E-Stop Problem??

[ZR Machine]

My VF-4 was running a fairly long program last night and just stopped. The alarm said #107 E-stop. I check the button all fine then hit reset it would not reset, just kept bringing up the same alarm. I shut the machine down restarted, same thing. Then after an hour of this it just started working??? Not positive what it was but pretty sure it will do it again. Any thoughts??
Thanks Dan

[gar]

051219-1548 EST USA

ZR Machine:

I am not near a manual, but I believe that the E-stop switch couples into the machine thru an optical coupler. I do not believe that there is any mechinical relay involved.

If you look in the manual under electrical circuits you should be able to find this input. I believe all the external inputs that go to optical couplers are sourced from +24 VDC. Whatever the source voltage, which is identified on the diagram, you should see that voltage at the output of the E-stop switch. Whether the E-stop is normally open or closed I do not know. You will find out if you check for voltage on its output side.

There should be virtually no voltage drop across E-stop when it is closed, and probably near the source voltage when open. Expressed a different way the voltage from common (machine enclosure) to the output of the E-stop should be near the source voltage when the switch is closed (the voltage drop across the switch when closed should be in the millivolt range), to near zero when the switch is open.

I assume that the E-stop switch is not your problem. From what you describe you have a thermal problem within the control. Could be the optical coupler or anything following this. Make sure that the fans cooling the main processor board are running. The optical coupler and main processor are in the rear cabinet at the top left.

If the problem reoccurs, open the rear enclosure, and setup a fan to blow at the main processor area, top left of cabinet. Be very careful of the high voltage in this cabinet. Keep in mind that there is at least 325 VDC, and 240 VAC 3 phase or 480 VAC present.

Ideally you should you a person knowledgeable in electrical circuits to work on this problem.

.

[jwarren]

Does your machine have a hydraulic counterbalance system? If so, if the pressure of the counterbalance system drops, the machine will go into E-stop that cannot be reset. This may be your problem. The system just needs to be recharged with nitrogen.

[ZR Machine]

I did have a problem with the nitrogen pressure switch before but it always set a low pressure alarm. It has been fine since this happened but still wondering what caused it and will it happen again!!

[Kool Parts]

ZR Machine,
The Estop button is notorius for screwing up. But I had the same prob with the counterbalance switch. If you are unsure you can jumper the plug, into the bottle (paper clip). But dont let the presure go below 1000.
Also if it does you can add nitrogen yourself, dont pay Haas for a new bottle.

Gary

[HuFlungDung]

Can someone outline the 'safe method' to add the nitrogen to the counterbalance? I know I'll probably never get a Haas tech to visit me, so I'll need to know what is involved as a DIY'er.
Thanks.

[Geof]

Can someone outline the 'safe method' to add the nitrogen to the counterbalance? I know I'll probably never get a Haas tech to visit me, so I'll need to know what is involved as a DIY'er.
Thanks.

You need a special charging valve assembly. It attaches to a high pressure nitrogen regulator, has a fitting that screws onto the valve on the Haas counterbalance cylinder, a vent valve, a valve on the line from the regulator and a screw that depresses the valve stem in the cylinder valve and a pressure gauge. You connect everything up with the tank regulator set low; make sure the vent is closed and the valve to the regulator line is closed and then carefully tighten the screw that depresses the valve stem and gas back flows from the counterbalance cylinder, fills the charging assembly and registers on the gauge. When the gauge has stabilised at around the same reading as on the counterbalance pressure gauge tighten the valve stem screw a little more to open it further. Now start bringing the pressure up on the regulator until the regulator gauge shows about the same pressure as the one on the charging assembly. When this is the case it is safe to open the valve between the line from the regulator and the charging assembly. When this is open slowly increase the regulator pressure which now feeds all the way through into the counterbalance cylinder. When the correct pressure is reached close the regulator valve, back off the screw that is holding the valve stem open in the cylinder valve and slowly vent the charging assembly. If the pressure gauge on the charging assembly does not drop to zero very quickly you may have the valve stem still open or leaking. Once the charging assembly is at zero pressure you can back the regulator of to a low pressure and open the valve on the regulator line to vent it. Then unscrew the charging assembly off the counterbalance cylinder valve.

You should be able to find all the parts to build your own charging assembly at a good hydraulic place. Or borrow a system; they are used for charging hydraulic accumulators. If you need them I can post pictures and give possible sources for the parts next week when my office is open.

[wms]

Well first you need to get one of these..a gas chuck..one that has a center depressing pin to screw on the Shrader valve..

It needs yo be a high pressure one..and the hose needs to be 2750 psi rated..remember you are going to crack the valve on a 2200 psi nitrogen tank..

And for gods sake don't try and use a regular air chuck and hose..at the minimum you are going to see 750 psi..that is what some machines use..others use 1150 or 1800psi..and there is oil in there also..not just nitrogen..

After that it is pretty straight forward..hook up the gas chuck and hose to the supply Nitrogen tank..than to the Shrader valve on the machine..screw the depressing valve in to charge the hose..then crack the valve on the supply nitrogen tank until the pressure is where it needs to be..close the supply tank valve..then back the depressing pin out to clove the Shrader valve..done..

By the way most if not all Haas guys can just come and top off your tank too..the all carry the stuff..so no need to exchange tanks most times..unless you have lost the oil..then new tank is in order..

[wms]

Sorry Geof bet me...must have been while I was off taking pictures.. : )

[HuFlungDung]

Thanks guys. I guess I do have a rough idea of what to do....it is similar to charging up CO2 tanks for the paintballer guys.

Ward, I take it you don't bother with a regulator on your nitrogen cylinder then, you just rely on the gauge on the Haas? And you just bleed off the line (after recharging is done) by releasing the Shrader depresser, then closing the valve on the supply cylinder and then cracking loose the hose fitting at the cylinder valve?

[wms]

You would be correct on all accounts..Sir HFD..

[Geof]

Thanks guys. I guess I do have a rough idea of what to do....it is similar to charging up CO2 tanks for the paintballer guys.

Ward, I take it you don't bother with a regulator on your nitrogen cylinder then, you just rely on the gauge on the Haas? And you just bleed off the line (after recharging is done) by releasing the Shrader depresser, then closing the valve on the supply cylinder and then cracking loose the hose fitting at the cylinder valve?

Ward's answer "You would be correct on all accounts..Sir HFD.."

I will agree this is cheaper and quicker than my procedure if you want to run the risk of having something go wrong and give you a face full of nitrogen at 2700 psi. You have no good control over the pressure you put in the counterbalance cylinder and no way to vent excess pressure.