Fillit / Tan Tan Radius on outside of line

Hi,

i have an drawing issue that is recurring in almost every drawing i make.

Sometimes i go from an ARC (R=200) to an straight line and the ARC overshoots the STRAIGHT line, so i want to make an extra curve to make a smooth transition.

So then i use FILLIT to make an ARC R=50 between the R=200 and straight line.

Usually this works fine, and if not it probable will work with 'tan tan radius' (Circle > T).

However sometimes fillit doesn't work and then i use TAN TAN RADIUS and start with a small radius to see the margin. Then when i try to use an bigger radius, that should work, the circle ends up on the outside of de R=200 and the straight line.

When i copy the lines to a new drawing it seems to work just fine, but in the original drawing it messes things up.

Example in the image below

Red line is R=200 and the horizontal line is the straight part. The yellow circle is R=50 and the green is R=100. It should work (in a new drawing) but not in this image.

Why?

Can you attach a drawing of the 2 lines and the 200' arc. In the image the lines appear tangent not sure how "the ARC overshoots the STRAIGHT line". Fillet should work, do you need the circles drawn as well? Just not sure what you're trying to do.

Maybe this helps:

The yellow arc is made by FILLIT and the green circle is made with TAN TAN RADIUS (Circle > T)

Both have an radius of R=50 but the circle ends on the outside of the line.

The overshooting part is the dotted blue line.

An example is easily made self.

I'd skip using the Arc command and just fillet the two lines specifying the desired radius.

Well duh

But why does it do this? It should work right in both ways, but it doesn't...

Maybe this helps:

[ATTACH=CONFIG]55224[/ATTACH]

 

The yellow arc is made by FILLIT and the green circle is made with TAN TAN RADIUS (Circle > T)

 

Both have an radius of R=50 but the circle ends on the outside of the line.

 

The overshooting part is the dotted blue line.

 

An example is easily made self.

The "dotted blue line" appears to be an extension of the 200' radius. It should veer away from the 50' radius arc. Still don't understand what the problem is.

Well duh

 

But why does it do this? It should work right in both ways, but it doesn't...

I suppose that would be determined by what version of the Arc command you are using and how you are specifying the points AutoCAD is asking for.

Give us a before and after drawing showing what you started with and what you want to end up with and we can show you several simple ways to do it. Should be easy with either arc or fillet, though fillet is usually less steps.

The fillet command from year dot often does not give the answer you expect, hence tan tan rad often is the only way, with some circle intercepts using a fillet approach there are up to 4 solutions, some other civil software we have asks if solution is correct or will go through all possibilities for you to accept, hence works every time.

Often I deal with polylines with a lot of segments representing irregular curves. To fillet two of them it's hard to tell which segments to use. I'll offset both of them radius distance, then draw lines from where they intersect to the best looking perpendicular to each polyline and draw an arc between them. After I use the same lines to trim the 2 polylines before joining them with the arc.

Fillet was introduced as an update to r12 AutoCAD and had been improved a lot since then. Most recently support was added to close a polyline using fillet. So many different situations make it impossible for software to know what you want it to do in every situation. A certain amount of user knowledge and input will always be required. The knowledge can be obtained from online forums if you can post what you are trying to accomplish instead of asking us to make a procedure work that you already know doesn't work.