DIY VASI
I'd like to make a small VASi, or something similar. To explain the background, I am doing some extensions using a small excavator. I have to scrape off about 500mm soil over a largish area of the site. I'm not really an ace digger driver, and I tend to drift up or down over large areas. Therefore I was trying to invent some simple device to help me keep level. Big excavators have all sorts of fancy laser levels, probably cost more than a small digger, but I just wand something simple.
I was thinking along the lines of a small version of a VASI at a suitable height, with the "glide slope" set horizontal, and a mirror or lens on the digger "dipper" - i.e. the arm with the bucket on the end, so that when the dipper is vertical, and the bucket sitting on the bottom of the excavated ground, I would get the "on the glide slope" lights to help me keep level, with appropriate lights for too deep (below glide slope) or too shallow (above).
So - anybody know how to make a VASI out of bits and pieces from my "come in handy" box? I have access to plenty of LEDs, but no fancy fresnel lenses or such like. Something about the size of a brick would be about right, that I could mount on my site level tripod.
Cheers
UFO