Flying Scotsman
With the outside connecting rods and pistons now fitted and working in their cylinders, it was time to do the same for the middle cylinder. The connecting rod itself was made some time ago but I still had the big end brass to do and thus will describe my approach
Flying Scotsman
This is another of those small milestones, that is, to fit the pistons and still have the wheels go around, any errors in the build will show up here. As has been shown in earlier posts I have deviated on Don's drawings to make life a little easier
Flying Scotsman
This is another big step in my book, that is getting the wheels connected to the crossheads via the connecting rods, the next big step to follow being the fitting of the pistons themselves, that will be the next job after all 3 rods are fitted.. There are lot'
Flying Scotsman
Next up was to machine the oil reservoirs to size, this is the last operation with the jig this way up. The carbide cutter once again made little work of cutting through the hardened metal. DRO readings were noted to ensure that both rods were identical. The picture shows the
Flying Scotsman
On to the outside connecting rods, these are the longest of all the motion parts, they are fairly slim too so I needed my trusty jig (block of solid steel) again plus another 1/2 thick section bolted to it to give me a large enough supporting platform. Using the
Flying Scotsman
As pointed out during the crosshead construction, the drop link design varied during 4472's career. My goal here is to try and make something that looks like the drop link in the late 30's but while also following the 'Doncaster' dimensions for obvious reasons.
Flying Scotsman
As I have laid out before, 4472 (and for that matter, all Gresley A1/3's) have had a variety of different crossheads fitted during their career. The crossheads themselves are pretty much alike, the parts that are very different are the oil reservoirs and the drop link. Thanks&
Flying Scotsman
This entry see's the completion of the main crosshead body and their mounting plates, 4 weeks solid work? The middle crosshead is a little more simplified as it has no drop link, I have simplified it a little more by not machining the lower tab which the mounting
Flying Scotsman
Today we see the crossheads finally take their shape at the front end, I won't say just how many hours this took to achieve, it was a lot. Last time I covered the machining, this time it was all hand work, beginning with the Dremel, using diamond grinding
Flying Scotsman
I now begin the most challenging part and profile the front of the crosshead where the tapered round section meets the square section. There will be a fair bit of hand shaping to complete this stage but I have removed as much material as possible by machining first, this involved
Flying Scotsman
Before starting I need to add something that I forgot to state and that's that, the crossheads are handed and this was taken into consideration when drilling the holes which are different either side. The left hand crosshead has it's nut (naturally) on the outside (left
Flying Scotsman
Continuing on with the crossheads and we have 11 pictures for this entry, I have tried to do the talking with pictures in an attempt to give a clear indication of how I am tackling the various machining processes and in which order. Oh, and yes there are some machine