I need help quieting vacuum motors.

[knight_toolworks]

After talking apart my melted fein to see how they reduce the noise it is pretty amazing to knock down a 100db motor to about 65db's with just a little foam and a plastic shell.
so the foam they use is a open cell foam a little stiffer then standard foam is. I can knock down about 6dbs by putting regular foam into the air inlet. another db wrapping the fein foam around the motor like it is done on the fein.
so any idea what foam to use? I have to order it so I need an idea what to buy.

[rcboats1]

Go to Home Depot and get the pink or blue insulation foam board. That is what I used for a generator box I made and it worked real good.

[knight_toolworks]

here are some pics. the fans are the cooling fans that lets these run in vac mode like they do. but most of the noise is from them. Just setting a piece of the foam that comes with the fein over them drops the noise from 100db to about 93db. or setting the top over them. another db or to if I cover the air inlet with foam. I tested normal foam and it did nto do anything. I can try a box of pink foam with the air intake covered and see.
http://i154.photobucket.com/albums/s266/knighttoolworks/posting/2C03D01C.jpg
http://i154.photobucket.com/albums/s266/knighttoolworks/posting/E68A288E.jpg
http://i154.photobucket.com/albums/s266/knighttoolworks/posting/A7657504.jpg

[ken_rychlik]

Build a box and put a set of mufflers from central vac on the outlets. Major noise reduction.

[knight_toolworks]

Build a box and put a set of mufflers from central vac on the outlets. Major noise reduction.
that would be easy to do. even one would be enough as they don't suck a huge amount of air.

[gerryv]

Kenneth's idea has a lot of merit. A central vac muffler is claimed to knock sound levels down by up to 50% and you can get them for about 10 bucks. A couple of them with the right foam in the enclosure sounds like something that could nicely for our cyclone dust extractor as well. Thanks guys. :)

[knight_toolworks]

I will give it a try but it may not work. these are more to muffle the noise from airflow. the noise in my case is from that fan. just like a router. Of course that foam that fein uses may be engineered just for that use.

[bob_s]

Try putting a layer of Quiet Brace from Home Depot on the inside of the box - it is like homasote coated with tar, but only $8 per 4x8 1/2 inch thick and absorbs a lot of sound. I put it under my sheathing on the new shop and the sound level outside those walls is very different than the one wall that was standard construction.
I'm planning on using this for noise reduction on the two 220V vac motors I have, but they really scream making them awfully hard to use!
I am planning to make a muffler for my cyclone with denim cotton insulation from http://www.bondedlogic.com/ it is supposed to absorb a amazing amount of sound in the 3 1/2 inch thickness. I have the Cyclone mounted in a corner and the sound coming off the walls is terrible.

the muffler shown here http://billpentz.com/woodworking/cyclone/muffler.cfm is what I am planning on using, although some have written that an 8 foot piece of insulated HVAC duct works very well and is a lot easier.

I'll post some info as I do mine, but I'm still moving equipment into the shop so it may be a couple of weeks.

[knight_toolworks]

I tried foam rubber on the inside of the box and over the air output it did not knock the noise down by even 1db. I put soem of the foam from the fein around the motors like they are in the fein that knocked it down 1db or so. but most of the noise is from those fans in the top. I was thinking like a baffle maze to make the sound have to bounce around for awhile before it can get to the opening.
these 120 fein motors are 100dbs where the 220's I have are about 96db's

[gundog]

I had a small office in the corner of my shop that I never used so I moved both vac motors the air compressor & dust collector in that room I had to install a couple vents to return some air but it has made a huge difference in noise reduction. I bet if I put some of that egg carton foam on the walls it would cut it some more. I would worry about not keeping the motors cool so covering with foam may make your motors not last long.

This is my manifold for the Vac motors I have it ducted with ABS pipe back to the room with the Shopbot. This is so much better than when I had the motors at the table.

Mike

[bruce_taylor]

I've been using these motor and have gone through a couple sets. When one went bad it shot out flames from the motor! I was glad that I didn't have it in an enclosure that I couldn't see what was going on. They also seem to get pretty hot when running. Just something to think about. I know how loud they are but I am hesitant to put much around mine. Just my two cents (worth about a penny these days)

[knight_toolworks]

they should not get too hot. my 220v ones get warm but thats about it. the exaust is maybe 100 or so degrees. well listen to me I melted two feins somehow (G) I will keep an eye on the temps.

[gene]

i run a roots blower . i went to a auto parts store and purchased a car muffler. now it it alot quieter

[knight_toolworks]

i run a roots blower . i went to a auto parts store and purchased a car muffler. now it it alot quieter
yes but that's different. these motors are like a router very high rpm fans ans it is the fan that makes the noise for the most part. the muffling the output may help some too. your roots would be muffled like a dc setup the airflow is noisy and muffling that will really help. these motors don't have a lot of airflow for the most part.

[garyc]

Steve...
You can easily use baffles and direction to reduce noise. Following Brady's lead, I assembled a multi motor unit that was not overly loud. Look at this thread: http://www.talkshopbot.com/forum/showthread.php?t=11813

Adding proper sound deadening material may make them quieter, but I never researched that option. Most options that reduce noise increase heat due to restiction of flow. There are a couple dozen of these 4 motor systems out there. As far as I know, no heat related failures.

[knight_toolworks]

I was thinking baffles too and line them with neoprene. since it is the cooling fans that causes the most noise heat is not an issue there.

[garyc]

Steve...
Heat IS the issue. The intake and exhaust for the cooling MUST be separated. If your baffles or sound deadening material restricts the flow, then there will be heat and the motors will burn down. If the cooling exhaust is recirculated into the intake, the motor will burn down.

Just like a car motor (which is another form of air pump) you will give up performance to reduce noise. Call Ward at Lighthouse Vac Motors. He will tell you what works and what doesnt. He has sold hundreds of these motors in various voltages and sizes. (And he knows every one that burned up due to a bad designed enclosure)

Myself and others have used a baffled design like the "Black Box" setup for 8-10 hours straight, some in 90 degree+ weather.

[knight_toolworks]

They are seperate. I meant the intake needs the baffles the worst but there is no heat there so it makes life easier.

[knight_toolworks]

If I created a simple baffle and each face was lined with neoprene that should do a lot I know foam can be used as thats how the fein is setup. the air output is not that noisy for the most part.
I can see using the vacuum muffler on the air output that would take less room then the baffle would. Here to get good baffling I will have to make a new vac box. I can manage baffling for the 220v motors but the ones that replaced the feins are too tall and will get in the way if I do much.

[gene]

one thing that helps stop sound from traveling is to not build square enclosures inside square enclosures . This will eliminate a drum effect and help with noise transfer. it helps with the sound to be absorbed and not transfered if the walls are not parallel to each other

[knight_toolworks]

one thing that helps stop sound from traveling is to not build square enclosures inside square enclosures . This will eliminate a drum effect and help with noise transfer. it helps with the sound to be absorbed and not transfered if the walls are not parallel to each other
I think this and the foam fein uses is why they work so well not a lot of foam and the dome shape does wonders.