All posts by Mark Stockbridge

Boiler Tested and Installed!

The Shay boiler has been completed and tested by Richard Jacobs of TrainMax, LLC in New Orleans, LA. As soon as I got the good news, I hit the road to pick it up. I was so excited that I managed to drive from Orlando to New Orleans and back in one day.

If you’re going to do a hydrostatic pressure test, GO BIG! One of the largest gauges I’ve ever seen used for testing a model boiler!
 

The boiler was lifted out of the shop with a forklift and placed into my SUV for the return trip home.
 

Using an rolling engine hoist, I was able to move the boiler into the shop for cleaning, priming, and installation onto the Shay frame.
 

After a wire wheel treatment to remove minor surface rust, I treated the boiler to a coat of primer to protect it while I continue work on it. It will eventually get painted black once the various accessory components are attached/welded on.
 

I’m very proud to own the first Shay boiler fabricated by TrainMax, serial #SH001.
 

The boiler test-fitted onto the Shay frame. Here, it is resting on 1″ square tubing while the front is held down with a ratchet strap because the firebox, with so much mass, wants to tip backwards.
 

Angle brackets welded onto the sides of the firebox. Care was taken to avoid existing firebox stay bolt welds. The horizontal gap in the middle of the bracket will receive a boiler clamp that bolts onto the frame.
 

The front boiler saddle tack welded into place on the frame. With the boiler now resting in its proper place, the temporary ratchet strap was removed.

Lots of plumbing yet to do!
 

Johnson Bar and Linkage

The Johnson bar is located in the cab and used by the engineer to put the locomotive in forward, neutral, or reverse. There are typically a series of notches in the arch designed to hold the lever in any particular position. Often, the engineer will move the bar all the way forward or backward and then “notch back” a bit once the locomotive is underway to make the engine run more efficiently.
 

Two pieces of steel were stacked and clamped on the rotary table and alignment holes were drilled, followed by milling the arch radius.
 

Both arch pieces were bolted together for alignment and re-positioned vertically on the rotary table to begin milling the notches.
 

Using a .125″ carbide endmill, the notching process was slow going. Eventually, the two arches will be spaced apart so that the Johnson bar lever will move freely back and forth. Lots of slow but sure milling activity caused some slight magnetism!
 

Main components of the Johnson bar assembled with spacers for the lever.
 

Grip link attached to the lockout lifter. The guide block holding the lifter is moveable for spring tension adjustment. The grip is bent from brass sheet.
 

Johnson bar mount has a bronze bearing holding the lifting yoke shaft.
 

View showing the lifting yoke and adjustable link which will connect to the reversing rocker shaft on the engine.
 

U-Joints, Yokes, and Drive Shafts

There are many driveline components involved that transfer the power from the Shay steam engine to the wheels. Geared Shay locomotives are unique in that driveshafts connect the engine’s crankshaft to the front and rear trucks via slip joints and universal joints. This allows the locomotive to traverse steep inclines, sharp turns, and uneven track work usually found in mountainous mining and lumber railroads. A geared locomotive’s distinct advantage over a side rod locomotive is that all the power is distributed evenly to each weight-bearing wheel, making geared locomotives some of the most powerful steam engines in the world. They are not fast, but they are mighty.

Each universal joint has two yokes, one on each side. One type of yoke is designed to fit a round shaft while the other is permanently attached to a square slip joint tube. Both begin life on the lathe, and this one will fit a round drive shaft.
 

Drilling the cross hole for the yoke posts that will connect to the u-joint housing.
 

Milling flat sides on the yoke.
 

I used a digital level to turn the yoke 90° in order to mill out the center of the yoke. The trick to using a digital level is to “zero” it on the vise or mill table and then placing it on the part.
 

Milling the center of the yoke.
 

It was important to leave the end of the yoke flat for the key way broaching operation on the hydraulic press.
 

Once the key ways were broached, then the final shape was milled using a corner rounding endmill.
 

Short sections of drill rod were then inserted though the cross holes and silver soldered in place. The center part of the rod was then milled away and the inside contact points of the yoke posts were further strengthened with TIG welds.
 

The hubs that were cut off earlier from the backs of the ring gears were turned into u-joint housings.
 

I cut four sections from a chunk of 2-3/8″ pipe I had laying around and turned them down for u-joint retaining rings.
 

Drilling and counter boring the u-joint retaining rings. Each ring was matched to its own housing so I scribed lines to help with re-positioning later on.
 

One of four sets of u-joint housings and retaining rings ready to be cross-drilled.
 

I assembled a u-joint housing and ring with all the correct length bolts except for two longer protruding bolts which rested on top of the rear vise jaw. I also set up an adjustable work stop locator against the housing. When it came time to rotate the housing for the next operation, I simply moved the longer bolts to the next set of holes and re-positioned it against the work stop locator rod.
 

Drilling and reaming the holes for the u-joint yokes.
 

Here, the housing has been rotated 90° to begin the next set of operations.
 

Turning and parting off bronze bearings for the u-joint yokes.
 

Four assembled universal joint housings ready for their yokes.
 

Milling one of the yokes that will be attached to a slip joint square tube.
 

Slip joint square tubes ready to be joined to their respective yokes. These were eventually brazed together.
 

Steel slip joint shaft that telescopes inside of the square tube was turned from square stock.
 

One of the assembled drive shaft slip joints with universal joints on the Shay. The engine’s crankshaft is now connected to the trucks!
 

Brakes Shoes and Rigging

The Shay utilizes cast iron brake shoes that come into direct contact with the wheel treads. The eight shoes are cast into a single ring which makes it easy to machine them all at once.

First, the cast iron ring containing all the brake shoes was turned down on the lathe. This included the inside of the ring which was turned to a 2.5° angle matching the taper of the wheel treads (as per IBLS standards).

Here, the ring has been centered on a 10-inch rotary table placed horizontally on the mill to drill the holes for the brake beam hangers. Note that there are two halves to the ring: 4 shoes for the right side and 4 shoes for the left side.
 

The rotary table with the ring still attached was raised into the vertical position to mill out slots for the brake beams. Note that I fixed a sacrificial aluminum disc under the brake ring so that the cutter will mill completely across the casting.
 

Drilling and tapping the brake beam mounting holes.
 

The completed brake ring casting before separating the shoes.
 

Four finished pairs of Shay brake shoes ready to be installed.
 

The brake rigging is comprised of various hanger blocks and levers installed on the trucks. Fabricating these took a bit of time because there are so many of them and each one required several machining operations.

Yes, this brake anchor looks crooked because it’s supposed to be! The funky angle is to allow clearance for a lever and rod assembly to come through the bolster in-between the springs.
 

A flock of brake hangers.
 

The brake beams are made up of two 1″x1/2″ C-channels welded together back-to-back. Ugly welds got ground away. I also used some metal epoxy to fill in the joints.
 

A few quick coats of paint and it was time to assemble the brake beams.
 

Brake hangers in place and ready for the brake beam.
 

Here are the brake beams attached to their hangers. All that is left is to make the push/pull rods and a few levers, along with the steam brake cylinder (which will be in a future post).
 

Gears (Trucks pt. 2)

This is one of four stock Martin gear and pinion sets that need to be machined to fit the Shay trucks.
 

First, I opened up the bores of the ring gears on the lathe to a certain depth because I planned on reusing the cut off hubs later when fabricating the universal joints.
 

I made a simple fixture to hold the ring gear vertically in the horizontal band saw to cut off the hub.
 

The ring gears were positioned so that the saw blade would just clear the opened up bore depth.
 

I was pleased at how straight the saw cut through the ring gears on the fixture, leaving as much of the hubs as intact as possible.
 

Back to the lathe to turn the front faces of the ring gears.
 

A ring gear positioned on the mill to drill and counterbore the mounting holes using the bolt hole circle function on the DRO.
 

The pinion gears needed to be bored out as well. These will receive a special drive hub that will be TIG welded in place.
 

Turning chamfers on the pinion gears and drive hubs for TIG welding.
 

The pinion gears and drive hubs ready for TIG welding.
 

Completed ring and pinion gears ready to be installed on the Shay trucks.
 

I fabricated two simple frame stands that bolt onto my hydraulic lift table in order to easily roll the trucks in and out while providing a stable base for the frame and engine.
 

Getting prepared to work on one of the Shay trucks.
 

Drilling and tapping the gear mounting holes employing the same DRO bolt hole circle specs used for the ring gears.
 

Broaching key ways in the wheels. One down, seven to go…
 

Cutting a key way in one of the axles.
 

Completed wheel, gear and axle set.
 

Bearing bronze thrust bushings are installed in each firemans-side truck journal behind plates with adjustment bolts to ensure there is no side-to-side axle play.
 

I also bent and added the truck frame end bars at this time.

Now on to the truck brakes and paint…
 

Setting the Eccentric Angles

19 degrees

The eccentrics are designed to be paired together but flipped with their centerlines set at 19° from from the “horizon” line.

 

IMG_1543

In order to accomplish this accurately for both sides of the engine, I fabricated an aluminum positioning jig with a 5/8″ ground drill rod as a pin.

 

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There’s probably a proper mathematical formula out there to figure the angle, but since I’m not a trained “mathlete”, the bottom of the aluminum block was simply milled away little by little and the eccentrics repeatedly test fit with everything resting on a granite surface plate until the eccentric centerlines were at exactly 19º. It works for me.

 

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Then the whole assembly was securely positioned in the milling vise to be cross drilled for a roll pin. At this point in the process I was “in the zone” and unfortunately didn’t take any photos of the clamping, drilling, or cross pinning.

 

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To set the eccentric position, I removed the upper cylinder head and placed a dial indicator on the piston to find top dead center of the crankshaft while a digital level ensured that engine was perfectly level.

 

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Then the pinned eccentrics were slid onto the output shaft and the digital level placed on top of them, resting on a parallel. I rotated the eccentrics ever so slightly until the digital level read zero and then tightened the set screws. The process was repeated for the other side of the engine and now all the eccentrics were in theory, correctly timed to the crankshaft (or pretty darned close).

Eccentric Rods, Expansion Links, and Rocker Shaft

Eccentric Rods

The Shay uses an eccentric-driven Stephenson’s valve gear arrangement allowing engine reversing as well as permitting manual cutoff of steam admission to utilize the natural expansion of the steam, using its own energy rather than continuing to draw from the boiler.

Each eccentric strap is attached to the expansion link by a flat stainless steel rod.

Drilling eccentric strap mounting holes in 1/8″ thick stainless steel flat stock
The final widths of the upper and lower ends were machined and then the centers were tapered to meet. The lower ends were also shaped to fit the eccentric straps.
Machining the side tapers.
Test fitting the rods to the eccentric straps.

In order for the eccentric rods to line up with the expansion links above them, slight bends were put in the lower end.

Using a bender to accurately place bends in all four eccentric rods.
Completed bends. The upper expansion link holes were eventually drilled but I forgot to photograph that process.
Rods attached to the eccentric straps showing how the slight bends help to line up the upper portions to the expansion link.

Expansion Link Assembly

The curved and slotted expansion link pivots on the valve stem cross head via two eccentric eccentric rods. There is one expansion link assembly for each cylinder and both must be identical.

First came the pivot brackets…

Slots were milled in two pieces of steel at the same time.
Holes drilled…
…and countersunk.
Completed expansion link pivot brackets.

Next, came the fabrication of the slotted expansion links. Because the radius of the expansion link curve is greater than my 10″ diameter rotary table, I affixed a 3/4″ thick piece of aluminum to the rotary table and indicated it off the center with scribed lines and spot drill marks in case I need to remount it in the future.

Scribe lines and spot drill marks.
Scribed arc indicating the center of the expansion link. It’s out there!
To ensure both expansion links are exact duplicates, I stacked two steel plates in position over the scribed arc. A couple of homemade angle clamps did the trick for one end.

I then drilled and tapped holes for bolts to provide additional hold down capabilities. These bolts will also secure everything in place as the outside shape is milled away and the angle clamps become separated.

Once the two plates were sufficiently mounted, I commenced with milling the curved slot.
 

I placed some high visibility duct tape on the rotary table degree marks to highlight the 12 degrees of rotary movement needed. This made it easy to repeatedly hit the ends of the milling path as the cutter went deeper.
Finally through both pieces of steel!

Next came the outside shape of the expansion links…

This is where the additional bolts came into play, holding down the pieces as the bottom of the links were shaped.
Drilling oiling holes.
Completed expansion links and pivots.

Upper Rod Ends

The eccentric rods are attached to the expansion links via stainless steel rod ends. These were ganged together whenever possible to ensure they were machined identically.

Eccentric rod ends test fitted to their expansion link assemblies (two of them actually will get flipped over).

Expansion Link Block

A bronze link block rides in the curved slot of each expansion link. These blocks need to be machined with the same arc properties of the link, so the aluminum block fixture on my rotary table was put to use again.

Each link block has a single hole so a larger piece of bronze was bolted to the aluminum fixture using what would become the final mounting holes.
Both link blocks were machined together with the intent to split them after unbolting from the fixture.
Completed link blocks.
Link blocks positioned in their expansion links.

Rocker Shaft and Brackets

The expansion link assemblies are controlled by a rocker shaft that connects them to a lever in the cab of the locomotive.

First came the fabrication of the brackets…

Completed rocker shaft brackets.
Rocker shaft brackets bolted to the cross head guides.

Next came the rocker shaft arms which have a tapered arc design requiring a unique setup using the aluminum fixture and rotary table again.
 

The arms were silver soldered onto a drill rod and assembled in the rocker shaft brackets.

Reversing link arms were then fabricated to connect the rocker shaft assembly to the expansion link pivot brackets, one on each side of the engine.
 

The small cylinders were silver soldered to the arm links…
…and then threaded for the rocker shaft arm.

The whole assembly moves back and forth quite nicely once squirted with oil.

Steam Header

Steam produced in the boiler will enter the engine under high pressure though an assortment of copper pipes and brass fittings and is designed to be easily removed through the use of the two custom steel flanges.

Turning the main body of the flanges which will mount directly to the cylinders.
 

Using the bolt hole circle function on the DRO, it was easy to layout where the 3 flange cover mounting holes were going to go.
 

Drilling and tapping the mounting holes for the flange covers.
 

Machining four flats for tightening the main flange bodies to the cylinders with a wrench.
 

Flange covers before drilling the mounting holes and side holes for the piping.
 

Drilling through holes which will be used to mount the flange covers to the main flange bodies.
 

Flats were machined and then a hole was drilled and tapped in the side for the steam piping.
 

Steam header assembly ready to mount to the main flange bodies which are already on the cylinders. The temporary pressure valve and gauge is for testing running the engine on compressed air
 

Completed steam header mounted to the cylinders. Hi-temp gasket material is sandwiched between the flange halves to ensure against leaks. Almost ready for air!
 

Cylinder Cocks and Linkage

Cylinder cocks are valves that release steam condensate (water) that occurs when cylinder temperatures are significantly cooler than that of the incoming steam, typically when the locomotive begins to move. As hot steam comes in contact with a colder surface, liquid water will form which does not compress! As the pistons move up and down, damage can occur if there is too much water in the “compression area”. As soon as the cylinder temperatures rise due to the continuance of incoming steam, the amount of condensate lowers at which point the valves can be closed. Cylinder cocks have very small openings which allow just enough water to be expelled without a drastic reduction in steam pressure, allowing the engine to continue to create power until they are closed for normal running.

There are four manually operated cylinder cock valves, two for each cylinder (top and bottom). The brass valves were purchased online and the linkages, drain pipes, and elbows were fabricated from brass. A simple hand lever opens and closes all four cocks at the same time (up is open and down is closed). The linkage design was inspired from a photo of a prototype Shay running in Cass, WV.

Pistons and Rings

The 2″ diameter pistons were turned from gray cast iron.

To ensure concentricity, each piston was mounted on its piston rod, chucked up and turned to the final diameter.
 

Piston ring grooves turned with an indexable cut-off tool. Since my lathe is not capable of turning slowly enough, I fabricated a crank for the lathe and slowly hand-turned the spindle while advancing the tool to avoid chatter.
 

It took some time but yielded good results. Bonus: it was also a pretty good workout for my left arm!
 

Cast iron piston rings were fitted and compressed with a hose clamp and slathered with oil in order to slide down into the cylinders.
 

Valve Stem Guides and D-Valves

Valve Stem Guides

The valve stem guides, one on each side of the engine, keep the valves properly lined up on the steam ports as the “monkey motion” goes up and down.

I started machining the guides by squaring up two blocks of steel.
 

Next, the valve guide channels were milled.
 

Then the sides were milled away and flange holes drilled.
 

The valve stem crossheads were machined from bronze.
 

Brass valve guide retainers to hold the crossheads in place.
 

Then I turned and machined the link block washers that mount to the valve stem crossheads.
 

One of two complete valve guide contraptions waiting to be installed on the engine.
 

Valve guide assembly mounted to the main crosshead guide.
 

D-Valves

The D-valves are used to divert incoming high-pressure steam to the top and bottom of each cylinder via ports in the steam chests. They are actuated through a complex pushrod system driven by eccentrics on the crankshaft.

The D-valves were born of this chunk of squared-up brass.
 

I machined the valve stem keeper slots for both valves on one side and then flipped the block to machine the “D” shaped recesses on the valve face, leaving enough material between them for the separation cut and finish mill.
 

After splitting the two valves apart.
 

D-valves, stainless steel valve stems and valve stem keepers.
 

D-valve assembly installed in the steam chest and connected to the valve stem guide.

Treadmill Motor Break-in System

I was lucky enough to salvage the motor and controller from a free but broken treadmill. After complete disassembly, I discovered that the safety switch was at fault, so I simply bypassed it (no longer a need for it as there was nothing much left of the treadmill to “run” on).

Using some scrap steel shelving, I welded together a simple open box that holds all the treadmill electronics, including the push button control board. This assembly simply sits on top of the shay frame with the wires running out to the motor.

 

The 2.5 hp DC treadmill motor has a screw-on steel flywheel as it was designed to only run in one direction (driving the running tread forward). Upon digging through a local bike shop’s trash bin, I managed to rescue a used bicycle wheel sprocket which I welded to the flywheel’s hub.

 

After hearing about my project, the bike shop’s owner was kind enough to donate a used pedal drive sprocket complete with an aluminum hub that fit perfectly on the shay crankshaft. I purchased a brand new chain from him to connect the two sprockets.

 

The treadmill motor and its adjustable bracket is mounted on a piece of angle iron which is firmly attached to the shay frame using two c-clamps. Lining up the two sprockets is a very simple task.

 

I squirt lots of oil into the open oil passages while it runs. The oil eventually works its way through the bearings and emerges nice and dark which tells me that the surfaces are breaking in well. I’ve had it cranking continuously for up to two hours with no issues at all.

With the sprocket and chain reduction, I found that the lowest speed setting will turn the crankshaft at around 85 RPM. Pointing a digital laser thermometer at the bearings and engine block journals early during the break-in period indicated that the parts rarely surpassed 25-30 degrees above ambient air temps. Now they regularly run less than 5-10 degrees above normal.

Below is a slow-mo video of it running. The only noise you hear is that of the chain and sprocket!

 

https://youtu.be/NZaIP8KXhFk

 

This break-in method will definitely help keep everything nice and loose as parts are continuously added to the engine. Soon I’ll be running it on compressed air!

Cylinders

The 2-cylinder Shay has a bore and stroke of 2″ x 2-1/4″.

I started by face milling one end and then flipping the casting to make sure both surfaces were perpendicular. Once the cylinder ends were “square”, the casting was bored.

 

Then the steam chest faces were machined flat.

 

The 2 steam ports and single exhaust port were then machined. The center exhaust was milled slightly larger which means the D-valve dimensions will need to widened to accommodate.

 

Drilling and tapping the holes for mounting the cylinder heads.

 

To machine the angled steam passages on both ends of the cylinders,  I fabricated an aluminum block fixture to which each cylinder was mounted and clamped in the mill vise at 22°.

 

Machining the steam port passages.

 

Turning the lower cylinder head.

 

Boring the lower cylinder head for the piston rod.

 

Tapping the bore for the piston rod packing nut.

 

Test fitting the lower cylinder head with the piston rod in place before the head bolt holes were drilled.

 

Turning, tapping, drilling, and parting off the packing nuts.

 

Completed piston rod packing nuts.

 

Packing nuts installed in the bottom of the lower heads.

 

Quick test fit of the upper heads.

 

The upper cylinder heads after drilling all the bolt holes. I also turned the tops of the cylinders to match the diameter of the heads.

 

I ordered four small brass cylinder petcock valves and machined the bosses onto which they will be mounted.

 

Then I tapped threads for the valves and drilled the tiny steam relief ports.

 

I also drilled and tapped two mounting holes (one in each cylinder) for linkage standoffs which will eventually connect and control all four petcocks.

 

The four petcocks temporarily fitted. Use of thin copper or brass shim washers will ensure the valves are positioned correctly when tightened.

Eccentrics and Straps

These components have often been referred to as “monkey motion” because of the unique way they wobble around when the engine is running. Properly setup eccentrics are key to efficient valve timing and result in a good running and powerful steam engine.

The four eccentric straps are bronze castings that were ganged together for initial machining to ensure uniformity.

 

Then they were individually faced to the required thickness.

 

I drilled and tapped a hole on both sides of each eccentric strap, one half was tapped, the other half a through hole for 5-40 bolts. After the straps are split, these bolts will hold the strap halves together while the center is bored.

 

Using a slitting saw, each strap was cut down the centerline.

 

Once the saw cut through one side, I placed a clamp on it to reduce harmonic vibrations as the cut continued on to the second half.

 

All four eccentrics ready to be bolted back together for boring.

 

I fabricated a jig to hold the straps in place during the boring process which ensured the exact same final dimensions for all the eccentric straps.

 

Eccentric rod recesses were milled and mounting holes drilled and tapped.

 

Dual oil holes were drilled in the top of each eccentric strap for easy-access lubrication.

 

The eccentrics were turned from cast iron round bar. I turned the final diameter on a good portion of the bar and then machined each eccentric one at a time, individually match-fitting each eccentric strap.

 

Once fitted, I oiled the parts and broke them in for about 5 minutes while running the lathe.

 

Each eccentric was then parted off and the cast iron bar was refaced to start the next eccentric.

 

I made a clamping fixture by squaring up a block of aluminum and turning a clearance-fit recess for the eccentrics to be mounted when drilling and reaming the offset hole.

 

Scrap angle iron was used to create three simple hold down clamps which bolted to the fixture.

 

I scribed a lateral line and spot drilled two marks to help with future positioning when mounting on the crankshaft as the eccentrics will need to be angled 19° from horizontal at top dead center.

 

I center drilled the .25″ offset hole then drilled it 39/64″, leaving 2% material for the final 5/8″ reamer.

 

Reaming the hole to final size.

 

Drilling and tapping for set screws. This is where the previously scribed centerline came into use for positioning.

 

Completed eccentrics and straps.

 

Exhaust Manifold

Steam will eventually need to exit the engine, so a simple collection header block was fabricated from a huge chunk a bronze I had laying around. The “used” steam will then be piped forward to the smoke box in front of the boiler and directed upwards through the smoke stack. This will produce a venturi effect that pulls hot gases through the boiler, thus helping to heat the water and make more steam. Simple as that!

The completed bronze exhaust manifold is mounted to both exhaust ports on the cylinders with a gasket in between each.

 

I began by face milling each side to square it up and finishing the ends with an end mill for a total length of 7″.

 

Next, I clamped the manifold upright and drilled a hole halfway through. Then I flipped it and drilled again to create single hole that runs the entire length.

 

The manifold outlet hole was drilled in the bottom which intersects the lateral hole in the center.

 

All three holes were then tapped 1/4″ NPT.

 

The manifold was turned on it’s side to drill the exhaust flange holes. This is where the manifold will meet the cylinders.

 

The completed exhaust manifold minus two brass 1/4″ NPT plugs that will go into the ends to close it up.

 

Boiler Update

Richie Jacobs of TrainMax, LLC in New Orleans has provided more photos of the progress he’s made on the Shay boiler and it is looking great!

A glimpse of Richie in his native habitat…

 

Inner fire door ring and back firebox sheet

 

Throat sheet tacked in place. Note the amount of beveling, hence all the grinding that Richie has been up to!

 

Mud ring welding in progress.

 

Blow-down/drain couplings.

 

Firebox and boiler shell together for the first time!

 

Throat sheet, front tube sheet, crown sheet, and staybars.

 

Dry pipe coupling on the back head.

 

Staybars welded to the crown sheet and an inside view of the dry pipe coupling on the back head.

 

Auxiliary steam pipe.

 

Boiler shell tacked in place.

 

The firebox and boiler shell attached to a welder’s positioning rig – a boiler rotisserie if you will!

 

Connecting Rods and Crossheads

The connecting rods are made up of several components all working together to transfer linear motion from the pistons into rotational motion on the crankshaft.

The rods are steel with bronze split bearings at the bottom or “big end”. The upper crosshead bearings utilize bronze bushings.

I began by stacking both rod blanks in the mill to shape the upper ends and drill the hole for the cross head bolt.

 

I used an aluminum jig to set up the rod for profiling the side tapers.

 

The main rod bearings are milled blocks of bronze that were split and surfaced.

 

After splitting the bearing block, machining the mating surfaces, and fitting the halves together with superglue, I used four pieces of scrap aluminum held tightly against the sides with a rubber band to precisely indicate and center the bearing block in a four jaw chuck.

 

Boring the center hole prior to reaming to final size.

 

Test fitting a crank journal pin after reaming.

 

Profiling the outer rings of the bearings.

 

Back over to the mill to profile the exterior of the split bearings. These outside grooves are for securing the bearings in place within the rod straps below.

 

Both rod straps were machined out a single piece of steel and then split apart.

 

After drilling the mounting holes and rod bearing wedge adjustment slots.

 

Rod bearing adjustment wedges.

 

I fabricated a simple jig to position the main rod bearing at a precise distance from the cross head bearing in order to drill the through holes for the rod bearing strap. This assured that both rods were built to the exact same length (6.250″ between centers).

 

Fully assembled connecting rods.

 

Cross Heads

The bronze cross heads are attached to the tops of the connecting rods and the piston rod. The cross heads move up and down in the cross head guides on which the cylinders are mounted.

Bearing bronze blanks were turned in the lathe to match the inside diameter of the cross head guides.

 

The sides were milled down and various features were machined such as drilling and tapping the cross head bolt hole and creating oiling ports for the cross head bolt bearing.

 

Finished cross heads fit nicely into the cross head guides.

 

The cross head bolts are machined from steel hex stock, turned and threaded to size.

 

More boiler work!

Ritchie Jacobs of Trainmax in New Orleans has made some great progress on the shay boiler lately. He is very active when it comes to Facebook live videos and often documents the various things he is working on. I have come to really enjoy his videos as he thoroughly explains what his viewers are looking at, whether it’s a full scale locomotive or a model one. Check out these videos and photos he posted of some of his recent work on my boiler…

Steam dome video 1 (YouTube)

Steam dome video 1 (YouTube)

Steam dome video 2 (YouTube)

Steam dome video 2 (YouTube)

Throttle dry pipe video (YouTube)

Tube sheet work:

Rear tube sheet video (YouTube)

Rear tube sheet video (YouTube)

Firebox tack-welded up…

It’s starting to really come together!

Crankshaft

The beating heart. The crankshaft is what will translate the power of the steam engine to the gears and wheels to make the locomotive move down the rails.

I began by machining 1/2″ steel blanks which would become the four counterweights.

The 1/2″ holes for the main shaft and crank throws were drilled and reamed.

Then the angles were milled. A 1/2″ pin registered the counterweights together as they were machined all at once. Flipping the group over yielded the same angle on the opposite side. The next step was broaching the keyways (unfortunately, I got got ahead of myself and didn’t take any photos of that process). In order to make the broaching job easier, I did however upgrade my manual 20-ton HF hydraulic press by replacing the original jack with an air-operated jack, which I did take photos of.

This is the new bottle jack installed with the air motor situated behind it.

I robbed the ram from the old bottle jack and welded it to the cross beam which gives me about 2-1/2″ adjustment on the parts to be pressed.

I also turned an aluminum knob and attached it to the pressure relief valve for quicker jack raising.

The finished mods in place. Now all I need to do is squeeze an in-line air valve lever to vary the speed of the press. It works great!

Next, I had to machine the final curved shape of each counterweight. On to the lathe…

I made a simple aluminum fixture to hold the counterweights in the 3-jaw chuck to turn the final shape.

Keyways then needed to be cut in the crank throws and main shafts next. Back over to the mill…

Using a #304 woodruff cutter I cut the key ways in the crank throws and main shafts.

For final assembly, I heated the counterweights to 400°F in my heat treat oven for about 30 minutes before installing the crank throws and main shafts which had been chilled with dry ice. The components were machined for a .001″ interference fit and went together quite easily with the temperature differentials.

While the crankshaft does spin in the bearings, it is TIGHT!! I’m going to have to do some minor lapping to break it in for sure.

The finished crankshaft, engine block, crosshead guides, and cylinders mocked up on the locomotive frame. It’s starting to really look like a shay now!

Crankshaft Bearings

I started by milling a hunk of square bar bearing bronze into individual blocks.

Next I milled the recesses between the two outside flanges to create a tight slip fit into the engine block bearing journals.

I milled the bearing blocks taller than needed in order to split the bearing down the middle on my bandsaw.

Back to the mill to finish the split halves.

Split bearings ready for their bores!

Using the engine block as a fixture to ensure good bore alignment for all three bearings, I center drilled and stepped up the drill sizes before the final size of 39/64s.

I then finished the bearing bore with a 5/8 reamer. This pic is of the center bearing being held in the end journal for drilling/reaming. Since it is a wider bearing, it was positioned as high as possible before machining as the drilling process would try to pull it up.

The final reamed split-bore bearing halves.

Machining an oil recess groove in the bottom half of the bearing using an 1/8″ ball end mill.

Bearing caps installed and after test fitting a 5/8 drill rod it appears that the bore alignment is very close to straight but super tight! It will definitely require some break-in time with the crankshaft once it gets fitted.

Heat Treat Oven

Some of the grey iron castings required annealing as I ran into a few hard spots during machining.

For $50 I picked up what was left of large pottery kiln and then repurposed the fire bricks into a smaller design shop built oven.

I welded up a simple frame from 3/4″ angle and flat stock, made a door out of leftover sheet metal and attached it with two heavy duty hinges. The fire brick was hand cut to fit the frame and door and then channels were carved for the high temp Kanthal heating element. Refractory cement helps hold things together.

The old kiln’s analog control box was gutted and cut down to house the new digital Inkbird PID temperature controller and solid state relays. The oven runs on 240v and two 15amp fuses were installed for circuit protection. One toggle switch turns on the main power and a secondary switch turns the coil on and off.

A high-temp thermocouple was placed in the top center of the oven to relay real-time temperatures to the PID controller which regulates power to the heating elements.

A coat of red paint finished off the oven and after installing some high-heat door gasket material, it was ready to start “cooking” some cast iron.

This thing heats up FAST!! During a test fire, it reached a target temp of 1500° in less than 20 minutes and during actual annealing, the oven held high temps for nearly 12 hours with castings inside and the door latched closed. All in all, the oven worked perfectly as it is vital that gray cast iron cools very slowly after reaching approximately 1450° and holding for one hour. Almost like baking brownies!

The annealed castings now machine like butter.

Crosshead Guides

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The crosshead guides were farmed out to a local machine shop for boring since my little ol’ 11×26 lathe is not rigid enough for the job, not to mention the steady rest that came with the machine is too small. Along with the boring, the local shop was charged with turning each guide to length and truing up the ends.

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Using the electronic touch probe on my DRO, I was able to indicate the center of the bore and locate, drill, and tap the top and bottom mounting flanges.

Milling, drilling and tapping various mounting holes for linkages.

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Clearancing for the rods.

Unfortunately, the local machine shop that did the main crosshead guide bores for me left some noticeable chatter marks that needed to be dealt with.

I ordered some thick steel pipe with the same bore diameter of the crosshead guides and cut/milled away enough material to create a “cap” of sorts in order for me to hone the inner surface of the guide.

Once clamped in a bench vise, I had a perfectly complete bore to hone.

Using a flex-hone mounted in a hand held drill and some cutting fluid, the honing process took less than 2-3 minutes per guide.

The difference was remarkable! The majority of the surface is quite smooth but some very slight pitting still remains. My theory is that oil will hold to these areas better for improved lubrication.

Engine Block

After figuring out which side to mill first, I created custom T-slot hold down brackets designed to fit in the “valleys” of the engine block when turned upside down on the milling table.

1-2-3 blocks and shims were utilized to level the engine block as best as possible.

Using a facemill, I then milled the minimum amount off the bottom of the block and drilled/tapped holes for the bearing caps. The bearing journals were milled in one operation, oil galley holes drilled, and then the mounting pads on the side were milled square in order to later indicate the block after flipping it over. The engine block ends were also milled square at this point.

Using the same hole spacing for the bearing caps, I drilled and countersunk holes in a 3/4″ thick aluminum fixture plate to flip the block 180 degrees in order to mill the top.

I inserted two parallel bars in the bearing channel and held them apart with a spring to indicate and transfer the centerline to the top.

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Next, clearance holes were milled for the connecting rods.

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Then holes were drilled and tapped for the crosshead guides.

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The block was then mounted at an angle in order to drill oil holes from the front down to the oil holes drilled in the bearing journals. An endmill was used to countersink the holes for the oil cups to be fitted later.

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Main bearing caps were also fabricated and installed.

Trucks

The trucks are comprised of a growing number of parts which has caused production to slow to a crawl but it is gratifying to see them begin to take shape. They also are gaining weight – roughly 65 lbs each and that’s without the brakes and gears!

Truck bolsters and springs:

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Fireman’s side journals:

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Engineer’s side journals:

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Archbars:

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Accurately bending the arch bars was quite the chore and after several attempts it began to resemble a shay truck!

Drive Shaft Bearings:

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Work on the trucks continues…

Gondola Riding Car

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For a birthday gift, my dad recently surprised me with a set of RMI archbar trucks and couple of very nice steel frames from Capt. John Boots of Big Boots and Western Railroad. This immediately inspired me to throw together a freelance design 2.5″ scale gondola riding car to eventually be pulled by my shay.

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I welded on two steel stringers down the length of the frame to help provide support for the poplar slats which were run through a router table to create lap joints.

Ash wood beams lined the outside of the frame and then each wooden slat was screwed to the steel.

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After a trip to Lowes for some exterior paint closely matching early D&RGW rolling stock color, I brushed on multiple coats to properly seal the woodwork.

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Stakes made of poplar were bolted to the sides (through the wooden beams and the steel frame) and then side and end boards were built up.

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I used white transfer paper (similar to carbon paper) to trace letters and then with white enamel I hand painted the road name on the sides.

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I purchased a 3D printer and designed stake pockets that slip over the bases of the stakes and cover the recessed bolts holding them to the frame. I learned quickly that 3-D printers are slow! It took about 36 hours to print all 14 stake pockets required for the gondola. Once installed and painted, it is difficult to tell that they are made of plastic and not cast iron. I even created square head bolts and washers into the one-piece design.

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I found a very nice open-source 3D file for an early D&RGW brake wheel online and printed it out too. I also designed a brake wheel pawl and gear as well as the brake bracket to attach it all to the end beam. 3D printed truss rod square nuts and beveled washers help to finish off the ends of the gondola.

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Since the frame of the gondola is already very sturdy, real working truss rods aren’t needed so I made up some to look the part.

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Hand grab irons were forged from 3/16″ steel rod.

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A pair of folding seats and short non-swiveling posts from Bass Pro Shops provide nearly first-class comfort in this open air riding car.

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All in all, this was a fun project and I can hardly wait to start working on the second car frame, which just might become a double-decker stock car.

Boiler Progress!

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Boiler work is progressing after a computer that ran the CNC plasma cutter at Trainmax LLC had to be replaced. The process of mapping out where the various boiler shell holes and cuts need to be made must be fascinating but probably not as fun as watching the actual precision cutting! Check out these production videos from Richie at Trainmax:

CNC Plasma Cutting a 2.5″ Scale Shay Boiler Shell – part 1

CNC Plasma Cutting a 2.5″ Scale Shay Boiler Shell – part 2

Truss Rod Assembly

The iron castings for the truss rod anchors were too hard to machine and drill so I decided to mill my own out of steel blanks. I set up four inside anchors on one steel blank and four outside anchors on another. By milling them together at the same I was able to keep the angles consistent. I then cut them apart, drilled the mounting holes and radiused the corners.

I also chose to fabricate the queen post bases out of single blocks of steel which, in my opinion, look more attractive.

After cutting and threading the 3/16″ and 1/4″ truss rods, everything was assembled and tightened on the upsidedown frame.

Once flipped over, the frame suddenly takes shape, especially when sitting on a pair of RMI arch bar trucks. Now I’m inspired to begin work on the actual shay trucks!

At this point the frame is about 95% complete. I’m hoping to begin work on the rest of the shay trucks soon so I can get the frame off of the RMI archbar trucks temporarily holding it up.

The Boiler

I enlisted Richard Jacobs of TrainMax LLC in New Orleans to fabricate the shay boiler. He will also provide hydrostatic testing and certification for safe operation.

The steel has been purchased and most parts have been cut out on his CNC plasma cutter. Richie is a great guy and has steam coursing through his veins. He is passionate about railroading and is very knowledgeable when it comes to fabrication and repair for both small scale and full scale. I’m really looking forward to a “Big Easy” road trip when it comes time to pick up the boiler.

Castings!

I picked up a set of castings from John Buckwalter in Paisley, FL and they are beautiful! I spread them out on my work bench only to realize the mountain of machine work ahead of me! I have most of the tooling and I’m ready to go – this is going to be fun!

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The piece of wood in the trunk is a hunk of Florida red oak which I’ll cut down for the front and rear buffers (or bumpers).
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The only thing missing in the photo is the engine block which was cast and received a few weeks later. I can confirm that it is one heavy chunk of iron!

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Since there are a total of eight wheels, I decided to try and knock them out first. Once turned, they will come in handy when it’s time to build the trucks and give the frame something to sit (and roll) on. The treads will be turned last. 

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In order to get a high degree of accuracy when turning the axles, it’s vital that my lathe centers are as close to dead-on as possible, so I fabricated an “old school” test bar out of some scrap steel and aluminum. I was able to get the lathe centers within .00015″ – more than accurate enough for my purposes.

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Here’s the first axle after being turned…

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…and here’s the first axle assembled with wheels and bearings.

Brake Foundation Guides and Brackets

Using 3/16″ x 3/4″ steel flat stock I fabricated the various brake foundation guides and levers. As this is tedious work, my homemade bender saved the day. It’s proving to be pretty accurate and easy to use.

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The plans called for flat horizontal “wings” at the tops of each u-shaped bracket that would contact the bottoms of the frame rails. I opted for a somewhat cleaner appearance and went with a simple u-shaped bracket in which the vertical sides are welded directly to the frame undersides (the frame is upside down in the above photos).

 

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To fabricate the brake levers, holes were drilled in 3/16″ x 3/4″ flat stock and the subtle side tapers were machined on the mill. End radii were quickly finished on the grinder and any sharp edges were knocked down with a file.

 

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These photos are of the frame upside down and the screws are only temporary…

Frame Bolsters and Running Board Brackets

The Shay is beginning to gain some weight! The frame bolsters are now welded in place, although I still need to drill the all-important drain holes in both.

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A few more welds and some clean-up grinding and they will be done.

 

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The bolster pads and retaining rings were milled flat and turned on the lathe. Still left to do: center drill the holes before welding onto the bolsters.

 

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I used my homemade bender in an assembly line fashion to fabricate the bottom halves of the running board brackets. A digital protractor came in handy to accurately measure the bend angles on the first piece, then that piece was used as a template for the remaining brackets.

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A little clean up grinding left to do but it’s starting to take shape!

The Frame

I figured the shay frame is as good a place as any to start. I cut steel C-channels to length and stitch-welded them back-to-back to create the two main I-beam frame rails.

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It didn’t take long to realize how long this locomotive was going to be!

 

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The next step was to mount the frame rails in the mill, square up the ends and get them to exactly 76 inches in length. Then the arduous  task of drilling the 96 holes called for in the plans began. Lots of measuring and triple checking here. Thank goodness for the accurate DRO system!

 

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The engine mount reinforcement plate was then welded in place inside the right frame rail.

Setting Up Shop…

My garage was to be the new shop, convenient to my kitchen, bath, and bedroom – a perfect way to stay close to the project, as this will take a few years of commitment to complete.

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I purchased a 1967 Bridgeport 9 x 42 3-axis mill along with a huge assortment of related equipment including milling vises, a 10″ rotary table, various end mills, collets, chucks and precision measuring tools.

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It was a great deal and a super way to start my shop.

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Next came a brand new Grizzly 11 x 26 gearbox bench lathe and cabinet.

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Both the mill and the lathe were treated to digital readout systems with top-of-the-line magnetic scales from DROPROS.com. Precision is the name of the game here and these systems do not disappoint!

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After re-positioning the equipment around the garage several times, I finally settled on what I felt was an efficient shop layout. An iPod cranking out tunes on overhead speakers completes the comfortable work environment.

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A shop is not a shop until it gets a foreman’s desk. I picked this rough beauty up for $20 and after some sanding and painting it is ready to see some action.

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A trip to Harbor Freight yielded this light-duty shear/press/brake. It’ll be fine for some of the smaller work but I needed something a bit more substantial to bend heavier gauge steel.

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Using some scrap angle and pipe, I welded up my own bender onto a 1/2″ think steel plate for use in my 20-ton press. It made no fuss bending 3/4″ x 1/4″ steel bar.

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I bought a Phase II quick change tool post for my lathe. This gave me a chance to mill a new compound tool post plate to replace the stock Grizzly one.

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I’ve also been stocking up on steel and getting close to making chips fly…