Now that I have your attention - the “coal car” for a steam loco is also called a tender. A good friend made this loco for me and did an awesome job. It needs some body work and paint. I am making the tender for it.
This is my first go of printing the base for my Reading tender for my G-1sb project. It is completely utilitarian, printed at draft speed - a proof of concept print without any details yet. I had to print it vertically to get it to fit. It is by far the largest item I have printed so far. The rear beam is facing up FYI….
I don’t get why/how some supports just merged into the print instead of contacting with a touch point. All in all for the size I am pretty happy with the print. It has already proved its point and will be revised shortly.
The supports aren’t “merged” in to the print, per-se. But the overhangs you’re printing need supports and the overhangs can’t be reached from the base because of the angle of the print, so PreForm just grafts some supports right in to the object. I’ve seen it do this on a number of my objects, too. I usually try to reposition the print to prevent it from happening.
Looking at your object, the side depicted in the final photo doesn’t appear to have any overhangs, it’s perfectly flat. Tilt the print the other way, so the side with the overhang features (your first picture) is facing towards the base, not away. Then if you regenerate supports I think you’ll see they’re all on the “underside” and grow out of the base, and the top, perfectly flat side, won’t have any supports at all…
The support merging I am referencing is on in the last/bottom photo which is flat. I angled it slightly to get the most visible faces without supports. In this case the supports are going to be in the tender shell - which I don’t care about. Supports touching almost any other place will be in highly visible areas.