Another thing just came to mind: We were building an A/V store and I watched one of the cabinet guys (who also did framing; that should have been a big red flag!) was marking off shelf mounting heights.
He was using some kind of marker to note the shelf marking heights. The marker was twice as wide as the height tolerance. I got him a pencil.
We developed some car speaker boxes, about four feet wide by five feet high, with horizontal rails. To make them versatile, I had them install some steel rails with PEM nuts in them, installed in positions defined to within 0.005".
The first one didn't work too well. They said, quite correctly, that they couldn't put the rail supports exactly where I defined them to be. No problem! I went out there the next day with my new purchases: a three foot rule and a six foot rule, marked to 64ths of an inch on one side and hundredths of an inch on the other. That was about 200 bucks of ruler. They made them perfectly after that. Once they knew how serious I was, they stepped up. Those speaker displays were SO easy to use!
(By the way, I dropped a PM to tca the other day to ask him if he needed to know anything about voltage drop. That seems to be the one thing we're not talking about here. What a great forum!)
A good answer is easier with a clear question giving the make and model of everything. "The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
