air supply problems

[d.evans]

My Mistral 07.07.05 is having problems with the air supply. I've tried every adjustment I know of to correct it, but my machine keeps stopping in the middle of programs.
The regulator keeps dropping below 3.5 bars (minimum) before the compressor kicks back on to maintain a level above that. THis causes the dreaded "air lube fault" error and the machine stops. I've tried adjustiong both the regulator, and the compressor. But my adjustments seem to drift back to an unsatisfactory level.
Any ideas?

[#2#]

Sounds like your compressor isn't keeping up with the machine's air consumption. If the compressor has not given you problems in the past I would check it out. Maybe a clogged air filter or loose belt has caused its efficiency to drop.

I definitely would not mess with the pressure going to the CMM. Too little air and your bearings could not be keeping everything square or they could drag and cause damage.

[d.evans]

I think we have an air leak between the compressor and the regulator for the CMM. When comp turns on, it is registering 4.5 bars, but at the same time the regulator is seeing 3.5, just barely enough to keep it running. Seems we're losing 1 bar somewhere.

[Andrew Gardner]

I had the same problem at my last shop. The compressor just wasn't keeping up. It took a lot of complaining to the maintenance dept. before anything was fixed. Turned out that one of the compressors had went down, and I was the only one that noticed.

[T Miller]

It was awhile back but they put a pressure tank on the airline right before the air dryer so if pressure drops off some the tank will help it keep up.

[djayne]

We have an accumulator tank to help take care of any air supply fluctations.

[why me]

Air

I would check the Filters and seals around them. Are you hooked up to an air dryer I have had problems in the past with those restricting air flow.

[Don Meredith]

When our first Xcel (7-10-7) was installed in 1990, the plant air supply was deemed not fit for use (oil and water). So we had our own compressor to run the Xcel and a Validator (manual CMM). As time went on, the maint ppl cleaned up the plant air with filters and separators to the point where it was safe to use. We still have our compressor as backup, connected via a check-valve so whenever plant air pressure drops below 80 psi, our compressor fires up and provides an uninterupted supply.
Before air comes into the CMM room, it goes through: 1) a centrifugal water separator, 2) a refrigerant drier, and 3) a three-element oil separator.
We are never aware of drops in plant air pressure until we hear our compressor running.

BTW, we now have three Xcels (the 7-10-7 and two 9-15-9s; the Validator is long-gone) and never get stopped due to lack of air pressure.

Now if we could just get that kind of control over the room environment......

[d.evans]

filters

I would check the Filters and seals around them. Are you hooked up to an air dryer I have had problems in the past with those restricting air flow.

Do you mean the filters at the back of the cmm or the filters inside the compressor?

None, btw, look bad. The compressor has less than 1000 hrs use on it, and it is in a clean closet with ventilation in the ceiling.

My supervisor got on the phone with the compressor mfg today, and the customer svc guy said he thinks the compressor is malfunctioning. The pumps don't turn on until the pressure drops to 4 bars. The tech guy sid it should turn on at 6 bars, which, if it did, would solve the problem we're having.

[Jan d.]

We still have our compressor as backup, connected via a check-valve so whenever plant air pressure drops below 80 psi, our compressor fires up and provides an uninterupted supply.
Before air comes into the CMM room, it goes through: 1) a centrifugal water separator, 2) a refrigerant drier, and 3) a three-element oil separator.
We are never aware of drops in plant air pressure until we hear our compressor running.

Wow Don, that's one heck of a setup you have there. This is the way everybody ought to plan their CMM room.

I think, though, that a nice big pressure vessel, right outside a CMM room, is not only a great way to stabalize the pressure, but also a way to catch more crud before it reaches the FR unit on the CMM. Make sure to plumb in a way to let the junk out occasionally (like a ball valve at the lowest point on the vessel that you can open occasionally to let the junk blow out).


Jan.

[craiger_ny]

My problem with Air Supply is that all 18 songs on their Definitive Collection can be found on their Greatest Hits. So why should I buy their Greatest Hits? Then they turn around and release an Ultimate Air Supply compilation of which 13 of its 18 songs can be found on their Greatest Hits. Not only that but they have more than one Greatest Hits. Last I knew they already had like somewhere around 6 compilation albums. Come on now. 6 compilation albums, two Greatest Hits? How does Air Supply have almost half as many compilation albums as Bachman Turner Overdrive? I dare ask, were they half as good? I say no but they do have about half as many. I say Air Supply doesn't hold a candle to the band that brought us the cowbell. 2 perhaps 3 compilations OK, maybe. But 6? I have a big problem with this.

[rebeldude]

The current CMM I am running doesn't have an air supply. Suprised me!

But as far as the group Air Supply, they don't hold a candle to Lynyrd Skynyrd either

[tking]

I had the same problem at my last shop. The compressor just wasn't keeping up. It took a lot of complaining to the maintenance dept. before anything was fixed. Turned out that one of the compressors had went down, and I was the only one that noticed.

I worked in a die cast shop years back, losing the air supply to a running die cast machine can cause a lot of downtime and tool damage (core pins). The CMM at this location would lock up long before the pressure drop would affect the die cast operations . Maintenance eventually learned not to ignore me when I called to advise them that air supply was going down. When I called and they "jumped on it" they could usually get the air back on line before they had problems on the floor. If they couldn't they at least knew to stop die cast machines at a safe point to prevent major problems. I went from a PIA to a white knight. Funny how that works, huh?

TK

[djayne]

I worked in a die cast shop years back, losing the air supply to a running die cast machine can cause a lot of downtime and tool damage (core pins). The CMM at this location would lock up long before the pressure drop would affect the die cast operations . Maintenance eventually learned not to ignore me when I called to advise them that air supply was going down. When I called and they "jumped on it" they could usually get the air back on line before they had problems on the floor. If they couldn't they at least knew to stop die cast machines at a safe point to prevent major problems. I went from a PIA to a white knight. Funny how that works, huh?

TK

We had almost the exact situation here. I would call maintenance and let them know one of the air compressors was down and I knew this because I was on the end of the supply and my LK machine was very sensitive to air loss. It took a couple of months of crashing CNCs from inexperience operators trying to restart their machines in the middle of a cycle before they started listening to me. Finally the situation was resolved by spending a butt load of money on 3 new air compressors.

[tking]

djayne,

It's just a chuckle ain't it?

TK