Ball Hopper Monitor Patterns/Castings Attempt

[Casting Iron]

I have contemplated what my 2nd engine will be, as a casting project, and I really like the 4hp Ball Hopper Monitor engine.

I was lucky to have JasonB direct me to a fb group, and found a lot of original Baker factory brochures there, along with a large number of photos of Baker engines.

And I was able to make contact with a 4hp Ball Hopper Monitor engine owner (full sized engine), and he was kind enough to take quite a few photos of his engine, along with some critical measurements.

There are so few photos available of disassembled BHM engines that it has been tricky to get the internals accurately 3D modeled.
I don't like to make approximate engine design if possible, and so I have gone to great lengths to exactly match the original 4hp BHM engine both internally and externally.

And then the question of how large the engine/castings should be came up.
I toyed around with various sizes, and actually purchased three different sizes of gear sets, and am designing around those three sets.
The castings I am contemplated would have either 10", 12", or 14" diameter flywheels, which are on the large side for many.
The 14" flywheel would give a 1/2 size 4hp engine, and I think that would be beyond cool to make a BIG engine like that (perhaps not easy, but doable).

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[Casting Iron]

I purchases a 2nd 3D printer from Prusa, which is the XL.
So far I have been pleased with how well it works, and it does not seem to have the bed lifting issues that my MK3 has.

This is what I will print the BHM patterns on.

This is a sample that came with the printer, and I used it to get a feel for what this printer is capable of printing.

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[Casting Iron]

This is a JasonB designed flywheel, 12" diameter.

Looks very nice.

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[Casting Iron]

Making 3D printed patterns for engines requires a few extra steps beyond just making a typical 3D model.

There has to be machining allowances added to the surfaces that will be machined, and draft angle added, so that the patterns can be pulled from the sand.

Shrinkage is handled in the 3D printer slicer program, with the printed part being scaled up by a factor of about 1.015.

I have gone to great lengths to get the draft angles correct on the various Ball Hopper Monitor parts.
I have also carfullly studied the parting lines on the original full sized BHM engines, and plan on matching those parting lines.

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[Casting Iron]

A few more 3D models to be used to 3D print patterns.

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[Casting Iron]

More 3D models to be used to 3D print patterns.

I could make the connecting rod from ductile iron.

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[Casting Iron]

Some of the cores required.

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[crueby]

Shaping up to be a fascinating  build, watching along!   

[Casting Iron]

Spark plug that I will use.

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[Casting Iron]

Overall engine will look about like this.

I came up with a base, which probably does not match any factory base, but looks good I think.

The 1/2 size engine will be about 28" tall, with 14" flywheel, 2.5" bore.

The engine with 12" flywheel will be about 25" tall, 2.125" bore.

The engine with the 10" flywheel will be about 20" tall, 1.75" bore.

I consider these engines on the grand scale, which is what they call the large model locomotive scale.

With 3D printing, the patterns could be printed at any size, for those who are into smaller model engines.

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[bent]

Looks pretty cool, can't wait to see more about getting castings from the 3d prints. 

[fidlstyks]

I have a 6 hp Monitor, and wanted to make models of it also.
   Pacific Model Design made this kit.
  Maury at Lone Star also made a Monitor kit. I am searching for where those patterns went to.

[pirmin]

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