Thread: Shop Maintenance

Originally Posted by ChipSplitter

Can anyone tell me why threads seem to degenerate so quickly anymore? I can't remember it ever being so bad when I was lurking or first joined.

Sheesh, this one isn't even on the second page yet!

Most of us are adults here...(I hope). Could we all begin to act our age??

It's just certain posters and the way they come across that gets people riled up. I'm pretty sure you could ask a serious question and get good feedback still. I threw out the joke about fake members because it was clear this was going to be a trainwreck from the get go, wouldn't do that to a "real" thread.

Originally Posted by otrlt

Shop Maintenance,

. All CNC's need air, so change your compressor's oil and air filter every 6 months.

Not so. 4 of my machines do not need air to operate. Only one absolutely has to have air, and that's to shift gears.

We have a 40hp screw compressor with integrated air dryer feeding into a 400 gallon dry tank. This gives class 1-4-2 air providing the shop. The tank has an inlet connection to be supplied air from a 5hp backup compressor with dryer to limp the shop along if needed.

We also have a regenerative dessicant dryer and filter system that provides better than class 1-1-1 for our laser and powder coating booth. The dessicant dryer is capable of handling all moisture from the compressor should the refrigerated dryer fail. In the event of a dryer failure, it's just inconvenient to briefly supply noncritical equipment with wet air.

The dessicant needs to be changed every 3 years, the oil every 2 years (IIRC) and filters every 4000 hours. Inspections are more frequent.

The dryer also has alarms on it, so if it stops getting cold we know before water gets anywhere.

The whole system was only about $18k.

Are compressor failures common?
How much effort is put into "air quality" your feeding your machines?

I've been compressor shopping this week, my Costco commodity 5cfm won't cut it for my new (to me) haas vf2's air/oil lube and tool change demands.

I had been looking at compact 5hp screw compressor/filter/dryer packages (kaiser air tower and such)(quiet is a huge plus for me)
OR tie a few el cheapo units to a dryer

I'd be some ticked if my fancy screw went down and I was down!

Originally Posted by Stirling

Are compressor failures common?
How much effort is put into "air quality" your feeding your machines?

I've been compressor shopping this week, my Costco commodity 5cfm won't cut it for my new (to me) haas vf2's air/oil lube and tool change demands.

I had been looking at compact 5hp screw compressor/filter/dryer packages (kaiser air tower and such)(quiet is a huge plus for me)
OR tie a few el cheapo units to a dryer

I'd be some ticked if my fancy screw went down and I was down!

IME screw compressors are reliable until you've racked up too many hours. I see them for sale at 10,000 hours for that reason. (I think they also need a rebuild around that time, but it varies)

In any case an el cheapo won't last near that long either.

You can kill rotary screw compressors with constant starts/stops if you set them up wrong though.

Im thinkn its a millenial thing,why have two compressors when one is enough.....and spend the money on something like a new I- phone .I always used to buy cheap compressors at auctions,didnt need them,but they were cheap ,or no one wanted one that day ,I got it......So with me having a few ,people wanted to borrow them ,never buy one ,cause it was too old ,or dirty or noisy or summat.....Lightbulb moment,I hire them out.Ended up with dozens ,simple swapover ,a length of rubber hose and electric cord ,meantime I fix your old comp ,or you do a deal on a new one that takes the fancy.......So I ended up selling new ones on credit too....Sold the whole little enterprise as a going concern to a travelling tool salesman as a sideline for his wife and kids to run...And I still bought cheap compressors as I saw them around.

Screw compressors dont normally die suddenly ,if oil, oil separators and air filters are changed in time.....neglect oil change and the oil system may clog with shellac......but things do go awry.....First would be electric shutdowns for overtemp ...generally caused by dirty coolers ,if air to air.Even clean shops clog the air coolers over time......water coolers need water ,quite bit,come under local health regs and are health inspectable (cost).If you need dust collection too (grinding/paint booth F/I)then cooling water can be used twice.....On a bigger screw ,50,000hrs is common,with rebuilds (bearings /seals) etc every 15,000hrs .Electric motors need the cooling cleaned regularly ,or insulation will break down and short coils.Greased every 1000hrs too .Not too much ,not too little.....Finally a screw will need a lot of ventilation,or it will produce a greenhouse effect in the shop.

Originally Posted by john.k

Im thinkn its a millenial thing,why have two compressors when one is enough.....and spend the money on something like a new I- phone .I always used to buy cheap compressors at auctions,didnt need them,but they were cheap ,or no one wanted one that day ,I got it......So with me having a few ,people wanted to borrow them ,never buy one ,cause it was too old ,or dirty or noisy or summat.....Lightbulb moment,I hire them out.Ended up with dozens ,simple swapover ,a length of rubber hose and electric cord ,meantime I fix your old comp ,or you do a deal on a new one that takes the fancy.......So I ended up selling new ones on credit too....Sold the whole little enterprise as a going concern to a travelling tool salesman as a sideline for his wife and kids to run...And I still bought cheap compressors as I saw them around.

In high school I worked for a shop that bought cheap compressors. Always ganging up several of them because each one had bypass leaks and only put out 1/4 of the airflow. Or trying to tell them that the power light on the air dryer doesn't mean it's actually working. At one point I think we had four tanks driven by a single overspeeded compressor that ran our sandblasting for a few minutes at a time.

My favorite was a 10hp reciprocating compressor that had a motor go out. I replaced the motor and found out the compressor would randomly bind up and kill the motor. No motor protection other than an oversized breaker meant for a reflow oven, of course. So I replaced the compressor head with a "new" on we got at an auction, but it didn't work because the motor was already damaged. So I replaced it with another random motor from a different dead compressor, and it ran great for a day, until the flywheel was visibly bouncing up and down 1/4". Found out the compressor head was left sideways outside and the bearings were full of what amounted to oil based mud. So I had the honor of taking it apart and replacing the bearing, then it finally worked without issue from then on.

It was a fun job in high school but I'm glad I'm not dealing with their mismanagement anymore.

But yeah I stay away from used compressors now.

I think millennials have a buy once cry once. Always just have a newer unit vs older. Mentality. Thinking one newer is a better safety factor than 2-3 redundant items. (And they spend like a mother f'r. Remaining available credit is tjeir savjngs account....)
More of a no repair no hassle warranty.
Comes with the cheap disposable commodity mentality. And I get it. But there is lots of money to be saved buying used. I'm an 1984. So melennial but barely? I like used!

Unfortunatly I live in a norther smaller town, so used on neiche items is hard to come by. Working from a home garage shop my needs are neiche.
Needs to be as low draw as possible, but quality. Commodity items have killed this bracket imo.

Being "remote" most warrenty centres are 550km away. So even if it's warranty I have to pay a small
Fortune for the drive to and from, plus hotels and meal sub. It's a killer.
Do that a few times and it's the cost of a new kaiser air tower all over again..

Originally Posted by Strostkovy

IME screw compressors are reliable until you've racked up too many hours. I see them for sale at 10,000 hours for that reason. (I think they also need a rebuild around that time, but it varies)

In any case an el cheapo won't last near that long either.

You can kill rotary screw compressors with constant starts/stops if you set them up wrong though.

Our main Kaeser has 52k hours on it now. It once burst the oil cooler and was down for most of a day while they fetched a new one from their warehouse. It was down for an afternoon once when it stopped pumping because of a faulty pressure switch. Other than that it just keeps on churning out air. It has a refrigerated dryer that has never had any problems at all. Gets serviced whenever the service light comes on, which is about three times a year. It does a lot of starting and stopping too.

We of course have a backup, but we've never had to use it.

Originally Posted by alphonso

Not so. 4 of my machines do not need air to operate. Only one absolutely has to have air, and that's to shift gears.

Do tell..? I don't think I have seen a cnc (not a machine) that didn't need air?

Originally Posted by Mike1974

Do tell..? I don't think I have seen a cnc (not a machine) that didn't need air?

Lathes generally don't need air for any functional reason...

We have a maintenance plan with our supplier who will do 6 month services.

We also focus on redundancy of critical infrastructure and equipment.

24 hours of downtime would pay for an additional compressor.

Originally Posted by gregormarwick

Lathes generally don't need air for any functional reason...

Well, to be fair, need or not, if the machine is plumbed for air, it most likely will not run without it...

Originally Posted by gregormarwick

Lathes generally don't need air for any functional reason...

My CNC Swiss lathe has an air cylinder that opens and shuts the collet. I worked on many a swiss cam automatic that had air motors on them for cross hole drilling and some that had an extreme amount of attachments using air to advance front drilling spindles to allow longer strokes. Even on manual lathes I have seen air operated collet closers.

Originally Posted by Mike1974

Do tell..? I don't think I have seen a cnc (not a machine) that didn't need air?

Four of my lathes do not need air to operate. One does need air to shift gears.

One VMC, Kira/Tree VTC 30(similar to Robodrill) does not need air either.

Originally Posted by alphonso

Four of my lathes do not need air to operate. One does need air to shift gears.

One VMC, Kira/Tree VTC 30(similar to Robodrill) does not need air either.

Curious to age? Even back in early 2000's Haas lathes (and mills) needed air to run. Can't say what it did on the lathe, as the toolsetters were manually operated when they first came out. Maybe air over hydraulic (or opposite? not sure how it works) for the turret index?

Originally Posted by gregormarwick

Lathes generally don't need air for any functional reason...

Apparently you like chip brushes better than I do..............

Originally Posted by ChipSplitter

Apparently you like chip brushes better than I do..............

I did say functional.

Each and every one of the machines in here has a blowgun hanging from the door, I assure you of that!

I've never understood the idea that screw compressors must run continuously and not be cycled on and off. As long as the oil comes up to a temperature that drives off moisture and condensate (>140F?) I can't see where start/stop cycling would be a problem?

Originally Posted by gregormarwick

Our main Kaeser has 52k hours on it now. It once burst the oil cooler and was down for most of a day while they fetched a new one from their warehouse. It was down for an afternoon once when it stopped pumping because of a faulty pressure switch. Other than that it just keeps on churning out air. It has a refrigerated dryer that has never had any problems at all. Gets serviced whenever the service light comes on, which is about three times a year. It does a lot of starting and stopping too.

We of course have a backup, but we've never had to use it.