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vizion
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Hi
I have an old electric paper guillotine.
Guillotine have two esential functions apart from those associated with positioning the paper ready to cut.
1. Using power (usually electric motor) to operate the blade which cuts the paper stack.
2. Using power (an electric motor or manual turning of a wheel) to put pressure on the stack of paper immediately prior to cutting. Some types of paper need more pressure than others. For electric operation the amount of torque can be varied by the operator setting the level of torque deemed appropriate. When operated manually the operator simply adjusts the amount of force he/she applies to a wheel which directly turns a shaft on which the pressure plate is mounted.
My old electric guillotine has manual operation for applying pressure. I am retired and use the guillotine for personal projects. Manual operation of the wheel is slow, inconvenient and leads to inconsistent results.
The pressure plate must be able to move vertically to any position between its topmost point and a fraction of a millmetre above the cutting table. The wheel is mounted on top of an extrenally threaded shaft which passes through an internally threaded fixed plate placed horizontally above the cutting table.
1. I want to build an additional electric motor drive to turn the head of the shaft so the pressure can be automatically applied when a button is pressed. This would be most easily accomplished using a belt drive but a gear driven arrangement would not be too difficult to arrange. The pressure plate would need to be lowered until such time as some form of variable torque limiting controller caused the motor to stop applying additional torque. Until released (see next para) pressure would need to be maintained whilst cutting occured. After the cut has been made pressure should not be released until the blade has had time to retract to its rest position. If that is not done then the retraction of the blade can disturb the stack causing the operator additional work tidying the stack before undertaking an additional cut of the same stack. This happens frequently if each sheet of paper is printed with multiple copies of the same image.
2. Ideally it would be nice if the the pressure could be automatically released after the blade has done the cutting. I have no doubt I could fit a microswitch which may be tripped according to the position of the blade. However some form of time delay would be needed to allow for blade retraction.
There are two types of release needed.
(a) Default-Partial release: Simply releasing the pressure sufficiently to allow the operator (me) to withdraw the paper, turn the stack of paper so I can make a series of subsequent cuts c with a different orientation an a stack of the same size.
(b) Full retraction: Probably triggered by activating another control after the default action has occured: This would fully retract the pressure plate to its topmost position at the end of the job.
I can design and carry out the physical engineering (I have a myford lathe and other engineering tools) but I have no idea how to I should set about choosing a motor or controlling it. The design would need to ensure that there could be no mechanical force applied which would tend to raise the pressure plate above its topmost position or touch the cutting table
Is anyone willing to help me here?
Thanks in advance
David Southwell
I have an old electric paper guillotine.
Guillotine have two esential functions apart from those associated with positioning the paper ready to cut.
1. Using power (usually electric motor) to operate the blade which cuts the paper stack.
2. Using power (an electric motor or manual turning of a wheel) to put pressure on the stack of paper immediately prior to cutting. Some types of paper need more pressure than others. For electric operation the amount of torque can be varied by the operator setting the level of torque deemed appropriate. When operated manually the operator simply adjusts the amount of force he/she applies to a wheel which directly turns a shaft on which the pressure plate is mounted.
My old electric guillotine has manual operation for applying pressure. I am retired and use the guillotine for personal projects. Manual operation of the wheel is slow, inconvenient and leads to inconsistent results.
The pressure plate must be able to move vertically to any position between its topmost point and a fraction of a millmetre above the cutting table. The wheel is mounted on top of an extrenally threaded shaft which passes through an internally threaded fixed plate placed horizontally above the cutting table.
1. I want to build an additional electric motor drive to turn the head of the shaft so the pressure can be automatically applied when a button is pressed. This would be most easily accomplished using a belt drive but a gear driven arrangement would not be too difficult to arrange. The pressure plate would need to be lowered until such time as some form of variable torque limiting controller caused the motor to stop applying additional torque. Until released (see next para) pressure would need to be maintained whilst cutting occured. After the cut has been made pressure should not be released until the blade has had time to retract to its rest position. If that is not done then the retraction of the blade can disturb the stack causing the operator additional work tidying the stack before undertaking an additional cut of the same stack. This happens frequently if each sheet of paper is printed with multiple copies of the same image.
2. Ideally it would be nice if the the pressure could be automatically released after the blade has done the cutting. I have no doubt I could fit a microswitch which may be tripped according to the position of the blade. However some form of time delay would be needed to allow for blade retraction.
There are two types of release needed.
(a) Default-Partial release: Simply releasing the pressure sufficiently to allow the operator (me) to withdraw the paper, turn the stack of paper so I can make a series of subsequent cuts c with a different orientation an a stack of the same size.
(b) Full retraction: Probably triggered by activating another control after the default action has occured: This would fully retract the pressure plate to its topmost position at the end of the job.
I can design and carry out the physical engineering (I have a myford lathe and other engineering tools) but I have no idea how to I should set about choosing a motor or controlling it. The design would need to ensure that there could be no mechanical force applied which would tend to raise the pressure plate above its topmost position or touch the cutting table
Is anyone willing to help me here?
Thanks in advance
David Southwell
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