Multiple sensor problems, yet good sensor readings

[BobHill]

Thanks to the good work of Chris Rawls, a frustrating problem solved and the machine is back to work and hard at it. I was getting multiple type sensor problems (and with many different woods, including a very flat MDF). I would get "clear bit sensor," "board problem," with no comment on what it was, and yet it would go through many of the proper routines, until another type of sensor problem would stop it. When the 0, 7 checks were done, the bit showed as it should have as did the wood checks on all the wood that gave the problem notices.

The one thing I did notice was that when I turned the machine on and while nothing but the LCD was "working" I heard a very faint 60 Hz hum and very faint it was... although after some time (and all the checking with Chris on the phone), it did a bit louder (if I turned the machine OFF, no hum, ON, a hum).

After a conferencing with the Chris's they came to the conclusion that although a motor wasn't running, there still would be power going to it, just not enough for it to run (and shouldn't run at that step of the operation). However, something within the power supply and/or voltage transformer was causing spurious voltage to be misdirected and thus could easily drive the sensors crazy.

A new transformer and power supply arrived via DHL today, and a relatively quick exchange to the machine, it's up and running some pretty sophticated carvings at the present time ....

Conclusion: Pay attention to not only what you might see visually that just doesn't look right, also pay attention to sounds that don't seem right. A 60 Hz hum is alway an indicator to question what might be going on. This MAY or MAY not be the problem for others, but it certainly cleared up mine.

Bob Hill
Tampa Florida

[pkunk]

Bob, good to hear you're running again and that it was a simple repair. I don't think I'd be able to hear a hum like that unless I used a stethascope! All my years around this loud stuff before hearing protection became a thing plumb wore 'em out.

[The Bard]

yeah, Chris' roxxor!

[BobHill]

Thanks, Pkunk. It is nice to be operating. And one more big kudo to the CW crew, of course. The hum thing was just a new wrinkle that might just be occuring to some of the other sensor problems. And from looking at the "old" transformer and power supply, you'd never know there was a problem.

Absolutely ROXXOR !
Bob

[liquidguitars]

A 60 Hz hum is alway an indicator to question what might be going on

Did the hum go away after you did the repair? If not should we think its a normal 60 Hz sound for the CW?

I was wondering if it’s a long run from your service panel as it could be low power. "We all know what that will do to power tools" introduce a dust collector and it will be worse.

[BobHill]

Liq,

I didn't say, did I ! NO more hum of any frequency ... only noise now is that of the machine motors working as they should. Motors go off, no noise except from me whooping it up with a very large grin on my puss.

Bob

[liquidguitars]

Yea I would think that a little hum would be ok coming from the unit, so I am a little confused about your hum to power relationship posted.
As people will be checking and thinking that the sound is a defect or not.

[BobHill]

Normally a hum is due to flowing ac current and without anything ac being activated, there should be no hum, even though there is apparently a very low amount of voltage. This was also something they said at LHR.

Thus the "signal processing algorithm won't be able to tell the hum from the real data " which apparently is pretty common around digitized signals at a time when both are needed. In our case, flowing ac is not needed during anything being motorized, so there should be no hum.

Bob

[BobHill]

Well, first let me say that the machine is running fantastically still, however, so much for my great pontification on the HUM. While ending the project just now, the machine is on, I started to do the clean up (manually first) and there it was. Still the very low hum .... and off it went, when the switch was clicked to 0. But still the machine works (which is the important factor). Thus, it served to replace the transformer and power supply and for whatever reason that exchange fixed my sensor problems and made the machine work, so except for acting as a lightning rod for inspiration, the hum apparently meant nothing as far as the original problem indicator. Those damn Gremlins again, all humming Irish tunes to the ac tuning fork, I guess.

Bob

[liquidguitars]

I give them Guinness but not after 12:00..