After the initial test print yesterday, I found the model to have significant warping down the sides... and only down the sides! After some pondering and remembering the early days of printing long flat sides... I figured the issue, as with most problems when resin 3D printing, was there were inadequate supports.
If you look carefully you'll be able to see the warping lines at regular intervals along the sides of the locomotive shell. not only that but there was significant bowing of the sides as well which is also due to lack of supports, it's much more noticeable when the two models are placed side by side.
The good print is on the left with the bad print being on the right.
I also post cured the good model on the left to UV light for much longer than I normally do, about 50 minutes. The reason for this was to doubly make sure that the resin was properly cured thus preventing future warping over time.
Over curing the model often results in the model becoming more brittle however I think the downside of it being more brittle is worth it if it means it will resist warping over time. You can tell the model on the left has been cured much longer simply due to the colour, it looks like a more dull grey compared to the model on the right.
Right now I've got the second underframe attempt printing, it's coming out much better now that I've increased the number of supports.
As for lighting, I'm using some left over 1.8mm LEDs, while they are not perfect they are very close, I don't want to waist the LEDs so to make them fit I need to increase the headlight openings ever so slightly. When it all comes together I don't think the larger headlights will be noticeable...
As you can see the headlight openings are slightly smaller than the 1.8mm LED head.
Another challenge will be light blocking so the resin doesn't glow when the LEDs are illuminated.
Deciding to build a roller coaster for the next video... Have I bitten off more than I can chew?.. Nah it'll be right 😁
Some final shots of the completed model, I now have a fully functional running Comeng train that I used to catch back in the late 90's.