How to draw radius line between 2 non-coplanar objects

[Anonymous]

I'd like to draw a radius line between these 2 objects.

[Alfred.NESWADBA]

Hi,

you'll need first to defined an UCS (>>>details<<<) so that the plane for the arc is defined. Then start command _ARC.

- alfred -

[Anonymous]

Thanks but I can't seem to wrap my head around the UCS part. I see from other folks that had the same problem to put a UCS at the center point but I'm not sure how to do that.

Happen to know of any tutorials or youtube video's explaining this in detail?

[beyoungjr]

Before I offer a UCS creation example I'll ask if you want the radius of your new object to be normal to the top plane (as viewed directly above the two objects in the Z axis)?  If that is what you want then I think you need a partial helix.  If you want a true radius defined from a new plane (UCS) then we will further go into the UCS creation.

Upload your file as.  If you need an example I will use your file so you are more familiar with the outcome/s.

Cheers

[parkr4st]

attached is a quick dwg.

the straight line is drawn with 3dpolyline command and has the two ends of the arc.

command ucs   select align z axis option and snap to the ends of the polyline,  that orients the z axis to the line

then  ucs option   rotate on the x and y axis one at a time to orient the xy plane where you want the arc and draw the arc.  see radialline_2

after you understand the routine there is no need to draw the 3dpoly line, just align the z axis to the desired endpoints of the arc and set the UCS xy plane as needed.

dave

[Anonymous]

Each point of the desired arc must be within a single plane.  A plane is defined by 3 points. You have 2 points already - the objects at the start and end of the arc.  A third or last point is needed before you can define the plane associated with the UCS and draw your arc.  Your third point will determine how the arc will route between the 2 objects.

Search for AutoCAD UCS, I am sure you will find plenty of examples - maybe not specific to your situation but along with looking up UCS, if you investigate arcs and circles, you can piece together everything you need. 

[Anonymous]

Here is the file. I guess I'm trying to create a compound curve here. I tried parks radialline files above but the top/plan view is a straight line, that should be curved like the elevation/front view unless I'm doing something wrong on my end.

[john.vellek]

Hi @Anonymous,

I am terrible with working on UCS issues because I just don't do enough of it but I thought I would give this a try. Is this what you are trying to create?

Please select the Accept as Solution button if my post solves your issue or answers your question.

[Anonymous · Accepted solution]

Generate an arc for a plan view and a different arc for an elevation view. Make a solid for each of the arcs such that you extrude them to get the intersection of both curves.  Explode the solids to meshes and explode the messes to leave the single entity common to both curves.

Note: Get rid of the perspective view before creating the arcs as it distorts the location of the end points.

Another way would be to create on arc as a surface and project the other arc onto that surface.

[beyoungjr]

Hi again,

In the drawing you provided you have a horizontal line and an arc.  You also had the drawing set as a perspective view so distortion of endpoints was obvious.  To set the view parallel you can just right-click the viewcube and select parallel.

Onward...

I could not predict what 2 points on the 3D solids you wanted to send the radius through so for simplicity I chose the center of each as the target through-points.  The 2 solids exist 58 units apart (top face of lower to bottom face of upper) in the z axis.

Rough Construction Object Process...

I created a line from the center of each target face, then I altered the Z end point of the lower in Properties, to equal the upper (z endpoint for both = 4 units).

I rotated the new line 90 degrees with copy option in rotate command.

I created a vertical line from the right endpoint at a -90 distance.

I mirror the vertical line about the rotated line and trim/extend as necessary to create a closed triangle.  The triangle reveals the true center point of a circle/arc which will be used for a 90 degree quadrant on one defining point.

I create an arc (or trimmed circle) using the lower intersection of the triangle and the radius at the quadrant, YELLOW ARCS.

I copy the circle in the z axis by 29 units and again to 58 units.

UCS Process...

I create a new triangle from the end of the 1st arc, through the mid-point of the 2nd arc, to the endpoint of the 3rd arc, then back to 1st point, RED TRIANGLE.

I create a new UCS using the mid of the 2nd arc as origin, the end of upper arc as X+ axis, and peak of triangle as Y+ axis, saved as "Red Triangle" UCS.

The new UCS orients the workspace so that you will create a 3-point circle in 3D, then trim the circle to the upper and lower 2D arcs from above.

Save the new UCS if you wish and return to WCS (World).

View the result from a top view and notice that the new arc disappears behind the 2D arcs but is a true arc in it's own UCS.

These processes will work for any two target points you wish to identify on the 3D solids, or with a line projecting from a solid.  This is why I did not define any angles or radii for my instructions.

I suppose I could have made a screencast and can if you prefer.  Revised dwg attached.

Cheers,

Blaine