O-27 Re-railer - Marx Friendly

thingiverse

When I laid eyes on wolverineboat's O27 re-railer, I knew I would be building one - or more than just one, in fact. However, as soon as I got started, I realized I would need to put some work into it. I collect, repair, and operate Marx trains, both O scale and 3/16ths, and I could see that Marx wheel sets wouldn't be able to pass through easily. After two weeks of tinkering and tweaking, 11 test prints, and a little bit of cussing, I think I've successfully designed a Marx friendly O27 re-railer. Marx O and 3/16ths wheels will pass through without any difficulty, and perhaps just as importantly, it will re-rail trucks - at slower speeds, too fast and you'd likely get air. Not only have I tested the O and S scale cars, but I've also moved my 1998 diesel, my 999, 666, and 333 through it without any problems. I'll definitely be printing more of these and incorporating them into my layout. Print Settings Printer: M3D Micro Rafts: Yes Supports: Yes Resolution: 250 microns Infill: Medium Notes: I've printed this in both M3D's PLA and ABS-R, and the results are acceptable in each case. Although I prefer PLA, both the raft and support are discretionary. I use the support material to make the channels on the underside clean and the raft for the support material to stand on. However, I turn off my printer's model on model support as it will fill in those channels. Post-Printing I printed a number of test renditions while designing this thing and encountered some pronounced warping of the piece. However, I was able to include a few design ideas into it to counteract that. I also had difficulty removing the raft. It's unclear whether my printer needs fine tuning or if it's the amount of model in contact with the raft or if it's the ABS-R filament I'm using on the last few prints as I've run out of PLA. In any case, a little elbow grease and some sandpaper are enough to solve that problem. How I Designed This Of course, wolverineboat did the heavy lifting here by figuring out the measurements and shape of the re-railer. Taking those same measurements, I started from the bottom up, making my re-railer much lower on the outside to admit Marx wheel sets. Initial test prints showed that solid construction was prone to very noticeable warping, particularly on the long edge. Numerous Google searches and several YouTube videos later, I incorporated several channels on the underside and some small hollow tubes running through the body of the piece. The idea is that these small interruptions all along the long side would reduce the length of the lines extruded and therefore reduce overall warp. It seems to have worked - my last few test prints show little to no warping. I also created some voids - under the rails and in the long side - with the same intent. I certainly learned a lot along the way, and I'm happy with the result. Custom Section I'd be curious to see if anyone can spot any improvements and welcome any pointers or suggestions. Like wolverineboat's thing, license is non-commercial share alike. I love that such a wide cross section of experience and creativity can build upon that of others to come up with things we all can make and enjoy. Cheers.