im looking to build a stand alone dvd dulicatior, anyone know how?

I'd say the only way is to put them into a computer. Otherwise you
will need to get a professional duplicator (no idea on price).

Do you want to duplicate one-to-one or one-to-many?

Do you require labeling or will this be done manually?

You can get one to one duplicators for $250-$300. I have two DigiCopiers (http://www.addonics.com) that function as both a single USB 2.0 Burners and a one to one DVD+/-R/RW Standalones.

You can also purchase one-to-many duplicators that can range from fairly expensive to very expensive (examples at: http://www.aleratec.com/ and http://www.microboards.com/dvdduplicators.htm)

You can also get kits to add your own drives to (search Google for DVD duplicator kit).

The problem with trying to build your own is that it needs a controller (you can buy these... but that is probably more hassle than it's worth).

You can also slip a couple drives into a computer and dedicate it to that task.

Be aware that if you have added copy protection to your DVDs, the duplicators may not be able to copy them.

John