On the attached PDF drawings, I was provided with the absolute minimum of information to draw them. When I attempt to draw these arcs using the "conventional" methods on the arc drawing menu, the arcs do not come out to the dimensions listed on the drawings.
Is it something I'm doing wrong or do the pdf files have wrong info?
An arc with a 54.5" radius and an arc length of 168" would subtend an angle of over 176 degrees. Nearly a half circle. The chord length of such curve is 9'0-15/16", as labelled. So it wouldn't look much like that picture at all. But the numbers are consistent.
Thank you. The picture was throwing my perspective off and making me doubt myself.
I just drew two circles one at 4-6.5" and offset that 5 " drew a line from center through any point on the arc. draw another circle from that intersection at 9'-0 15/16" .... trim accordingly..
I get an arc length of 13.96,
SO it appears you've got the common .04' of slop there!!!
That's still closer than I got using the chord length and radius technique. Ah well.
1. Draw a circle of R radius.
2. Switch to ortho mode, draw a line, snap to the center of your circle then drag your cursor up past the circle, click somewhere out in space.
3. Offset the line right and left 1/2 the chord length.
4. Trim command, pick your right and left line, enter, then pick the circle near the bottom.
5. Erase the vertical lines.
6. Offset the circle downwards the width given on the drawing.
This method is the easiest; it puts the rounding error in the arc length. They both check within 1/16" per my calculations.
The 14' arc has a 176.6 degree delta and the 14'0-5/16" arc has a 172.2 degree delta.
