Triangles on Surface wont cover the whole surface

hello i am trying to turn a curved surface into a series of triangles.  Ive got it working well, but it just wont go all the way to the edges.  reference the photos below.  Ive looked at several tutorials on how to triangulate a surface and they all seem to have this same problem but they dont address it.  its okay if the triangle is of a different proportion then the rest, i just want it close to the surface edge and not just stop and leave a gap.  it seems to work on the top and bottom, but not on the the right and left sides.

also for some reason on one of the sides of the object the pattern switches orientation so instead of not reaching the edges on the right and left they dont meet the edges on the top and bottom.

Ive attached the model and the GH def.

thanks,

Andrew