Unusual scaffolding & item in print preview

I'm getting unusual scaffolding & item in print preview, please see "Hot_print model.jpg" and "Hot_print preview.jpg".

I originally printed it with the flat base sitting on the printer's bedplate, but naturally there was lots of scaffolding due the overhanging sections, which took ages to remove & left a lot of witness marks, which reduced the aesthetic effect of the 3d logo.

So I flipped it 90 degrees, so I'd only get the scaffolding witness marks on the back of the logo, but I got the unusual print preview (of scaffolding & item) attached, and subsequently didn't proceed to print.

Could it be a CAD model error_? (I created it in 3ds-max, using unioned booleon solid objects, see "HOT.stl" attached).

Any ideas why I got this in my print preview please_?

It looks like your model have errors in mesh. Please fix the mesh of the model and try to prepere it again. Increasing .stl accuracy (more polygons) will also be helpful because geometry of the model will be visible on print.

I also suggests changing the orientation of the model, you should place the model on "flat" 

I will certainly look at improving the CAD model, thanks.

Currently I use 3ds max & Rhino, but just downloaded OpenSCAD. Do you know which is best for this kind of model improvement_?

Is there a good CAD model "repair" s/w or online service_? (that's cheap/free)

I'm aware of Nettfab & Emendo.

I also suggests changing the orientation of the model, you should place the model on "flat" 

I originally printed it with the flat base sitting on the printer's bedplate, but naturally there was lots of scaffolding due the overhanging sections, which took ages to remove & left a lot of witness marks, which reduced the aesthetic effect of the 3d logo.

I originally printed it with the flat base sitting on the printer's bedplate, but naturally there was lots of scaffolding due the overhanging sections, which took ages to remove & left a lot of witness marks, which reduced the aesthetic effect of the 3d logo.

.....if I can't improve/repair the CAD model, I'll just stretch & twist it in 3ds max so all the "overhangs" exceed 20 (or 30)  degrees and print without scaffolding/support or only have it less than 20 (or 30) degrees.

@csjp88 - You can easy remove the white spots, check this topic: http://forum.zortrax.com/index.php?/topic/803-how-remove-white-spots/?hl=%2Bwhite+%2Bspots

My personal favorite for doing anything with STLs (including repairing) is meshmixer.

Meshmixer is highly recommended by me too.  Use it for all my SLA prints and with adjustments the custom supports are great too.  Haven't tried printing custom supports yet  but will soon and post results of with Zortrax auto support vs. Meshmixer autosupport (Default settings in MM I find always need to be adjusted) so its really custom support settings.

@csjp88 - You can easy remove the white spots, check this topic: http://forum.zortrax.com/index.php?/topic/803-how-remove-white-spots/?hl=%2Bwhite+%2Bspots

thanks, I will try this :)

Meshmixer is highly recommended by me too.  Use it for all my SLA prints and with adjustments the custom supports are great too.  Haven't tried printing custom supports yet  but will soon and post results of with Zortrax auto support vs. Meshmixer autosupport (Default settings in MM I find always need to be adjusted) so its really custom support settings.

Thanks, I will certainly try Meshmixer, before think of paying for another s/w :)