This is a model to demonstrate the use of the Gears available in the A & B Gears Sets and the Mechanisms Set from the 1950's. The illustrations from the manuals have been built on individual bases. The main frame section consists of a 20 vdc Cricket Ball drive motor with a series of reduction gears mounted to a 2-1/2" x 5-1/2" flanged plate fixed to a pair of rails that hold the modules. Any of the modules can be added or removed by laying the flanged base over the rails. Each module is able to slide on the rails to adjust the overall chain drive tension.
Main Frame Section
Here we see the motor with a worm gear, powered by a regulated variable voltage power supply. This in turn drives a 60 tooth gear wheel. Also on this shaft is a 19 tooth pinion driving 57 tooth gear wheel which also has a one inch sprocket that will drive the modules.
The rails are flat girders that are butt joined to make up any length required depending on the number of modules on hand.
Here we see the motor with a worm gear, powered by a regulated variable voltage power supply. This in turn drives a 60 tooth gear wheel. Also on this shaft is a 19 tooth pinion driving 57 tooth gear wheel which also has a one inch sprocket that will drive the modules.
The rails are flat girders that are butt joined to make up any length required depending on the number of modules on hand.
Epi-Cyclic Module
This unit might be useful to drive a mill to grind grain. Mostly it's just fun to watch it spin aimlessly.
This unit might be useful to drive a mill to grind grain. Mostly it's just fun to watch it spin aimlessly.
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Intermittent Drive Module
Power from the chain is turned 90 degrees through the bevel gears which continuously drives the main shaft. The worm gear turns the gear wheel that has 4 pins which press against the plate. The plate is on a spring loaded assembly. As the gear wheel rotates the pins push the plate away, disengaging the dog clutch at the end of the drive shaft causing the output shaft to stop turning. As the gear wheel continues to rotate, the pins move away from the plate. The spring will then push the output shaft toward the main shaft allowing the dog clutch to re-engage which transfers power to the output shaft and the fan starts turning.
Power from the chain is turned 90 degrees through the bevel gears which continuously drives the main shaft. The worm gear turns the gear wheel that has 4 pins which press against the plate. The plate is on a spring loaded assembly. As the gear wheel rotates the pins push the plate away, disengaging the dog clutch at the end of the drive shaft causing the output shaft to stop turning. As the gear wheel continues to rotate, the pins move away from the plate. The spring will then push the output shaft toward the main shaft allowing the dog clutch to re-engage which transfers power to the output shaft and the fan starts turning.
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Front View - Dog Clutch - Open
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Front View - Dog Clutch - Closed
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Rear View - Dog Clutch - Open
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Rear View - Dog Clutch - Closed
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Counter Rotation Module
The mechanism of the left in the picture below demonstrates counter rotation. The drive shaft is powered from the drive chain through a sprocket. There are 2 pinions on the drive shaft, one meshing with a crown gear on its right side, the other pinion meshing with a crown gear on its left side. When the drive shaft is rotating the 2 driven shafts will rotate in opposite directions from each other. The pinion / crown pair translates the motion 90 degrees.
Forward / Reverse
The mechanism on the right uses counter rotation principle to build a forward / reverse gearbox. The drive shaft is powered from the drive chain through a sprocket. A crown gear at the end of the drive shaft meshes with one of two pinions on the control shaft but not both at the same time. When the control shaft is to the left, the pinion on the right meshes with the crown gear and the large pinion on the output shaft turning the output shaft in the forward direction. When the control shaft is to the right the pinion on the left meshes with the opposite side of the crown gear turning the control shaft in the opposite direction. The left pinion remains engaged to the large pinion even though its position has changed. The output shaft now rotates in the reverse direction.
The mechanism of the left in the picture below demonstrates counter rotation. The drive shaft is powered from the drive chain through a sprocket. There are 2 pinions on the drive shaft, one meshing with a crown gear on its right side, the other pinion meshing with a crown gear on its left side. When the drive shaft is rotating the 2 driven shafts will rotate in opposite directions from each other. The pinion / crown pair translates the motion 90 degrees.
Forward / Reverse
The mechanism on the right uses counter rotation principle to build a forward / reverse gearbox. The drive shaft is powered from the drive chain through a sprocket. A crown gear at the end of the drive shaft meshes with one of two pinions on the control shaft but not both at the same time. When the control shaft is to the left, the pinion on the right meshes with the crown gear and the large pinion on the output shaft turning the output shaft in the forward direction. When the control shaft is to the right the pinion on the left meshes with the opposite side of the crown gear turning the control shaft in the opposite direction. The left pinion remains engaged to the large pinion even though its position has changed. The output shaft now rotates in the reverse direction.
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Differential
When a vehicle drives around a curve the inside wheels turn at a different rate than the outside wheels because the inside curve is shorter than the outside curve. A differential allows both wheels to be powered even though they turn at different rates. Each wheel is connected to its own axle and crown gear and can rotate independently. In other words if one wheel stops the other can still turn. Each crown gear meshes with 2 pinions. Both pinions are mounted in a cage that is rotated by the large crown gear. The large crown gear meshes with a pinion on the drive shaft which is powered from the drive chain through the small sprocket. Although the cage is mounted to both of the wheel axles it is not fixed to either of them and can turn freely. As the cage rotates resistance in the pinion / crown mesh turns both wheels at the same rate. If the left wheel slows, the cage continues to rotate. The pinions now turn on the slowed crown gear and in turn rotate the opposite crown gear faster which turns the right wheel.
The model actually demonstrates a shortcoming of this design. The drive chain turns the large sprocket that is connected to an eccentric throw which drives an axle in a left / right motion. When at the end of travel the axle puts pressure on a wheel and stops if from turning. The other wheel continues to turn. A real life situation is when the left wheel is on ice or mud or off the road. Because the right wheel has more friction the power is directed to the left wheel causing it to spin uselessly. If both wheels are stuck then either the engine stalls or something breaks.
When a vehicle drives around a curve the inside wheels turn at a different rate than the outside wheels because the inside curve is shorter than the outside curve. A differential allows both wheels to be powered even though they turn at different rates. Each wheel is connected to its own axle and crown gear and can rotate independently. In other words if one wheel stops the other can still turn. Each crown gear meshes with 2 pinions. Both pinions are mounted in a cage that is rotated by the large crown gear. The large crown gear meshes with a pinion on the drive shaft which is powered from the drive chain through the small sprocket. Although the cage is mounted to both of the wheel axles it is not fixed to either of them and can turn freely. As the cage rotates resistance in the pinion / crown mesh turns both wheels at the same rate. If the left wheel slows, the cage continues to rotate. The pinions now turn on the slowed crown gear and in turn rotate the opposite crown gear faster which turns the right wheel.
The model actually demonstrates a shortcoming of this design. The drive chain turns the large sprocket that is connected to an eccentric throw which drives an axle in a left / right motion. When at the end of travel the axle puts pressure on a wheel and stops if from turning. The other wheel continues to turn. A real life situation is when the left wheel is on ice or mud or off the road. Because the right wheel has more friction the power is directed to the left wheel causing it to spin uselessly. If both wheels are stuck then either the engine stalls or something breaks.
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