I know it has been mentioned before, with regard to sound proofing cabinets, but maybe we should start a new thread concentrating on just that, so as to get all relevant designs, models and sizes in one place. I know I will be needing to design one for my next 1000 x 1500 machine, in the not too distant future, and have managed to get hold of some second hand double glazed units for it. So if anyone has built one, maybe they would contribute the details here, with pictures would be even better. SketchUp plans would be even better!! If you are thinking about needing one then discuss it here. Cheers Gray
I'm currently building an enclosure for my machine, I'm doing the box within a box concept. Both the inner and outer box will be made out of MDF, 3/4 inch MDF for the outer box, 1/2 inch MDF for the inner box (to save a bit on weight). Each box will be separated by an inch of carpet padding foam. The dimensions will be roughly 48 inches wide by 30 inches tall and 32 inches deep. It's bigger than I need for the standard size C-BEAM but I plan on upgrading my machine to either the C-BEAM XL or a Sphinx XL style build and wanted the room to expand. I'll be taking some pictures during the construction process and will be posting some relatively soon.
I was thinking of using an inner and outer skin, about an inch apart, but then pumping in a few tubes of expanding foam. As I say I got hold of a few second hand, but good, double glazed units, and some new ones. As a tip, go to the actual shop or yard where they put the old units, before they scrap and smash them. The guy I went to, was only too pleased to off-load some to me, because it saved room in his skip. He even gave me some new ones because they had been made the wrong size! Gray
Sorry mate! "Units" is a term used for "double glazed units", before they are fitted into the frames. If you have a window frame which measures say, 1500mm x 1000mm, they will make up a complete, sealed double glazed window (unit), to fit in the frame. It is very common for people to get the measurements wrong and need to make new ones. Usually these end up in the skip. Obviously, if you can utilize one or two of these for your cabinet, although quite heavy, they would give a great view. Gray
I've recently been reading about silencers/mufflers for dust collection. Apparently people have made DIY versions or just used a length of insulated ventilation duct. The sound reduction is significant. So this is something to think about either for properly ventilating your enclosure while reducing noise, or adding onto your dust collection if the vacuum/collector is outside of the enclosure. Forgot to add a link to the relevant page: Dust Collection Research - Homemade Muffler
Foam is ok for treating surface noise vibrations and for diminishing internal reflection but it's not very effective at blocking sound transmission. Use a dense material to stop sound. Adding multiple layers of Gypsum Board ("sheetrock") to the inside of that wood enclosure should keep most of the noise enclosed.
I made a box like this out of MDF about 10 years ago... and OMG did I regret it. As long as you are never going to move it and you have several bods to help then go ahead but I found the weight of thick MDF projects builds up really quickly, and that's without taking into account of the machine inside. In the end I went for MDF on the outside box and plywood on the inside box. A bit of weight for stability and lightness with the ply that still meant it was strong. I could still move the final setup (just) but the first version I had trouble with a couple of us trying to move the thing.
I've currently got the outer box built and on casters to help handle the weight, I've gotten my foam, but still need to build my inner box. I had been going back and forth on making the inner box out of plywood instead of MDF, I may go that route based on your suggestion I just hope I get enough sound reduction out of that.
You could put some acoustic matting on the inside to dampen the first hit. Something like flat bevel acoustic tiles to stop chips catching in it. It's low profile and is only going to be reducing the first reflection. It would probably do better than heavy MDF because it is still a flat surface and being enclosed it will be bouncing around like crazy. Its like how people thought hardwood floors were really cool... until they got it installed and suddenly their home audio system sounds like crap because the floor is reflecting all the harsh sounds where carpet is dampening it... Actually, thinking about it, carpet would be a cheap alternative to lining the box too. Not as good performance but it's just to to stop the high frequency reflections before the main sound dampening of the sandwich filling..
I’ve nearly gotten my cabinet completed, I’m happy with it thus far, getting ready to perform first cuts with it to see how well it works. Outer box Inner box Closed cabinet Open cabinet
I did a quick noise test while cutting MDF, it was peaking at around 85 dB and outside the cabinet it was peaking at right around 50 dB. I’ll be repeating the test once I can cut some aluminum, but thus far I’m quite happy with the performance.
I was completely wrong regarding using MDF. The added weight actually helps keep the machine from vibrating which reduces the sound coming from the CNC. So eventually I went with 18mm MDF too lol. Not afraid to say I was wrong either. You live and learn. I did have to put my unit on 8 heavy duty industrial castors though.
Yeah it certainly makes things heavy, I’m happy with using mdf for the outer box and plywood for the inner. It already is super heavy using mdf for both would probably been overkill. It’s already going to be bear to move down the two flights of stairs when I move.
I planned with my unit... it actually unbolt into two separate units that fit through my flat doorways as I built it indoors and plan on putting it into a garden workshed eventually.
I am building a 1000x1000 Sphinx, and I plan to make an enclosure for it (for safety, and may later thicken walls for some sound isolation). With the X/Y/Z-motors extending from the V-Slot frame, the overall X/Y/Z-footprints extents are ~1150 x 1150 x 550mm. I have a separate control box which will be located outside the enclosure. I will run NEMA23, limit switch, spindle, etc. wiring through a port cut in the CNC enclosure wall. This is my first Openbuilds project. Any suggestions on how much clearance distance I should allow from the edges of the Sphinx X-Y footprint to the interror enclosure walls? And, what stand-off distance from top of the Sphinx Z-axis to the ceiling of enclosure interior? I have checked the web for some reference images of CNC enclosures. I have seen some commercially available enclosures which appear to have only ~100-150mm clearance around the entire X-Y-Z perimeter of the CNC to each of the interior enclosure walls. Seems a little snug, but maybe as long as you can get to work area and a little room to nudge the CNC frame for some maintenance that's OK. I want to conserve bench space of the enclosure, but not later regret I chose too small an interior. Any recommendation on how much wiggle room is needed inside the enclosure for "normal" operation would be appreciated. Thanks!
