Modelling the Kerr-Stuart Brazil Class 0-4-2ST locomotive in 16mm scale. - Keith Bucklitch
Steam and Exhaust Tees and Footplates.
1. Steam Tee.
1. These are mostly made from brass, silver soldered together in a similar manner. The feed pipes to the cylinders may be made from 1/8" copper pipe which is easier to bend if there is any slight misalignment. Cut a piece of brass for the cross arm of the tee, face the ends to length, centre, drill and tap to size. Mark the position for the leg, centre pop and drill a hole, 3 or 4 mm diameter through to the longitudinal hole. The leg of the tee is similarly cut to length, turned and threaded for the connecting pipe (5/32 x 40 tpi for steam, 3/16 x 40 for exhaust) as per the drawing. Reverse in the chuck, and turn a short (1.5-2 mm) nipple to fit firmly in the hole on the cross arm. Assemble and silver solder together.
2. Exhaust Tee.
Make the steam/exhaust pipe-work by turning/threading/drilling as appropriate. Try the assembly in the frames. You may have to make some adjustment to length to wriggle them into position but they should fit with a little adjustment. (NB When assembling the steam tee, it may be easier if the front spacer is temporarily removed.)
3. Blast Pipe.
This is made from some 6 mm (1/4") hex brass. Face the end and drill 1.6 mm diameter for 26 mm. Open out to 5/32" and tap 3/16 x 40 tpi. for 5 mm depth. Part off at 25 mm long. Reverse in the chuck and turn the barrel down to 4.5 mm diameter for 18 mm. Shape a cone at the end. Screw on to the exhaust tee. Check that the blast pipe aims centrally up the chimney. You can do this by inserting a drill bit down the petticoat pipe into the blast pipe.
The lubricator is made from a length of 15mm copper tube. Two brass ends are soldered into this. These are thick enough to allow screws to be inserted without piercing the lubricator. After soldering these in place, check the fit in between the and face the length accordingly. A length of 9 mm bar is bored 7/32 and threaded 1/4" by 40 tpi. Part off approximately 8 mm long. A short step is formed at the lower end. Drill a 1.6 mm hole in the side as indicated on the diagram. The filler pipe is silver-soldered into a 6 mm hole in the barrel. The drain pipe is 3.2 (1/8") copper pipe, bent as shown. This should be long enough to emerge under the frame. (It does not matter which side.) Turn up a small cap from some 5 mm (3/16") hex brass and cross drill 1.5 mm. Fit a plug of gasket material in the bottom of the cap to form a seal.
The connection to the steam tee is a length of 1/16" copper pipe. The end of the pipe should be crimped to close it, and a 0.5 mm cross hole drilled through. (Should you subsequently feel that insufficient oil is reaching the cylinders, the cross hole can be progressively opened out to a maximum of 1 mm.) The pipe is soldered into the filler pipe, just above the barrel of the lubricator. When measuring the length of the pipe, it should reach the steam tee connection with a constant gradient. Under no circumstances must there be any 'sump in the pipe otherwise it will not perform correctly. Slide a connection nut on the pipe, and solder an olive to the end.
Make the filler cap from 10 mm brass bar. Face the end, turn down to 1/4" diameter for a distance of 6 mm and thread 1/4" by 40 tpi. Turn a shallow recess at the shoulder to fit a suitable 'O' ring. Knurl the cap and part off approximately 4.5 mm from the shoulder. Cut a screwdriver slot with a hacksaw to assist removal of the filler cap when it is hot.
5. Front Footplate.
I made the front footplate from some 1 mm steel, but brass is equally suitable. Cut to the shape shown on the drawing. Fret out the opening for access to the lubricator, and file a piece of the same material to be a close fit in the space. This should have two pins soldered into it to retain it in place. For ease of removal, file up a lamp bracket and solder to the cover. You will probably also need to solder a small piece to the footplate to stop the lubricator cover falling in backwards. The holes for the steam and exhaust pipes should line up with the holes in the base of the smokebox. Secure the footplate in position with 10 BA countersunk screws.
6. Rear Footplate.
Make the rear footplate from some 1 mm (20G) material. Brass or steel will do. Cut a rectangle 99 by 106 mm. Mark and fret out the cut-out for the firebox. Note the position of the holes for the fuel supply at the rear of the cab. The holes for the cab sides can be drilled at this stage, but the holes for the reversing lever are left until the position of the lever has been determined. Cut the steps from some 0.5 mm material, fold up as per drawing and rivet in position on the footplate.
If you have any questions, or comments or find any errors in these notes please contact me by email. Email Keith Bucklitch.
Copyright © 1998, Keith Bucklitch
Last Edited - December 23, 1998