Homebrew PCBs

Hello!

I am following this nice group for a while. This is my first post.

I've got old X/Y coordinate table which used to be simple pick and place 
machine. There's no Z axis and mechanics is not strong enough for 
holding any machine with drill or mill tools. One crazy idea crossed my 
mind... what if I put one UV light source to this machine and plot with 
UV light directly to photoresist coated FR4? I can make small optical 
mask with (e.g.) 10 mils aperture, which floats on thin air blowing 
beneath the mask. It could act as single (fixed) aperture photoplotter 
for direct exposure of PCB photoresist.... Is this kind of stupid idea? 
Anyone had experience with that?  Would be UV LED enough? Exposure time 
is critical here, but I am talking about PCB prototyping.

Any comments?

Regards!
Marko