Arc drawing

[FredGarvin]

Does anyone know of a way in 2002, or any version for that matter, to draw an arc using the radius and the arc length? The closes I have been able to find is using the center, end, distance method but the distance is the chord length, not the arc length.

Any suggestions?

 

[Bayou]

You can draw an arc using start point, center, angle. Use the radius and relative positioning for the center. Then the angle is just the arc length / radius.
The best is just to get a cogo plug-in.

 

[FredGarvin]

Yeah, I would go that way, but I am looking for a straight forward method for a machinist of mine. He is convinced that AutoCAD should be able to do this without any kind of extra calculations. I told him he'd have to or we'd have to come up with a lisp routine to do it the way he wants.

 

[CarlB]

Fred,

I wrote a lisp for something similar-you select a line or arcthat your new arc will connect to and be tangent to, then you specify radius, and either length or delta.

Email me at cab@eeiteam.com if interested.

Carl

 

[ohiocad]

As close as I've managed so far for something like this, is to draw an arc (whichever method is appropriate at the time, i.e. center point, or first, second, etc.) from a starting point, at the correct radius, to a given length, just guessing about where it would stop. From there, I select "lengthen" and "Total" and give it the number it needs to run. This modifies the actual arc length, not the chord dimension.

2 steps, not one, but it's as close as I could find. Hope it helps.

 

[tigrek]

Hi Fred,
Here is a Lisp I improvized just now. Hope it serves.


;to draw an arc by Center, Start and ArcLength
;

http://www.homescript.com

(defun C:ARCLen()
(setq pcenter (getpoint "Center? &quot)
(setq pstart (getpoint pcenter "Start point: &quot)
(setq Radius (distance pcenter pstart))
(princ "\nRadius &quot(princ Radius)(Princ "\n&quot
(setq Arclength (getreal &quot;arclength? <CW minus>&quot)
(setq angle1 (* 180
(/ Arclength Radius PI)
))
(princ &quot;\nAngle &quot(princ angle1)(Princ &quot;\n&quot
(command &quot;_arc&quot; pstart &quot;_CE&quot; pcenter &quot;_A&quot; angle1)
)

 

[FredGarvin]

Thanks for the help everyone. Much appreciated.