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Messages - phongshader

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As I suspected...I got up this morning to check to see if the auto zero was still working...it is not. So I replaced all the leads from the C25 with shielded wire, ran an earth lead from the chassis to the router table put it all back together and it works again...for the moment. My thinking on the ground from the chassis to the router table is that was the only variable between last night and this morning was when I tested last night the chassis was sitting on the router table (aluminum) so, in theory, the table was grounded to the chassis. If there is a good reason not to do this please let me know.
Thanks again.

Thanks again for the all the help.
when I can afford to get a scope I will be able to find the problem.
I do have a scope that I bought for tracking down a problem I had with a fuel injection/ignition system I built a few years back. How would I use the scope to track down rf problems?

This scares me, for the last week I've been chasing down this bug of why the auto tool zero was not working with the help of all of you. Going through all these iterations but ultimately changing nothing on the machine, settings, wiring, or otherwise. Out of frustration today after work I went into the shop to see if I could find that elusive ground loop we all know is there with a voltmeter and ran the auto zero routine to see if there was any voltage between the C25 grnd and the chassis grnd while running the routine...none, so just for kicks I let the machine run through the whole routine and....it worked?!?! I repeated it 5 times and 5 times it worked. How is this possible? Like I said this really scares me, for no rhyme or reason it started working so I guess  for no rhyme or reason it could stop working. Ahh well I guess I shouldn't look a gift horse in the mouth.  ;D We'll see if it's working tomorrow. Thank you all for your patience and help. I'll probably need it again soon. ::)

I went through and checked continuity:
0 continuity between chassis grnd and C25 grnd pin
0 continuity between chassis grnd and C25 +5v pin
20.5M resistance between chassis grnd and table/spindle/tool
0 resistance between C25 pin 15 (probe signal) and touch plate
0 resistance between C25 grnd and clip
0 resistance between C25 pin 15 and C25 grnd when clip is on touch plate
Measured voltages:
4v between C25 pin 15 and grnd when probe circuit open (clip not touching plate)
0v between C25 pin 15 and grnd when probe circuit closed (clip touching plate)
0v between between chassis grnd and C25 grnd
0v between between chassis grnd and and C25 pin 15
0v between between chassis grnd and C25 +5v pin
I'm going to re wire the Estop as soon as I post this. Thanks for the heads up blockhead and Rob

I most definitely did not ground the -v/0v of the power supply to the chassis 220vac earth, or at least not intentionally.
I measured the voltage between the C25 ground and the grounded spindle and it is 0v.
I'll check in the morning... must sleep now.

So this is a lot to understand but what I'm getting as the take away is that I need to eliminate the 220v earth/ground. The 5v power supply I installed does not want to share it's ground with 220v earth. I've attached a schematic of how the machine is wired at the moment. I added, I guess foolishly, the 220v earth, that was not originally installed when I got the machine. Any how Could you please look at the schematic and point out the flaws in grounding.  You talk about 0v I'm unclear as to what is 0v in the schematic the 5v power supply has a line, neutral and ground input and a v+ and v- out where is the 0v in the schematic?
Thanks again for helping me out!!

so you have a clip that goes to the tool what is earth (common) and the signal wire going to the touch plate.
ground is the ground pin on port1 between pin 15-16 and signal wire is pin 15 on the C25 board
also what is the voltage between the clip and the plate if it is below 2.8vdc that might be the problem.
Have you got a separate 5v power supply you could try
I do have a separate 5v power supply, you can see it in the attachment
the ESS should be on it's own 5vdc line with a common (earth) it the best way to do it, a lot of noise problems I was having went away after I rewired the whole machine to a common and it`s own 5vdc line for the ESS.

and moved the high and low common and power wires so there was no side by side wires, a cross over at one spot what is fine and the high and low common have there own star point side by side what is also fine.
The power supply I installed for the ESS is grounded to the chassis, common to the earth ground of the 220v from the house. What I'm unclear about is there are now 2 grounds, one from the C25 board and one to the chassis/earth from power in from the house. The power supply I installed  has line, neutral, and ground, the ground on the ESS is derived from 5vdc- from the 5v power supply I installed, where s the common ground for the vdc? The chassis is grounded VAC, the ESS/C25 is VDC. I'm probably not understanding how the grounding works but hopefully some one can straighten me out.

Why not use a crocodile clip onto the tool when you want to use the tool offset / probe function
I am using a crocodile clip on the tool or when the tool is to big for the clip I clip it to a bolt head on the spindle mount, but for the testing I have been clipping to the tool. To add a little more to my grounding theory if I touch the ground to the tool in the middle of the zeroing macro I can feel the machine react to the contact, not much, but there is something happening and this is long before the tool reaches the touch plate.
Then put the 5v (pin 13 or 15 input..forget which one you are using) to your insulated calibrated height block.... (You could use a piece of blank PCB (printed circuit board)....
you just described my setup as it stands now, although my circuit board is loose so I can move it around to the work piece.

what version of Mach3 are you using?

(other than that I'm out of ideas).
Version R3.043.062
what is the code you are using if it`s not coded for you screen it wont work to well put it in code tag's

I'm running the 2010 screenset.

Like I said before I'm totally new to all this, especially the electronics part. A little back story here. I bought a Chinese machine with an AKZ250 motion controller card, set up the auto zero probe with an external power supply (9 volt battery) and it worked, and then one day it didn't. I swapped out the AKZ250 card for an ESS/C25 combo and the auto zero still didn't work, played around with it, re calibrated the motor tuning and it started working, just not consistently. I moved the touch plate grnd lead from the front of the table to up onto the spindle mounting plate and the auto zero stopped working. Now if I were reading this I would think that this would be a noise issue because now one of the probe leads is running past another stepper motor and a spindle however I believe there is pretty good noise suppression on the C25 board and I'm running 5v through 2 2.2k res in series to the touch plate. What I am thinking now is that there is a grnd loop issue because  the auto zero macro runs as it should when the C25 probe leads/touch plate is isolated from the table, spindle, tool, and doesn't when the grnd lead from the C25 is touching the table, spindle, tool. Does this make sense? If this is indeed a grounding issue how would I go about fixing it, or even testing it beyond the test I've done?

Try changing the z axis settings on the homing and softlimits settings page under configuration...

There is a checkbox for negative home, can't remember if toggling that solved my problem (I had two at the time the z was crashing int o the top of the carrige but that was the safe home setting...)
I'll try that but I don't think that's the issue. the auto zero macro works, more or less, when the C25 grnd is NOT touching the tool/spindle and I touch it to the touch plate, that is I start the macro, z goes down towards the table, -z, until I touch the bob grnd to the touch plate, z stops then it does it's double touch routine then retracts to 1.5" above what it thinks is zero. Now when the bob is grounded to the tool/spindle and I run the macro when the tool hit the touch plate it keeps on going even when the probe led is lit and I have to hit the e stop to keep from crashing into the table.

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