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ClydeSight2.0! Bryce 5 Tutorials
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Make
a Working Simple Steam Engine in Bryce — Why a Steam Engine?
I have always been fascinated with steam engines! Whether it is a locomotive with many drive wheels, or a simple industrial engine driving a flywheel, this type of machine is a wonder to watch. Steam engines have an elegance of motion and a grace in working that I find very appealing. Part of the appeal is the way these machines transfer directions of motion through linkages, which is a great way to learn Bryce linkages.
First Things First:
We have to understand a little bit of physics to model a steam engine, even though Bryce is not limited by physical laws. Let's get that out of the way now.
Steam Engine Parts:
The simplest steam engine has four basic parts: A Piston Housing, a Piston Rod, a Crankshaft and a Flywheel. Of course, it also has a boiler, a regulator and other parts, but we can ignore these in our basic Bryce model.
What we want to do is use Bryce's Linking and Tracking features to make the rotating motion of one object (the Flywheel) cause lateral and rotating motion in another (the Piston Rod), and rotating but NOT lateral motion in yet another object (the Piston Housing) while at the same time keeping everything perfectly aligned. As you'll see, this is quite simple to do and can be very useful in a variety of projects.
Steam Engine Motion:
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When the steam drives the Piston forward from the back of the Piston Housing (the cylinder that houses the Piston), a shaft attached to the Piston, called the Piston Rod, moves along with it. The motion is back and forth along a single axis (i.e. the X axis). |
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The Crankshaft attached to the Flywheel moves along TWO axes (i.e. the X and Y axis). |
| So, the problem is how to get the Piston Rod to move on the second axis without breaking it! | |
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The solution is to hinge the Piston Housing so it can always point in a straight line to the Crankshaft. Thus, the Piston "rocks". |
We can get Bryce to do this for us in our model. But read on, there are two
additional considerations before we start!
Steam Engine Parts Alignment:
We have to align the parts correctly for the engine model to work. If we don't get this part right, Bryce will make some surprising assumptions when we establish the linkages and our model will be ruined!
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From the Top: The Flywheel has an axle. The axle can only extend beyond the Flywheel on ONE side, the side opposite the Crankshaft. (If it extended beyond on the crankshaft side, it would get in the way of the Piston Rod). We won't use an axle on our model, but this is a good thing to know! The Piston Housing and Piston Rod must be aligned in a straight line with the Crankshaft-- not the Flywheel. |
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From the Side: The Piston Housing hinge must be aligned with the center axle of the Flywheel so the Piston Housing will rock evenly during the rotation of the Flywheel. |
The Final Words on Simple Steam Engines:
This design for a simple steam engine is not very practical because of the rocking Piston Housing. It would require flexible tubing to get the steam to the Piston, and the risk of the tubing breaking under the stress of constant flexing is something to be considered. However, I did once ride on a "Paddle Boat" that used this engine design. It had three pistons and worked very slowly. The boat was intended for touring, so they were in no hurry anyway!
Most steam engines use a more complex set of linkages, allowing the Piston Housing to remain stationary. But that is MUCH more difficult to get to work in Bryce (I'm working on the problem even now!)
However, since Bryce is virtual, our little design is quite feasible in the fantastic world of virtual reality.
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