Difference between revisions of "Shifter"
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| + | A shifter allows the driver to shift [[Drivetrain#Gearing|gears]]. | ||
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==Actuation== | ==Actuation== | ||
===Mechanical=== | ===Mechanical=== | ||
| − | + | Mechanical shift actuation uses a cable or linkage system to transmit driver input directly to the shifting mechanism of the engine. One of the primary benefits of a mechanical shifting mechanism is that it mimics the actuation used on motorcycles. This means integration with the engine requires limited design work. Additionally, mechanical linkage shifting mechanisms are often robust, which can make them reliable and long-lasting. They also tend to be relatively simple, which can help to keep costs down. Commonly, stick shifters are found with the clutch actuator built in, enabling the driver to clutch and shift in one move. This cannot be implemented on an electronic or pneumatic system without a more complex controls scheme. | |
| + | |||
| + | Most implementations mean the driver has to take their hand off the steering wheel to shift gears. This can be dangerous as it can affect the driver's ability to control the vehicle. Another issue is that the minimum and maximum shift times can be longer than other types of shifting mechanisms. | ||
| + | |||
| + | These systems can be converted to an automatic system, but since a pneumatic or electronic actuator would be required to do this, it is likely simpler to design the system around the actuator itself. | ||
===Electronic=== | ===Electronic=== | ||
| − | + | Electronic solenoids can actuate the shifting mechanism, allowing for quick and precise shifts without the need for mechanical linkage or cable. These solenoids can be mounted directly next to the shift lever of the engine. OEM solutions are available, which can make it easier for teams to integrate them into their vehicles. For example, Pingel offers a range of electric speed shifters that can be used for FSAE vehicles. However, it should be noted that these solutions can be expensive, which may be a limiting factor for some teams. Another advantage of solenoid shifting mechanisms is that they are often the simplest upgrade to automatic shifting due to the lack of high pressure gas packaging, storage, and routing. A custom solution is not hard to design as well, with the only inputs to the solenoid being LV power and control signals, which FSAE cars will already have. | |
| + | |||
| + | In addition to the potentially prohibitive cost of an OEM solution, electronics are a frequent source of difficult to diagnose issues, so teams not comfortable with adding further electronic failure points may want to look elsewhere. The designer will want to look at power draw from the shifter and ensure that the LV battery and alternator will sustain a full race's shifting. | ||
===Pneumatic=== | ===Pneumatic=== | ||
| − | + | Pneumatic shifting systems use a pressurized gas powered solenoid to actuate the shift mechanism. Like electronic shifting, the actuator can be packaged very close to the engine's shift lever. Additionally, OEM solutions such as those from MPS Racing are available. Pneumatic systems are renown for their shift speeds. | |
| − | + | ||
| − | + | The pneumatic solenoid itself can be much smaller than a comparable electronic solenoid but the gas tank will likely be much, much, larger than either. The gas can be compressed N2, CO2, or air, with limited differentiation on performance, and will likely be driven by availability. The tank is subject to specific rules about packaging and driver protection. | |
| − | + | ||
| − | + | Unlike electronic solenoids, gas actuated systems have an inherently limited number of shifts dependent on the quantity and pressure of gas in the tank, activation pressure, and how much gas is discharged per shift. As the level of gas in the tank becomes very low, shifting may become difficult or impossible if the required shift pressure is lost. Anecdotal accounts of a car running out of air during a race are rare. Frequently the investment into a larger tank, or higher pressure is low for a team that is already running a pneumatic system. | |
| − | + | ||
| − | + | The pneumatic cylinders and gas tanks are very common industry components and are often inexpensive, and are extremely reliable. The routing and regulators are the most frequent fail points, and a double stage regulator is recommended. Push-to-connect pneumatic fittings can reduce failure modes in the routing and enable inexperienced teams or team members to easily service the system without fear of damage. | |
| + | |||
==Automatic Shifting== | ==Automatic Shifting== | ||
not going to touch on driver controls (paddles or whatever) | not going to touch on driver controls (paddles or whatever) | ||
| − | [[Category: | + | [[Category: Drivetrain]] |
| − | |||
Latest revision as of 12:22, 10 March 2023
A shifter allows the driver to shift gears.
Actuation
Mechanical
Mechanical shift actuation uses a cable or linkage system to transmit driver input directly to the shifting mechanism of the engine. One of the primary benefits of a mechanical shifting mechanism is that it mimics the actuation used on motorcycles. This means integration with the engine requires limited design work. Additionally, mechanical linkage shifting mechanisms are often robust, which can make them reliable and long-lasting. They also tend to be relatively simple, which can help to keep costs down. Commonly, stick shifters are found with the clutch actuator built in, enabling the driver to clutch and shift in one move. This cannot be implemented on an electronic or pneumatic system without a more complex controls scheme.
Most implementations mean the driver has to take their hand off the steering wheel to shift gears. This can be dangerous as it can affect the driver's ability to control the vehicle. Another issue is that the minimum and maximum shift times can be longer than other types of shifting mechanisms.
These systems can be converted to an automatic system, but since a pneumatic or electronic actuator would be required to do this, it is likely simpler to design the system around the actuator itself.
Electronic
Electronic solenoids can actuate the shifting mechanism, allowing for quick and precise shifts without the need for mechanical linkage or cable. These solenoids can be mounted directly next to the shift lever of the engine. OEM solutions are available, which can make it easier for teams to integrate them into their vehicles. For example, Pingel offers a range of electric speed shifters that can be used for FSAE vehicles. However, it should be noted that these solutions can be expensive, which may be a limiting factor for some teams. Another advantage of solenoid shifting mechanisms is that they are often the simplest upgrade to automatic shifting due to the lack of high pressure gas packaging, storage, and routing. A custom solution is not hard to design as well, with the only inputs to the solenoid being LV power and control signals, which FSAE cars will already have.
In addition to the potentially prohibitive cost of an OEM solution, electronics are a frequent source of difficult to diagnose issues, so teams not comfortable with adding further electronic failure points may want to look elsewhere. The designer will want to look at power draw from the shifter and ensure that the LV battery and alternator will sustain a full race's shifting.
Pneumatic
Pneumatic shifting systems use a pressurized gas powered solenoid to actuate the shift mechanism. Like electronic shifting, the actuator can be packaged very close to the engine's shift lever. Additionally, OEM solutions such as those from MPS Racing are available. Pneumatic systems are renown for their shift speeds.
The pneumatic solenoid itself can be much smaller than a comparable electronic solenoid but the gas tank will likely be much, much, larger than either. The gas can be compressed N2, CO2, or air, with limited differentiation on performance, and will likely be driven by availability. The tank is subject to specific rules about packaging and driver protection.
Unlike electronic solenoids, gas actuated systems have an inherently limited number of shifts dependent on the quantity and pressure of gas in the tank, activation pressure, and how much gas is discharged per shift. As the level of gas in the tank becomes very low, shifting may become difficult or impossible if the required shift pressure is lost. Anecdotal accounts of a car running out of air during a race are rare. Frequently the investment into a larger tank, or higher pressure is low for a team that is already running a pneumatic system.
The pneumatic cylinders and gas tanks are very common industry components and are often inexpensive, and are extremely reliable. The routing and regulators are the most frequent fail points, and a double stage regulator is recommended. Push-to-connect pneumatic fittings can reduce failure modes in the routing and enable inexperienced teams or team members to easily service the system without fear of damage.
Automatic Shifting
not going to touch on driver controls (paddles or whatever)
