simplify3d setup or bug ?

What exactly are you asking?

Simplify3d will render what it actually sees in the stl. You need to run that model through a repair service such as netfabb.

When you make designs, you cant take part A and part B and just put them next to each other and call that a solid piece. You actually need one of the parts to be slightly inside the other.

The better slicers such as the one in Simplify3d will see the two parts as individual parts and not merged.

Actually, the parts need to be merged into one piece - not just set next to each other, or even slightly overlapping each other.
Merging makes multiple parts into one part.

using the correct terminology can make a big difference.

just overlapping parts does not make them "one part". The OP would still have the same issue - the slicer would still "see" 2 separate parts and slice accordingly.

Properly merging the parts will make them into one part that the slicer will slice as one part.

Not properly merging parts is frequently the cause of models not being manifold as well.

yeah, I guess it would. I don't use "online" software for modeling - it isn't convenient for me.
in fact, I was going to try fusion 360, until i found out it was cloud based - big nope.

If it was a stand alone, fully downloadable program, it would be different - looks like it has some features that I would like - but when you live in the boonies like we do, you don't have access to cable internet. We have the best option available to us out here, but it isn't good enough for running cloud based stuff like that. even a minor glitch (which happens often) in the service could cause some big problems..

I will stick with my stand alone programs - even if they are free. 123D Design works quite well for 99.9% of my needs. Blender is another I have, as well as Sculptris (fun to play with, haven't tried printing anything out of it yet tho). I also have Sketchup, but don't really care for it.

The only "paid" program I have is AC3D, and it was less than $100 - it allows me to modify any existing stl file, as well as create new models - but a bit more complicated to use.

The thing these programs all have in common is a "merge" function to make multiple parts into one part. So, yeah - i guess software choice does make a difference.

I tried using Simplified3D for first time today
and it was sending data to printer but had a problem,
before it started printing, so could not check print quality.

When I change Temp setting of extruder it Always set Temp to 230C, at printer.
I tried lowering it several times, at different temps, but always went back to 230

It's definitely saving the changes in process settings
but not getting to printer, when print is started ???

Anyone know Why ???

Note: it looks like it is using the correct G-code (script) command
for Extruder-temp (M104 S190 T0), which should be 190C, not 230