Property lines via bearings

[Curtis Johnson]

I agree with Bill ... if you have good information from the survey, it is quite easy to re-do the survey, including curved lines with Chief's tools.

[billemery]

I draw each segment independently in Chief, and then join them with the Point to point tool, much like Spencer does in Revit.
I find it much simpler and more controllable this way.
If the survey is correct everything snaps together for a closed polyline

[sutcac]

That actually does sound simpler, and lo and behold only 45 words to explain it. ;-)

[amddrafting]

Geez, forget I even tried...

I like to be clear and concise when I explain my step by steps. Sorry if it is a burden to read. I honestly have been using this method since version 9.0 so I didn't realize that there was an input line option, or have but never put 2 and 2 together.... it was the way I was taught and have found it more accurate than manipulating lines (which I have done before with varied results).

[Ben Palmer]

If i am given this information for a curve, how do I input it into Chief using the New Arc input tool?
Length: 112.59'
Radius: 531.50'
Chord: 112.59'
Tangent: 56.51'
Delta: 12degrees 08minutes 14seconds

See attached pic...North is up. (the above info is for C83)

[Nicinus]

If you know length and radius, you can figure the delta of arc. Draw one arc. You know second arc is tangent to first arc, draw second arc, now do third arc tangent to second.

Draw line connecting the two end points of arcs. This line will be parallel to line that connects two end points of straight lines. Rotate and then connect.

With info you have here, you should get perfect results .

I've played with this a number of different ways according to the suggestions in this thread in order to educate myself, and from what I can tell (or understand) this is the solution that seems to work best for me. I'd just like to go through the steps so that I'm not doing anything stupid, as the process to me is a bit cumbersome.

1) In this case I have length and radius (which seems to be typical for plats I end up with) so I create a point and use New Cad Arc

2) Taking care to enter clockwise or not, I enter the next arc which will automatically be in tangent

3) After all arcs are entered, I create a closed loop with a line, and do the same on my plot

4) I rotate the arc polyline segment by making the line parallel to the plot line I just drew

5) I use point to Point to Point Move to place it on the plot and delete the two temporary lines

Although this certainly seems to work with the precision needed, but unless I'm missing something it sure seems as entering it into a table for Chief to generate, á la Revit, would be much desired.

[Nicinus]

As a side note, in Revit it is very easy to switch your plan between True North and Plan North, something I personally find invaluable when designing. Even if you know north is down the left corner or somewhere, it makes a big difference seeing it level when you are considering sun for windows our outdoor areas, etc.

[Glenn Woodward]

Ben,

How come the arc length and the chord length are both the same?
Shouldn't the cord length be less than the arc length?

[Nicinus]

If i am given this information for a curve, how do I input it into Chief using the New Arc input tool?
Length: 112.59'
Radius: 531.50'
Chord: 112.59'
Tangent: 56.51'
Delta: 12degrees 08minutes 14seconds

See attached pic...North is up. (the above info is for C83)

I think you gave the wrong info on either chord or length but based on what I've learned so far, since you have chord length I would probably enter the curve segment as a line to create the closed polyline and then convert that segment to a curve by entering the data in the dialog and locking chord?

[Ben Palmer]

I noticed those two were the same as well...double checked it, and that is what is given...however, assuming the length is correct, i don't think we really need the chord length info anyway?...the angle, length & radius are the relevant info right?

So what angle do enter in? 12degrees 08minutes 14seconds?? I assume I need to adjust this angle somehow? Is this the starting direction? ...the chord direction? something else?

Thanks for your help.

[spencerdesign]

12degrees 08minutes 14seconds

Hi Ben,

I believe this would be the bearing of the chord.

[Nicinus]

It's a large radius so it makes sense the length and chord are similar, but they shouldn't be identical. Either way, if you create the straight lines you can take a measure on the remaining gap and see if it's the same as the chord. If it is, place a line and then convert to curve with the radius given.

[Ben Palmer]

... if you create the straight lines you can take a measure on the remaining gap and see if it's the same as the chord. If it is, place a line and then convert to curve with the radius given.

Yeah, that is what i've been doing, but what angle do i use (see more below). It would be nice to just input the information of the new curve like I do for the lines and be done...isn't that what we should be able to do?

I believe this would be the bearing of the chord..

That is my thinking...but that angle doesn't compute...Chief wants to send it in the wrong direction...so i figure I need to convert it somehow...i did the lot starting at the SW corner...so when I'm ready to input the arc, i'm coming from the SE corner...that angle will want to go to the NE...vs to the NW...so I'm thinking i need to subtract that angle from 180 since 180 is in the -Y direction in Chief. Even if I started in the opposite direction it would need to be negative 12 degrees...right?


Thanks again for everyone's input.

[sutcac]

I just did one and found it easier to just input the bearing of the chord as a line, then click to convert to an arc and then just set the radius. Worked perfectly showing the correct radius. Still think the whole approach is unnecessarily complicated.

[Doug Park]

Every once in awhile I like to try one of these just to see how easy it is:

This is what I got.

Assumptions, top line is at perfectly horizontal. Radius as given was correct.

I started at the lower left and worked around clockwise.

For the arc I simply closed it with a line converted the segment to an arc and then typed in the radius.

I added the scaled version of the image as a sanity check. The computed acreage appears to confirm that the entered data is correct.

The result seems to indicate that the arc length given is not accurate.