Dampen Workshop Noise with Paper Pulp and Kool-Aid — OH YEAH!

noise dampener

If you’re fortunate enough to have a garage and a workshop, you probably also have neighbors. The truly blessed must work within the confines of an HOA that restricts noise, porch couches, and most types of fun. [Mike] is among the truly blessed, and when he decided to design a cabinet for his CNC equipment, he took noise dampening into consideration.

[Mike]‘s design isn’t a blanket noise dampener; it’s specifically designed for the high-pitch symphony of his router, compressor, and vacuum. He also sought to avoid vibrating the cabinet. To achieve this, the sound-dampening panels are hung on eye hooks with a 1/2″ gap between them and the frame. The backer boards are cut from 3/4″ plywood. [Mike] considered using cement board, but thought it might be overkill since he plants to shell the cabinet in a layer of 3/4″ plywood.

The deadening material is paper pulp made from various shredded papers. After soaking the shreds in water and blending the mixture to an oatmeal consistency, he drained most of the water through a cloth bag. Then he added just enough wood glue to hold the pulpy goo together. The tropical punch Kool-Aid powder isn’t just for looks; it provides visual confirmation of even glue distribution.

[Mike] made some tape walls around the edge of his backer boards to hold the mixture in place and painted on some wood glue to hold the pulp. He spread the tropical concoction to 1/2″ thickness with a tiling trowel to avoid compressing it. The peaks and valleys help scatter any sound that isn’t absorbed. Pudding awaits you after the jump.

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DCF77 signal filtering and decoding

dcf77-filtering-and-decoding

[Udo] decided to build a clock using the DCF77 radio module seen above. This of course has been done before: the hardware draws a clock signal from the atomic clock in Braunschweig, Germany. So he grabbed a library for Arduino and got to work. But he was getting rather poor results and upon further investigation realized that the library had been written for 20 Hz modules and his operates at 300 Hz. This means better accuracy but the drawback is that the hardware is more susceptible to noise.

So began his journey to filter, process, and decode the DCF77 protocol. That link goes to the project overview. It will be in several parts all of which will be linked on that page. So far he has applied a low-pass filter and coded some exponential smoothing. He has yet to write the other four parts, but does mention that early testing shows that this technique will make the reception better than what is achieved with commercially available clocks. He was able to lock onto a signal that had more than 80% noise ratio. That’s impressive!

Just want to see a clock that uses a DCF77 module? Check out this PIC-based atomic clock.

Noise pollution tit for tat uses the Baha Boys as a weapon

Here [Matthew Br] explains the situation he’s in with the neighbors that share this wall of his apartment. When they listen to music they like it loud and so he gets to ‘enjoy’ the experience as well. But he can’t ignore it any longer, and has decided to use a sound volume detector to blast some tunes right back at them.

He taped a microphone to the wall and wired it up to his Arduino. It monitors incoming sound and, using an adjustable threshold, it will trigger when the neighbors are too loud. We think he was wise to include some time filtering that makes sure the loud noises are sustained and not just the result of someone bumping into the wall. When the system does detect loud music for a sustained period it triggers [Matthew's] own CD player to pump out Who Let the Dogs Out? by the Baha Boys. It will play for a period of time, then shut off to listen and see if the neighbors are still rowdy.

He documents an actual run in the latter half of the clip after the break. We sure hope he’s living in a building with just two units, otherwise this will drive the rest of the neighbors batty as well!

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Real-time depth smoothing for the Kinect

[Karl] set out to improve the depth image that the Kinect camera is able to feed into a computer. He’s come up with a pre-processing package which smooths the depth data in real-time.

There are a few problems here, one is that the Kinect has a fairly low resolution, it is also depth limited to a range of about 8 meters from the device (an issue we hadn’t considered when looking at Kinect-based mapping solutions). But the drawbacks of those shortcomings can be mitigated by improving the data that it does collect. [Karl's] approach is twofold: pixel filtering, and averaging of movement.

The pixel filtering works with the depth data to help clarify the outlines of objects. Weighted moving average is used to help reduce the amount of flickering areas rendered from frame to frame. [Karl] included a nice GUI with the code which lets you tweak the filter settings until they’re just right. See a demo of that interface in the clip after the break and let us know what you might use this for by leaving a comment.

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Quiet Dust Extractor from Scavenged Materials

As with many of the projects covered on hackaday, [bongodrummer]‘s Dust Sniper came about because of a lack of effective commercial solutions, in this case to the problem of quiet dust extraction.

Workshops are generally full of dust and noise, both of which take their toll on the human body. This is why safety regulations exist for noisy and dusty workplaces and–as [bongodrummer] rightly points out–we have to take precautions in our own home and community workshops. Hearing protectors, dust masks and safety goggles are integral, but reducing the amount of dust and noise in the fist place is paramount.

Using mostly scavenged materials [bongodrummer] did a quality job building the Dust Sniper–and all for a bill of materials totaling £20. It has an integrated work surface, automatic switches on 2 vacuum lines to sync up with power tools, a cyclonic air filter that prevents clogging the HEPA filter and reducing suction power, inlet and outlet soundproofing, and a plain old power outlet for good measure.

Whether or not you’re interested in building an integrated workbench/extractor system like this one, we recommend you check out the details of the cyclone filter and the sound reducing components. Not only are they an interesting read, but they could be useful to apply in other projects, for example a soldering station with fume hood.

We think it would be really neat to include more cyclones in our projects. Stick around after the break to see [bongodrummer]‘s prototype cyclone filter in action.

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Serial port controlled CPU fan

[Christian] was running a Linux box as a home server but needed a way to quiet the noisy machine. Like many Linux servers, he’s using some pretty old hardware which doesn’t have an on-board header for the CPU fan which generates much of the unwanted sound. Those headers are nice because software can monitor the CPU and board temperature and adjust the fan accordingly.

[Christian's] solution was to use the serial port for the task. He built a small circuit in which serial pin 3 drives the base of a transistor, pin 5 provides ground, and a floppy drive power cable supplies 5 volts. From there he wrote a RUBY program to monitor the CPU temperature and generate a PWM signal on the serial port, throttling the fan speed as needed.

[CC Photo Credit: Garrette via Flickr]

Electronic vuvuzela

Want to annoy fellow fans but  don’t have the lung power to do the job? [Hunter's] electronic vuvuzela is just the thing you need. The plastic noisemakers were so prevalent at the world cup this year that some folks came up with audio filters to remove the sound. The electronic rendition is much smaller, using a 555 timer to mimic the instrument on a small speaker. [Hunter's] build has buttons for five different notes which can be altered with some potentiometer. There’s no schematic but then again for something that’s annoying you don’t want to make it too easy to replicate.

Update: Hunter added the schematic to his site which spell doom for those who enjoy peace and quiet.

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