< Smokebox 3 >
The crossbar to catch the smokebox door dart is a simple steel bar with a slot at the center. The photo shows backface of the smokebox front ring. Two steel brackets to hold the crossbar are fixed on the ring. Additionally, the brackets have brass angles for centering of the crossbar.
The door hinge's band plates are cut from 7 mm square bar. Two blanks are soft soldered on a steel flat bar to hold the blanks in each cutting processes. First, milling the side to 1.8 mm in thickness. Next, drill through the bearing hole.
The round face between the thin part and the bearing part is cut in the rotary table. Here the soft solder is melt and the each plates are separated. After that, drill holes for rivets and cut round shape of the each end.
Finished band plates. Here they are annealed for the next process.
Set the band plates in the hinge brackets. Deform the band plates along the smokebox door fixed on the front ring with the door handles. Clamp them together and drill through the holes for rivets.
Fix the band plates on the smokebox door with iron rivets. I utilized a copper plate as an anvil, so as to protect the round head of the rivets.
The handrail stanchions holding the smokebox door's handrail were made from a brass rod. I need three of them here, but also need a lot of them for both boiler sides. So I prepared some tools for the lot production as follows.
A form tool to turn out the sphere head and turn the tip. The form tool is cut from a round tool steel, hardened and tempered. Next the thin neck part is turned with a parting tool.
Reverse and chuck the job with a handmade brass collet. Turn a step and thread with a die.
Drill the cross hole with a jig as shown in the photo. The brass column holds the stanchion firmly without damage to the thin neck.
The smokebox handrail is made from a steel rod, anneal and bent with a former. I designed the former assuming 10% spring back and got an almost desired result. First I bent one side, inserted a stanchion and bent another side.
The holes for the handrail stanchions have to be drilled truly vertical to the rounded door surface. The angles were calculated and the door was fixed precisely on the machine table. The stanchions are fixed with nuts from backside.
The smokebox round handle has a support bar to screw up the handle. Root of the bar wounds around the handle ring. I made it from 2.5 mm stainless steel wire. Anneal and bent it in a jig as shown in the left photo. Hook it on the handle and squeeze the tip.
Assembled smokebox front. I added four posts that will hold a locomotive number plate.
