View Single Post
Old 11-16-2012, 07:49 AM
AGLA AGLA is offline
LawnSite Bronze Member
Join Date: Mar 2002
Location: Cape Cod
Posts: 1,718
I thought of this thread when I was out on a site that did not lend itself well to easy measurements in terms of orientation to the house or any other well anchored points to measure from, yesterday.
Last year I bought a "double right angle prism". This allows me to measure off of a line and know that I'm accurately doing so at a right angle. It costs about $100 and is a little bigger than a film container with a 2" handle on the bottom of it. On one side there is a window that you look in. The top of the window looks 90 degrees to your right, the middle looks straight ahead, and the bottom looks 90 to the left. Using this and a laser distance meter is a wonderful thing.

I was at an odd flag shaped lot with no bounds, a curved driveway and a house at an odd angle to the circular cul-de-sac with 30 trees, two light posts and a driveway to put on my plan - all of it more than 50' away from the front of the garage and offset to the right of the garage and house as you look at it ... with some topography going on. The road is 150' from the face of the garage.

I hang my laser around my neck with a lanyard (that came in a bag of promo stuff at a trade show), carry my clip board with graph paper and prism , and mechanical pencil in my teeth. I lined up with the end of the garage, looked at it in the middle windo of the prism, walked backwards until I saw the first tree in the top window - when the tree lines up with the end of the garage in the prism widow, Iknow I am at the 90 degree angle point, I shoot the beam at the garage for my x coordinate and shoot the tree for my y coordinate ... step backwards and repeat for every tree.

I simply plot them out by extending the lines of the face and side of the garage and using the offset and fillet commands with the appropriate distances and copy a dot and annotation to each.

I overlayed a google earth image as a check. The tree shadows indicate a pretty good measurement ... maybe 45 minutes in the field. I got distances in excess of 150' (low light conditions) with my Bosch DLR 165 laser (~$150).
Attached Images
Reply With Quote
Page generated in 0.03921 seconds with 9 queries