random estop

[kolokithas]

Hi erase,

Have you considered the option that the cpu of the controller creates these random e-stops??Now the exact reason for the problem it might lies inside the thousand of transistors that consist an IC.As for the i/f,no one guarrantes that a new circuit will be less acceptive to interference.Normally the new designs should resolve the problems of EMI/RFI but once again "no one guarantees that.I also have DeskCNC controller (2nd gen).Indeed the Main IC of the controller needs cooling(noticed the heatsink?).I have placed a small blower on top of it.By reading the first threads of your problem,one thought crossed my mind:why he doesn't purchase another controller?(i see after that you already done so).Theoretically talking,the final word is that if everything seems good on your wiring/software setup/voltage etc. and the problem still persists then the suspect is the controller itself.Sometimes with electronics we know the result of a problem but we dont know the cause.The matter is what do we want,we want the particular part to work(no matter the cost)or we want to search in deep to find the problem?In the second case of course you gain invaluable knowledge but some times we need something to work not how it works.Btw,Fast support is the key for a succesfull company!!!

Till the next time...
"Many questions,one aim"
Panos

[rancherbill]

I'm a computer guy not an electronics or CNC guy.

Your OLD board worked. This does not mean that everything was perfect, rather that particular configuration worked.

When you put in the new board it had a weakness that was more susceptible to an existing problem in your total unit.

To quote your last post:

As i mentioned Ive noticed a reduction in stops recently, in fact i dont recall any today or yesterday. the only thing i can think of that is different other than slightly cooler weather, is that I have left the controller on all day and night for the last couple days.


Unless you have a system that was made by Oral Roberts and is healing itself, there is an external factor that is causing the problem - power or heat.

Based on my experience, I would first look at power in the broadest terms, incoming AC, powersupply, grounding etc.

Incoming AC can have many problems spikes, surges, sags, transients, ground loops, polarity etc. Is the wall plug wired correctly, is you machine and the controller on the same circuit breaker, AC ground hooked up, do you have some kind of filter on it, etc?

Is the power supply of a good design? There is another discussion going on in another forum as to a good power supply design. They are on their third schematic and have had 20 posts in three days.

http://www.cnczone.com/forums/showthread.php?t=29797

It is a lively discussion with many good corrections, situations, and scenarios being discussed and incorporated into the evolving design.

Some possibilities that come to mind with the weather, your spouse hasn't been turning on the dryer, you haven't had some other piece of equipment turned on in the shop, your neighbor hasn't been welding in his carport, a large industrial user has temporarily suspended some outside operations etc etc.

The other possiblity is that the ambient temperature in the shop is has been lowered just enough by the cooler weather to get you out of the flakey zone. A previous writer has made some good suggestions. Maybe try operating with the covers off and / or blowing air with a fan.

I hope this might be a different perspective on troubleshooting the problem.

Please post you eventual solution as I am curious as to what works for you. There are too many threads on the site that are left dangling. It's like reading a book and last page is missing.

[erase42]

Hi rancherbill,
I installed ANOTHER new board and still have the same exact situation. Ive sort of given up on the temerature being a factor as I have experimented with space heaters and small duct from a window unit. No specific temperature zone seemed less problematic than another. I have tried diverting airflow away from the sinks to a extent to achieve slightly warmer operating temperatures, monitored with a digital temp sensor of course. The board is and has been fan cooled. None of the heatsinks on either the controller or the motor drivers gets more than slightly warm with the fan running.
Having said this, I still feel that I have less, and sometimes no stops between 1 and 3 or so. I realy havent documented this but its it seems that after I get back from lunch, I can run my larger files with no problems.
The power supply for the motors is not home made, it is a 24v 12a power module that looks to have come from a large photocopier or something. I trust it, and I dont belive its power has anything to do with the control board in any case, just breaking down the system for you.
The power supply for the control board and the logic portion of the motor drivers is a radio shack wall brick. All of a sudden i question it though. It is the only thing that I changed when the old board went bad. Hmm never thought of it till now. Its not a transformer, but must be some solid state regulator since its rated for 1.5A and is barely larger than one of those jelly packets at the restaraunt. Ill have to look into replacing it with somthing else. By the way, that power supply, the radio shack cube, and the computer tower is all plugged into a UPS power supply.

Ive done tests like wiggling wires shaking the control box and pressing different parts of the control board with a pencil eraser, all while the machine is running in attempt to cause a failure. No success.
Ive also disabled the Estop function in the software, although Im not entirely sure what exactly that does, but It would seem that it should ignore an Estop command from the control board. That didnt help. There is in fact no estop switch connected to the system. There is only a jumper between the estop terminal and ground in order to close the circuit. Ive checked that connection ONE MILLION times.
As for the power in the area, I cant say. Its a commercial area but I have no huge machines or welders in my half of the industrial park. If there were power issues, wouldnt the UPS take care of most of it? I can tell you that Ive been at the shop alone, late at night with nothing else in the shop or the area opperating, and still out of nowhere the machine will go into estop.

This is getting long, so Ill stop, but I do appreciate someone elses angle on this.

Ed

[rancherbill]

I'm happy my perspective gave you another possible culprit - the wall brick P/S.


Don't always place all of your trust in the UPS. I am a 100% believer in using a UPS. They are best thing since sliced bread. There are 2 basic styles one of which is better. Here is my "computer guy" view of the elctronics in a UPS.

The first style uses a trickle charger to keep the battery charged. When there is a dip in power or a total failure it turns on the inverter to keep the voltage within a normal range. It works well, the down side is that the filtering during normal AC operation is that you are only getting filtering like a good power bar.

The second type is a true UPS. All of the AC power is used to charge the battery and then the inverter is produce 100% of the AC out. The battery acts as a huge filter for the system. this type is far superior and, as always, more expensive.

I still think it is something external in your local environment. You have said it is better on rainy days and from 1 - 2 in the afternoon. Are you located near a grave yard? Maybe ghosts and goblins are having fun with you?

I know it's impossible to see behind all your industrial neighbours doors, but, charting occurrences might indicate a pattern that might prove external vs. in machine origins.

[erase42]

i was aware of that about the UPS, but other than taking it apart, is there a way to tell what type it is?

[rancherbill]

Google
Price
Manufacturer datasheet

or .......

Take off your shoes, pour some water on the floor and grab acouple of bare wires. If it's the cheap one there will be a voltage drop/sag for a cycle or so (1/60th of a second). If it's a good voltage will remain constant.

You might have to do it several times as feeling the voltage sag is some times hard to detect.

On second thought maybe research is a better technique.

[faststeve]

I'm not familiar with the deskcnc, but why does it ruin a part when you Estop ? Most controllers don't mess up when you hit the Estop or a limit switch !

[erase42]

Hi faststeve, it ruins a part becasue I use to to run a hotwire cutter. when it stops, and worse when it starts, the wire burns a groove in the foam peice which is normaly 8 feet long and worth anywhere between 3 and 60 dollars. there is a very precise ballance between movement and heat, and the stop start process blows it all to hell Sometimes I can sand the area out, but on most things its just a loss.

Ed

[rancherbill]

What's happening.

THere hasn't been any post in a while.

[erase42]

well i finally just replaced the computer, ive replaced everything up ot it and now it itself. It hasnt stopped yet, meaning it hasnt failed. I set it off on a 2 hour file when I left here yesterday and it finihed fine with nop problems over night. i guess my serial port had a glitch in it. Only problem now is that the software wont accept the settings i need. no matter what i do, it still creates toolpaths for a 3 axis mill.