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Blake Kopachena
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I have a little project, I am building a simple lift that is moved with cable by a 3-phase motor which has it's speed controlled by variable frequency drive. I am going to be implementing PID control into the VFD via PLC that will be based off of a distance reading from an ultrasonic sensor for error detection. There are separate levels with different setpoints in the program. Problem is that I will not be using much load on the lift, and it will not move very fast. The 3-phase motor which meets these specifications is not used commonly and is very expense. So I purchased a 1/3HP 3-phase motor that is rated at 1750RPM for a cheap price. Obviously the speed is too fast for my application. I figured that I would use pulleys to reduce the speed of the lift by 1/4, using a small pulley on motor and a larger pulley with a bearing. I would use a double grooved pulley which would have a belt going to the motor pulley, which was smaller, then have a cable which goes from the pulley to the lift and then finally to another pulley on top w/ a bearing. While I was looking for pulleys, it occurred to me that the only change that will occur is the rotational speed. The displacement will be the same, thus lift will move same speed regardless of pulley size. I would have to somehow attach a smaller pulley onto the speed reduction pulley. But the problem is that if I'm off by a a few mm, the pulley will move away from the cable while spinning. I can't find a double grooved pulley which does this anywhere. I was wondering if there was a little solution for a dilemma. I was thinking about using gears, but I am not sure how to go about this. The shaft on my motor is 5/8 drive, so i will probably need something that is a 5/8 keyed bore. Where could I go to purchase these parts?
Thank you,
Thank you,
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