Is there a way to make a chamfer with one specified length and an angle. I often want to make a 15 degree chamfer for plain bearing seat entries. I would like to do this directly onto the 3D part, not in the sketch environmet.

There is a strong possibility that the next release of IronCAD with have the Chamfer ability you are looking for.

IronKevin

Good answer, 10 points for the Iron folks.

In the meantime. Here's an example for a 120 degree inclusive chamfer as applied to a hole. (30 degrees complementary)

You need two pieces of information.

X = (Chamfer diameter - Hole diameter)/2
(Or any value being the length of the desired chamfer)

and the formula

X*TAN(PI()/6)

Where 6 derives from 180/30 (Somehow converting Degrees to Radians)

If I understand your post correctly you would substitute 12 (for the value 6) in the above formula.
(180/15=12)

Depending on which way you want your chamfer to go you would plug the values in the chamfer dialogue boxes as follows:

If you want the chamfer applied on the diameter (This is how I normally use this) put the formula in the first box and use the X value in the second box.

If you want the depth of your chamfer to equal X with the angle applied towards the surface, use the X value in the first box.

It also seems to work backwards when applied to an edge. Once you get the correct values it is easy to switch them around in the boxes to get the chamfer that you want.

I hope this makes sense.