Building Kozo's New Shay locomotive

[vcutajar]

Just out of curiosity, but what did you do to make those screw in fittings leak proof?

I am asking because shortly I might need to do something similar.

Vince

[crueby]

Just out of curiosity, but what did you do to make those screw in fittings leak proof?

I am asking because shortly I might need to do something similar.

Vince

Hi Vince,

Combination of things. For fittings with a large enough flange on the bushing and fitting surfaces, I used viton o-rings or gaskets cut from sheet viton (both are readily available, even through Amazon who sell 100 count bags for a few dollars). Viton can handle pretty high temps, but not direct flame. In a lot of places used some high temp brush on thread sealant from the home center. Stuff I got was Block blue sealant. The instructions said to brush on and assemble, but it only worked for me on these small threads by brushing on the threads and letting it dry before assembling, otherwise it pushed out of the threads during assembly. For a quick seal on ones I was removing a lot during tests, used wraps of ptfe plumbing thread tape. Hope that helps!

[Steamer5]

Hi Crueby,
 You are making nice progress! You will find the barb on the blowdown valve a great place to add the water to the boiler as well when you steam her up! Didn't take me long to find a better way to put water to the boiler rather than use the hand pump! Still pays to check that the hand pump works every steam up!

Cheers Kerrin

[crueby]

Time to throttle up the build... okay just time to make the throttle assembly.

Got started with turning down a disc of brass rod to size (first one side as shown in photo 1, then turned it around and took the other side down).

After that, drilled all the holes through for mounting to the bushing on the boiler, and drilled/tapped all the holes for the safety valves (2 of them), the snifter valve (which allows air to pass into the engine when the throttle is closed), and passages for the steam to come up from the boiler. Lots of holes in all directions, I'll leave that up to Kozo's book to show in detail - took lots of referring back to the plans to make sure it was all correct since there are several intersecting passages. (photo 2)

Last to drill was the passage for the throttle valve stem itself. The outer end of this is larger to take the bushing that leads out. (photo 3)

Fourth photo shows it all together, with the bushing silver soldered in place and the mounting screws sitting in thier holes.

Then I turned attention to the valve stem - the end of this is tapered at 12 and 30 degrees. (photo 5)

Once the end was done, turned down the rest of the stem to size (loose fit in throttle body outer hole). (photo 6)

Then, turned it around and threaded the end to take the clevis. (photo 7)

Last photo shows the pieces so far - next up will be to make the mechanism that threads onto the bushing, which holds the throttle valve stem in a spring loaded setup so that releasing the throttle lever in the cab snaps the throttle closed.

-----------------------------------------------------

Kerrin - you mention using the blowdown valve as a place to add water - do you use an external pump, or just a tube up higher than the top of the boiler with a funnel? In the book Kozo shows using the fitting under the sand dome to add water, though that means taking off a few pieces to access.

[crueby]

First of the new year deserves some new parts! More of the throttle linkages done, ready to move on to the throttle lever end of things.

Started out making up a batch of clevises and link arms out of square brass. Marked out and drilled the holes (photo 1), and milled the openings for the arms. (photo 2)

One of the parts is a ring that slides on the throttle bushing, with arms that hold the linkage at one end and a spring at the other. This sliding arm is used to adjust the position and tension on the throttle valve stem when closed. So, drilled a hole in the end of a brass rod and turned the outside down to size. Then, used the mill to put a shallow slot in the side, turned it 180 degrees with the rotary table (the adapter that holds the lathe chuck to the table is a VERY handy item), and milled a matching slot in the other side. (photo 3)

In a piece of sheet brass, I drilled the outer holes in the arms, and milled a slot in the center that made a sliding fit into the grooves in the center ring. (photo 4)

With that part slid into the ring, it was silver soldered together. In the background is another of the arms in the linkage. (photo 5)

Next photo shows milling off the excess from the arms, to leave a tapered shape.  Hard silver soldering is something I wish I had learned years ago - would have been able to make better parts much easier for a bunch of the earlier projects....

After filing the ends round, the armed wing was complete. (photo 7)

Last photo shows the parts so far. The holes in the arms closest to you get a spring, and the two left clevises will get a threaded rod sized to fit the distance to the throttle lever in the cab (to be made next).

[crueby]

Got on a roll this morning/afternoon and got several parts for the throttle lever assembly made. First up was the lever itself, which is made from a turned handle silver soldered to a bar stock lever. The handle was freehand turned on the lathe, and smoothed out with files. (photo 1)

The reversing lever, made later on in the book, shares a lot of the same kind of parts as the throttle so I am making up two sets. Second photo shows the two handles after parting off and threading the end for a short piece of screw cut off a bolt that will be used to hold it to the bar for silver soldering. (photo 2)

Next up I clamped two lengths of bar steel in the vise and drilled/tapped the end to match the bolt sticking out of the handle. (photo 3)

Next photo (4) shows the two handles soldered up.

The throttle lever is a little shorter, and it has a stub sticking out the side to take the clevis from the throttle assembly. (last photo)

Next up is the locking lever - next post....

[metalmad]

Hi Crueby
She is looking great
Still following along down under.
Pete

[crueby]

On to the locking lever, which holds the throttle in one of the preset positions that will be notched into the rails the lever rides between. This is a strange tapered/notched shape, so it was made on the end of a longer bar, and will be sawn off after the rest is shaped. Otherwise there would be no way to hold this little sucker. For scale, that is a 3/8" mill bit in the photos. Started out by taking down the two sides, to make a narrow tounge. (photo 1)

Second step was to drill the pivot hole in the side of the tounge. (photo 2)

Next up was to mount the bar at an angle in the vise, and mill a taper into the tounge side. All these milling operations were done with a series of light cuts, so I did not put too much stress on the part - did not want to risk catching it and bending it. (photo 3)

Then, turned the part over, set it to the angle needed, and milled in the taper on the base of the latch. (photo 4)

Last milling operation was to flip it over again and mill the final taper on the back side of the base. All these operations left a shape that looks a bit like a tiny snow shovel. The 'blade' end of the shovel will latch into notches in the rail, and the hole in the upper end will provide a lifting point for the moving handle. (photo 5)

Next photo shows the parts after milling, but before sawing off the main bar. You can see that there is one part on either end. One will be used for the throttle, one for the reverse lever.

After sawing off and cleaning up the ends, the two parts are done. You can see why it is neccessary to make them from the outer end in - otherwise way too hard to hold safely. (photo 6)

Last photo shows the parts next to the throttle lever itself, after drilling/tapping the rest of the holes in it. Well, most of them - there is one more guide block on the lever that I will make next time.

[crueby]

Hi Crueby
She is looking great
Still following along down under.
Pete

Thanks Pete - glad you enjoying the show! 

[b.lindsey]

Lots of work in these little parts but they look good crueby. That cab will be filling up with controls and valves and links of all sorts soon

Bill

[fumopuc]

Hi Crueby, still following long, also from the other side of the pond.

[kvom]

Thought I'd reply to the question about filling the boiler via the blowdown valve.  On a lot of the 1.5" models I've seen the blowdown is threaded to take an adapter that allows a standard garden hole to be screwed on.  Typically this adapter has a 1/4-NPT male thread and can be found at most hardware stores.  It would probably be too large a thread to do directly to the blowdown at your scale, but a reducing bushing could work.

[crueby]

Thought I'd reply to the question about filling the boiler via the blowdown valve.  On a lot of the 1.5" models I've seen the blowdown is threaded to take an adapter that allows a standard garden hole to be screwed on.  Typically this adapter has a 1/4-NPT male thread and can be found at most hardware stores.  It would probably be too large a thread to do directly to the blowdown at your scale, but a reducing bushing could work.

That makes a lot of sense - thanks for the explanation!

[crueby]

Going on with the throttle lever mechanism - now that the locking lever was made, needed to make the bracket that holds it in place. As with the lever, used a piece of steel longer than needed so there was a way to hold it, and slotted the end to go around the lever and the arm. (photo 1)

Then, needed a slot going crosswise for the 'shovel blade' part of the lever to sit in. I dont have a mill that narrow so I cut it with a jewelers saw (cut down each side, then across the bottom to remove the waste). (photo 2)

After that, I drilled the mounting holes (2-56 thread) in the bracket, and drilled matching holes in the lever arm. First drilled one, ran in a screw, and drilled the second to make sure they would line up. (photo 3)

Last two photos show the assemblies so far (the one at the top in the photo is the reversing lever, bottom is the throttle lever). Next up will be to make the little bracket/handle that activates the locking lever - that might be a few days, I have some work to finish up on an RC model for a run next weekend. This small work should be good practice for a model I want to make someday - one of George Britnell's Tiny engines.

[ths]

Miss a few days of this thread, there's another 27 chapters! Great stuff you've been doing, those levers came out well. Hugh.