Centroid Community CNC Support Forum

I set out this past winter itching for a project to tackle, and I wanted to build a CNC router that was at least 48x96”. I had a budget of $15K and wanted to see just how much of a machine I could put together with this. Now that I have nearly finished this build, I must say that I a quite pleased and surprised with what I ended up with. The biggest challenge I faced was finding a decent, accurate, rigid machine design that could be disassembled because this machine would have to fit into my basement with limited door access. The whole project started when I found a used Shopbot PRS Alpha machine that was being sold at an auction in Wisconsin which I won for only $3,500. It turned out that this machine was from around 2007, was purchased for a high school shop program, and the machine was only used to make a couple of cuts (for reasons I don’t understand). It was practically new but since I live in New England, this meant ROAD TRIP! The only thing I didn’t like about the shopbot was the control system which was proprietary, used non-standard G-code, and was limited as far as expandability and flexibility. I looked at them all and decided to power this router using CNC12, which I knew little about, but turned out to be a great choice.

My wife and I flew to Wisconsin, rented a minivan, and somehow we were able to break this very LARGE machine down and fit it inside the van with no room to spare. After a winter of some long nights in the basement, fabricating, waiting for parts, and utilizing some clever backyard engineering….below are some specs on my CNC. Be kind because I am only a hobbyist and have no formal experience with CNCs….but I am pretty happy with what I ended up with.

• Shopbot PRS Alpha PRS3 60x96 table with closed loop Oriental Motor servos and controllers. I used the OEM drive system because it met all the specs for my needs. I just needed to make some custom interface cables to connect the controllers to the Acorn board.
• Centroid Acorn controller with ETH1616 input/output expantion board and wireless pendant
• 7.5kW Chinese ATC spindle with 15-tool fork-type rack
• Lasertree 30W diode laser with pneumatic deployment and built in crosshair alignment laser
• Stepcraft OTK-3 Tangential Knife with pneumatic deployment
• Logitech Streamcam 1080p webcam (for use with the exiting new Paper Tools system)
• Five-zone vacuum hold down system powered by two 5kW ring compressor blowers
• Custom spindle cooling system with radiator and temperature controlled fans
• Wireless infrared touch probe located in ATC tool rack
• Custom dust collection system with dockable dust shoe, air blow-out system, and shoe presence detection
• Fixed tool height touch off device with dust removal nozzle
• USABLE WORK AREA of 60.75x96.1” WITH ABOUT 6.0” OF Z travel

I am very impressed with the Centroid Acorn system and how it has performed during my initial testing and cutting. A complete photo album of my build can be seen here on Google Photos for anyone who might be interested in seeing them.

What an interesting story, and a great looking machine!
Do you have plans to regularly use it for anything specific?

CentroidFrog wrote: ↑Tue Jun 24, 2025 2:24 pm What an interesting story, and a great looking machine!
Do you have plans to regularly use it for anything specific?

Thanks! Yes, I plan on using it for many things including cutting EVA foam flooring for boats, cutting Sunbrella outdoor fabric for marine canvases, various hobby woodworking projects, and other things that I haven't thought of yet

Cool project, and yes Centroid motion control is very smooth like a high-end industrial CNC.

Uwe

Awesome job, you're gonna like it! My PRS is nothing compared to yours when it comes to all the bling, but it's been working great since 2019 with CNC12!
I see you followed ShopBot's original circa 2007 Alpha wiring methodology. Sorry, had to say it, because mine was the same way.

right on! thanks for posting, great photo album!

You should share your post to the ShopBot and Centroid Facebook groups to inspire and encourage other SB'ers to make the swap.