I read an article in a trade journal a couple years ago about the sanding process for cabinet doors and face frames at one of the larger national companies.
Their sanding table was vertical, more like a painter's easel than a dining table. They said this got the product closer to the sander's line of vision than a horizontal surface would. They also raked light across the face of the doors (parallel to the easel) rather than having the light shine directly from a perspective 90º from the product.
The lighting thing is something photographers do all the time to accentuate defects. (Amaze yourself sometime with a flashlight that shines across the face of something you have already sanded, versus directly onto it.)
Does anybody have experience with a sanding table like this? I am interested in adding the light stations to this process and am wondering if this should be oriented vertically rather than horizontally.
From contributor G:
Your sander people will get large arm muscles from holding up a ROS all day. You may get random sanding results as they push and/or lean on the sanders, as opposed to just guiding the sander over the work on a flat table.
The next experiment is to array the lights to verify an even distribution across a horizontal surface.
One of the tricks in photography is the use of something called "hard" light. Hard light is an abbreviation for a small light source. This is used to accentuate crevices. It's how you make wood grain show up in a photograph. Conversely you would diffuse the light if you want to mask discrepancies. Diffused light is a bigger apparent light source, and consequently kills the shadows that create texture.
Those of you who haven't seen this effect should break out a flashlight and shine it on to something you have just sanded to perfection. Direct the light 90º onto the subject, then redirect it so that it rakes horizontally across the sanded product. You will be amazed at the difference apparent light size and orientation makes.
This trick should not only improve your photography but it will make sanding take less time because you only sand the parts that need to be sanded, rather than just sanding it all because you can't see the scratches.