Vacuum table dust

I’m thinking of making a vacuum table for my X-Carve and have been reading the various posts on this forum.
What puzzles me is if I use a vacuum pump, what stops dust (when the cutter breaks through) from being sucked into the table and back out into the room? If I use a shopvac or similar then that won’t happen because it will collect the dust but I would have thought that a shopvac wouldn’t like to suck for very long with very little airflow through it.
Perhaps I could use the same vacuum to suck dust away from the cutter (upwards) and also as a vacuum pump for the table, i.e. divide the suction pipe.
Enough suck to go round I wonder?

I experimented with this for this very reason. With a vacuum table you want all the holes plugged, so no dust will make it in the table, but this almost guarantees to destroy a shop vac when you block air flow completely.

I opted to use a vacuum pump, designed specifically for this, and it worked great, but ultimately i stopped using it because id need to have the dust collector AND then pump running for long periods, so I returned to low profile clamps and abandoned the vacuum table.

I use a shop vac with mine. I allow some air to pass through either from the table or at the pvc pipe I attach to.

I’ve been running the same vac for almost 2 years without burning it up. Make sure the filter is clean when you use it.

That’s what I thought. A vacuum table sounds like a great idea but the price to pay is two vacuums running - more noise and more power consumption. Maybe the low-tech low-profile clamps is the way to stay.

I’ve been using his one almost since the X-Carve launched with a shop vac. It doesn’t look that nice anymore.

Vacuum table systems typically use a regenerative blower with a canister filter.they are big and expensive. I’ve been consider building vacuum table myself. The tabletop I made for my XC has the channels built in. Just need to drill the holes. I’ve been thinking of using one of these for the vacuum.

I am wondering if one could use a dust collector (not a shopvac) as both the vacuum table and the dust collection. Most dust collectors have dual 4" ports. What if we Use one 4" port for the downdraft table and the other for the dust collection. The dust collection port could even be reduced to a smaller hose to allow more airflow to the down draft table. Has anyone ever tried this? Or would the open dust collection hose not allow the downdraft table to achieve a good enough seal?

I recall a post on this forum from someone who tried it and if I remember correctly, it didn’t work well.

Works fine for me Vacuum table/ wasteboard

I wouldn’t think that would work well. Dust collectors use an impeller so large volume but not a lot of vacuum. Dust collectors are designed to have more flow and less actual vacuum. For collecting the dust. They actually become less efficient when obstructed. I’m glad it’s working out for you. One less thing to plug in and make noise.

I’m in the middle of adding a full vacuum table to my 1000mm machine. I have the plenum cut, a stack of spoilboad material, vacuum motor, vacuum gauge, filter and a fresh air valve (to keep the bearings cool). The plenum is mounted and the spoilbord is cut to size/skin planned off one side. I still need to seal the grooves in the plenum, build the filter box, mount and wire it all up.