Sound abatement...

[Bolt55]

Hi guys,

I'm closing in on buying a PRSStandard48 and it will initially be going into my basement. I'm concerned about noise with my neighbors and other household members. I'm looking at various enclosures, panels and blankets that I might use but I was wondering how some of you may have dealt with noise?

Thanks in advance for your help.

Mike

[adrianm]

The biggest thing you can do for noise is to use a spindle rather than a router.

I couldn't beleive the difference when I switched.

The biggest noise issue I have now is squealing when using spiral bits, I've never managed to dial that out but straight bits are very quiet if not as efficient.

[phd1658]

Adrian is absolutely on the money..........unfortunately, I didn't have the money to go with the spindle! My "solution" was to build a room out of sheetrock around the bot (I had plenty of construction material already). I insulated between the walls and ceiling with acoustical foam, then lined the inside walls and ceiling with same. The neighbors can not hear it and my wife doesn't complain.....at least not about the noise! The biggest thing to consider if you go this route is allowing enough room to work in, including materials handling. Also, the more sound proof you make it, the greater the dust build up concern. Make sure you have a good collector/filter and keep it clean between jobs. The dust shield that Shopbot sells for routers is a BIG help as well. I also put my computer in a separate cabinet (on wheels) with it's own cooling fan and filter. Good Luck!

[don_roy]

I agree with Bill but I have styrofoam on the walls (I have a pored concrete foundation) and I put fiber glass in the ceiling but no sheet rock and the noise is not bad upstairs in my house. As for outside you can hear it if you listen well but othewise not really noticible. No one complains and I live in a development.
Don

[dlcw]

Mike,

Several things make noise on these machines. The turning router/spindle, the cutting noise and if you have a vacuum holddown, that makes a lot of noise as well.

The router/spindle issue can be resolved by using a spindle. Turn on spindle, stand next to it, and you can barely hear it running. Turn on a router, put in earplugs and headphones and it's still hard to think :D

The cutting noise can be resolved, somewhat, by dialing in to the sweet spot of RPM and feedrate for each bit and material type. When a bit is screaming, that means it is hungry for more material. Slow down the RPM or increase the feedrate. My plywood cutting noise is almost completely drowned out by the vacuum noise because I finally dialed in the sweet spot with bit type, RPM and feedrate. What a difference! What I found was that if you think you are pushing to fast, you probably aren't. I was scared at first to push the machine hard because I figured it would just lead to broken bits. What it lead to was dull, overheated bits and poor cutting results. With a 3/8" mortise compression bit cutting 3/4" plywood I run the spindle at 12000rpm and feed at 6ipm. Sweet!

The vacuum holddown can be resolved by setting up your vacuum motors outside or in another room and add plumbing back to the CNC. This vacuum system is fraught with leaks and problems however. I have 4 220vac vacuum motors attached right to the 4 zones of my plenum from underneath. Each motor has a muffler which helps a little with the noise, but I chose KISS over noise reduction.

You can also take the route of building a room around the bot, but when I first did this it got quite hot in the room because of the vacuum hold down system.

[curtiss]

The PC router is not too loud at 10 to 13 k. Your dog might not like it...

Some info on dust...

http://home.comcast.net/~rodec/woodworking/articles/DC_myths.html

[kubotaman]

I have a spindle on my Bot. I bought it new when I bought my Bot. I would highly suggest that if at all possible to purchase your machine with one. I know it is a considerable amount of money difference but in the long run it really is worth the money. I have been around routers for 35 years and it still is too noisy for me. As stated above you can actually have a conversation standing next to mine while it is cutting. I realize it may be too expensive at first but if you do buy the router setup and want to change it later to a spindle it will cost more than if you had bought the spindle at first. Just my thoughts.

[geneb]

When a bit is screaming, that means it is hungry for more material. Slow down the RPM or increase the feedrate.

This is THE best description of the issue I've ever seen! Thanks! :D

g.

[Bolt55]

Hi guys, thanks for the input! It's a great help!

Mike

[myxpykalix]

here is something that you need to consider is that you will need to make sure your cold air return or heating ducts are not in the area of your bot. You don't want your furnace sucking in the dust spewed out by your bot in the cold air return and an open heating vent will invite dust to get back to the furnace.

[bcondon]

I have two areas for a shop. In the basement, I have 8" of fiberglass insulation but no sheetrock. For table saws and planers, it is fine on the first floor.

Sheetrock CAN MAKE IT WORSE becaus eif you sock it to the ceiling joists,
the noise is transmitted and sometimes amplified through the framing. A friend built a sound studio in his house and showed me a few things.

My shopbot is located in an added room on the back of the garage. I built with 2x6 and filled with fiberglass insulation, blue boarded and then plastered the room (and the garage). There is 12" of insulation in the ceiling so Ido not disturb the birds...

The structure has vinyl clapboard... The neighbors don't have a clue that I have the machine and work as early as 7:00 AM so that is good.

Additionally, I build a closet around my dust collector, with 2x4 wood frame, 4" fiberglass insulation and two layers of wallboard 5/8 inside and 1/2" on the outside. The two layers if for fire, not noise.

Th screaming bits will be adapted to by changing the RPMS now that we better understand what the machine is telling me!

Bob Condon

[plemon]

I spoke with a sound engineer when planning my shed and he listed the following things as key to sound proofing - dead space, baffling and air tightening. For baffling I used egg cartons as a cheap alternative to acoustic foam. Its not as good but it does make a huge difference. Having an extra wall cavity makes a huge difference, of course if you line a shed then you effectively have that. I lined my shed with half inch plywood (its a steel shed) on floors and ceiling and insulated with r3.5 rated batts. I also filled all gaps with expanding foam and put skirting over gaps in wall joins. The final thing is decent rubber seals for doors and windows (don't forget double glazed windows. The only thing to remember is decent venting and if you offset the outside vent from the inside vent and add some baffling in the cavity between the two you will reduce noise escaping through your ventilation.