Worked on this bridge the last two days and about ready to see if I can print it with the resin printer in pieces. The bottom, top and end bracing all prints separately. Each of the sides will have to be cut into 2 pieces to fit the build plate. The sides could be printed as single units with the Ender filament printer but I want to see if I can get the rivet detail to print with the resin printer. It is too small for the filament printer. The roadway through the bridge would be too narrow for larger roads vs. the little used road to the coal mine. I kept it narrower so that it doesn't overwhelm the scene as it will cross over the main line just above where it enters a tunnel portal. Hope to maybe report back tomorrow if it prints ok and I can get it glued together and I don't have to end up redesigning parts or all of it. The bridge is a Warren Truss (equilateral triangles) and loosely designed on pictures of some I found on the internet. I'll probably print the deck for it on the filament printer. Sumner
Neat model! Recently, I've found it helpful to add keys and ways to help with alignment during gluing. Example, for my smokebox front I added a flange that slides into the boiler, and a slot at the bottom that keys into a cube I added to the bottom inside of the smokebox.
Thanks, I've done the same but was having a hard time deciding where to cut these and your post made me think about it more and I came up with the following... ... Thanks the cuts will be behind the rivet plates out of sight mostly. Won't be printing today as we took a ride just west of town a few miles and ate lunch all by ourselves. Only saw one other car on the whole trip. Boy, do I love living here. Sumner
That looks great. I'm still lips-deep in the locomotive, but I look at others' projects and get jonesing about other things. Your bridge has me thinking...
First print is done and I think the second might be done as I write this. It is going to take a 3rd to finish all of the braces. Here is where things are now. . . . . . Sumner
Moving on.... . . It took a total of 4 prints with the size of my build plate to print all of the parts of the bridge. The print above didn't come out so good the first time around. Some breakage of parts during the printing. I redesigned it a little and the second go around (shown above) is printing as I type this. Hopefully it will be better. Some of the bracing is very thin and easy to break. I had printed extra bracing and ended up needing some of it. I think after doing this one I could get a second one glued up a little more square. Might print another one at some point but not now. The deck the truck is on above is part of the model and the bottoms of the trusses are glued to it. I designed a second deck with side railing that can sit on the primary deck shown in the image before the one above. I wanted the option for the railing and also this deck can be painted (railing and road surface) and then slid into the bridge. That should make painting it and and bridge somewhat easier. The primary traffic over this bridge would be to and from the coal mine with no real through traffic on the road/bridge. After taking the pictures above I found out that I can heat areas with a heat gun and get some of the warping out. I'll work on that a little but this is by no means suppose to be a commercial product and I don't want to spend much more time on it other than painting. Need to move on and I'm satisfied with the look. I'll probably put the print files up after painting it. It wasn't easy for me to assemble but I don't have much experience with kits and kitbashing. to be continued..... You can find the files to print the bridge, abutments and shoes on my thingiverse account later. You can find all the files to 3D print this object and others on my thingiverse.com account ( HERE ). Sumner
Nice! Yep, consumer resin is fragile. I'm eventually going to play with some of the Siraya resins to see if that can be mitigated. I'm designing the locomotive frame with a brass spine and a slip-over "decorative" piece with rivets and fixtures, which will also insulate the wheels, and Siraya makes a "mechanical" resin that won't powder-up when rubbed...
Actually I've been using Siraya Tech Build Sonic Grey and love it. Most of the print is fine and it stays amazingly flexible. The only parts I had breakage on where the very ends of the "X" cross members above and the single top cross members not shown in that image. Those ends are only .020" ( .050 mm ) thick where that glue to the top of the side trusses and resemble rivet plates with the rivets shown on them. I could bend the 'X' part all around and not break them. You can see the broken end on the bottom left 'X' member on the bottom left leg of it. I probably broke that one when I was removing the supports. I was thinking that it was maybe you who put me onto the Siraya Tech 'Build' resin. I'm so happy with it and the detail I haven't tried any of the other resins I bought before buying the 'Build'. I've been curing for 3 minutes on most pieces after the wash cycle and that seems to not make them that brittle but seems like the resin is cured. Sumner
I do a 3-minute cure also, and the parts are solid but rather pliant. But, over time, they harden and turn brittle, I think due to the fluorescent lighting in my workspace. I'm thinking that painting soon after curing might be important to arrest that... Wasn't me touting Siraya resins, haven't used any yet. I'm almost finished with my initial bottle of black Elegoo plant-based, anxious to switch to gray as the dark color makes it hard to see and photograph.
My first spool of filament was black and I hated it. Harder to hide if painting and just didn't like looking at it if I didn't. I only use grey now with filament or resin. If I paint I use a gray primer so if I miss a spot with that it doesn't show. Siraya Tech of course has a number of resins and I have another one of theirs besides their 'Build' but haven't tried it yet. Love the 'Build' ( HERE ) for everything I've been doing so far and .... .... has good enough detail for me and seems to so far stay flexible and pretty strong. Not as inexpensive as others but I'll pay the price as it works so well. I just finished my first bottle and got lots of prints out of it. I'm all florescent in the shop so will have to see if that makes a difference over the long run but am also painting most things on the layout but haven't painted my servo control switch boxes and recently started printing them with the resin printer instead of the filament printer. Tried the resin on the servo mounts but it is more critical in have the right size pilot holes for the screws that are used vs. a filament printed ones. The resin can crack easier with too small of a pilot hole. I do know though that people are printing my servo mounts with resin printers so it can be done. Sumner
I've collected a few spectral power distribution charts for various lights, here's one for fluorescent bulbs: Note that little blip at 400nm, not much energy but the effect will accumulate over time.
.... bridge continued. Paint-booth is working great. For info on building it click ( HERE ). . . . . The rock face behind the bridge and tunnel portal will continue upward to the upper level where there will be another set of track s and a long bridge that will cross the canyon paralleling the tracks shown above. I'll also brush on some more highlights on the bridge when it is ready to be put in place and glue the roadway down flat on the bridge decking. To be continued..... You can find the files to print the bridge, abutments and shoes on my thingiverse account later. You can find all the files to 3D print this object and others on my thingiverse.com account ( HERE ). Sumner
