It's been a while since the last update and a few things have gone on so we'd better have a catch up.
When we last saw them most of the castings for the rear axle had just been delivered. This meant that someone who doesn't have a proper job had to spend most of his time standing in front of the boring machine turning them into something useful. Here are the brake shoes ready for lining. They are cast as a pair then separated, however, we have left them as one piece for lining so once the lining is on them it is easier to pick up a diameter to machine the brake drum to.
Annoyingly the first quote for lining them came back as just shy of £800 which seems a bit strong to us so we'll just get some linings and rivet them on as per the original design ourselves.
Then there was a big pile of SG iron that was to get turned into a rear axle. Sadly we are not good at taking pictures so there is quite a jump. This is the spring pad on the near side bolted onto the spring with the radius rod in place. The thing was we didn't have a measurement for the axle beam itself and with so many dimensions that you are trying to meet you have to start somewhere. Now the spring pads are in place we can get a width for the axle beam. The piece of channel and two studs is temporary. The proper thing is a piece of 1" plate with four studs. The radius rods are adjustable and allow the chains to be tensioned. The hole at the bottom takes the brake actuating shaft and you can see the hole at the top that takes the pivot pin for the brake shoes.
A spring slipper that allows the whole rear axle to be moved front to back. You start to spot where there were a few quick wins to help improve payload.
And a closer view of the off side. The funny block at the bottom with the cover bolted to it is an oil bath to keep the brake shaft lubricated. Why they did this is completely lost on me because it causes nothing but trouble - mostly to do with depositing oil on the brake drum. The eagle eyed may be able to spot that we have machined it to take proper modern oil seals and they will get lubricated with grease like what they should have done at the start.
At the other end of the radius rod there is a palm which bolts to the engine suspension plate. The exciting thing is that all of this lined up absolutely bang on first time.
Now what is needed is the big bit of bar that joins the two spring pads together. As you can see this is a very big bit of bar indeed. This is where having a big lathe is very handy.
What else? The brakes are getting there slowly. This is the brake cylinder mounting all tidied up and bolted in place. The spindle isn't supposed to poke out the back of it but it is because the piston hasn't been made for it yet.
The front cover for the cylinder took an age to make for some reason. Anyway, it's done now.
And some more links getting made for the brake system. In this case yet another yoke for the hand brake rod and crank for the handbrake actuating shaft (part way there which is why it is covered in welding spatter.
The water pump valve block got finished and here it is sitting in its rightful place. This allows you to either direct water to the boiler or spill it back to the tank. The bulb at the top is supposed to smooth out the flow a bit. Hmmmmm. Properly fiddly casting this one and a right pain to machine. The funny Y shaped fork at the bottom takes the lever which operates the by-pass valve.
And as an aside here is the S with its tipping body propped up while it gets the new tappets made and fitted to the inlet valves. They've all come back from the heat treatment place so they are ready to go on and set up. Tipping bodies are a complete and utter pain in the arse and I am never having anything to do with them ever again. Note all of the asbestos string. Pretty, eh?
Back to the Super. One of the jobs I'd been putting off was trying to do something with the cab roof. Namely trying to bend the bloody ash beams to shape. I did some reading on this and watched some YewToob videos on the subject which were mostly to do with furniture making but it was better than nowt. Right, off we go. First measure things and work out what radius you want to bend it to. Now take a large sheet of boiler plate and mark out the radius on that. Cut 18 bits of 2" angle then weld them to the plate to form a jib to which the hot wood can be clamped - I've got no pictures of any of this by the way. Now we need something to steam the wood. Reading suggested we needed a bit of 4" drain pipe and a wall paper stripper. What we ended up with was a 4" drain pipe and a crappy domestic steam cleaner which would run for the three hours or so that the wood needed to steamfor. So, bung the wood in, set it going and three hours later whip it out and clamp it to the jig. Leave it to dry for three days as recommended and hey presto!
I'd set the jig up the for the radius we wanted. The idea that the woood would spring back slightly didn't cross my worried mind. Fortunately I'd tried to bend the tight radius first which meant that the tight radius was now very close to the other beam we needed.
Right, grind all the angle brackets off and re-set them on a guess as to how much the wood was going to spring back. Repeat the exercise only using a piece of aluminium pipe because uPVC pipe can't really take the temperature for that long.
Too far. Reset the jig again and try again.
Too far the other way. It was at this point it occured that ash may be good for steam bending but I doubt that it was going to take too many cookings before I wrecked something. It also occured that the chances of hitting the exact radius needed was somewhere close to zero. It was at this point we decided to stick at 19 and make a firring piece to get the radius spot on that way. I took a strip of tulipwood and glued it with Cascamite to the top of the beam. Then after planing and sanding it it ends up with a join that once it is painted you would never know it was there. Now the radius can be marked out by measurement and after buying a cheapy bench sander here...
It was possible to sand the firring piece to the correct radius. Here's the front one in place
And the rear one. The beams were supposed to be held in place with finger joints but because the "ash" bend is metal in our case I have bolted the beams in from the ends using barrel nuts so you can't see very much at all. Note the roof planks sitting in just the right place. All of this wood is painted in a sandy beige colour so the mis-match in the types of wood shouldn't be too obvious. The only real cost is reducing headroom in the rear a little.
So after only a couple of weekends it is ready to put the roof planks on. Once the planks are on it will be covered in duck canvas to help keep the rain out.
I think we'll be doing the curved beams for the body as glu-lam rather than hot formed - unless someone tells me how you bend these things properly to the right radius. I really don't fancy trying to hot form eight of these things to the same radius.