Article: 1/12 Scale 1869 Allerton Steam Pumper

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I started with the expansion two tanks since I realized that these would be the hardest to produce and would need the most development time to resolve. These show them finish turned in aluminum and polished while still attached to the parent stock. They have been cut off and drilled to reduce some of the weight and I now have two of each cast in white metal to work with. Eventually they will have a copper finish.

To take a break from CAD drawing I then started to turn the two upper portions of the smoke stack with some spare aluminum round bar I had left over from the Model T build. I also visited the local recycling yard and found some additional round bar for the rest of the stack; but will wait until it warms up a bit since I will have to use the 10" lathe in the garage. The picture below shows the two parts, the part on the left wi


Here the two are stacked as they will be when assembled together.



Next will be the frame build which is the most critical component since it will be the foundation that all components will be added to and built up and down from. Kind of like the chassis of a car.

Ken

[Egon]

Nice expresso machine it will be interesting to follow, working steam ??

[xken]

Egon, Small expresso machine but great for only sips of coffee. No live steam this model is being built at 1/12th scale to be a kit for Model Expo Inc.

Here is the start of the frame assembly, this component will be cast as one piece and will be the foundation for the build.
This shows the side rails and the center band for the boiler. The half round detail was made by temporarily soldering a 1/8" diameter rod into a U channel as a holding fixture and then one surface was filed off flat. The ends were then relived to enable the overlap onto the frame section.



Here is a close up showing the overlap detail and the addition of the mounting bolts that are 00-90 size. Once cleaned up of solder the bolt heads were filed down to a more correct height.


This is an overview of the frame showing the start of the front water pump box with the small (cast) expansion tank in place. The great challenge with this assembly is enabling the part to be cast in one piece 8-3/4" long with metal to flow and form the ring. To do this .100" wall is needed on the side rails, note the beveled inside surfaces to maintain a thin top surface in appearance yet attain the .100" flow channels. The holes are for the flywheel shafts with molded in flat bearing surfaces.


The cast small expansion tank set in place. Eventually this tank will have a copper finish. The driver seat will be located above this.


Here is the start of the front axle mount assembly which is a separate component from the frame and the lower half of the water pump box. The threaded retaining bolt shaft is 1-72 threads.
The drilled holes are for the bolt heads that will be cast in on the flange on three sides.


This build will be slow going due to all the detail involved balanced with the need to make sure production casting requirements are maintained. This model will be 98% cast metal parts and be the first kit ever offered of a horse drawn fire apparatus.

Ken

[Don Garrett]

Well.....you got me with this one Ken. Looks like down the road I'll be needing to send Model Expo another order.

[spinellid82]

This is a beautiful subject of which I am sure you will replicate just as beautifully. I have always been fascinated with early firefighting equipment.

[GusSMHDV]

Nice

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Here the 00-90 bolts were soldered to the flange using the drilled holes. Bolt heads also added to the axle hub flange and bottom surface of pump box. I then cut, fixtured and soldered the brake pivot shaft in position.



Next I turned the axle pivot grease catcher out of aluminum not having a piece of round brass bar the needed size. Then I turned the axle pivot center with two locating pins for the axle halves. (Waiting for brass order to arrive) The retaining collar (top disk) was cut, this will have a stabilizing bar added to it that attaches to the lower rear bracket on the boiler. All is held in place with the axle retaining nut, 1-72 size.


Now the front pump shaft locators were turned and soldered in place. These allow access to the internals of the pump for maintenance and repair. Across the hex flats the size is 7/16" for a sense of scale.



This shows the front with the small expansion tank set in place.



Hopefully my brass stock order will show up today. Ordered last Friday

Ken

[spinellid82]

Talk about humbling, you do all this [I][B]with[/B][B]out[/B][/I] the proper stock. That is truly impressive!!!

[chassisdude]

Amazing work Ken..Im looking forward to diving into brass building...(baby steps for me of course) Watching your work progress and reading your book really helps ..Great stuff..

[xken]

David,

you do all this [I][B]with[/B][B]out[/B] the proper stock[/I]

It is a Marine thing adapt and overcome! Still waiting for the delivery.

Michael, you to can do it! I hope the book helps and if you have any questions just ask. Just remember every journey starts with the first step.

Ken

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Now I moved forward to the water intake valve. First I had to thicken the lower portion of the pump box. First I turned a disk with a aligning hole and used an aluminum tube to hold in place when being soldered. Then the valve body was turned with an indexing rod the same size as the hole, handles will be added to this part. I then turned a brass bar to the needed size and then very carefully sawed a half round wedge the thickness and length needed.



I then drilled a 1/32" hole to be used with a scribe to hold in place while being soldered. Once soldered in place I then drilled the hole through the pump body and inserted a rod and soldered it place to hold the wedge during future soldering operations.



This shows the rod soldered in place. Note that 50/50 soft solder was used as a filler on the front edge. Solders at a lower temperature than the Staybrite solder.



Two handles were turned and soldered in place into the valve body. This part was turned to allow water to be sucked into the pump from a hydrant or water source. Next was the hose attachment nozzles. Two parts were turned starting with 3/8" diameter rod then turned as needed, counter bored on the ends to indicated tube and then threaded with a 1/4-28 die. The parts were then sawed at two mating angles and soldered to the valve body. This shows the roughed in phase and will be filed to blend the transition from the body to the round shaft eliminating the sharp edge seen in picture.



Here is an overview to see the relationship of the parts so far. Now the filing to blend the transition on the valve body. Then onto the upper portion on the pump body.



My brass stock shipment arrived just in time Friday afternoon to enable this valve to be built.

Ken

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I started the upper portion of the pump box by building the bottom flange and sides with the two holes drilled in the side for the hose valve attachment points. Then thinking ahead to the acorn nuts (again like playing chess be a few plays ahead) I decided before adding the top to add the large expansion tank base and acorn nuts.

To minimize the side joint I decided to bevel the mating edges of the box and top part as seen below.



Here the top surface was marked with blue ink from a marker to draw upon with a scribe point. The center circle is where the expansion tank base will be located and center drill point spotted as well as the perimeter locations for the acorn nuts.



Next came the tank base which was turned starting with a 3/8" diameter rod that was flared to meet the top and the turned in flange was then highlighted with blue ink and then carefully hand filed into the 12 sided flange shape needed. The large bent tube shape will be added to the round boss on the top.



Then the acorn nuts! These are challenging my eye sight since I am starting with 5/64" hex bar and turning them with made tool bits and they are 5/32" high. They have a 1/32" stem that is inserted into the holes and then soldered from below on the bevel to maintain the clean detail on the top. This is why the top could not be soldered to the box first. Once completed then the top will be soldered to the sides. Here you can also see the sides of the 12 sided flange.



Back to making acorn nuts. The two front corners will have the bracket for the seat mount so those two will need longer stems and will be cut last.

Ken

[chassisdude]

Beautiful workmanship..What is the scale of this build ?

[spinellid82]

Ken is not capable of doing anything less then beautiful work. Beautiful seems to be his baseline and it only gets better from there.