The board is the part
that comes with a price.
MASSO vs Centroid Acorn — what the licences, the PC and the support actually add up to.
Acorn is a proper control kit. The board arrives with its relay module, its power supply and its cabling, and the software is free to download. It is the closest thing in this comparison to a like-for-like product.
It still runs on a Windows PC that you supply, with a 1920 × 1080 display that is not in the box. A MASSO is the control system — screen, motion control and I/O in one unit, with no computer in the chain.
Centroid Acorn What an Acorn build takes
- 5parts to buy: the kit, a PC, Windows, a display, and a keyboard and mouse
- 4connections to make and keep good
- 2pieces of software to keep in step: Windows and CNC12
Fewer parts than a Mach build, and the kit is well specified. The computer and the display are still yours to buy, own and replace.
MASSO What a MASSO build takes
- 2parts to buy
- 2connections to make
- 0operating systems or drivers to keep in step
The screen is part of the controller, so there is no separate display to specify, mount or replace. The controller executes only job files and does not run arbitrary code.
What each one costs to buy
Taken from the manufacturers’ own stores, not resellers. Acorn hardware prices do not include the CNCPC, the display, or a CNC12 software licence above the free level.
| Centroid Acorn Hardware kit | USD |
|---|---|
| Acorn kit, 4 axis | US$369 |
| AcornSix kit, 6 axis | US$999 |
| CNC12 software, free level | US$0 |
| CNC12 licence, Pro or Ultimate | US$179–US$399 |
| Factory technical support | US$120/hr |
shopcentroidcnc.com, checked 9 September 2026. One hour minimum on support.
| MASSO Complete controller | G3 | G3 Touch |
|---|---|---|
| Core | US$750 | US$1,090 |
| Advanced | US$950 | US$1,490 |
| Professional | US$1,550 | US$2,090 |
masso.com.au, checked 9 September 2026 — see the full controller range
Three things about the software worth reading first
CNC12 being free is a genuine strength of the Acorn kit, and it is the first thing most people hear about it. These are the conditions attached, all published by Centroid.
The free level caps file size
CNC12 at the free level limits G-code programs to 50 KB for mill, router and plasma, and 5 KB for lathe. Centroid’s own example of a typical hobby part is a 5 KB file. Production files and anything from a CAM system routinely run past that, and removing the cap means a Pro or Ultimate licence.
Licences are tied to one board
A Pro or Ultimate licence is issued against the serial number of a specific Acorn board. It does not move to another board unless Centroid issues an RMA, and replacing the BeagleBone module inside the kit invalidates it. Three machines means three licences.
Licences are per machine type
Mill, Lathe, Router and Plasma are separate licences. A Mill Pro licence will not run the lathe software. You can mix them on one board, but not run two at once, so a shop with a mill and a lathe buys twice.
All three published at shopcentroidcnc.com, checked 9 September 2026. A MASSO is one purchase per machine, with no separate software licence and no per-machine-type charge.
Put your own numbers in
The Acorn kit and the MASSO controller are both published prices. Everything else is yours — the PC, the display, how much factory support you expect to buy, and what an hour of stopped machine costs you. If it comes out in Acorn’s favour, it will say so.
Your situation
Starting point, checked 9 September 2026: US$641 fanless industrial PC (OnLogic CL260, entry configuration) and US$199 Windows 11 Pro (Microsoft Store). Change it to your own figures.
Required, not included in the kit. A touchscreen is recommended by Centroid.
Charged at US$120 an hour, one hour minimum. The community forum is free.
Control system only, over 5 years across 1 machine. Drives, motors, the frame and the spindle are left out of both sides, because you need them either way. Licences are counted per machine. All figures USD.
Where you notice the difference
Both are capable controls with long track records. These are the things that decide whether you are still happy in year three.
Replacing a Centroid Acorn control
Most people reading this are not building from nothing. They have a working machine and a control system that has started costing them time. A retrofit keeps the machine and changes what drives it.
Your drives usually stay
Acorn drives machines with standard step and direction signals, and so does MASSO. The mechanics, the frame and the spindle are untouched, and in most cases so are the drives and motors you already wired in.
The PC and display come out
The computer, the monitor, the keyboard and the Windows licence all leave the cabinet. One unit takes their place, which is the difference the two maps above are showing.
The documentation is open
The documentation is public and ungated, so you can read exactly what is involved before you buy anything. The MASSO CNC System pages set out what a full conversion includes.
When an Acorn is the right answer
Three situations where nothing on this page should move you.
It already works
If your Acorn runs, you know CNC12, and it has not caused you trouble, there is no argument here for changing it. Centroid has been building motion control for over thirty years and it shows.
Your files are small
If your work stays inside the free level’s file size cap and you are happy on the community forum, Acorn is very hard to beat on purchase price. The argument on this page is about what happens when you outgrow that.
You want the PC there
A PC at the machine runs CAM, keeps files locally and gives you a full desktop. Some people want exactly that. A MASSO deliberately removes it, which is the whole point and also the trade-off.
Tell us about your machine
Tell us what you have or what you are building and what you need it to do, and we will tell you which tier fits and what a retrofit involves. If a MASSO is the wrong fit, we will say so.
Ask about your machine
A few questions. A technician reads it, not a bot.
