Posted by:
roger wilson
(---.hsd1.mn.comcast.net)
For those folks who have not used a power wrapper that is powered with a DC motor might try one sometime.
A DC gearmotor has the advantages of elininating all of the use of different sized pulleys to get the desired low wrapping speed.
DC motors have very good low speed high torque characteristics which make for very precise sub 1 rpm wrapping that is necessary for some of the fancy and or even simple wraps.
DC mtors have the ability of trivial direction reversal. The only thing needed to reverse dc motors is the use of reversed input line leads to the motor.
The typical DC power wrapper motor setup will consist of the following components.
1. DC gear motor
2. 1:1 pulley setup for both motor and head stock
3. Adjustable DC power supply for either voltage or pulse width depending on the speed control method.
4. Foot pedal that will fully regulate either the DC voltage to the motor, or the pulse width to the motor is using pulse width speed control.
5. Reversing switch to reverse the motor which may be on the end of a cord for easy movement down the wrapper, or built into the power supply to reduce the number of cords.
The down side of a DC gear motor - if you use a gear motor compared to a non geared motor is the loss of the ability to use the wrapper for turnining duties. i.e. the typical dc gearmotor will have a top speed of 300,500, 1000 or so rpm. This would be compared to the much higher speed of a non geared motor which would use a pulley arrangement to reduce speed.
Another nice option with respect to pulleys is the use of timing pulleys with timing belts which have cogs on the belt and pulleys to eliminate slippage with very light belt tension.
If you have any questions about the use of DC motors on a power wrapper, just drop me an e-mail
hflier@comcast.net
Roger
