Hello everyone,
Sorry for the long posting, but the devil is often in the details and as indicated before, I am a novice in this area. In a previous thread on this project (Forward and Reverse Motor Controlls) I introduced what my project is (see project description below) and got some good direction from this community. I'm now ready to continue my project and will appreciate your expert comments on the description below. Thanks in advance....
As time has allowed I’ve assembled the chair and settled on the gear system (roller-chain and two gears) and have determined it takes 15 foot pounds to move a 200 lb person sitting in the chair. So that appears to have been the easy part of the project.
After converting the 15 ft lbs: = 20.337 269 28 Newton meter or
=2880 ounce inch, or 632.1015 nM*n (milliNewton meter) I’ve searched the previously referred websites and others for a motor of this magnitude with little luck. I was hoping to find a take-out, but realize I may be buying new.
It looks like the major components I need to acquire are the
• Power source (ac/dc converter matched to controller and motor),
• User control buttons and cables
• Controller and cables,
• Timer and Bell or buzzer device,
• Sensors
• Motor.
The Motor Specs:
• Bi-polar, Constant Voltage or Resistance Limited
• PM permanent Magnet or Hybrid
• 650 mN*m or equivalent
Q1. Can anyone refer me to a source for this type of motor?
The Controller:
I think I’m looking for a Bi-directional DC Motor Speed Controller for a 4 wire bi-polar stepper motor.
Q2. Can anyone refer me to a source for a bi-directional DC Motor Speed Controller for a 4 wire bi-polar stepper motor that would be appropriate for this project?
The sensors:
I presume the sensors will connect into the controller. I’m thinking that a small magnet placed on the gear located on the chair post will be the signal for the chair location. Then on a stationary plate will be four sensors to pick up the magnetic signal as the magnet passes over the sensors.
Left Rotation:
Sensor 1: a sensor to indicate a position of 315 degrees from the starting point. This will indicate the motor control to slow down.
Sensor 2: a sensor at 350 degrees position cutting power to zero.
Right Rotation:
Sensor 3: a sensor to indicate a position of 315 degrees from the starting point. This will indicate the motor control to slow down.
Sensor 4: a sensor at 350 degrees position cutting power to zero
Q3: Based on this design the two sensors opposite of the rotation will have to be “off” as magnet passes over them. My thinking is that each set of sensors will be tied into the controller so as they are “off” at the appropriate time. Does that sound correct?
Project Recap: Motorized Revolving Chair
Attach a stepper motor to a chair seat to make it rotate in both directions.
The chair needs to rotate one revolution and stop in the time period of one minute (approximately).
Operation:
1. The seated user presses a button to start the chair rotating to the right.
2. The motor is delayed in starting causing a waiting period of approximately 10-15 seconds, and then the chair starts to rotate until it competes 360 degrees and then stops. Although the motor may need a slowdown period, from the user’s perspective a sudden stop is acceptable.
3. After approximately 15 seconds a timer bell sounds indicating the end of the rotation.
4. The seated user then presses a different button to rotate to the left (or possibly presses the same button depending on the electronics or programming to be added to the control mechanics)
5. Again, the motor is delayed approximately 10-15 seconds, and then begins to rotate the chair to the left 360 degrees and then stops.
6. After approximately 15 seconds a timer bell sounds indicating the end of the rotation.
Thank you for your feedback.
Dmend
Sorry for the long posting, but the devil is often in the details and as indicated before, I am a novice in this area. In a previous thread on this project (Forward and Reverse Motor Controlls) I introduced what my project is (see project description below) and got some good direction from this community. I'm now ready to continue my project and will appreciate your expert comments on the description below. Thanks in advance....
As time has allowed I’ve assembled the chair and settled on the gear system (roller-chain and two gears) and have determined it takes 15 foot pounds to move a 200 lb person sitting in the chair. So that appears to have been the easy part of the project.
After converting the 15 ft lbs: = 20.337 269 28 Newton meter or
=2880 ounce inch, or 632.1015 nM*n (milliNewton meter) I’ve searched the previously referred websites and others for a motor of this magnitude with little luck. I was hoping to find a take-out, but realize I may be buying new.
It looks like the major components I need to acquire are the
• Power source (ac/dc converter matched to controller and motor),
• User control buttons and cables
• Controller and cables,
• Timer and Bell or buzzer device,
• Sensors
• Motor.
The Motor Specs:
• Bi-polar, Constant Voltage or Resistance Limited
• PM permanent Magnet or Hybrid
• 650 mN*m or equivalent
Q1. Can anyone refer me to a source for this type of motor?
The Controller:
I think I’m looking for a Bi-directional DC Motor Speed Controller for a 4 wire bi-polar stepper motor.
Q2. Can anyone refer me to a source for a bi-directional DC Motor Speed Controller for a 4 wire bi-polar stepper motor that would be appropriate for this project?
The sensors:
I presume the sensors will connect into the controller. I’m thinking that a small magnet placed on the gear located on the chair post will be the signal for the chair location. Then on a stationary plate will be four sensors to pick up the magnetic signal as the magnet passes over the sensors.
Left Rotation:
Sensor 1: a sensor to indicate a position of 315 degrees from the starting point. This will indicate the motor control to slow down.
Sensor 2: a sensor at 350 degrees position cutting power to zero.
Right Rotation:
Sensor 3: a sensor to indicate a position of 315 degrees from the starting point. This will indicate the motor control to slow down.
Sensor 4: a sensor at 350 degrees position cutting power to zero
Q3: Based on this design the two sensors opposite of the rotation will have to be “off” as magnet passes over them. My thinking is that each set of sensors will be tied into the controller so as they are “off” at the appropriate time. Does that sound correct?
Project Recap: Motorized Revolving Chair
Attach a stepper motor to a chair seat to make it rotate in both directions.
The chair needs to rotate one revolution and stop in the time period of one minute (approximately).
Operation:
1. The seated user presses a button to start the chair rotating to the right.
2. The motor is delayed in starting causing a waiting period of approximately 10-15 seconds, and then the chair starts to rotate until it competes 360 degrees and then stops. Although the motor may need a slowdown period, from the user’s perspective a sudden stop is acceptable.
3. After approximately 15 seconds a timer bell sounds indicating the end of the rotation.
4. The seated user then presses a different button to rotate to the left (or possibly presses the same button depending on the electronics or programming to be added to the control mechanics)
5. Again, the motor is delayed approximately 10-15 seconds, and then begins to rotate the chair to the left 360 degrees and then stops.
6. After approximately 15 seconds a timer bell sounds indicating the end of the rotation.
Thank you for your feedback.
Dmend