I can not attach anything to the middle of a conic arc in sketcher. I can attach entities to the ends but not anywhere along is length. I can trim an entity to a conic, but the result is a floating end with dimensions. Points will not attach to the length of a conic either.
Re: Can not attach entity to conic arc in sketcher
Splines also exhibit this in sketch mode. If you need to place something along the length of these constructs you will have to use at least one more feature (datum point etc.). You can of course split up the constructs in sketcher to make use of endpoints in some cases.
I don't think it is a bug but it is worth asking PTC to explain the behavior.