Concave arc in part editor

[Travis Wiescamp]

I'm having trouble cutting a concave arc in a display cube. I know start stop points and the radius but I'm not sure how to use those to make the cut I need. The fillet tool uses the info I have but it only makes convex cuts if I'm not mistaken.

In the attached pic I'm trying to make the "horn" pieces on either side of the keystone.

The cube is 10-1/4" x 27-1/8" and the radius I need is 38-3/8". I need the arc to start at one corner and cut off 6-1/4" off the other short side so it leaves 4". I hope that makes sense with the pic.

It this possible or do I need to calculate a mid point and use the arc tool?

Thanks,

Travis Wiescamp

[Leo Graywacz]

You need to do this in the contour area in the part editor. Use the trim function to connect the arc to the line on the side you wish to cut. The go in to the main area and right click and choose cut pocket using closed contour. Click on the closed contour and it will turn green, then on the bottom a NEXT box will appear. Click it, and then check the cut through box and hit OK, then yes on the next pop up box and the area should disappear.

[DanEpps]

You can take Leo's approach a step further and create the whole part as one piece.

Take your cube to the contour area and draw out the pattern for both sides. Then go back to the edge profile area. Choose (or create) a flat-bottom tool and "route" the lines you drew earlier.

[DanEpps]

To get a better idea of what I described, look at this video.

I have some other videos on the site that might help also.

[Leo Graywacz]

You had an unnecessary step in there Dan. There is no need to extend the lines before you use the 2 point chamfer.

[Travis Wiescamp]

Hey,

Thanks for the responses but the part I'm having trouble with is drawing the concave arc using just the known radius and 2 fixed intersecting points.

The "fillet tool" requires the radius and 2 intersecting points, which is exactly what I have, but from what I can tell it only will cut a convex radus. So how would you go about drawing the arc to start with?

Thanks for the help.

Travis

[Gary Puckett]

Travis,

Here is a DXF file take it and place it over your display cube and then cut the part.

Gary

[Kerry Fullington]

Travis,

In the part editor you can't create an arc with just two points and the radius. You will need to calculate the radius chord length and the rise of the arc and use three points.

[Gary Puckett]

Travis,

Is this what you need?

Gary

[Travis Wiescamp]

Gary,

Thanks for the help. Yes that is what I needed but Kerry answered the main question. It just seemed like if the fillet tool could do what I needed there might be a way to do the same for a concave cut but I guess not.

Thanks