Camvac silencer

[selectortone]

Rather than post to a six-year old thread I thought I'd start a new one. This is probably old hat to the regulars but I thought it might be of interest to the newer turners (like me!) here...

I copied the idea from what the guys at my club built to reduce noise from their Camvac dust extractor during demos.

Here's my Camvac 286 in it's normal place in my workshop. Handy for the lathe and the adjacent bandsaw:

The outlet hose disappears under the bench and is connected to a silencer box:

Here it is with the lid removed. It's just an old plywood box that was knocking round the workshop (I knew it would come in handy for something!) to which I added some baffles and some scrap acoustic foam. The outlet hose connects to one end and the exhaust exits from the other via a hole covered with a grill to stop any small furry creatures deciding it might be a nice place to sleep:

The Camvac isn't particularly noisy to start with - my Henry shopvac is a lot noisier - and with this system it is really quiet. No apparent loss of suction.

 

[woodpig]

Gosh, you must have been reading my mind Terry... Clive pointed out the silencer Paul was using on his Camvac on Saturday at the Ellingham show. You should do a write up with some pictures and get it posted on the club website. Sadly I don't have a Camvac or I'd be copying your design. Then again something similar might work on my Nilfisk wet and dry?

 

[Grahamshed]

I like this idea, it would fit nicely on the bottom of my demo stand. Any idea where you ge tacoustic foam ?

 

[woodpig]

Egg crate foam.

http://www.ebay.co.uk/itm/Advanced-Acou ... SwBLlVcFFb

 

[selectortone]

^ Yep, that's the stuff. Even cheaper if you have a mate who has a recording studio and has some free offcuts! :wink:

 

[Paul Hannaby]

I wonder how much the flow is reduced by the extra pipe and baffles?

 

[Grahamshed]

Thanks for the link woodpig.

 

[collectors]

Hi, looks like a great idea. Would you know how much it reduced the noise?. I know you might not have a DB meter, but a ball park percentage would help. Thanks
Chris

 

[SVB]

I wonder how much the flow is reduced by the extra pipe and baffles?

That was what I was thinking Paul, I have a triple motor camvac on an oil drum size bin which is noisy, I'd like to get it quiet but for me these things are either noisy or quiet, getting the odd 10 or 20% reduction is really neither hear (sorry!) nor there.

S

 

[woodpig]

If it's practical for your setup, just fitting a hose to the outlet and poking the end out of your workshop will also reduce the noise.

 

[Jasper42]

I have record power shop vac, very loud. Built it a small box outside my shed,ran the pipe and power lead through the wall ands works off a remote. Keeps the volume down although the long haired general was not over impressed....

 

[selectortone]

Hi, looks like a great idea. Would you know how much it reduced the noise?. I know you might not have a DB meter, but a ball park percentage would help. Thanks
Chris

The silencer reduces the noise enough to have a conversation in the workshop without raising my voice. The difference is quite noticeable. Coupled with a new, quieter lathe, the aural environment in my workshop is a joy to work in.

As I said in my original post, in my simple system there is no noticeable loss of suction - tested by putting my hand over the inlet with and without the exhaust pipe connected. Yes, I know - subjective rather than empirical, but the Camvac does what I bought it for - it collects the vast majority of the dust I generate when I'm sanding at the lathe, or using my bandsaw, and the silencer does not interfere with its efficacy in any significant way.

If you are using multiple collection points or more complex pipeing schemes your mileage may vary.

 

[collectors]

Hi, looks like a great idea. Would you know how much it reduced the noise?. I know you might not have a DB meter, but a ball park percentage would help. Thanks
Chris

The silencer reduces the noise enough to have a conversation in the workshop without raising my voice. The difference is quite noticeable. Coupled with a new, quieter lathe, the aural environment in my workshop is a joy to work in.

As I said in my original post, in my simple system there is no noticeable loss of suction - tested by putting my hand over the inlet with and without the exhaust pipe connected. Yes, I know - subjective rather than empirical, but the Camvac does what I bought it for - it collects the vast majority of the dust I generate when I'm sanding at the lathe, or using my bandsaw, and the silencer does not interfere with its efficacy in any significant way.

If you are using multiple collection points or more complex pipeing schemes your mileage may vary.

Thanks for getting back, will certainly have a go with your idea.

Chris

 

[Robbo3]

Not to take anything away from the OP, but when Paul Hannaby (see his question above) demonstrated at our club (West Oxfordshire) he brought his Camvac & if I remember correctly he put the outlet hose in a cardboard box. It was the quietest dust extractor that I have ever (not) heard. Even those of us at the back of the room could hear him quite plainly.
If I've mis-remembered, I'm sure he will correct me.

 

[Jackie H]

In my wall mounted box I used acoustic tiles (Amazon, not the egg box type). I used the single exhaust pipe supplied by RP for the purpose and slit it in to 2 pieces. I got the fittings for the cut ends from Plastic Pipe Shop and glued the flanges into a rebate I made in the the box. The cut pipes fitted the flange perfectly.
I measured the sound level using an android app on my phone. Not the most accurate, however see pics, before and after.
It doesn't appear to affect performance of the vac. The baffle design is just like a car exhaust and is not meant to create too much back pressure. As I said it does work well. If I remember correctly 3dB represents a doubling of sound pressure so actually quite a significant difference.

.

 

[Paul Hannaby]

Adding extra lengths of corrugated pipe will increase the resistance to airflow and will reduce the performance of the machine. Whether the reduction is significant depends what you're trying to do.