likely the pita factor dissuades most.
I have been tempted - I was at a garage sale this summer, where the pro pfotographer turned to the dark side was selling off a 4' x 6' unitl, complete with 5000k tubes for $100. But where would I store it when I didn't need it, let alone convince my wife that I really did have an occasional use for the thing?.
If you haven't needed it to date, do you really want to build it?
I have been tempted, particularly with the appearance of 5000k compact flourescent tubes in the last year or so, to build a 12"x12" or so unit .
My plan, when I get around to it is to build a light table unit flush into the enlarger desk, off to the right hand side of the baseboard (i'm left handed) and outfit the top with 1/4" thick tempered glass, backed by translucent mylar drafting film, perhaps stuck on with a thin layer of vaseline.
I plan on putting an OC brownie safelights in the box as well. I was going to wire it with a diode in line to cut the 7.5bulb light output by half or so, since it will be potentially quite close if it is on, and I inadvertently have paper nearby.
I might even throw in a red source to aid in confirming that lith masks are appropriately lined up before sliding the assembly onto the baseboard, or into the neg stage. Tilting them to look through towards the ceiling safelight always sems to shift the alignment once it is tipped back into the horizontal plane.
The white light side I was going to wire in with a finger guard on the switch, so that you would not be able to inadverently turn it on when you 'meant' to fire up the safelight in the viewing box.
