< Platework 2 >
[Brass angles and copper rivets for assembly]
It needs a lot of brass angles to assemble the side tank. At the corner of the tank, Brass angles with 45-degree slant end are employed. If three angles will be gathered, two flats of an angle should be slant.
The photo shows how to finish 45-degree slant end in two flats. In this case, the machine vise is tilted 35.26-degree, instead of 45-degree.
More than 200 copper rivets are necessary for one side plate. I employed milling machine's X-Y stage control. The photo shows preparation of this operation. A length of steel bar is bolted onto the stage. The bar should be truly parallel to the stage. Then X-dial collar is reset at the end of the bar, while Y-dial is reset at the edge of the bar.
Center drill is used at start, and then straight drill follows. A brass angle for assembly has been glued behind the plate. Then the drill goes through the plate and the angle.
If you assemble side tank with rivets, you have to investigate the procedure carefully. Otherwise, it will become impossible to continue halfway. In my case, at the start, all of angles on the side plate were riveted. After that, front plate with angles was riveted onto the side plate. I employed silicon caulking to seal the angles, while the window bead was soft soldered.
This tool is 'rivet snap' to form a snap head at the tip of a rivet. However I utilized it as 'dolly' which holds a rivet head and guard it from distortion, when riveting.
The rivet-snap was push into a hole on the worktable, and supported by brick and anvil from the floor. The side plate should be parallel to the table, while riveting.
[Bending the roof]
Now is the time for the bending roll work. Actually, locomotive roof radius is too large for this size of bending roll. The pushing roll should be controlled in 0.05mm tolerance. I controlled rotation angle of the pushing bolt with a paper protractor glued around the bolt.
Careful operation is necessary. The pushing roll should be truly parallel to the under rolls.
Paper radius gauge printed by CAD. Front and back edges of the roof should be finished in the same radius.
Area of 20mm from a side edge should be cut, because the radius is not precise here. I employed a round wood bar to fix the roof on the table.