woodapple

Hi Folks,

I'm looking for information on vacuum clamping set-ups for template routing and have found numerous websites describing different methods. The most attractive (cost effective) seems to be using an old refrigerator compressor as the vacuum source. Does anybody have any direct experience building and using a system like this? If so, I would like to hear your take on it. Thanks.

Eric

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Thom2

I can't say much about using a refrigerator compressor, but I'll show you my rig anyway.

here it is set up for use:



and here's a shot just to show the basic components:



FYI: One of the first pieces of equipment I ever bought for my shop was a 60g air compressor. My Dad was a mechanic/autobody repair tech for many years and I grew up having a large compressor in the shop. I do enough other stuff besides woodworking that I could never survive without a decent size compressor.

With that said, aside from the compressor purchase, this vacuum rig I built cost me $10 .... yes ... $10 ..... I know you can't believe it, I know you've been shopping and gasping at the prices of these rigs .... but I'm telling you ...... T-E-N D-O-L-L-A-R-S

I will admit that I was lucky enough to have a lot of the pieces laying around to complete it, but the major component is $10 and miscellaneous hardware will set you back another $20 or so, plus a guage ... hmmmm ... you should be able to be into a setup like mine for under $40 if you play it right.


First thing you'll need to do is make a trip to HF to get the major component .. you know ... that super-whoppin' expensive T-E-N D-O-L-L-A-R component

Super Expensive T-E-N D-O-L-L-A-R component can be found here:
http://www.harborfreight.com/cpi/cta...emnumber=92475

You can also pick up this guage from HF for $13 ... I think I've seen it on sale for under $10 tho'
http://www.harborfreight.com/cpi/cta...emnumber=93547

Now you've got the two major pieces you'll need, go home and tear apart that vacuum pump, the only thing you'll need is the gut (in my picture it's the silver box smaller than a pack of cigarettes). Take the gut and head to the local GOOD hardware store that has a decent assortment of brass fittings. Do whatever you need to adapt the inlet to your air hose nipple (I later installed a ball valve on the input side). On the output side, you'll need a tee if you plan on running the guage.

There you have it, now you know the secret to my inexpensive vacuum rig

gregW

that's pretty cool Thom...thanks for the info.

are you using it to make aluminum push sticks?

(they look like aluminum chips in the first picture..)

__________________
Greg

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Thom2

If you're familiar with Lee Styron (www.leestyron.com), I spent a year or two making the push sticks for him that were sold with his Shark Guards. I've since given up that gig, but the vacuum jig was AWESOME for that work.

Here's some other pics if you're interested:

http://bt3gallery.fhauto.com/view_al...e=SharkFeeders

and here's a good shot of why my shop used to be nicknamed "Tinseltown"

jigmaker

What size air compressor are you using, i am thinking of using this to draw a vacuum on a vacuum veneering bag.

AxlMyk

Someone on E-bay has several of these.
http://cgi.ebay.com/Gast-Vacuum-Pump...QQcmdZViewItem

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My Gallery @ http://www.routerforums.com/axlmyks-stuff/

kp91

Thom,

Love your setup, especially the price! Thanks for sharing the ingenuity. I might just have to make a trip to HF to play around with this one!


Jigmaker,

the spec sheet from HF says 4.2 CFM, so most any shop air compressor should work. Tank size shouldn't be too important, since you'll need a valve to shut off the bag after you've pulled the vacuum (assuming no leaks).

__________________
Doug
1 John 1:9

jigmaker

kp91

I am working on a vacuum controlled switch to operate the compressor so it will maintain a constant vac., i will post the results when i get it working. My compressor will produce 4.2 cfm at 40 psi.

Thom2

I am running a 60g compressor, but it wouldn't need to be that big for this application. There is a big difference in air demands between vacuum clamping and veneering too.

One thing to remember with clamping, the bigger the template, the less vacuum you actually need, the rule of thumb is that 1psi = 2" of vacuum. With this in mind, here's some examples of the force applied to a template.

12"x12" (144") panel @ 2" of vacuum = 144 lbs
12"x12" (144") panel @ 10" of vacuum = 720 lbs
12"x12" (144") panel @ 20" of vacuum = 1440 lbs

With a venturi, the air consumption is related to the amount of vacuum you're trying to pull. If you're trying to pull a full 20" vacuum all day long, you're gonna work the dickens out of your compressor. If you're templates are big enough tho, you can cut back the vacuum significantly and still have plenty of holding force.



Turning the compressor on and off with a vacuum switch is not going to work for the venturi setup. I highly suggest you look at air solenoids if you're going to use a venturi vacuum pump. You don't need to operate the compressor, you need to control the air flow to the venturi. The compressor motor needs to be able to control tank pressure and can only do that if it is controlled by the pressure switch on the tank.

jigmaker

kp91

Thanks for that info i guess i better do a little more research before i get into this very far, i have built a vac. pump using a refrig. compressor and it works, but i thought i would use a system using the venturi ,that way i could be using two bags at the same time. Not only that but i enjoy playing around with this kind of stuff, it keeps me off the streets, as my wife would say.