View Full Version : Obviuos questions

11-18-2012, 10:30 AM
Just what is a super PID and what is it for??
When threading on a lathe, does it disengage when it reaches the length desired?? Say if I wanted a thread length of one inch, do I have to stop it manually at the same point, I think that would be highly improbable for me.
Is it wise to make parts on a hobbyist CNC router one at a time?? I've had issues with making parts next to each other and offset by 1.00". Usually they overlap by 1.00" instead of separated by 1.00".
Needless to say I have never attempted lathe threading, but, I have destroyed countless trials on my router. These simple answers may save a man's desires.

11-18-2012, 10:55 AM
I am not a spokesman for the product but it is generally intended to accurately vary and control the rpm of a Universal (series) motor.
The likes of which are used in routers etc.
In a lathe threading application the spindle is just set for a certain rpm and runs continuously, on a simple non-dsp controller such as Mach, the spindle is fitted with a 1/rpm sensor to synchronize the Z axis, on a Dsp controller an encoder is fitted to the spindle and the Z axis is geared off of the spindle encoder at a ratio dependent on the thread pitch.
But in both cases the spindle runs at a constant rpm.

11-18-2012, 12:56 PM
Just what is a super PID and what is it for??

www.SuperPID.com - Super-PID Closed-loop Router Speed Controller (http://www.superpid.com)

As for the lathe, I've never used one, but if you're talking about a CNC lathe, the g-code should handle everything.

Is it wise to make parts on a hobbyist CNC router one at a time?

I've made parts one at a time, and I've made them 100 at a time.
Making more than one shouldn't be difficult.

Why don't you post some examples of what you want to do, and tell us how you're trying to do it, and we'll get you squared away so you can enjoy your machine.

11-24-2012, 12:31 PM
I have no examples to show it was a general question. I've never threaded on a lathe before and was curious. So a PID is like a speedometer?

11-24-2012, 12:42 PM
The Super PID is a replacement speed control that uses a sensor to monitor the speed of the router spindle to better maintain a constant rpm.

11-24-2012, 12:54 PM
PID is something different than axis gearing, as in lathe threading.
PID, Proportional Integral Derivative, is the three basic components of servo control, based on a feedback device of some kind.

This is used on all types of feedback control devices, not only servo motors but temperature, pressure and flow sensors etc.
The geared Threading on a lathe is where the controller is a Dsp controller common to all axis, the controllers moves the Z axis dependent on the electronic gear ratio between the Spindle encoder (master) and the Z axis (slave).

One simple example where PID is used in the case of temperature, is if your home thermostat is a simple On/OFF bimetal type (non PID) , the temperature will consist of fairly wide swing around the set point as the Furnace carry's on producing heat when the bimetal opens, and vice versa, there will be a heating delay on closing, this is an undesirable swing.
If you have a PID type, however simple, it anticipates the coming temperature set point and starts to cycle progressively on and off until the temperature is reached in a gradual sense.
This produces a much nice smooth precise control.
In the case of the SuperPID, the feedback is by a simple retro-reflector on the motor shaft.

11-26-2012, 09:02 AM
O.K. so basically a thermometer for your motor and or spindle. See, it's as I thought something more exotic and incomprehensible having to do with CNC. And I thought, it was metal working!!

11-26-2012, 11:41 AM
A 'simple' explanation if you wish ;)
Description of the PID Algorithm (http://www.jashaw.com/description.html)