[machinedude]

Plasma cutting can be crude in table design largely because the process is not a high precision process and the tables tend to depend on THC way to much in my opinion. they also are not built to be rigid on the gantry's since there is no cutting forces there.the tables are built to be tough since they get hammered with loading sheets and plates but are not built very accurate. the gantry's are usually built light so they can accelerate at a high rate so corners can be turned on a dime at a high feed rate. not all plasma tables are built the same so the high end tables might be ok if things are solid enough for a dual purpose machine but that does not sound like the case here. sounds like a lot of things will have to be improved and beefed up taking a guess before you get to where you will be happy with the results.

i would take a hard look at the motors driving the axis's and make sure they can handle extra cutting loads placed on them and i would do some drive calculation's to make sure you can get to a resolution you can live with. there are all kinds of things to consider here and a lot of things you can look into before you spend all kinds of money and get in too a big project. i would check the machine backlash on all the axis's as well to see if your getting into more than you wish as well.

just a few point to consider and evaluate over all before taking the dive.

[machinedude]

as for vacuum tables a shop vac is not going to produce enough vacuum on a table that big. not to mention the level of vacuum is not as strong as a typical commercial vacuum system. with wood working you need a lot a volume and a lot depends on how well the system is built. for wood working 15 hg of vacuum would be ideal. and the surface area of the work piece has a lot to do with it as well. the smaller the piece the less hold down force you have. the cost of a vacuum supply on a table your size would be substantial. if your thinking of pulling vacuum through a spoil board even if the table is zoned you will need something big to get that result.