Sound Proof Enclosure for MPCNC

I work from home, and my MPCNC is in my garage, which is right next to my office. I’m still waiting for the electronics for the MPCNC, but figured I would build a sound proof / sound dampening enclosure in the meantime. I searched the forums but couldn’t find much about what other folks here have done. If any of you have some pictures / ideas about what you’ve done, that would be great!

I found a couple ideas on youtube, so I’m leaning towards enclosing it in an OSB box with some dense foam insulation boards and probably a door with a plexiglass window. I’ll probably add a cutout of foam to go over the plexiglass when I don’t want to look in.

Thoughts? What works? What doesn’t work?

No experience here with the mpcnc yet, do have experience with routers. You probably will be better off aiming for sound dampening vs sound proof. What about your shop vac? If you want to dampening that too you’ll also need to think about ventilation so it doesn’t overheat. If you plan on cutting on material bigger than your machine than you might think about making the enclosure removable or least having doors/slots on the bottom for sliding material around.

I did something similar for the stand on an aquarium.

The structural foam works well. Ideally, you would layer one or two different types of foam for the different frequencies. OSB->structural foam->upholstery foam. The different foams help block different sounds.

I’ve considered enclosing my MPCNC a few times, I just haven’t gotten around to doing it.

Make sure you have a camera for monitoring cut progress remotely. A CNC machine can go from, “Everything’s fine” to “OMG the garage is on fire” in short order if something binds. I’ll typically piddle around the garage while my CNC is running, but I’ve never left it for more than a minute or two while it’s running. It’s not like a 3d printer.

This guy made a good video comparing several sound dampening foams vs old towels. Worth watching. You might consider just having some of these on the back, top and side panels of your enclosure. The front can be plexi glass or a thick clear plastic sheet.

But here is another good build.

I had built up a dust collection system in my shop just like this one:

http://www.startwoodworking.com/post/how-silence-your-shop-vac

It was an article linked off of Instructables:

I just built the vac enclosure, not the added stowage for the collector - I had a full garbage can cyclone lid setup through a tubed dust collection network. It was a pretty great system but carpentry was replaced by chainsaw carving and it’s a whole other kind of dust collection required with that so I tore it all down. I didn’t line the box although I DID intend to line it with low pile carpeting - I just never got around to it and have subsequently torn the box apart only to now be considering putting it all back together again…I tore it apart well before my MPCNC days and now see the value in it again.

The box was amazing! It took the vacuum from “I should be wearing hearing protection” to easily holding conversations with it running. I baffled the port on the bottom. Just like a car’s muffler. It seemed odd and simple but it made a difference. Basically I followed the instructions but then converted the bottom port into three channels with angled back wedges to force the wind/noise to take a long way out. I’ll do up a drawing when I’m at my other computer and post it for you.

I’m considering doing this for both the MPCNC and the laser build:

I think it’ll work just fine and a “window” can be made with just two sheets of acrylic/plexi - one on one side of the foam, another on the other, though bolted together to hold them in place. It’ll be light enough to lift off as a unit I assume or make a hinged lid that hinges the top and one full side for easy access. I think it’ll need to be well lit inside though. LEDs.

And I agree on the monitoring. I’ll set the MPCNC up to run, put my ear muffs on and grab a chainsaw (electric) and work on a carving while the MPCNC is running. All sorts of things have gone “wrong” for me. Mostly related to holding tabs not holding and middles popping up and binding with the tool making all sorts of smoke. I was going to watch the holiday sales and see if I could pick up a cheap wifi camera to monitor it from my desk if the need arised but I soon realized that’s silly. Why monitor it if you can’t quickly DO anything about anything that goes wrong? I read on this forum somewhere about a Raspberry Pi control /camera setup that actually lets you interrupt the MPCNC remotely. I plan to implement that one day but not until I get my processes set such that I don’t have as many “oopsies” as I currently do. Once I get more into 3d carves (which take MUCH longer) I’ll be looking to set this up.

You also need to consider cleaning access or some system for getting the chips out of the cut. I find on a long cut out I feel obliged to clean all the rough cuts after each pass with a vacuum. I’ve seen machines with blowers to clear the cut which I’d do IF I enclosed the MPCNC. I’d use the blower to clear the cut and I’d make sure I had strong crossflow through the enclosure to a vac attachment (like a floor sweep) to keep things clear. I’d also be tempted to wrap my DW660 in filter paper in that case.

I have my 3d printer on a little etekcity wifi switch. I could do the same with the spindle and controller on the MPCNC to kill it remotely.

My biggest MPCNC accident was when the stepper driver board for the z axis burned up. The bit grabbed the wood and pulled the Z axis down and the endmill kept diving deeper and deeper into the project. Even with me standing next to it, it was billowing smoke when I hit the kill switch. I kinda stared at it a bit dumbfounded for a minute or so before it dawned on me I should do something.

I built an enclosure of using 1/2" MDF and weather stripping for my MPCNC. It also features a plexiglass window in the front and LED light strip for illumination. The front door opens up for access. I took my inspiration from Shapeoko enclosures. With that being said when it is closed it reduces the sound to less than that of a household vacuum running in the house. I think it comes out to be 63dB. Now I would like to get the towels in there for further reduction. Will use a staple gun or something.

Hey, I just posted about my enclosure here:

https://www.v1engineering.com/forum/topic/mpcnc-in-switzerland/#post-76124

It’s made out of 16mm MDF, has foam tape to seal the edges and 2 plexiglass windows (with plexiglass inside and outside, sealed with elastic caulk).

This alone reduces the noise by about half, and I plan to install something like what is mentioned in this article:

https://hackaday.com/2014/08/17/dampen-workshop-noise-with-paper-pulp-and-kool-aid-oh-yeah/

The biggest problem right now is that my MPCNC sits on the floor, so all the vibrations get transfered and the low pitch noise can be heard in the entire building. But I plan on building a table for it and using some sort of vibration dampener between the table and the MPCNC.

P.S. A friend of mine who used to work as a carpenter told me that for good sound dampening you need multiple boards of different thickness, since they are better at absorbing different sound frequencies.