically. It’s for marking metals.

The vendor who sold me the machine had said, “Oh yeah, it can do foam.” They weren’t lying, but they also weren’t specific. It’s tempting to think “you can laser cut it” means “it’s easy.” But different foams—polyethylene, polyurethane, EVA—react completely differently. The “one setting fits all” advice ignores the nuance of material density and thickness.

Can you laser cut plexiglass?

Short answer: yes, but only cast acrylic. Extruded acrylic (which is often sold as “plexiglass”) will produce a frosted, white edge that looks terrible.

Why does this matter? Because I once ordered 200 acrylic awards, specified “clear plexiglass,” and assumed the engraver would handle it. The laser cut them just fine, but every edge was cloudy. The client rejected half of them. That mistake cost $890 in redo plus a 1-week delay, and trust me, explaining to a client that “technically, it’s cut” doesn’t win you any points.

With a Gravotech CO2 laser (like the LS900), cast acrylic cuts beautifully. You get a flame-polished edge that’s nearly glass-like. The key parameters I use: Power 70%, Speed 50%, with a 100W tube for 1/4” acrylic. For thinner sheets, increase speed. For thicker? Two passes, lower power.

Fiber lasers (like the IS400 or IS1200) are not for cutting plexiglass. They’re for marking metals and some plastics. I’ve seen people try, and it’s a mess. The IS400’s beam just burns the surface rather than cutting through.

What is a "CNC station" even mean for a laser?

When I first saw “Gravotech CNC Station IS400,” I thought it was a router. It’s not. The term “CNC station” in the Gravotech world refers to a fully integrated laser marking system that’s typically used in industrial settings—think serial numbers on metal parts, barcodes, or UID markings for defense contracts.

The IS400 specifically is a fiber laser. It’s fantastic for marking steel, aluminum, and hardened plastics. But I’ve seen people ask if it can cut wood or engrave leather. It can engrave some things, but its primary job is permanent marking on metals. The numbers said it was versatile. My gut said “but is it right for my business?” I went with my gut and bought a CO2 for cutting and the IS400 for marking. That separation saved me from another expensive mistake.

Is the Gravotech Gravograph software a nightmare?

It’s not a nightmare, but it’s not Photoshop either. I remember opening the Gravostyle software for the first time and thinking, “Where’s the ‘just make it work’ button?”

The learning curve is steeper than I expected. The software is powerful—it handles multiple tool paths, variable depth marking, and database integration for serial numbers. But the interface is very industrial. The question isn’t whether it can do the job. It’s whether you’re willing to spend the time learning it.

I downloaded the manual (available on gravotech.com). I spent about 10 hours on it over two weeks. Now? I can set up a marking job in 2 minutes. The key is understanding the difference between the “Engraving” and “Marking” modes—they’re not the same. Marking is high-speed low-depth; engraving is slower and deeper. Mixing them up will waste materials and time (I’ve done it, ugh).

UV laser marking vs fiber marking: which one do I need?

Per FCC guidelines on advertising (ftc.gov), I can’t claim one is “better” because it depends entirely on your material. But I can tell you the difference based on my experience.

A fiber laser (like the IS400) uses a wavelength around 1064 nm. It’s absorbed by metals and some plastics. It creates a permanent, high-contrast mark. The downside? It’s not great on clear or reflective materials.

A UV laser uses a shorter wavelength (355 nm). It’s “cold” marking—it breaks chemical bonds rather than heating the material. This means you can mark glass, plastics, and even some foods (batch numbers on fruit) without damaging the surface.

If you mark metals every day? Fiber. If you need to mark sensitive materials or clear plastics? UV. My shop has the IS400 (fiber) for metal parts and I’m considering adding a UV for the plastic and glass work. The total cost of ownership (i.e., not just the machine but the setup time for each material) makes the UV worth it if you do mixed materials.

What mistakes will I make with my first Gravotech engraver?

I made three big ones in my first year (2017). You might not repeat them if you read this.

Mistake #1: Not testing the material.

I ordered a bulk batch of laser blanks for engraving. They looked identical to what I’d tested. Different batch, different coating. The laser charred the surface instead of marking it. 300 items, $1,200, scrapped. Now I test every new batch on one piece before running the job.

Mistake #2: Ignoring the focal point.

I set the material, hit start, and it barely left a mark. The laser was out of focus. On the IS400, the focal distance is critical. For the LS series? Even more so because of the longer work area. Get a focus tool. Use it every time. (I really should have done that from day one.)

Mistake #3: Assuming rush shipping is worth the risk.

In March 2024, we paid $400 extra for rush delivery on a special piece of acrylic from a new supplier. The alternative was missing a $12,000 event. The vendor promised it would arrive in two days. It arrived on day four. We missed the event. After getting burned twice by “probably on time” promises, we now budget for guaranteed delivery from established suppliers. The $400 wasn't the problem—the uncertainty was. Per USPS pricing effective January 2025 (usps.com), standard shipping is $0.73 for a letter, but for materials, the cost of certainty far exceeds the shipping fee itself.

The vendor failure in March 2024 changed how I think about backup planning. One critical deadline missed, and suddenly ordering from two suppliers doesn’t seem like overkill.

How do I pick the right Gravotech model?

This is the question I get most often, and it’s the one people get wrong.

The M20 series is a great starter for marking metals. The LS series (LS100, LS900) is for CO2 cutting and engraving on wood, acrylic, leather, and foam. The IS series (IS400, IS1200) is industrial fiber marking. You will have a bad time if you buy an IS400 expecting it to cut plywood.

The numbers said to buy the cheapest model so I could upgrade later. My gut said get the model that matches your primary material. I went with the LS900 for versatility (CO2 can handle more materials) and the IS400 for the metal marking jobs. I didn’t buy a “cheap” machine first. That decision saved me about $8,000 in wasted time and re-buying.

Here’s my checklist (I really should have written this down years ago): think about your material first, not the machine. What will you process 80% of the time? Buy the machine that excels at that. The other 20%? Outsource or buy a second machine later. The spreadsheets often point to the cheapest option. Something felt off about the cheaper machine’s build quality. Turns out “lightweight frame” was a preview of “imprecise cuts.” I trusted my gut again.