Building Stage 2

The heading photo is a little misleading in that it shows one of the cylinders set up on my Sherline mill ready for "surgery". This is NOT required when building the kit. But I just can't leave well alone, so I decided to do a little addition. I will describe this then go on to the assembly as detailed in the instruction booklet.

Cylinder Drain Cocks

The locomotive comes with a cylinder drain that actually is more like an exhaust line drain. It is a cock place below the blast pipe that when open will allow any condensate that gets blown out of the exhaust port to drain down to the track rather than being forced up the stack. However, I don't like the idea of no way to drain the cylinders themselves, and I wrote Andy Probyn and he said that there was no objection to me fitting conventional cylinder cocks if I wished. I ordered a set of drain cocks from Reeves, the size determined by the space available to fit them more than anything else. It worked out that the 1/4" by 40 tpi cocks should fit and so they were obtained.

The first stage was to machine a flat for the cocks to seat on. I milled a 5/8" circular flat at the end of each cylinder with the Sherline mill. As you can see from the heading photo although the cylinder is big in relation to the mill the setup was not at all difficult. Actually, to hold the cylinder down I fitted the studs as outlined in the instruction manual. The Stage 2 kit comes with lengths of threaded rod that you screw into the cylinder with some Locktite and saw off to length. I then ran on a couple of nuts and used the hold-down clamps on the mill against the nuts to clamp the cylinder to the table. That way I did not risk damaging the bore of the cylinder.

Once each flat was milled I put the drill chuck in the mill and without moving the tables drilled an 1/8" hole about 1/4" deep. This was to act as a pilot for the tapping drill for the 1/4" x 40 tpi thread. I could not drill the tapping hole as the head of the lathe couldn't be raised high enough to enable the drill to clear the work. Two holes on each cylinder were drilled this way.

I then moved the work to the drill press to open up the hole for tapping. I set the depth stop on the drill press to give me about 3/16" material left at the bottom of the hole. The next step was to drill the hole into the cylinder, and I used a #30 drill and propped the opposite end of cylinder up by about 1/2" so angle the drain hole towards the end of the cylinder. When fitted up and properly adjusted there should be about 1/8" dead space at each end of the cylinder, and I wanted to be sure the drains holes fell within this space. You can just make out the drain hole in this view of the cylinder.

Finally the holes were tapped 1/4" x 40 tpi and the drain cocks screwed in. The seat nicely and as the milled flat is below the outside edge of the cylinder they are slightly recessed. This makes for quite a neat installation and also ensures that they do not protrude too much. Cylinder drain cocks are frequent casualties of derailments! I will make up the linkage to operate them later.

Stage 2 Assembly

Having already put in the studs for the cylinder covers the next stage was to cut out the gaskets. Maxitrak supply a sheet of cartridge paper out of which you cut out gaskets. Not a difficult job, and I cut the holes for the studs with a scalpel. The cylinders with the rear covers fitted are shown here, with front gaskets yet to have their stud holes cut.

Before jumping in with the next step and bolting the cylinders to the frames I decided to do a trial fit up of the front end plumbing. Easier to do it now and see how it all fits rather than try to decipher it when things are screwed up and maybe difficult to get at. The fit up is shown on the bench. The top pipe is the steam pipe from the regulator and goes to the two steam chests. The bottom pipe is the exhaust and goes via a four way connector to the blast pipe, which is standing vertical. The four leg of the fitting holds the exhaust drain cock, which you can see at the bottom. The fittings are compression fittings with olives that compress around the copper pipes. Very easy to fit up and no soldering!

So now I had convinced myself I knew how the front end pipes went together it was time to assemble the motion. The first step is to bolt the cylinders to the frames. As I have the 7.5" gauge version there is a 1/8" spacer that goes between the cylinder and frame to move the cylinders out to be in line with the wheels. The instructions make no mention of these spacers for the wider gauge kit, by the way. Some filing of the mounting holes in the frame was required in order to get all the bolts to fit nicely into the cylinders. Also you must check alignment at this point to ensure the extended center line of the cylinder goes through the driving axle center.

The cylinders are fitted with the pistons installed and the rear covers screwed on. Also the exhaust pipes must be fitted BEFORE you bolt up the cylinders as there is no way to fit up the plumbing otherwise. You can see the the left hand cylinder and exhaust pipe here. The pipe goes through a hole in the frames and the cylinder bolted up. The four way fitting is then put on the pipe and the other cylinders exhaust pipe is put through its hole and into the fitting. Then the s econd cylinder can be bolted up. I actually had to cut about 3/8" off each pipe to make them fit properly. While doing this you also have to keep an eye on the cylinder alignment, and sometime I wished I had an extra hand or three!

Anyway it was done. The right hand cylinder is shown bolted on here. Loctite was used to ensure the bolts won't work loose in service. There must be quite a bit of stress and vibration on these bolts they take the back and forth thrust of the cylinders to the frame.

Once the cylinders are on the frames the motion bars and brackets can be fitted up. Now this was not just a simple matter of bolting the brackets to the frames. In the first place as supplied the motion brackets fouled the side rods and just touched the wheels flanges. As this was with no boiler etc. fitted I could expect the suspension to settle some more as the other parts were added and this would certainly cause the wheels to rub against the motion brackets. So I cut and filed the brackets as shown here. The one on the right is as supplied and the one on the left has the relief filed out for the side rods. I have yet to do the relief for the wheel flanges.

The motion bar is attached to the rear cylinder cover by a stud and nut. I had to file the ends of the bars a little to ensure they seated snugly. The other end is attached to the motion bracket by a small angle bracket. The instructions say you may have to either file the motion bracket or shim this angle bracket to ensure the motion bar is truly parallel to the piston rod. Well, as mentioned, I had to do a lot of filing! I then positioned the small angle brackets, marked the hole positions on the motion bars and motion brackets, removed them and drilled them.

Final fitting up of the motion bars has to be done with the crossheads screwed on to the ends of the piston rods and fitted over the motion bars. At the same time you have to install the connecting rods in order to position the crosshead on the piston rod correctly to give equal dead space at forward and backward dead center positions. I had to saw about 1/4" off one piston rod as the screwed end projected into the crosshead too far to allow the connecting rod to be fitted. The motion must then be checked to ensure there is no binding and nothing fouls anything. This view shows the assembly on the right hand side. It all takes a little work to get everything in line. You are juggling several setups at once.

I had another problem on the left hand side. The left hand crosshead has an extra bracket fitted to drive the crosshead feed pump. This fouled the side rod end at the top of the rotation of the wheels. Quite a bit of filing was needed to give what I considered to be a safe clearance. I will be watching this closely as weight gets added to the engine. This is the left hand setup. You can see how I had to file the motion bracket in two places to clear the side rods and the wheel flange. You can also see how close the pump drive extension is to the front "big end" of the side rod.

Once the pistons, motion bars and connecting rods are set up the next step is to install the steam chests an valves. Again you must ensure the steam pipes are screwed into the chests first as they, too, pass through holes in the frames and go into the Tee connector in the center of the engine. Gaskets are cut out of the cartridge paper again, and the studs are cut from the threaded rod as before. Actually I had cut all the studs before starting to fit anything up.

So the steam pipes are screwed into the steam chests, the steam chests placed on top of the cylinders with their gaskets, making sure the steam pipes fit nicely into the tee connector. The valves MUST BE INSTALLED on the valve spindle as you fit up. Then the studs are screwed down through the steam chest and gasket into the cylinder with a drop of Locktite. If you forget the valves you have to pull out the studs, and as they have been locktited(?) in its a heck of a job. Guess how I found out!

Actually I think this is a slight design flaw, and I think it can be fixed. You can only remove the steam chests by taking out the studs, as the chests have to moved sideways to release the steam pipes from the Tee connector. I think it would be a good idea to cut the frames to make the hole for the steam pipes in to a slot, so both steam chests can be lifted up and then separated. Of course, in a finished engine that would also mean removing the boiler. But at this stage when fitting up and taking down several times to get things right seems to be the normal process it would make it easier. And it is almost impossible to remove the studs after the Locktite has really set without destroying the threads. When I get the boiler I will see if there is any reason not to cut the slots.

At this point it looks like this. The last step in the assembly is to install the valve rods from the eccentric rods to the valve spindles. There is about a 1/4" offset so the rods have to be "kinked" slightly. This is not a problem, I just put and end in the vice and pulled a little and then treated the other end the same way. So after all this the engine looks like the picture below. Now I had to set the valves and pack the glands etc. The fun I had with that will be the subject of a future installment. Stay tuned!

Go to Contents of Stages 3 and 4