That’s impressive! I haven’t been able to get a decent reading with my phone, I think my microphone is quite broke…
That’s impressive! I haven’t been able to get a decent reading with my phone, I think my microphone is quite broke…
There is trick to reaching these levels of sound suppression… no windows. If you look at my enclosure, it has not windows; there is a video camera inside that I use to watch the job.
Windows are a good way to let sound out. It is possible to design windows that are “decent” at sound suppression - but one has to work at it. In particular, they need to be double paned and use thick materials.
Hello-I have been reading the forums for while but this is my first post. I have gained so much great information from everyone that has contributed and I hope to do the same for others in the future.
I have recently ran into an issue with my Nomad Pro. I live in a loft that has concrete floors and the woman below me has complained about a noise that sounds like loud bass coming from a video game, I know it is the Nomad she is speaking about. I have the Nomad on some padding that I bought from Amazon that someone else mentioned on the forums and that sits on a wooden workbench with metal legs.
I am thinking that an enclosure is necessary but I do not know where to start. I don’t think that I have the ability or knowledge to build my own. I have never worked with t-slots… I have read that mbellon builds these for others. I’m not sure if he has sold any for other Nomad users? I am very interested in any solutions or suggestions!
Hello @Martsy!
I design and help design enclosures for CNC machines and I can help you. Yes, there a lot of factors that go into an enclosure… but before we go there, there are a bunch of things to try.
The noise through the floor issue is an example of “coupling” where the machine couples with the enclosure and the enclosure couples with the floor and… 
Is the noise the only reported issue? Are there other things you want to do? Super noise reduction? Super dust/particle safety?
Is the neighbor cooperative? Would they be open a quick test (I’m going to make you happy… but I want to try a short serious of things; would you be willing to tell me what you think when I tell you I’m going to make noise)? If so, we can try to decouple the Nomad enclosure as is and potentially avoid the time and effort of a “super” enclosure (which doesn’t have to be expensive - T-Slots is not the only way to handle things).
Get one of these (we need it for a “super” enclosure too):
Cut two pieces that cover the underside of the Nomad enclosure and stick out about 1/2".
mark
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Hi Mark!
Thank you very much for your response,Mark - it sounds like you have the potential to be my hero. This may sound horrible but I did not confess that it was my cnc that was causing the problem. My fiancé received an email from the HOA regarding the complaint. I couldn’t confess to him because I promised him the Nomad would be the quiet solution to all the power tools I was using in the house. I think he would be pretty upset that I was the cause of the problem. I would like to fix the issue without anyone knowing that I am the issue. The reality is I am a closet CNCer 
My goal is to minimize the noise as much as possible, super noise reduction would be fantastic. I only work in plastics and have used a ShopVac or Dyson for the clean up, and that has worked well so far. The noise and vibration are my main issues for now. I will order the pad you referenced tonight. Do you think I should put anything under the metal legs of the table? I am willing to spend some money on a solution if it means I can use my machine. Thanks again!
This may sound horrible but I did not confess that it was my cnc that was causing the problem.
I understand.
My fiancé received an email from the HOA regarding the complaint. I couldn’t confess to him because I promised him the Nomad would be the quiet solution to all the power tools I was using in the house.
I understand.
I think he would be pretty upset that I was the cause of the problem. I would like to fix the issue without anyone knowing that I am the issue. The reality is I am a closet CNCer
Without experiments (which involved the other party), we’re left with going all out, maximal everything, and going heavy (mass helps).
My goal is to minimize the noise as much as possible, super noise reduction would be fantastic.
I understand. My enclosure is so quiet one cannot hear it cutting sitting 3 feet from it (for many jobs; hogging (fast roughing) and the noise goes up a bit.
I only work in plastics and have used a ShopVac or Dyson for the clean up, and that has worked well so far.
The noise and vibration are my main issues for now. I will order the pad you referenced tonight. Do you think I should put anything under the metal legs of the table? I am willing to spend some money on a solution if it means I can use my machine. Thanks again!
Depending on the table you’ve got, the table may be part of the problem. We’ll need to talk.
I can say with 75+% chance of correctness that the problem you reported - as I understand it - can be solved with decoupling. We’ll try what is known about double decoupling. I can explain how to cut the material to do this.
I need to understand exactly how you’ve got things set up. My image my not be correct.
Going for maximal everything is non-trivial $$$.
mark
You are spot on about decoupling, the main addition since making my enclosure was to print some chunky feet out of ninja flex to replace the solid plastic ones. It has made a big difference to the vibrations transmitted to the floor. Even though the shapeoko is on a rubber pad inside the enclosure!
You are spot on about decoupling, the main addition since making my enclosure was to print some chunky feet out of ninja flex to replace the solid plastic ones. It has made a big difference to the vibrations transmitted to the floor. Even though the shapeoko is on a rubber pad inside the enclosure!
In enclosure design it’s actually pretty easy to have 20, 30, or 40 dB of noise suppression for frequencies above 400 Hz - its a design/cost tradeoff as to how much. Below that, “sound” is increasing more of a “vibration”. Depending how the vibrating object is mounted, an many other parameters, there is little that can be done except to decouple. In small enclosures inside houses, one goes for double decoupling… which is exactly what you’re doing.
All multistory buildings have surprising “windows” of near transparency for vibrations through upper story floors. A CNC machine with it’s broad spectrum of generated frequencies is particularly good a finding the “windows”. Decoupling makes a large difference, double decoupling a huge difference.
Based on the description of the problem, one I’ve seen many times before and even had to solve for my equipment, it’s pretty clean to me that this is a LOVELY coupling problem - hence my suggestion we start there… especially since it’s a low cost thing to try (and is necessary for all solutions).
@Martsy will talk offline; understanding exactly how things are positioned and what we try will determine if a custom enclosure is necessary or not. A custom enclosure can have other benefits… but we’ll get to that as necessary.
mark
Good morning Mark,
Thank you for your generous offer to talk on the phone. Is there a good time I can call you this afternoon/evening?
Thank you,
Martha
Anytime is good. Remember I’m on the west coast.
mark
I’m considering how to build an enclosure on top of a folding table. Space is an issue, but of course I have an XXL on the way.
Anyway, I’d like to reduce noise as much as possible so when it comes to decoupling, that’s where I run into questions about how I might accomplish that with a folding table…
I’m wondering if I might be able to use something like these: http://www.amazon.com/Isolate-It-Sorbothane-Vibration-Reinforced/dp/B0042U6Z9O/
…and maybe build clamps into the side of my table that I can clamp down the XXL before folding, then unclamp when the table is unfolded so the XXL is just resting on those pads.
I’m considering how to build an enclosure on top of a folding table. Space is an issue, but of course I have an XXL on the way.
Nice! That’s going to be an interesting challenge. The table top is a drum head. What’s known as a Dirichlet problem in Physics. The table needs to be build with cross bracing to ensure that common resonant frequencies do not get amplified.
Anyway, I’d like to reduce noise as much as possible so when it comes to decoupling, that’s where I run into questions about how I might accomplish that with a folding table…
Yup, this is going to be fun.
I’m wondering if I might be able to use something like these: http://www.amazon.com/Isolate-It-Sorbothane-Vibration-Reinforced/dp/B0042U6Z9O/4
Those and many like them are quite effective… but for the legs of the table against the floor. The table top should, ideally, have as much of the machine in contact with it as possible. Neoprene sheet is common and well chosen solution for that. I use two layers of 1/8" stuff since it is so cheap.
…and maybe build clamps into the side of my table that I can clamp down the XXL before folding, then unclamp when the table is unfolded so the XXL is just resting on those pads.
That’s not really an issue. The table top is going to need some care to avoid turning it into a drum, amplifying sound. The enclosure also needs some thought. Total weight is going to be an important tradeoff if you’re going to be doing setup and break down frequently.
I don’t hear anything discouraging, just things that need good planning.
mark
Dumb question…when you say cross-bracing, is that different than a torsion table?
As for sorbothane against the floor…I’m actually planning to put the whole thing on wheels.
Dumb question…
The only dumb question is the one you do not ask.
when you say cross-bracing, is that different than a torsion table?
A torsion table is one way to build a strong table that is largely noise resistant.
As for sorbothane against the floor…I’m actually planning to put the whole thing on wheels.
S’OK with me. Good decoupling will have to be thought as the legs will transmit to the floor effectively. Some wheel choices are better than others at providing some dampening.
mark
I’ve been back and forth with a local fabricator for a couple of weeks and finally told them to go ahead and a custom design for my Nomad:
I had them add sound suppression and I’m fairly pleased with the outcome. I’d say it cut the noise level by half which is a huge improvement.
I’m going to alter a few things in the coming weeks:
- Get a larger vacuum host for the inside to help with suction and sound level when it’s running
- Add some strip lights so I can see what’s going on
- Potentially add a camera
- Buy a larger underlayment that is meant for keeping vibration to a minimum. The current one is fine, but not meant for this application.
- Get a small touch screen and dedicate it to Carbide Motion so I don’t have to keep one of my computers tethered to the Nomad. I would automatically have the files at the ready thanks to Dropbox.
Note that I kept the sides, back and top on the Nomad but removed the front plexiglass (obviously no longer needed with the door on the front of the enclosure). I was going to remove some bits like @mbellon did but decided against it as I wasn’t sure how much it would affect precision. I’m milling items that require high precision so I can’t chance jeopardizing that.
I seriously just got this thing on my desk but wanted to snap a shot of it. It is a little big BUT I wanted to leave room in case a larger machine is in the future or I want to add things to the inside without worrying about space constraints. There is plenty of room in this beast and I’m very happy about that!
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NICELY DONE!
Shorten the tubing inside the enclosure. Reduce the bend angles as much as possible. The vacuum performance will go up markedly.
I’d say it cut the noise level by half which is a huge improvement.
Half? That’s only 3 dB (3dB = 1.995X). Measure, I bet you’re much better than that!
For reference, the Nomad with it original enclosure runs at 61-65dB with the door closed. I run at 52-54dB, measured 2 feet from the enclosure front, door closed.
Find a smartphone app and measure.
Get a larger vacuum host for the inside to help with suction and sound level when it’s running
I have a 2.5" connector right on the enclosure. The 50 mm tubing attaches directly. Inside the enclosure I have an adapter for the tubing.
Where is the air inlet (air out has to equal air in)? The cabling inlet? Can you please add a picture to your posting showing them? In my enclosure they are one and the same.
Did you caulk yours? I have seals that hold the sides. Regardless, I caulked them to ensure no whistling. Overkill… but good insurance.
What’s the bottom design and material?
Anything special keeping the door closed?
Buy a larger underlayment that is meant for keeping vibration to a minimum. The current one is fine, but not meant for this application.
I have feet under mine so I have 4 independent decouplers. Sheet decoupling is fine. I usually go with 0.125" or 0.25" Neoprene.
Potentially add a camera
The camera is nice as one can watch from “anywhere”. I went with camera only - no window - to obtain the maximum possible sound suppression (the door is covered just like the top and sides).
My camera is steerable. I sometimes move it around but it’s mostly overkill. My camera had infrared illuminators; they work so well there are times that I forgot to turn the LED on!
I’m milling items that require high precision so I can’t chance jeopardizing that.
My understanding is the Nomad is tested for precision and accuracy without sides. I’m sure the sides help in some circumstance… but not by much. Keeping them on certainly doesn’t hurt.
I, like you, allowed plenty of extra space… but you’re is considerably larger than mine. If I did mine again I would add 2" more on the sides; plenty of depth.
I left the back on. That made structure sense and it’s a pain to remove anyway.
Since my original posting I added 6 inch tall poly “sides”. They add some stiffness but primarily they keep any large stray swarf from escaping the sides. Easier cleanup.
One of the reasons I left the sides off is that they tend to channel they sound out the front… the side sound proofing doesn’t get to do it’s job (very much).
Add some strip lights so I can see what’s going on
I love my LED bars. I recommend that lighting be done such that it doesn’t radiate directly at you. Consider a dimmer… they can get pretty bright.
My friend Tim went with two LED spot lights. YMMV.
Do take time to think on the color temperature that works for you. I prefer clean white; others like the softer, more yellow choice. YMMV.
Get a small touch screen and dedicate it to Carbide Motion so I don’t have to keep one of my computers tethered to the Nomad. I would automatically have the files at the ready thanks to Dropbox.
There are postings about low cost Windows tablets (< $200) being used quite satisfactorily. It doesn’t take much to run CM.
or I want to add things to the inside
Leave any electronics outside. The small particles tend to accumulate on them. @Tshulthise left them outside on his SO3 XXL enclosure.
mark
P.S.
Nice dust head! 
For vibration isolation there are a lot of variables. The pads that you linked say they support several hundred pounds per pad. That means they are probably too stiff to work well for an 80 lb machine unless you cut them down to a much smaller size. Ignore the "absorbs 97% of vibrations claim too. That is for near a full load and probably for high frequencies.
The idea of adding a couple sheets of neoprene will help a little bit but essentially that will only take out the very highest frequencies and keep the machine from moving.
The ultimate solution is to put the machine on a stiff base that has spring isolators between it and your table. The softer the springs the better the isolation. But, you have to get isolators that can handle the shear loads that the tilting table will cause. Look for the Sorbothane isolators that screw in (and buy some that are rated to carry around 25 lbs each and that can handle your shear loads) and screw them into a stiff board that you attach the Nomad to. That will give you very good isolation. McMaster.com also carries a range of isolators and they list all the relevant specs you will need to pick the correct one for a tilting table.
I built my SO3 enclosure expecting to have to add isolators to the feet but I’m getting great noise attenuation without anything. I don’t even have seals on the door and its pretty quiet with the door closed. You will find that by the time you get your enclosure finished you probably won’t care that much about littler things. Make a list of what is most important to you and spend your energy fixing the top one or two things on that list 
Good luck.
I have to disagree… and my results and others show that the isolation is very fine for the Nomad. Multiple layers allow for plenty of motion and suppression.
The Nomad frame needs to rest flat on something. Sheet isolation works quite well. I’ve done and other have done it too… with excellent results.
I use the fancy pads - when necessary - between the table and floor; mass. The Nomad sits on the Neoprene, then the floor of the enclosure, then the enclosure has feet. Isolators on each foot.
The table is heavy and stiff. I did tests and did not need to add isolators. A lighter or less massive table would benefit from isolators under the feet.
Barely a vibration shows in a glass of water.
Yes, there are many variables but a small, compact machine like the Nomad cannot really get much vibration going that require springs and such. There just isn’t that much mass moving and it’s not moving (or stopping) very fast. The Nomad is pretty massive compared to it’s gantry, momentum and such.
Complex cantilevered designs are whole different story. There I agree, especially when the machine has some weight and the rapids and cuts can really move and there is some serious mass moving around.
… OH! We are talking about different issues and designs!
I don’t even have seals on the door and its pretty quiet with the door closed.
I bet your door closure is pretty good. T-Slots aren’t that tight and leak a fair amount, hence the need for seals. Definitely something to watch, sealing the doors is way down on the list… plenty more important things come first - and seals are trivial to add later.
mark
Same deal with the rubber mat under my shapeoko! I am using a Chinese 1.5kw spindle now though which is much much quieter than the stock dewalt so my machine has taken a proverbial nose dive in its sound profile and overall ‘noise’ in all senses of the word.
That means that the frequencies that the machines are putting out are higher than I thought. The sorbothane isolators will pretty much eliminate all high frequency vibrations and provide isolation for much lower frequencies than a natural rubber or neoprene mat. It would be interesting to be able to measure the difference to see how much.
Has anyone measured any of the vibration profiles created by the Nomad and SO3? That would be the best place to start if we want to get to the best solution.
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