DDSCV1.1 3 and 4 axis offline motion controller

[Boyan Silyavski]

Boyan don't get me wrong here I'm not trying to put you or the controller down here but this needs to be said and made clear for sake of others reading what you wrote and thinking it will work same for them when chances are it won't and here's why.?

What speed was the machine traveling when power failed.? The law of physics dictates that inertia will make the axis continue on for some unknown distance if traveling at reasonable velocity. So unless you have absolute encoders or Glass linear scales on the axis you will have lost position.

Now in your case you have Servo's which more than likely will have incremental encoders which don't retain there position when power is lost so they have not had any affect on keeping position. These controllers Also don't have positional feed back so equally it has no Clue to where the axis was when power failed.

So the fact you got back into position as nothing to do with the controller and everything to do with the fact your using servos which can accurately home. Probably using the encoder if using index pulse for homing.?
Steppers or Servo if traveling at any reasonable feedrate position will be lost if power fails. The function of getting back into Exact position as nothing to do with controller and everything thing to do with the HOME sensing type, be that encoder index or Home Switch.

This is no different to any other Controller be that PC based or Stand alone. The only exception is if your Encoders are absolute type or have Glass linear scales in which case the Servo drives are doing the work not the controller.

Dean, you are untiring my friend in your criticism, the way i am in my optimism. Ok,as you say- for the sake of others reading that:

1. First of all if electricity stops mach3 goes to nowhere and when you restart it you see a couple of rows of Zeros, hence the machine does not know where it is initially. Not so with the offline controller. It knows exactly where it is, even if its a though further as you say because of inertia, though i measured exactly the difference and it was 0.1mm on Z, on my machine only the Z is prone to inertia, all else locks into place when stopped suddenly, of course not if i am moving at 20 000mm/min

2. My experience shows that proximity limit switches/ Chinese at least/ have an error of approximately 0.4mm or i could call that hysteresis / imagine a backslash/ even if you home repeatedly again and again. Always first time off 0.4mm. Then right correctly. I tested aluminum, brass and steel. First i thought / on yellow machine/ that my error was a design error, cause not sensing perpendicular to them. Now on this machine sensors are NC, perpendicular steel/ best material for sensing/ as far as i remember when reading documentation
What i am saying is that even if you home in mach3, if you are machining steel or aluminum,not wood you would be way off 0.1-0.4, so let's not brag about continuing the job correctly, cause i have been there, done that with aluminum and its not ok. In short, if power stops in a middle of metal job you are f%%d up and can not depend on home switches but instead of that have to use Zero Z axis DTI setter or touch probe.So its absolutely useless speaking how PC will recover from power failure.

3. Show me a PC controller that does not lose position due to delay between the time you hit reset/ pause and the time the command is executed by the machine. Not so with offline controllers. Its i could call it- an exact stop controller.


So in short: PC or Offline controller it will go out of position by small negligible amount which in both cases must be corrected if milling steel or aluminum. If working wood the offline controller has the edge, as you just hit continue and that's it. The PC controller needs to home, find X, Z zero additionally due to proximity limit switch error which is not so negligible at ~.4mm. Plus maybe you need to fix Windows because of the sudden loss of power and in most of the cases you need to fix Mach3 by checking if the screen works correctly or you need in most of the cases to reinstall it again to make sure all is as it must be. As i had many problems after sudden stop of power. That's why i say it again i love the offline controller.

I wonder, can't you just see it- its cheaper and simpler. More reliable and easier to exchange in case of fault. I wonder when you Dean as a maker of CNC machines will accept the fact that the controller responds better to your KISS principle.