sound deadening for steel machine stands

[Tim Sherwood]

Steel cabinets can act as a big sound box. They multiply the volume of any machine tool fastened to them. I'm looking for ideas to deaden those reverberations . My jointer is really rumbles on it's cabinet stand.
What have you used to reduce these sounds?

 

[tvrgeek]

I have use clone sound sheets as used in cars. Known as "constrained layer" sheet.
I first question why so much vibration. Old or crappy Chinese V belts would be a big cause. You can also glue MDF to flat panels. You can also isolate the machine from the stand with rubber isolation blocks. ot the snake oil sold for audiofools, but the real ones from industrial suppliers. A set of 4 usually under $20.

 

[Tim Sherwood]

I just replaced the old belt . I Didn't think about it creating vibrations. I could have used the link style belts . I'll check into those sound deadening sheets. They should do the trick.

 

[Howie]

I just replaced the old belt . I Didn't think about it creating vibrations. I could have used the link style belts . I'll check into those sound deadening sheets. They should do the trick.

I ordered 3/4 cork and rubber pads from amazon for all my stationary tools. Segmented belts help a lot.

 

[tvrgeek]

Link belts are OK, but you can also just get decent cogged belts from Gates. Chinese belts are not round and have bumpy splices. The other problem with Chinese belts is no two seem to be the same size, so in a multi-belt drive ( my TS has 3) they are different tension so increased vibration and bad torque transfer. Only the tightest belt is actually driving. Many tools have an odd size belt. My jointer I just added a plywood block under the motor so I could use a Gates belt. I found standard for my drili press and had to go to D&D power to get a quality US made set of belts for the TS OEM from Harvey were crap.

I hate V-belts and much prefer the multi-rib but older machines seem to be stuck with them. Biggest problem is use of a sheave in a smaller diameter than the belts are rated for. My drill press, table saw and Jointer all violate the belt spec for minimum sheave diameter.

 

[Wilsoncb]

Not sure if this can be helpful for your situation but if you look at sound deadening in car there might be something that could help. First they used a Killmat, Dynamat or B-Quite material stuck to sheet metal panels to stop their vibrations. It’s a tar sheet like material with aluminum foil on it. Then they use a combination of mass loaded vinyl sheets with thin foam sheets. The key for use of this is to eliminate any air holes. Sounds will escape any enclosure if there are any holes. Also material that has a higher mass, like the mass loaded vinyl is best for creating a sound barrier.

 

[Oka]

sound deadening any of this will work. Just bear in mind you need to seal around the edges. Otherwise the dust will stick.

I use Hipp wrap shrink tape. It works well, and got for free, but anything that covers the seams will work.

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[smallboat]

Not sure if this can be helpful for your situation but if you look at sound deadening in car there might be something that could help. First they used a Killmat, Dynamat or B-Quite material stuck to sheet metal panels to stop their vibrations. It’s a tar sheet like material with aluminum foil on it. Then they use a combination of mass loaded vinyl sheets with thin foam sheets. The key for use of this is to eliminate any air holes. Sounds will escape any enclosure if there are any holes. Also material that has a higher mass, like the mass loaded vinyl is best for creating a sound barrier.

I’ll need to dig and see if I can find a link but I did some work for a company in the King or Pilot Mountain area over 10 years ago. They made sound deadening products by recycling the scrap material left from auto manufacturers. They had. arange of products from panels to roll material you could stick to a wall and paint or paper over. Pretty interesting stuff.

 

[Tim Sherwood]

Do these automotive style sheets need to cover the whole surface?

 

[Wilsoncb]

Do these automotive style sheets need to cover the whole surface?

Yes and no. First keep in mind this applies to controlling the sound from either entering or exiting an enclosure. I’m assuming your jointer has an enclosure with the motor in it. The question is, what is generating the noise? My guess is the overall vibration is the biggest problem? I would experiment to see if you can narrow it down. Start with putting some rubber feet, or even some plywood under the unit to see how much is due to it sitting on a hard surface. If you have a separate mobile cart, you may need to put some dampening material between them. Hold your hands on the cabinet to see if that reduces the amount of noise. I think after you do those things you’ll know better what to focus on. My gut feeling it will be a few different things, hopefully it will be one major issue you can focus on.

BTW, now you got me thinking…what could I do to reduce noise rather than just excep it.

 

[Roy G]

Tim, have you run the motor without the belts on it? May have some bad bearings.

Roy G

 

[smallboat]

Found the info I mentioned. United Plastics Corporation 511 Hay St Mt Airy, NC. Their web site isn’t responding well for me, probably my end. But if you are interested, you can find them. good luck

 

[tvrgeek]

Those automotove sheets are the "constrained layer" I was talking about. Cheap ones are tar based and will stink. Better ones are a butyl compound. Off brand work as well as the grossoly overpriced Dynamat. They have two functions. One is to add mass and so lower the frequency of resonance. The other, to a lessor extent, is to convert some of the sound to heat. If you go to industrial supply houses, you can get even higher performing materials. Boat supply houses have materials they use in engine compartments.

You don't need to cover the entire panel. If it is, say 14 square, then a 12 x 12 sheet works fine. Any extra and trim, slap on over top.

You reduce noise depending on the source. Belts are a big one. Blades/cutters, sheaves, and basically anything spinning in air will make noise. In the real of hobby or small shop woodworking the only solution is to wear hearing protection. In large scale industrial shops, machines may be enclosed and fed robotically to reduce the noise on the floor.

Usually, one method of reducing noise is to seal the cabinets where the noise is generated. That won;t work on woodworking machines. Holes for the blades, holes for cooling air, holes for dust extraction.

 

[Tim Sherwood]

Thanks guys for some great tips. It SOUNDS like I'll have to check into each probable source of vibrations.
I have run the motor without a load . The bearings feel and sound fine. But is is an old heavy cast iron beast. It is noticeably louder than a modern motor. With a new , import, belt installed it does rumble loudly. The cabinet itself is a big empty cavity and acts like a drum box. It has a 4" round air hole fight in the center of the front panel. It does a fine job projecting sound. The cutter bearings are new and quiet . The carbide cutter head seems to run quieter than the old straight cutters did.

 

[tvrgeek]

Get a god belt. Gates AX series.

 

[Tim Sherwood]

How effective would a spray foam be ? I once used it on the under side of a cheap kitchen sink. It seemed to do a good job. I just sprayed it in random ropes.

 

[Partman]

Rubberized undercoating

 

[tvrgeek]

How effective would a spray foam be ? I once used it on the under side of a cheap kitchen sink. It seemed to do a good job. I just sprayed it in random ropes.

Just about useless. It neither adds mass to lower resonances or converts vibration to heat.

 

[tvrgeek]

Rubberized undercoating

Not very effective.