Create line tangent to circle with angle constraint?


#1

Hi,

I am looking to create a line tangent to an arc with an angle constraint. I can't seem to find a method of doing this without creating construction lines first.  

I envision it going something like this.
  1. enter command Line
  2. select Tangent option
  3. select curve for line to be tangent to
  4. enter Angle constraint in degrees
  5. Enter line length

I know there are other ways to accomplish this, but I am looking for a way to do this with 1 simple command and without having to create construction lines first.

Thanks,


(Pascal Golay) #2

Hi Brandon- so you want the line to be a certain angle off tangent, or you want it tangent to the arc but sitting at a point that is at a specific angle along the arc?

-Pascal


#3

I am looking to specify an angle, lets say 45° , then create a line tangent to the arc at 45° with a given length.

Here is a screenshot of how i usually do it in AutoCad

I enter the line command, then I select tangent and then pick the arc. That is the first point. The second point is specified with “@5<45” and it draws the line.


(Pascal Golay) #4

Hmm- yeah… the @5"<"45 format does something but not the right thing - dangerously close to the right thing in some cases though, it seems to me… Right off hand, I do not see a way to do this all in one operation in Rhino.

-Pascal


#5

My comment was cut off. It was @5 “less than symbol” 45. I think the less than symbol cut the end off?


(Pascal Golay) #6

Mine too- apparently discourse does not like that character- I edited mine to put that in “” so it shows the whole message now…

-Pascal


#7

Yes it does something close, but I cant seem to figure out a rhyme or reason why it does what it does? A couple times it ended up perfect for me, but most of the time its a little off or way off.