First-time poster here. I’ve been using the Shapeoko 5 Pro 4x4 for a while now, and I’m finally building a fully enclosed system to manage noise, dust, and workspace efficiency.
(please mind astersik pasted from QuillBot.)
I know STC ratings can be misleading, especially when applied to CNC enclosures, so I ran Grasshopper simulations for sound performance and manual structural analysis to ensure the frame can handle the weight.
All tests passed, but I’d still love feedback before I finalize the build.
Enclosure Design & Materials
Frame: 4x4 post-and-beam construction (structurally verified in simulations). 6x6x6 footprint
Outer Layer: 3/4" plywood for rigidity and durability.
Soundproofing Core: 3/4" Sonopan inlaid between the 4x4 framing.
Interior Layer: 5/8" drywall in front of Sonopan for extra mass.
Accessibility: Large hinged/removable panels for easy bit changes and maintenance.
Ventilation & Dust Control:
Dual-fan exchange system for airflow
1” PVC passthrough for wire ducting
2.5” hole for dust hose integration
STC & Soundproofing Performance
Simulated STC rating is 55-65, with some tests yielding 80, though that seems unlikely in real-world conditions.
The goal is to reduce cutting noise below 40-50 dB outside the enclosure.
Since the enclosure is inside my shop, the building wall provides an additional sound barrier
Budget: $1,500.
Looking for Feedback On:
Anyone else built a 4x4 post-frame enclosure? Tips on managing weight and flex?
Best way to integrate airflow while keeping sound sealed? Any proven muffling strategies?
Would adding a second drywall layer be overkill, or worth the extra weight?
Hinge or gas struts ideas
I’d appreciate any thoughts, critiques, or experiences before I move into full assembly. Let me know if you’d like to see my simulation results.
It’s very well thought out but Id greatly reccomend replacing sonopan with a rubber horsemat to dampen vibrations. Sonopan is severely over-rated and is less effective than a sheet of drywall in testing. I’d also add a 3mil sheet of rubber directly under the machine, this will create a tiny bit of a decoupling effect with enough rigidity the jerky movements of the machine will go into the torsion elements of the frame of your table. Ensure the middle can take a point load of the machine plus the maximum load you intend to put on it. The S5P is notorious for being willing to sag if you give it the chance. A 30lb point load on the front center of the machine is enough to sag .060 If you’re a signmaker thats probably fine but noone likes doing finishing work by hand the machine could have done.
Edit: additionally as it looks like your maintenance will increase in difficulty look into E2 oiler blocks for your Y and Z axis. These can greatly reduce the time to get at some of the more difficult to reach rails. (only need 1 per rail)
Haha, yeah, I don’t believe in starting small! If I’m going to build something, it might as well be rock solid. Overbuilding is part of the fun—plus, I’d rather have it too strong than regret cutting corners later. I’m in architecture, so this kind of stuff is what I enjoy! Thanks!
Appreciate the detailed feedback! I had some reservations about Sonopan’s actual performance, and your input confirms some of my concerns. A rubber horse mat is a good addition to the design same with the 3mil rubber layer under the machine to introduce minor decoupling. Definitely worth testing.
I ran load simulations on the frame, and with 6’ spans supported by 3 columns, the maximum bending moment is 1620 in-lbf with a deflection of only 0.041 inches—well within allowable design standard.
The hinged panels ensure full access from all sides, so I’m not too worried about accessibility.
That said, the E2 oiler blocks for the Y/Z axis are a great tip—I’ll definitely look into them for simplifying long-term maintenance.
Thanks for the reference post! The enclosure is definitely on the heavy side almost 1000, so I’m considering adding 9 casters rated for 2,200 lbs to make it movable when needed.
I haven’t worked with Rockwool Comfortboard80 before, but it sounds like a great alternative for sound dampening—especially since it’s rigid enough to attach directly to a frame. I’ll look into how it compares to Sonopan and other materials I’ve been considering.
I appreciate the insights! Out of curiosity, what’s your attenuation like with Comfortboard80, and what’s the composition of your enclosure from inner to outer layers? I’m relatively new to this type of soundproofing and want to avoid overbuilding while still achieving solid noise reduction. Would love to hear your thoughts!
The pics in that referenced post were from a temporary table/enclosure setup I made in a basement.
The enclosure was just 1x6 fence boards for a light frame to which I attached the Comfortboard80. No panel sheathing. Could run the CNC & barely hear it from the main floor above.
With the front door closed(again made from fence board frame & Comfortboard80 panels) , you could easily have a conversation beside the CNC while it was running - though you could still readily hear the router & cutting noise it was not overwhelming. It does a great job of actually absorbing & dampening machine noise for only 1.5" thick. And you could layer it up easily if you want to. Adding OSB/MDF/plywood sheathing panels around the enclosure with Comfortboard80 lining the interior then cuts the noise level again.
My first big CNC cabinet enclosure consisted of a substantial frame & OSB panels - I was disappointed by how much noise still radiated from it & had to wear hearing protection while around it. Tried some acoustic foam panels inside - those did very little. Now that I’ve lined it inside with Comfortboard80 as much as possible, I can easily sit next to it while running CNC operations & nearly forget about it.
My own experience with noise dampening for my CNC has pointed out how critical it is to cover any/all cracks/edges around doors/access covers/panels with a good acoustic absorbent as the high frequency noise penetrates through those spaces amazingly well.
You dont start off small do you, LOL.