That was a great video, I have to watch more of his stuff!
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How does it drive on it and cut it without the wheels damaging the cuts. Especially those small bearings.
Looks like it “hangs” the lower gantry rail from under the table. Look at 2:40 in the video.
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What kind of sorcery makes a vacuum out of compressed air? DUDE. This makes it seem very feasible to do a LR sized vac table.
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Bernoulli’s Principle? (aka Venturi Effect)
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The actual pump in the video is fairly impossible to get in the states.
Nippon Pisco VU Union Straight Vacuum Generator VUL05-66A (360-6287)
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My mind is blown! Magic pressure inverter!
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Back at the machine shop we had an air tool that pulled vacuum on intake and exhaust ports to verify the valve seat and stem seals. Pretty sure it worked this way.
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OMG I am getting one, I don’t know why but I NEEEEED it. There are so many options. I have no idea why this seems so cool but for ~$12 I have to have it.
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Amazon has one similar to the video for $8 but the one you linked Barry is WAY better. You can get them with silencers even…cool.
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So now we need to make a Primo out of chopped Carbon Fiber with a vacuum hold down table. Really starting to like this thread!
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If I continue to tinker with things like this for the rest of my life then I am going to have so many random little gadgets, hardware, and misc items laying everywhere I won’t even be able to walk around my shop by the time I’m 50.
With that said, I just ordered the vacuum ejector. Can’t wait to play with it!
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I plan on helping the neighbors bleed some brakes as a tester…that is my excuse and I am sticking with it.
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Think I’ll share a few thoughts on using these for vacuum clamping. Obviously it works well as shown in the video, however… I think these venturi vacuum generators can produce a pretty good pressure drop (i.e. significant clamping force), but I don’t think they move a large volume of air.
As a result if you’re cutting parts out of your work piece, the clamping force may disappear as the parts are cut out (due to the vacuum “leak”) They should be great for any sort of carving operation that leaves the work piece solid though.
Of course, it is theoretically possible to make a bigger venturi to draw a larger volume of air…but you may need a really big compressor to keep up with the compressed air requirements!
Due to the above, I’m not sure it’s a great option for a full sheet lowrider. If you can get your sheet goods to seal with the table before applying vacuum it might work. I’ll note that for a full sheet lowrider, you won’t need much pressure drop to hold parts securely. You have a lot SI’s (square inches…48*96=4608) to work with, so even a 1psi vacuum will produce more than 2 tons of clamping force!
I’m thinking some vacuum pucks might be nice for those smaller jobs on the lowrider where work holding is a challenge. Maybe cnc out a gasket groove near the perimeter of a hockey puck, and a shallow pocket out the middle…
I’ve seen the venturi vacuum generators used for vacuum bagging composites. They work well in that application, and… if I can find it, I’m pretty sure I have one in a collection of stuff I was given by someone who used to do that sort of thing.
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Oh yeah good point, maybe a little pod system would be better.
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So, I found the venturi vacuum generator I was given… and I have some hockey pucks… I’ll need to get some gasket material… and probably some hose and fittings.
A little googling leads me to believe hockey pucks can be turned on my metal working lathe (who’d a thunk? 8^), so I’ll probably give that a try. I’d be interested to hear if anyone has thoughts on routing hard rubber though. I have no idea what sort of bit/spindle speed etc. might work.
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I’ve seen 2-stage vacuum hold-down systems where a shop-vac style pump is used to evacuate most of the air, then a vacuum pump or venturi is used for the last bits.
You might try freezing the hockey pucks before machining them. Don’t know what the dimensional changes might be.
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