Print a splitted big model

Splitted a big model using NetFabb Basic (just plane split) 3d-Coat (plane+join).

Troubles are coming from the printing part: the plane on the bed (normally the cut plane, since it's an organig model with no actual planes) always create problems in detaching (brakes or deformation) or with support residuals (no way to eliminate them completelly), so that the re-joining of the different parts is coming out with bad appearance.

There is any trick in putting the model on the bed, or to detach it? Better to don't put a big plane on the bed and use just support to position it?

Using PLA layer, 210° nozzle 50° bed, bed prepared with spray. Printer an FFF prototype not yet on the market, 350x350x300 printing area max xy speed 500 mm/s normal 80, slicer Simplify3D, controller Reptier.

https://drive.google.com/open?id=0Bx...lBRYUpMbTQ1VVk
https://drive.google.com/open?id=0Bx...jdsOTNlSFlldk0
https://drive.google.com/open?id=0Bx...1VFYURrX0RsWnM
https://drive.google.com/open?id=0Bx...kFaWlFLRHE5MHc
https://drive.google.com/open?id=0Bx...2NPbGVkUUNjVkk
https://drive.google.com/open?id=0Bx...UM0TmVpNUJiWVU

Btw really weird it's not explained we are not allowed to post images anymore.

well the first thing you need to do is stop using rafts. That'll mess up the layer on the bed straight away and is totally unnecessary with pla.

If I were you I'd use pva glue stick on the bed, have the bed at 60c, not 50 and maybe up the extruder temp to 215.

what speed and layer height are you using ?

Layer 0.15mm, 0.4 nozzle, speed as written normal 80mm/s, xy 500 mm/s, z 16.7 mm/s, others (infill etc) 50-80% underspeed.
Not using standard PLA but PLA Layer from this company.