Alan, sorry didn't answer your question. There are various kinds of resins with many properties including impact resistant. I'm having problems with fine details too as I've talked about here. I'm using a newer resin by Elegoo (ABS-like Resin), but it too is brittle in small cross-sections. There are others that I'm going to try. Each resin has its sweet spot regarding layer thickness, exposure times and rest times. I've been reluctant to try different manufacturers resins until I've mastered the ones that this printer recommends.
Two topics for today. First the Baldwin VO prime mover. The right side print was mostly successful. The fuel lines were too fine and simply didn't have enough integrity to print properly. The greater was also marginal. I fixed the drawings and they've just finished printing. You can see where the fuel line parted and was a bit warped. Similarly the throttle rack shaft was a little iffy. I enlarge both structures and then added some back reinforcements to the fuel line.
For the generator I tried, unsuccessfully, to actually print as set of v-belts connected to the properly rendered sheaves. They are actually separated and as such, too fine a structure to keep shape. Also, the bottom of the exciter cylinder didn't print. When I made the fixes and put it through the slicer I did see an "island" forming. An island is a part of the print that's forming without connection to the build plate or the rest of the model. I fixed that also. I re-drew the sheaves as empty and will use E-Z Line to make real v-belts. I also reduced the number of sheaves to four since I believe I overdid it. The engine has some significant shrouding covering the belt drive. This lends itself to building in brass or styrene. I will explore this.
I just pulled the fixed parts and all the problems were corrected. I upped the diameter of the shafts by 20%, plus the added supports (tiny) did give me a good print.
Here's the right side with good fuel lines and throttle rack. Obviously, I have clipped the supports so there's still a chance to break something. The gray resin shows details much more clearly than the translucent resin did. There are supports touching the fuel lines that will need to be removed. I'm going to grind them off with a small diamond burr in the Dremel Flexi-shaft. The flush cutters even with the flat ends facing the part, impart enough shock to break the small stuff.
Here's the revised genset. I went to four sheaves and fixed the bad print on the underside of the exciter by adding an additional support. It worked! The shiny corners are left over cleaning solution. When the piece is fully dry and goes through the UV curing process, that will be gone.
I then continued working on the engine house terrain. After some thinking I decided to expand the level area to the viewer side of the engine house. I want to have a storage area to display all these engines and loco parts and the area was too small. There was a significant scale 4 foot drop off back to layout level. I filled the bulk of the space with whatever I had laying around. For most of the space adjacent to the machine shop I used the piece of insulation foam that was removed in the machine shop "excavation". For the remainder: the left side is a sandwich of three layers of corrugated cardboard held together with hot glue, and the right side is a small piece of the remaining 1/2" German foam core that has been used from some many of my building bases. All three were held to the OSB base with hot glue. I tapered the undersides so they nestled more closely to the existing Sculpta-molded (STM) transition from the yard height. I then used paper towels soaked with plaster (in this case, Hydrocal) so I could minimize the amount of Sculpta-mold that would be needed to finish it off. I had just a tiny amount of STM so I strived to minimize the cubic volume needing to be filled.
This image is when the towels were in place, but before the last piece of foam core was added on the right. That was an afterthought. I needed a roadway to come around the building. and this small section was too low. I had a ton of Hydrocal left over from rock castings. I had no more Gypsolite plaster left. Hydrocal cures very quickly since it's really formulated for plaster castings. Gypsolite is slower curing and was used for plastering over the mountain. It gives much more working time in the soaking bath. For this small job, that didn't matter.
In this image I had added that piece of foam coat. In this case I had added some W-S tinting to the plaster so it wasn't so white. It really didn't matter since all of this, as you will see, was schmeared over with STM and that was tinted.
Here all the STM is added to level everything plus I filled the joint with DAP spackle. This is the kind that goes on pink and is pure white when it's dry and ready for sanding. I paid specific attention to the walkways leading to the access doors. These will just need some concrete colored paint and the walkways will be done.
This picture shows the new level surface for the storage area.
On the EH right side will be the parking area and that needed a more smooth surface. I sanded the STM that was put on last week and then spackled it to feather it to the original surface. This will be final sanded and maybe given even another coat. This will be paint and lined or graveled. Haven't decided yet. The drive will go all the way around the back of the building requiring spackling there also. With all this slop it's easy to see why the Stretch-n-Seal was put all over the building. It's doing its job.
The storage area will need to be surrounded by a chain link fence and maybe some yard lighting. I'm pretty good at making these fences now, but will have to get some more stock. I buy the 3/32" and 1/16" brass tubing in 36" lengths and have to order it on line. By Wednesday all this should be dry enough to start painting and ground cover. For all those who are contemplating scenery, especially involving plaster, it's a messy process. It looks awful until, all of a sudden, it looks real. You have to go through the messy stage to get to the other side. Don't be squeamish. I will admit, it's not my favorite part of model railroad building, but it is essential. I was procrastinating this part just because it's such a mess. Oh… and wear nitrile gloves. Plaster is awful for the skin sucking out every bit of moisture.
