Line of a certain length between two concentric circles

[Anonymous]

I have two concentric circles with the larger having a radius of 155" and the smaller being offset 12" to a radius of 143".

I need to draw a line along the x-axis that is exactly 16" long that touches both circles at its end points. How can I accomplish this? I've had no luck with web searches, unfortunately.

I'm using AutoCAD OEM 2020 so LISP routines are not available.

Thanks.

[imadHabash]

can you show us an image for your need please ?

[Anonymous]

I am trying to match the architect's 1'-4" measurement. The given measurements for the surrounding walls are incomplete and of no help with trying to figure this out.

 

[imadHabash]

sorry ... still not recognize your issue ? 

[Anonymous]

More than just applying to this particular situation, I'm curious if this is even possible. I can't find a way to even move the line along the path of the arc/circle while still maintaining its orientation along the x-axis.

[Anonymous · Accepted solution]

Draw a circle with a 155" radius.

Offset the circle to the inside 12 to get the 143" radius circle.

Pick any point on the larger circle and draw a circle with a 16" radius.

Draw a line between the center of the 16" radius circle to the point where it crosses the 143" radius circle.

This gives you the 16" line but it will NOT be aligned to the X axis.

Draw a line along the X axis and using the ALIGN command, align the 16" line (along with all of the circles) to the horizontal line. 

Move everything over to match up with the wall corner. 

The result is the location of the center point of the circles from which you can set the endpoint of the wall running up the page.

[leeminardi · Accepted solution]

Make a copy of the 155 circle 16" to the right.  Where the copy (the red circle) intersects the 143 circle is the right end of the 1' 4" line.

[pendean]

You don't have enough dimensions to draw much of anything in that image: ask the architect how he fudged it, ask for the actual DWG file to see what exactly they did?

XREF that PDF or IMAGE or whatever it is you have then just trace over it for now until you and your architect work out the details.

[Kent1Cooper · Accepted solution]

Copy the inner Circle [or Arc -- yellow in image] to the left 16" [blue result], and from where that intersects the outer Circle [or Arc -- red], draw a Line orthogonally to the right [green], first taking it past the inner curve, then grip-editing its right end back to the green-yellow intersection.

[Great minds think alike -- more than one basically-the-same solution posted within minutes of each other!]

[Anonymous]

@pendean I just need to get as close as possible for now. The hashed wall is the existing drywall (no dimensions given) while the wall on the far right will be a new drywall (given dimensions are irrelevant). The architect has given the dimension between the two, but drawings and reality... We'll field verify before creating the final millwork wall, of course, but that 16" dimension is probably going to remain the same regardless.

[pendean]

>>>...I just need to get as close as possible for now....<<<
@Anonymous XREF in that PDF or IMAGE or whatever it is you have then just trace over it.