Oldgreybeard
27th July 2015, 12:27 PM
I am now concentrating on motor control systems, in particular closed loop PWM control programming, as part of my study into Microprocessor control systems. I have been looking at some of the commercially available VFD / VSF systems and have now started to put together a specification for a system which addresses the particular needs turners in contolling the woodturning lathe motor.
The main components are;
- Graphic user interface (GUI) for automated setup of motor characteristics, user preferences and motor speed control parameters.
- Push button selection to automatically implement the user preferences / parameters based on type of turning activity
- Ability for user to edit or add defined processes.
The concept is to establish, during setup, a set of parameters which suit your personal preferences for various types of lathe activities. For example - supposing that you have a 15KG out of balance lump of wood on the lathe. I envisage that you would want to be able to select via the speed potentiometer a very low speed, say 50 rpm, you would want high torque and probably a slow ramp time for the motor to come up to the set speed. As the blank comes into balance and you increase the speed to say 200 rpm, you might still want a constant high torque but the ramp time could now be reduced a bit - you shouldn't have to go into the control panel to change the ramp time. Being able to tie some of these parameters together into an automated process (still controlled by the user by adjusting the speed knob), I think it will be possible to create a safer environment. Parameters which should be changed, but often are not because its a PITA will more likely be done if it only has to be done once and is then always implemented.
Of course there will always be ocassions when manual over-ride is required.
I have attached a simple questionairre to help me clarify what is important to woodturners and what is not. If you can spare a few minutes, I would appreciate your input and any additional comments.
Bob
353982
The main components are;
- Graphic user interface (GUI) for automated setup of motor characteristics, user preferences and motor speed control parameters.
- Push button selection to automatically implement the user preferences / parameters based on type of turning activity
- Ability for user to edit or add defined processes.
The concept is to establish, during setup, a set of parameters which suit your personal preferences for various types of lathe activities. For example - supposing that you have a 15KG out of balance lump of wood on the lathe. I envisage that you would want to be able to select via the speed potentiometer a very low speed, say 50 rpm, you would want high torque and probably a slow ramp time for the motor to come up to the set speed. As the blank comes into balance and you increase the speed to say 200 rpm, you might still want a constant high torque but the ramp time could now be reduced a bit - you shouldn't have to go into the control panel to change the ramp time. Being able to tie some of these parameters together into an automated process (still controlled by the user by adjusting the speed knob), I think it will be possible to create a safer environment. Parameters which should be changed, but often are not because its a PITA will more likely be done if it only has to be done once and is then always implemented.
Of course there will always be ocassions when manual over-ride is required.
I have attached a simple questionairre to help me clarify what is important to woodturners and what is not. If you can spare a few minutes, I would appreciate your input and any additional comments.
Bob
353982