I see that people are mostly posting finished products to the 3D printing forum, but this will be more of a work in progress. It actually started a good while back now when I got my first 3D printer, and was recently revived on receiving my new Anycubic Mono X printer. So what is it? (picture links to http://vanderheide.ca/blog/tag/mwcx/ - the best picture of this type of gondola I could find!) I see these on the rails close to home in Montreal, and while the one above is used to carry copper concentrate, I believe they are also used to carry zinc concentrate to the refinery in Salaberry-de-Valleyfield, (near Montreal). So yes, when I first bought a 3D printer, I used Tinkercad and printed a simple model... It's okay, but has several problems... The edge of the fiberglass cover never printed quite right (it is removable), and while I didn't print flat, the gondola still has a nasty layer line at the floor level (visible as a lighter line running across the bottom of the car). So fast forward to now, and I do want to step up my 3D printing quality and get a better print! I've since learned how to use Fusion 360, so I've redrawn and upgraded my old model... So now, that's my starting point! On the original model I used some micro-train trucks with 33" plastic wheels - it was the only roller bearing trucks I could find at the time, and honestly, I didn't know much about 33" vs 36" wheels. Not that I know that much more now! I want about nine or ten of these railcars for my layout since I'm planning to add a Zinc mine to it. But sometime ago, I bought a dozen intermountain CN coal-porters. I've got no interest in them anymore, so they all sit in their jewel cases unused (and one set is still shrink wrapped). Well, they have micro-train compatible trucks with 36" metal wheels, so perfect. I'm going to borrow those. Okay, so far I've run two prints on my new model. But I'm having a bit of a problem. The first time around I made the walls too thin, which warped. I also printed in two parts, the floor and the walls which were then glued together. I figured this would prevent the suction issues I had on my Tinkercad model. Okay, the model was a failure, but it was a necessary experiment. The trucks didn't fit well (wheels rubbed on the underside, not enough clearance for the coupler, etc). I corrected the problems, and launched a second print. This time in one piece, and oriented exactly 45 degrees to the build plate. Much better print! But again, more problems. First, is this curious deformation, looking at the end of the car, we see a curvature... So either the ends lifted, or the middle drooped. I'm not quite sure what happened there. We can see some of this same deformation from the side... See that the upper lip curves downwards right at the end? This was the end closest to the build plate. Honestly, in all my time printing with either printer, I've found this to be a problem with printing long rectangular shapes at an angle, and I have yet to really find how to correct this. Of course, predictably, the other end got a divot due to suction. I had a feeling this would happen, but I went with it to see what would happen and how bad it would look. So again, not a successful print, but I learned some more! First, this time the trucks fit better. I had a locomotive pull this car around the layout mostly successfully. It still needs a bit more clearance to let the trucks pivot a tiny bit more - on a particularly nasty curve, it did derail once, though the car is very very lightweight right now. So that's it for now. I hope to continue showing my progress, and showing what works, what doesn't, warts and all. We see a lot of amazing stuff from others (you know, the gods of 3D printing), and I always wonder about the journey to that final model, how they oriented the model, how some problems were resolved, etc. So this is going to be a sort of build log from a mere mortal of modelling Oh, and yes, the print is dirty with "white" residue, should be much deeper black. This is my first time using a new water-washable resin, and the first time post-curing the print in water. Yeah, so I did a poor job of cleaning off the resin. Next time I think I'll add a few drops of dish detergent to help clean the print. Hope you enjoy!