In reply to some of the above -
Chris - Yes, the limitations would be that there are learning curves involved with the 3d drafting software, and also with setting up the print.
Jason - I wouldn’t worry about your age. There are plenty of tutorials on YouTube that will help you learn. Just watch them at the same time you have the program open. Plenty of math will be involved so keep a calculator and pad handy. Since almost all 3d printers function in the metric world, you will have to get familiar with millimeters, if you aren’t already. Some people draw things to true world size and then reduce to scale, but I like drawing to 1/48. The simple formula that gets used all the time is - inch measurement from prototype times 25.4 (converting to millimeters) and divided by 48 (converting to o scale) For this project, I also used plans from RMC that I scaled and printed at actual O Scale, and then just measured with a metric scale. It’s nice having your son involved too - my son has three printers, and we both got into 3d printing together about 10 years ago, splitting the cost of our first kit printer (which is still functional and used) It helps to have a partner when figuring out all the quirks of these machines and materials.
Malcom - You are right about the hood, if would be daunting to scratchbuild those headlight angles. Even with the CAD drawing, they were the hardest thing to work out. It looks simple but you have multiple angles in different planes that intersect.
Mark - Brass is sort of out of reach for me, partially because I’m a cheapskate, and partially because I just don’t know enough about all the manufactures, running characteristics, and fair prices. But because the variety available in plastic is limited, building myself seems to be worthwhile to look into. (And fun) I build things in my day job, and we are sort of the go-to people for complicated and strange projects others won’t take on. I like to challenge myself, even if I might fail in the end, which is still a possibility with this project. This project is to essentially establish a template for building a locomotive.
Figuring out a sort of universal chassis/drive, that can be modified for length and wheelbase easily, is the other aspect, of this project. The fallback is to use P&D gearboxes and towers, but I’m also working on a dual motor, homemade China type drive, using 3d printed components and gearing. It’s a bit complicated, but if I can get it all engineered right, functional, and to run reliably, it would lower the over all cost of the locomotive significantly. There might not be tremendous pulling power, but I’ll mostly be building switchers, and if power is needed, I could used the P&D hardware on larger road diesels. My test will be if I can pull a dozen cars up our grade at the Cherry Valley club.
Assuming everything works out with this locomotive(s) (I’m building three versions of them - SP High Vis cab - Rock Island Standard Cab - and Monongahela Connecting low industrial cab/ALCO Hi Adhesion trucks) , my next subjects would be a FM 10-44 and an EMD SW-1 .
I will keep updating this thread as there is progress, but I’m also still building the G38/39 ore cars, and a few more DUNMORE Cabooses.