Fillet problem

Ok I feel dumb for posting this but I can't figure it out. I have a line and an arc which are offset to each other. How do I fillet between the arc and the line. Every time I try to do it, it doesn't give the solution I want. I have attached a file which will show you what I mean. I want to fillet between the horizontal white line and white arc with a unit size of 6 so that the result is as shown by the red arc.

File1.dwg

The red arc has a radius of less than 6.

The red arc has a radius of less than 6.

I draw the red arc by eye just to show what I'm trying to achieve.

The simple answer is that there is not enough room to draw the arc of radius 6 between your arc and the line, and so the fillet command will make a tangential arc at the other side of the arc produced.

I think you have some funky geometry and that it (the compound curve) won't work the way you want it to.

The red arc has a different center than the white one, which seems to be a bit problematic. If you do get it to fillet it won't look like the red arc as drawn, which has a radius of 4.615, or if it does, it won't be in the same place, more like the blue one.

It will work this way though. The angles are 45 deg.

@Remark - You solution works except that you have to move the centre of the smaller arc relative to the horizontal line.

However I have worked out a way of doing it by drawing a circle using tan,tan,radius and then trimming it up. Long winded but it works.

Thanks to everyone for there help.

Given the positions of your initial entities, I would be intrigued to see how you have managed it. Perhaps you could post a dwg file to demonstrate the final positions of the arcs and lines.

My solution works without fudging it.

My solution works without fudging it.

When I draw it using your method the vertical distance from the horizontal line to the centre of the arc is 3.879 where as my original drawing has the distance as 3.600. What you drew was geometrically correct but doesn't work when the distance is pre specified.

@eldon. I have attached a file with the circle drawn before trimming. Using the circle command type in _ttr, select the arc and the horizontal line then type in the radius 6.

File2.dwg

Geometrically correct. That's what one would strive for in constructing a compound curve since they would share one common tangent. My background is civil engineering and this is how a compound curve was laid out in the field when staking out the centerline of a road.

@eldon. I have attached a file with the circle drawn before trimming. Using the circle command type in _ttr, select the arc and the horizontal line then type in the radius 6.

Thank you very much for being so patient. I was still trying to get the Fillet to work (unsuccessfully). As you so rightly say, Circle TTR is the answer. Well done on solving your own problem.

Geometrically correct. That's what one would strive for in constructing a compound curve since they would share one common tangent. My background is civil engineering and this is how a compound curve was laid out in the field when staking out the centerline of a road.

The only point I was trying to make was my solution is also geometrically correct but doesn't rely on moving the arc in it's relationship to the horizontal line.