The Secret Society of Lathe Trolls

Doug 6N · Joined: 21 May 2007 Posts: 64 Location: Washington

Hi again:

Anyone know what kind of vacuum pump was originaly used for this purpose? I have a great system with a vacuum cleaner. Way too noisey though.

A quiet suction pump? Does such a thing exist?

Thanks

Doug

JayDC · Posted: Fri Feb 15, 2008 5:05 am Post subject:

I dunno about quiet, but I use a wall mount shop vac (garage vac) that I mounted on the other end of the room. Far enough away that the vibrations and noise don't make it to the record. I wired it to an outlet with a switch I mounted very close to the cutter. The unit has pretty high suction, I think it's about 10' away.

I suppose one of those central vac systems would be pretty quiet, just don't forget to catch the chip with a water bong.

Amp Doc · Joined: 21 Jun 2007 Posts: 109 Location: UK

I have a idea on this using a 8inch 240v fan. If you "funnel" the input to the fan down to say 1/2inch and the output of the fan down to say 6inch and make the input "funnel" 12inch long and the output funnel 6inch long the venturi effect should create quite a large suction like a expansion chamber on a 2 stroke exaust. I have not tested this but I use a simular setup on pa amps to cool the heatsinks by using a 4inch fan "pulling the air" through a 2in X 1inch heatsink. We worked out it doubled the air speed through the heatsink and it knocked 10oC off the full power running temp. This setup would be quite enough to mount near the lathe. I am going to test this setup next week so I will let you know.
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Doug 6N · Joined: 21 May 2007 Posts: 64 Location: Washington

Hi:

Yep. Using the water bong arrangement. Had'nt thought of the implications of that. Very Happy

Eventually I want to do some direct recording from the mic to disc. Hence the vacuum running in the background is not so cool. I live in an apartment so even putting it out on the lanai I can still hear it.

I seen pictures of pumps that were originally used. And all I have for a name is "Grunow Pump" Been unable to locate anything specific to this on the net.

There is a German made vacuum cleaner is this perfectly quiet but costs over $400. Not ready for that yet. Smile

But may be the answere. In the meantime I'm sniffing around to see what I can find.

Doug

JayDC · Posted: Fri Feb 15, 2008 4:02 pm Post subject:

Think distance.

Use PVC for the long lengths. Just put the switch close to the cutter.

I pretty sure any silent vacuum pump is going to be expensive, unless you really research it, and get a great deal on ebay.

Steve E. · Posted: Sun Feb 17, 2008 10:00 am Post subject:

test test test.

grooveguy · Joined: 22 Jun 2006 Posts: 40

The best vacuum motors, in my opinion, are the ones made by Lamb Electric. These are multi-stage turbines, anywhere from 3 stacked rotors up to 7 or 8. The absolute best is the one that runs with an AC induction motor at a conservative 1750 r.p.m. These are sometimes available on the surplus market, but were originally (and remain!) horrifically expensive. they are very quiet but take about 20 seconds to come up to speed. Vacuum pressure is uniform over any intake size, and on a 3/8-inch surgical tubing hose to the 'bong' (I like that name!) it really sucks!

The alternative is the Lamb vacuum motor that uses a "universal" AC/DC motor using brushes, like an AC electric drill. This motor generally has fewer turbine stages, and when the air is restricted the motor really winds up to a very high speed and starts to get hot. I use one of these on my lathe, and have it suspended with springs inside an insulated wooden box. It sits right below the turntable and causes no vibration or noise to speak of. I throttled down the voltage to this motor to about 60VAC, which gives more than adequate suction without the motor trying to tear itself apart. It will run for hours without heating up, even in the carpet-lined box.

The more popular Lamb vacuum pump (with the universal motor) is often found on the surplus market, and is even used in high-end garage vacuum cleaners and, I believe, on the Rainbow home vacuum cleaners. Contact me off-list with a private message if you want some photos of the installation.

Jim Wood

harper · Joined: 25 Jun 2005 Posts: 30

Ive been rigging up a vacccum system the last couple of days, using a compressor that was originaly used for a screen printing exposure suction table. It has an air intake and output, ran a tube from the intake to a glass bottle with water inside to collect the hairs, "water bong method" punched 2 holes in the lid for the tubes and sealed it with hot glue (hot glue is the best way for semi-perment adhesion, so you can pop it off neatly until you get it right) and then ran another smaller tube back out and stuck it right next to the cutting head. Works aok right now... now i need to isolate the sound inside a soundproof box....

MEGAMIKE · Posted: Thu Feb 21, 2008 7:28 am Post subject:

HI
I have an old speaker sub box that i encased my industale vacum ,with pading and in and out holes..be sure that the box is much larger than the vacum and that the vacum is a wet and dry one heating will be a problem if it is a house hold vacum. its great no noise :
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grooveguy · Joined: 22 Jun 2006 Posts: 40

Good job, MegaMike,

That's pretty much the same thing I did and it is quiet. I found that the voltage to the motor could be cut back substantially and still give enough suction; this really helps to keep the motor from overheating. Most vacuums "run-up," or increase their speed when the air supply is cut off, as in recording when it's choked back by a small tube to the cutterhead. As the speed increases the suction really doesn't go up much, so by dropping the voltage 20% or so, it still 'sucks' and then won't overheat. A hardware-store light dimmer works pretty well for this, but a better way is to take a 24V, 5A filament transformer and wire it with the proper phase to reduce the line voltage by 24V. Apply the full line voltage to the primary, then put the secondary in series with the motor. One hookup will increase the voltage by 24V, the opposite polarity will reduce it by this amount.

MEGAMIKE · Posted: Wed Feb 27, 2008 1:09 am Post subject:

thanks. i will try. Smile

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seas of cut grooves

JayDC · Posted: Wed Feb 27, 2008 5:53 pm Post subject:

vacuums suck..