[10001001]

Hi,

I have a FAGOR 8025-M that is acting up. Both the X and Y axis are behaving the same.

Durning the Axis Home Search Jog Mode and Program ( g74 Y, g74 X) behave the same.

You start the home search cycle and this is what happens:
The machine moves at a fast speed until it hits the axis reference switch. Then the machine reverses direction at a very slow speed, although the marker pulse pin has +5volts sitting on it the machine continues to travel like it is still searching for the marker pulse.


I have sent this control to FAGOR repair TWO times, and both times they tell me that the can not get the problem to reproduce on their tech bench.

Does anyone have any idea what I am missing, or what in my machine could be causing the control to behave this way?

Other information:
I have full control over the machine. Good encoder counts. I can fire up the machine, preset the X and Y values via g92 commands, and execute a program. The only thing that I can not do is home search as described above.

Any help is deeply appreciated,

Mike

[TAProwler]

Hi Mike,

That's an interesting one! My 1st thought is that an encoder is messed up - but that would not explain why BOTH axes have the same issue. That tends to point to something COMMON between both X axis and Y axis. However, that would most likely be in the control. But, you've had that looked at TWICE!

Humm.

Well, if it ain't stopping when it sees that marker pulse, then it can only be one of two things: 1) The marker pulse isn't being created; or 2) The marker pulse isn't getting back to the control. The first situation would be things like messed up encoder, or maybe power supply to the encoders (low voltage stuff). The later one would be broken wires, missing pins in connectors, or anything that would cause the marker pulse from getting lost or not getting back into the control. Might also be a grounding issue and/or a shielding issue on those multi strand cables.

Hopefully, that will give you some things to think about or check out (if you haven't already thought of them yourself). Hopefully, I'm not sending you on some wild goose chase(s). That is not the intent!

Oh, one more thing. Did you change any parameters sometime before the mis-behavior started? Just thinking that maybe some parameter change had an unintended consequence. Just thinking out loud.

Good Luck.
R/ Todd

[10001001]

Todd,

Your advice is spot on for this type of a problem. I even went as far as simulating the marker pulse with a switch. Everything I have tested on my machine is good. I would have just said that the control is bad a long time ago but there is always that what if I missed something feeling in my mind, especially when Fagor says that they cannot reproduce the problem on their test bench. Despite what FAGOR has told my two times, I put more faith in my trouble shooting ability and purchased a used controller. The new controller is a 8025M-K which is the same, but has more memory than the 8025M. After painstakingly transferring the parameters from the original control to the new one, (I had to do this manually because I don't have the software to do it.), my machine is now back into production.

I guess the moral of the story here is even the "Authorities" cannot always find the problem and persistence pays off.

I do appreciate your help,
Mike

[TAProwler]

Hey Mike,

Nice job troubleshooting.
Congrats on your persistence at it paying off for you.
My folks always taught me "If you want something done right, you usually have to do it yourself."
The older I get, the more I have found that to be the case, time and time again.
Glad you're back in action.

What you gonna do with the old control?
I might be interested in getting if, if the price is right (for parts).

I wish I had more memory in my F8025M!!!! That whopping 32K of ram is just NUTS!!!

Take care,
Todd

[10001001]

Todd,

I know what you mean about the 8025M not having enough memory. I am using it on a shape cutting machine doing a lot of nesting on plates. I have done some creative things with subroutines, and strategically laying out the parts on the stock so that I can just apply an offset then recycle the program to be able to process a whole sheet of raw stock.

The company I bought the 8025MK off of is offering me a credit as a core charge when I return the old one, so it is on its way back there. Here is their link SSSLMachinery.com - Beam Line, Beam Drill Line, Beam Line, Fabrication, Beam Line

This company buys worn equipment and rebuilds them to sell. They also have a collection of the older controls and servo amplifiers, etc. The way they explained it to me, when they rebuild a machine they go through the whole machine mechanically from head to toe restoring the machine to factory specs. They then, replace the obsolete electronics with state of the art equivalents.

Thanks once again,
Mike

[TAProwler]

Cool!
Thanks for letting me know.
R/Todd