V0.19: Clayton Steam Wagon--UPDATE #4

[chrisb]

Thanks for sharing images and descriptions!

[Kunda1]

It's amazing how many times ones mind can be blown.

[ppemawm]

All of the internal components of the steam engine are complete including the pistons, connecting rods, valving, and linkages. The cabin is also done so we have a nearly complete model of this fascinating truck with the exception of all the interconnecting piping between the boiler, feedwater heater, and water tank.

A few screen shots of the models are as follows with some brief comments on the process.

This is the complete assembly. The engine and cabin subassembly details were created in separate files and merged (File>Merge project...) with the truck and trailer file to obtain these graphics.
The file size has grown to 57.1 Mb which takes about 5 minutes to load.

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This is an exploded view of all the cabin sheet metal and wood construction. The roof was modeled with an Additive Loft from the PartDesign workbench using six(6) cross-section sketches. Although it cannot be seen in this graphic, the roof covering thickness varies from 9.5 mm at the rear to 4 mm at the front.
A PartDesign>LinearPattern of a pocket feature was used to simulate the beadboard of the rear wall of the cabin.

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All the internals of the engine are shown in this graphic. Also, the lubricator is shown on the far side (RH) with its cam drive off the crankshaft.

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The most complicated components are all the interconnected linkages required for the the valve timing and actuation.

This is the master sketch of the linkages. The left hand set is shown in blue and the right hand is in green. The position variable is the crank angle and the valve slider angle. This sketch can be used to determine all of the link positions as the crankshaft rotates.

Fixed positions are shown as small circles and the pistons and valves are simulated with squares. The master sketch helped to better understand the drawings before modeling any of the links in their proper location in 3D space. A crank angle was fixed at 90 deg and each body origin was located at its proper pivot point. In this manner, only the sketch attachment Z offset had to be specified.

The right hand linkages are Draft>Clones with the Y scale set to -1 to obtain the mirror image and located with Placement properties. I prefer this over the Part>Mirror because the model tree is less complicated.

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This shows the master sketch relation to the linkage models for the specified crank angle of 90 deg.

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.
The next and final task to tackle is all of the interconnecting piping which looks to be a 'bag of worms'. So, who knows how long that will take.

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.17091 (Git)
Build type: Release
Branch: master
Hash: 4a0be9d3ba28ca14906574370de1f2f005af0d54
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)

[yorik]

#ppemawmStrikesAgain