An ambitious plan to start with; have you got equipment, lathe, mill, / drill, measuring equipment, workshop / space etc, etc, when was the last time you used any of these ?, I hazard a guess that was in college or uni & your engineering background is in CAD designing etc as you claim not in any mechanical way. Not to worry, there are many superb models that have been made by non engineering back ground hobbyists.

A) nothing is a step too far… it's taking that first step.

B) There are always options… what is achievable with your present capabilities.

C) I would suggest you start with a smaller model i.e. as you say a Pottymill, Stuart type kit, 10V, etc. to get some practical experience first & to get to know your machinery.

D) We're all mad on here so join the gang…

As you have already bought a set of plans you've made a start. you need to ask yourself some questions though, do I have the capability to solder up a boiler to meet inspection / certification / insurance standards ?, can I form sheet metal, can I bend / solder tubing without kinking it ?, Can I make a clack valve / safety valve ( although these can be bought ) etc, etc.

I have a set of plans for a 'Minnie' but loco's are not my bent … at the moment! ( I don't know if I'll have the time to finish it ), I am sticking with smaller engines at the mo', the likes of Stuart 10V, 10H, progress, oscillators from plans from 'Elmer engines' etc. to which I can make mistakes without too much cost to material, time etc. & where I can get satisfaction of seeing them run ( albeit on compressed air ) in a reasonable time scale. You also have to factor in ongoing tooling costs that have to be approved by the finance director…SWMBO ! … don't be under the misapprehension that brownie points will get you every thing you want / need, … it doesn't work, believe me! it only takes one 'Aw sh1t' to wipe out any you have accumulated.

Never the less if you feel like starting off with a loco; go for it, you wont know if you can do it until you try. I'm sure that there will be other members who will offer their opinions & advice, the above is just my offering. One thing is for sure; once you're hooked, you're hooked.

Enjoy

George.

I'd make the Potty Mill engine first. Then maybe one or two more of similar nature. See if you actually enjoy all that tiny fiddling about and drilling and tapping 2mm holes etc. It's one thing to think about it, another to actually do it.

A loco can take up to a thousand hours of work or more. Many are those who have felt overwhelmed part way through and given up.

So its nice to have those couple of simpler projects sitting on display in the house to give you encouragement to keep going when things get tough.

Plus, it gives you a chance to prove your machinery and your own skills on lesser projects before embarking on the big one.

Edited By Hopper on 03/11/2018 07:12:30

Before you make a loco, consider the cost of materials and where you are going to run it.

Build a Pottymill and take careful note of how long it takes and how good or bad your learner skills are in practice. The Pottymill is a lot simpler than a loco and, although there's no brazing, casting work, or boiler to worry about, you have to understand the plans, source the materials and tools, work out how to machine the parts, and then assemble them. It will help calibrate your abilities and expectations.

Some people take to machining like a duck to water. Not me! Slow, clumsy, semi-skilled and likely to make small mistakes. It would take me years to make a 5" loco and I'd have to reorganise my workshop to accommodate a big model. But don't be put off by my incompetence – you might be a fast, accurate worker. Or not! Making something fairly basic with a few challenges like the Pottymill will tell you what you need to know.

Dave

I built my Stuart 10H with only a myford lathe and a Walker Turner pillar drill, I’d say it was a good first engine. Learned a lot and only ruined one casting! (Connecting rod… Misdrilled a hole…)