Down draft table?

[OldChipper]

I'm a newbie here, so if this question is in the wrong place, please be gentle!
Sanding dust is getting the best of me. I'm going to build my self a 2ft x 4ft table. Been looking at some of the many shop built ones on the net. So many to choose from. Would like to hear what you guys think? Most of my work is drawers (dresser) and cabinet doors, etc. too old for the big stuff anymore! I have a A/C blower unit or a 5hp 3ph delta vac, but I don't have 3ph, so I would have to try an find a single ph or build a converter? Just how much air movement do I need for one this size? My space is limited so I plan to make a solid cover so it will double as a assembly table.
Any suggestions, so ideas you may have are most welcome.
PS, I'm also a welder/machinist, so my project need not be limited to wood! I've built a spindle shaper, 20"BS, 24" planer, 12x28" wood lathe,etc.
thanks

[shoottx]

If you want to use the three phase DC get a VFD check here http://www.factorymation.com/s.nl/sc.2/category.11/.f

A down draft table takes a lot of CFM so using the DC would be the way to go.

Please add some personal information so we get to know you better, just edit your profile.

Oh and welcome to the site!

[master53yoda]

You would need between 1000 and 1500 cfm for good dust control.
If by an ac blower you mean like out of the air handler or a furnace blower that is the best way to go for a sanding table. You do not need the static pressure that the DC provides but the high CFM that the fan provides. I have built a couple using furnace fans and the 4" filters that are available at Lowe's or HD. The HP required by the fan to deliver the same cfm is typically 1 tenth that of a DC and High cfm is what you need for small dust. You could also let it run any time your in the shop and it will greatly reduce the overall fine dust in the shop.

3 phase can be handled by a freq drive as Shoottx showed you or if available it can be made from a separate 3 phase motor and capacitor bank. Contact me if makeing one is what you want to do and I'll send you the needed informaiton. It is to complex to go into in this forum. You will also need 30 amps 240vac of unused power available.

[MikeMcCoy]

I've tried a couple of variations of down draft tables (plus one commercial version) hooked up to a dust collector with mixed results. I ultimately found the Bosch ROS hooked up to a Fein Turbo vac to be better than any of those. It doesn't have to be a Fein but the dust collection on the newer sanders works extremely well.