Split in exactly half

 From:  BurrMan
1856.1 
I'm having a problem with this model. When I try to Boolean diff to get 2 halves it fails. If I Stepnudge it up a factor of .001 I cut it but with various flaws on the edges and not an equal cut.

Could be the way I made it causing issues.

I swept the polygon halves with the 2 rails and scaled it with the top one.

Then I swept the arc with the cirlce. (Scaled it up in z to meet the first part)

I mirrored both parts and joined them to get solids.

I trimmed the polygon odject with the torus, got rid of the artifacts then boolean union the 2 parts.

Ran join to creat a solid.

{Here's the catch}

Boolean diff the part with a line through the center fails unless I offset either a slight amount.

Is my construction method the culprit or is there another way I should try and cut this.

As I'm posting I figure the joining process is odd. I will re-attempt this by shortening the neck so it doesnt protrude so an initial boolean union should be enough. I will then try to diff with a line. (maybe answered my own question.

Any input is appreciated.

Yhanks,
Burr

[EDIT] I redid the creation by just shortening the neck and then I could just boolean union/join without all the trim first. It cut but when I zoom in it is still not centered (one half has a step) the short half is a nice result. Should I expect to be able to get equal halves with this process?[EDIT]

EDITED: 26 Aug 2011 by BURRMAN