Triangulation tool in Autocad ?

[tdubya211]

I have a survey with tons of triangulations which I need to plot. I know how to plot them using circles etc, but is there any sort of tool within Autocad which will take two radii and mark the spot where they cross ?

[UMRVJX]

I Think some kind of Lisp you should need....

[eldon]

I have a survey with tons of triangulations which I need to plot. I know how to plot them using circles etc, but is there any sort of tool within Autocad which will take two radii and mark the spot where they cross ?

 

As this method of surveying is not used commonly, I would be surprised if anyone had written a lisp. But you might be lucky. Also with circles, there are usually two intersection points, so you need to decide which one is the one that you want.

[Dana W]

As this method of surveying is not used commonly, I would be surprised if anyone had written a lisp. But you might be lucky. Also with circles, there are usually two intersection points, so you need to decide which one is the one that you want.

 

The "two circles, or even three" method is the best one I have been able to find. Before cad, I used to do 'em with a drafting compass.

 

Usually, this is the kind of data you get from the field guys for a "House Location Survey" which is done way after the property markers are placed. The most refined surveying instruments used would be a 100' tape and a large screwdriver to hold the 0" end to the ground. Been there done that.

Location surveys are usually required by Mortgage Underwriters to be provided before the purchaser of the property goes to "Settlement". They are supposed to show whether or not any permanent changes were made on the property since the last survey.

Then, Title insurance can be issued if the drawing shows the garage on the correct side of the property line.

 

There are other reasons to do this sort of thing, mostly for back checking existing markers and structures.

[BIGAL]

You could do a lisp for this pick point1 dist1 pick point2 dist2 draw a point at intersection theres a vlisp function for curve intersection.

 

Will paste tomorrow at work else check vlisp help for curve-intersect, in general draw two arcs, find intersect pt, delete arcs, draw point. (search here curve-intersect)

[BIGAL]

This is the code for an intersection point given two objects

 

(setq intpt1 (vlax-invoke obj2 'intersectWith obj1 acExtendThisEntity))

 

Note two circles give two soloutions this may be a problem.

 

Probably better off now I think about it, using a triangle soloution 3 known sides have to find the survey book again

something like a/anga =b/angb = c/angc 1 soloution