Hi Dom
Thanks for your post, I was hoping there might have been someone on this site who has tried this build before. It would be great if you were building it at the same time. I bought the full set of drawings as well as the book. (before I realised the book contained all the drawings anyway, however it is nice to see the drawings in full size.
I havn't really been able to find any real build logs etc for the Allchin. So I've been creating my own as I go, lots of pictures etc. One thing I've noticed about the drawings is there's some slight errors and some areas that dimensions, or details are missing but nothing too major. (I'm an Aerospace Engineer, so I'm pretty picky with drawings). I found it was a lot easier if I redrew the plans as I go on the computer using draftsight (which is basically autocad), I was going to do it in 3D but decided 2D was enough.
Most of the casting suppliers I've found i.e. reeves are very expensive with long lead times for what they are plus I have to pay extra postage. So I'm going to try to make a lot of it from stock. I'm thinking of replacing a lot of the gun metal parts with Steel or CI with bushes around any shafts etc. I will probably buy the smoke box door casting and fly wheel though. I would love to give machining the spur gears a go, however I priced up the cost of the gear cutters (you need almost a full set) and found it would be cheaper to buy the gears pre machined.
I've started with the boiler, which I want to get up to a reasonable state ready for silver soldering. I had a couple of go at trying to flange the copper (which is thicker than I'm used to) with wooden formers but the results weren't great, so I bit the bullet and used some spare steel plate for formers and the results were 100 times better.
I've also started the horn plates and connecting plates. I think I'll move on to the tender and the gears/ brackets etc so at least I can get something that looks like a traction engine, before completing the boiler.
I've attached a couple of pictures of my progress so far (not much really) the cheap mdf jig is just for temporary display, as I'm not trying to align anything just yet.
Peter