Re: Weekend Update 12/28/25

[lock4244]

Probably a safety thing.

I think largely end of life (40 years) and not worth life-extension vs buy new. Iirc, most were gone by Megantic.

[craigolio1]

Needed to replace the FEP on the printer. But with it running again, the first test print of the tanker looks pretty good.  Many fragile details print fine but suffered during support removal.   The underside  brake line detail was lost in the supports but printed fine as well.  The body is hollow but still hefty, won't need additional weight.  Lots of ride adjustments needed too.

Wow those look really good!!

[Jesse6669]

Wow those look really good!!

Indeed! What's the layer thickness and in what orientation were they when printed?  Anti-aliasing? 

I've never gotten tank cars or curved surfaces to print quite that nice, there's always some stepping visible.     

[Scottl]

There is some stepping visible still but hard to see at a distance.  I did this with .05 mm layers but plan to do the next at .025 mm to see if that improves it.  Otherwise,  print settings were just default using Elegoo 8K standard resin.  It was mostly a quick print as proof of concept and it seems worth pursuing it further.  I'll separate out the brake gear into a separate print and maybe go with wire for the long lower quarter rail.  The ladder is a bit clunky too so that needs some refinement.  The ride height needs adjustment but it is hard to find good reference images straight on.

[Scottl]

@Jesse6669 here us a close up. The rounding of the tank is pretty good. But the tank angle adds to the effect on the top. I hope thinner print layers will help.  It will be the first time pushing the new printer to its maximum capability.

[Jesse6669]

@Jesse6669 here us a close up. The rounding of the tank is pretty good. But the tank angle adds to the effect on the top. I hope thinner print layers will help.  It will be the first time pushing the new printer to its maximum capability.

Sanding can help but it gets dicey around stuff like rivets and weld seams.  You might play with the Anti Aliasing settings in the Slicer as well.

Another (possibly easier) option is to increase the size of the weld seams, and between primer and going a little heavy on paint on top.. it should cover them.

[Scottl]

Good suggestions, I'll give those a try with the next print.  I really would prefer avoiding sanding, those rivet lines turned out perfectly.

[samusi01]

Have you considered end caps separate and the body being printed vertically? I can usually get fairly good results doing that.

An example - 90' dimensional load:


Very much a WIP image from November... @vermonter_railfan may be able to chime in with other images of vertical prints.

[vermonter_railfan]

Very much a WIP image from November... @vermonter_railfan may be able to chime in with other images of vertical prints.

Here a shot of the same 90' load with some chrome paint. Vertical printing for a rounded object does still create some layer stepping on the edge but in my opinion it helps reduce the support nubs and other issues created while printing at an angle.




A different load done by @samusi01 which was vertically printed and attached in the center

[Scottl]

I like the idea of printing vertically, assuming I can get a perfect fit of the ends.  That is a nice example  but it looks to me like you have facets in the original shape geometry.  I did the maximum number  to avoid facets and it seems to have worked pretty well.

Part of the challenge here is the 0.5 degree angle to the funnel flow car halves.   They very low angle exaggerates the stepping considerably. 

My printer is running again so I'll try all of these things.  I'm very interested to see what the 0.025 mm layer thickness looks like.

Thanks for the suggestions and advice.

[garethashenden]

If it’s a funnel flow I’d be tempted to split it in the middle and print both halves vertically. Add a sacrificial ring to take care of the angle, and maybe some interlocking joint to make assembly easier.

[Scottl]

If it’s a funnel flow I’d be tempted to split it in the middle and print both halves vertically. Add a sacrificial ring to take care of the angle, and maybe some interlocking joint to make assembly easier.

I was thinking the same thing.  I'm just not convinced the center joint will be clean. This is all good to advance to the next version.

[PiperguyUMD]

Inching ever closer with the Russian Decapod. Tender was primed with Mr. Surfacer 1000, then painted with tru-color paints. Tender deck is NKP freight car red. The WM used a red lead based primer on the tender decks and cab roofs of their steam locos, and while this color might not be totally accurate, the I1s were off the roster by 1951 (I model Fall 1953) so I think this red/brown will be easier to weather to the point of being worn out. Thanks to pointers from the crew here, decals are ancient Northeast decals sprayed with microscale liquid decal film. I had to thin to about 50/50 with IPA. This worked well, and as an added bonus, completely disappeared with a few applications of Solveset.





I had to make a few tweaks on the boiler and print another draft. While working on the digital front, I whipped up something to give the impression of drifting valves. I drilled into two holes drilled in the top of the cylinders, and using drops of resin to secure them in place/fill the gaps. It will take a bit of touch up and there’s probably a better way, but I think this will work.



While the paint was out, I used some tru-color brushable engine black to touch up the bare metal exposed on the frame when milling.