Wow! I never expected this thread to generate so much knowledgable response!
Let me respond to the various things which have been mentioned so far. and add some background information.
The Stephenson valve gear - I will draw it up and share it here - just give me a few days to draw it!
The pony truck. I was thinking about adding it - but I now realise that it isn't a good idea - my railway has minimum curves of 4 ft 6 inch but other tracks where I am likely to run it (lockdowns permitting) are significantly tighter. Now I have enough information to suggest that I would be better leaving well alone.
I understand the desire to obtain accurate drawings for Linda - and I have come to the conclusion that sometimes it is better to act on limited information than to waite for accuracy. The model of the station building at Tan - y bwlch I am describing on the 3 d printing thread is a good example. It won't be totally accurate but does that really matter? It will at least contribute to the backdrop for the rolling stock.
So back to Linda - I wasn't really trying to make an accurate model. I just wanted something which would work. As in actually run under steam. The deciding factor was the valve gear drawing. I don't really like the idea of slip eccentric valve gear. Purely because it seems "naff" to have to push it to make it go the other way. I know that it doesn't matter if you are going round and round a circular track - but when I joined a local group and tried to run on someone else track (which is a loop) I realised the value of radio control - and if you have that why cant you control direction as well as speed.
I aught to admit at this point that I have been trying to build locomotives to my own designs for almost 10 years and of course I haven't had total success. The problem is that I have been trying to run before I can walk - having built an "Idris" - I then wanted to make an ACCURATE version of the De Winton George Henry. It is almost complete and it almost works. Here it is:
- IMG_0120.jpg (293.38 KiB) Viewed 8841 times
Of course before I had finished it I went to the National show and saw Garratts. I couldn't help it I wanted one:
- IMG_0267.jpg (338.68 KiB) Viewed 8841 times
Of course that doesn't quite work either. It is coal fired with full walshaerts valve gear and it is a compound. I spent ages trying to get piston valves to work and eventually hid slide valves within the piston valve outline. Anyway the Weir pump I built to provide boiler feed water worked - but was unreliable. That is what is holding that one back. It is no good using a goodall valve to pump water into a coal fired boiler it just puts the fire out as the steam pressure drops!
So you can understand the desire to step back and make something which someone else had designed again.
Hence the interest in the drawings for Charles - and making it roughly correct for Linda. The tender (for a large gas tank) being the incentive to make it Linda. If I had tried to make it into Blanche I would have ended up trying to make piston valves!
So the end result is satisfying - I have successfully created working Stephenson valve gear - knowledge which will enable me to finish the model of the De Winton. But more importantly I have another working steam locomotive to add to the "Idris". And it does work. The burner lights easily (with a 6mm hole in the bottom of the smokebox) every time.
It raises steam effortlessly, and while the poker burner is noisy - at least I can tell if it goes out. The O ring gas valve (in the files section of the steam loco builders site) shuts off when it is closed. I could never get the metal to metal ones in all the drawings to actually shut off properly.
Those lights flash annoyingly but I can see how much water is actually in the boiler. It doesn't lose steam pressure significantly when I add water.
Of course I am really pleased to be able to control it properly with the radio control. The O ring regulator which I have designed uses a course thread and allows full steam flow in 90 degrees of travel yet with radio control can be shut down quickly and controlled precisely. I know others will disagree but it works for me! I will post updated vidio over the weekend. The SWW group of the 16mm association have a virtual meeting this weekend and I will be showing Linda running outside.
So really I was trying gain the skills to finish my other projects.
I think you will see more of them shortly.
Trevor