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Discussion Starter · #23 ·
I finished most of the rear engine today and made most of the front engine parts so it should go together fairly quickly.
I want to show the construction of the expansion link which is the heart of the Walschaerts valve gear.

In the photo below from left to right are the link, backer link, backer pivot bar and ball bearing set.
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The pivot bar is 1/8" stainless turned down to 1/16" at the shoulder. It is a snug fit which keeps it perpendicular to the link back
It is then silver soldered to the link. You can see the snippet of solder and the flux ready for the heat
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Since the backer link is low carbon steel, I only pickle it in citric acid for 20 minutes as not to corrode the steel. It comes out slightly pink.
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The wire wheel cleans things up
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2-56 socket head screws hold the two pieces together and .070" spacers are used to provide a slot for the 1/16" wide radius rod
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Another tricky part of the Walschaerts gear is the combination lever which advances the timing at top dead center by moving the valve to the just open position.
The holes are drilled in an exact proportion of two times the lap plus the lead to the cylinder stroke. This ratio is usually around 10 to 1.
To stay in scale with the Samson, I need to have a very short combination lever which makes the two upper holes less that .100" apart. That means that the valve rod and radius rod need to be ground and filed to clear each other.
Here is the valve rod
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And the radius rod attached.
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So here is a side view of the chassis
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And a top perspective
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Wow Bill, making the expansion link from scratch is a marvel but the close fit on the expansion link pivots is a work of patience and precision, well done this job is coming along nicely. I can't wait to see it finished and running.
Russell
 

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Thank you very much for the detailed sharing, it will come in very handy in a couple of years when i will building my own.
I read all of your posts with a lot of interested.

With best regards Igor
 

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@bille1906
Thank you very much for you detailed posting and pictures.
But your wheels are in a "smaller corner" then mine?
I think that i do something terrible wrong( i like prototypical but it seems not to work!!!(Bigger loco's btw) it is not working
My wheels have a to large angle(3 degrees off), and yours "seems to be 90 degrees"
I hope you are willing to share for me a drawing with the proper cutting angles and what ever comes with it.
I think for the bigger locomotives "on scale" it must be almost an exact 90 degree angle and what i was doing so far is wrong...
This screenshot is prototypical but it will not work and thus wrong for scaling down...

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yes i 3d printed them for try and error before i am going to cast them in aluminium.
But what about your thoughts?
It seems we have two different wheels "running surface???"
What would be your advice or recommendation or thoughts, because what i did, it does not work( yes i am losing the prototypical idea)

Thanks in advance with best regards Igor
 

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Discussion Starter · #27 ·
Igor
three degrees is correct
This is what I use for wheel sizes and profiles. I think it is from G1MRA
61867
 

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Igor,
Your angle as measured on the screen is close to 12degrees. So something is wrong with your 3D model. We have been using 3 degrees for many years and they work well. Also you should have a radius between the flange and the running surface of the wheel (R in Bill's drawing).
Regards
 

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Discussion Starter · #29 ·
I was able to get both engines tested on air and they both run great. In the photo below, you can see the two bolted together with the strap which allows them to negotiate curves. The front deck is now complete and painted with the working headlight, hand rails and the sand box between the two decks.
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You can see the strap connecting the two chassis in the next photo. This has to be closely coordinated with the boiler mountings to prevent binding on turns. I first make it as short as possible without interference between the two chassis on y 7' radius track and then measure the distance between boiler mounts which I will use on boiler mounts. I also use a cushioned pivot on the strap which will give a little when going over dips in then track.
The piping is what I use on all on my compound locos. It is a bypass valve that lets only a small amount of superheated steam into the LP cylinder at startup which prevents LP cylinder lockup. As the amount of steam which bypasses the HP cylinder id so small, once the loco is underway, it is working on full compound
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The next photo shows the completed valve gear with the reverse arms and cross bar. The wires are for the headlight and haven't been routed yet.
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Here is the boiler shell which was cut out from a piece of type L 2" copper pipe.
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The end plate and tubes were drawn out on CAD. I used to just do it with a compass and straight edge but this is a little more accurate. I then cut it out and glue it to the plate cutout, The cutout is then clamped to the piece that will be the throat sheet and holes are drilled through both pieced so that the tubes will be perfectly aligned.
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A step drill is used to drill out the tube holes
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The throat sheet is then cut out to fit in the boiler shell. Both pieces are now done,
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Discussion Starter · #30 ·
As you can see from the last posting, the boiler is very long and narrow. Here I am setting the tubes up prior to soldering. As they are bunched together tightly, I make rings from 1/32" silver solder which will surround each tube.
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The solder rings melt and fill the gap between the times and the holes in the throat sheet
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The other side has full access so the standard brazing technique works here
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The assembly is cleaned up in citric acid and two pegs made from copper ground wire are set in place for support of the crown sheet during the soldering process
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Here a piece of copper is set in place to show how the pegs will support the crown sheet
The irregular shape on the top is for alignment on the sides and the center raised portion is to keep the steam pipe that goer from the dome to the throttle from dropping down. The valleys are for water flow
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Three pegs are set in the front to support thr tube sheet while it is soldered
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The saw cut in the boiler is 3/32" wide and the throat sheet is the same thickness so it makes for a nice soldering joint
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The throat sheet and front tube sheet are soldered in the same setting
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Discussion Starter · #31 ·
Bushings are turned from Bearing Bronze
62019

The firebox is the last to be soldered up
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Everything is finished with the soldering and cleaned up and tested
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The brass smokebox is cut from 2-1/8" inside diameter pipe which is a press fit onto the boiler. There is a a row of closely spaced rivets at the front and slightly larger rivets and more spaced out at the rear. I measure the spacing from the drawing and then lay it out with a compass. I clamp a wood block in the mill vise and rotate the pipe for each drilling.
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The stack is tapered with a radius at the bottom with four screws attaching it at the bottom.
I cant drill the holes out from the top as even mounted in a vise, the drill bit would slide off coarse and the chuck would hit the top of the stack with a normal length drill bit.
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I drill the mounting holes from the bottom prior to shaping the stack
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And then shape it on the lathe. You can see the hole poking through as the lower curvature is cut.
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The hole now needs a step to receive the screw head and provide a flat for it to seat.
I need a long step drill for this. I use a length of 1/8" drill rod and turn out .063" and .100" steps. I leave the .063 round but on the mill I make the .100" section into a D bit
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Following all your updates and threads whit great interested as always:

Bill, thank you very much for your detailed update.
I am looking forward to see your next update, especially on the heating part.

Btw why not coal, or is it easy to remove the gas thingy and convert it to coal???
I am pretty interested in your heating thoughts and how you handle gas, that was a pretty interesting topic on the ceramic burners, would love it again in detail, sorry

Thanks in advance and please keep up the great work, thanks, it will help me a lot
With best regards Igor

Ps
Sorry for my ruff american English
 

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Discussion Starter · #35 ·
Yes the ceramic burner could be replaced with a coal setup but with the dry firebox, the you would have to make sure you always had water above the crown sheet as the coal fire could be hot enough to melt silver solder (1100F) if it were to run dry. My friend Rob uses wet legs and dry backhead for his coal builds and hasn't had any trouble
I like the gas ceramic burner as it is quiet, easy to light, adjustable and it provides plenty of steam.
 

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I like the gas ceramic burner as it is quiet, easy to light, adjustable and it provides plenty of steam.
I can't argue with that, except the smell of coal, sorry about that.

1100f is not much indeed for coal burning.
Sinds i have the option for copper welding, would this not be a better option for a coal burner?

My friend Rob uses wet legs and dry backhead
Could you explane this one for me please, i dont fully understand, sorry.
What is a wet leg and what is a dry backhead?

If you think i am hijacking this thread send me a pm than i will remove this message, i am not curios but i would like to know it all:cool:

With best regards Igor
 

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Discussion Starter · #37 ·
The sides of the boiler that go down to form the firebox are what we refer to as legs. In most coal burners, there is a box inside the firebox that creates a space between it and the legs of the boiler thus surround the area heated directly by coal with water which prevents it from getting too hot.
Here is a photo of my Heisler boiler which shows the assembly parts of a wet leg boiler
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Discussion Starter · #38 ·
The smoke box is fitted with the stack It looks high now but will look more in proportion when the stacks are added to the boiler
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The smokebox front is made from a piece of 1/8" brass bar. I center pop where I want the center to be and then draw out the circle a little bit oversize. I drill a 5/32" hole which fits my arbor and then cut out the circle on the band saw. The circle is then mounted in the arbor and on the lathe it is cut to final size. It has a 1/16" rabbet is cut on the circumference. It is then drilled out and rivets are glued in with Loctite.
The smokebox door is made in two parts. The main part with the dogs is cut out on the CNC mill by Dennis. I then turn the domed part on the lathe in similar fashion to the front. The Baldwin name plate is from trackside details.
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00-90 hex head bolts are set in the holes with loctite in all but the left center hole which will hold the door closed. They protrude slightly and are sanded flush when set. The door is then set in place with the center hinge and the long 00-90 screw on the left center.
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Back to the boiler, the cab floor is mounted and the sight glass is set up with the bottom tube routed under the floor and to the boiler in front of the firebox. the throttle and clack valve are shown on the backhead as well as the window showing the ceramic burner
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The dome bases need a 1.062 radius so I set my bill that distance from the vice and adjust the cutter on the fly cutter to just touch it. This gives me the proper cut and I then move the Y axis to 1/2 the bar stock diameter
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The dome base is the checked for fit.
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The steam and sand domes are then set in place along with the bell harp
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I made a faux center mount that goes outside the actual mount to replicate the scale size
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and here is the progress to date
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Discussion Starter · #39 ·
The steam lines to the rear engine have a sharp bend at the smokebox. To duplicate this, I use 3/8" street elbows from McMaster and cut of the ends so that they can be silver soldered to my 3/8" tubing. There are two connections in each pipe that I duplicate on the lathe
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The smokebox front is finished up and a number plate from Trackside details is fitted on. A number 7 is painted red to match the prototype and attached with JB Weld
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The running boards, radiating pipes, air tanks, and domes are painted and checked for fit
The boiler wrap will be green to match the domes but more work needs to be done first
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Discussion Starter · #40 ·
I made the cab and a few other parts this week and painted the boiler yesterday
The cab is four sides soldered together. The outline and cutouts were done on the mill using the DRO.
On CAD, I will be using a 1/8" end mill so I set the zero at .0625" above the top and to the left of the left side. I then draw temporary lines .0625" from each cut and measure the distances.
Rectangle Slope Font Parallel Schematic

Rectangle Schematic Parallel Font Slope

My rivet tool is home made and just turned on the lathe
Household hardware Cylinder Gas Wood Metal

The female receptacle for doing rivets on the edge is set up with various holes to adjust the spacing. The holes for the rivets is drilled out to the diameter you want the rivet head to be. The punch tip needs to be smaller by about .020" which will stretch the material out to form a nice head
Wood Gas Metal Auto part Fashion accessory

For rivets midway on the piece, I use the following setup which was milled out of a piece of steel and has a setup for two different size rivets and spacing
Milling Drill presses Drilling Jig grinder Microphone

I use a guide for doing a straight line of rivets. I use a flat bar or parallels or whatever works for the job and hold them in place with mini vise grips.
Microphone Drilling Milling Wood Drill presses

Yellow Wood Gas Machine tool Engineering

The cab and roof are both made from .032" brass sheet. The roof is annealed as it has a sharp bend on the sides. It is annealed, then rivet embossed and then bent to shape.

The doors and window frames are cut on the mill using the same technique as the cabs.
Light Gold Amber Metal Machine


Rectangle Font Gas Wood Tints and shades


I am limited to 10 photos here so I will sign off and continue on another thread.
 
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