Hi sharky, can you please post the 3DM model file of your current progress?

That will make it easier to make some recommendations for you, it's otherwise hard to figure out some of the specific things that you're asking about - like the part about blending near the axle.

For the sharp crease in the middle - it looks like that may be formed by a kind of asymmetrical shape of the basin. Maybe try something like draw an outline like this - note that this outline is not fully symmetrical - one side has been squished to be flat:



I made that curve by drawing one half of it to start with, then mirroring it to get a symmetrical shape, then use Edit > Join to glue it together into a single curve object, then do some control point editing of the one side to squish the points to be flat just in that spot.


Then to surface something like that you can draw in a profile shape that comes downward hanging off of it like this:



Then select that hanging profile and use Construct > Revolve > Rail revolve
(http://moi3d.com/2.0/docs/moi_command_reference7.htm#railrevolve)

Rail revolve is pretty useful for creating rounded type shapes that are not necessarily totally symmetrical because the resolve conforms to the path curve shape instead of just being exactly circular like a regular revolve.

That will then make shape like this:



And then when you mirror along the flat area you will get pieces like this:




Symmetrical shapes won't meet up in that same kind of equal height ridge in the middle.

If you've been having problems with the ridge being too low, that probably means you've been using symmetrical shapes for the basin when it looks like it needs to be somewhat asymmetrical as above, at least that's my guess...

- Michael