power go's out cutter plunges into finished cavity

[Millertime]

Do any of you haas mill users have this problem power go's out and cutter plunges approx .100 deep into finished part.Shouldnt these machines have a break on the z axis to stop this from happening.I know its a haas right what do you expect!!!!!!

[gcode]

The counterbalance nitrogen cylinders don't have enough gas in them.. so they can't offset the weight of the head..

[landscnc]

Are you saying all haas or that one. Can you get gas added to them is what im asking.

[Millertime]

That was it I talked with maintnence they didnt have any nitrogen but they had plenty of plutonium and in the process they found that my flux capacitor was out of adjustment.

[GoetzInd]

We had the power go out and scrap a heat treated and ground VAR 300 shaft that was literally on the last pass of post ht machining. Twas a bad day. I know some builders have a auto retract system as an option.

 

Mike

[gcode]

quote:

---

Are you saying all haas or that one. Can you get gas added to them is what im asking

---

Very early Haas machines had a big lead

weight hanging on motorcycle drive chains

for counterbalances.

Life got interesting quick when one of those

chains broke.

Nowdays, Haas VMC's have 2 nitrogen cyclinders

like giant shock absorbers to counterbalance

the weight of the head.

You can check thier pressure,

and add gas to them. Its something that

should be part of a regular maintenance routine

on a Haas.

If you don't keep them within specified pressure

you can crash and burn during a power failure

but it also puts excessive wear and tear

on your Z axis drive motors, lead screw and

leadscrew bearings.

[Millertime]

Hey g-code I thought you were messin with me but obviously u were not.I appreciate the info I will be talking to maintnence about this.This problem occurs alot due to the heat and livin in cali especially when everybody is crankin the ac.Again thanks for the info.Dealin with this issue will probobly save our company some serious coin.

[Shawn Wentzel- Wenteq Inc]

There is an option for an early power detection feature- I dont know if it can be installed after the machine is built though.

[MotorCityMinion]

Gcode nailed it. We top off our cylinders about every 2 years.

 

Early power detection failure? The lights flash, your done, LOL.

 

Seriously, same here. Temp gets above 90 and the outages start. In most cases with the Haas, they stay good in Z when the power dumps. It's the one's that have below 1000 PSI that start to loose Z's. The seals in the cylinders can go bad on those as well. About $1500 to replace them, plus the scrap part. Keep an eye on the gage.

[workmantm]

I check the cylinders here no less than every 6 months. Depending on the temps and the scheduling I can check it every month. I've seen our Head fall when we cut power at the end of the day due to low counterbalance pressure.

 

I'd suggest teaching your operators to check it as part of the weekly maintenance on the machines. It's not even hard to check daily as you warm up the machine and get ready for the day.

[Millertime]

Is this a standard feature on all new haas mills.I had a look at my manual and could not find anything.We have 4 2005 haas vm3 moldmaker mills.

[landscnc]

Our old okks have the weights on them and when the chains stretch it sounds like the hunchback of Notre Dame is run amok. Thanks G. Maint. will be looking at the cylinders tommorow. We got 1 that drops a couple thou.

[Jayson Kramer]

Millertime you are not in chatsworth were the power goes out in the wind are you?

[Millertime]

No I work in hemet ca we get 100 deg plus weather and we get outages quite often.And today we had 2 outages but not due to the heat I guess the city workers were doing somthing with a power line and zap our power was out for 20 min or so at a time.Not good for a machine shop lota guys walking around with their thums up their a--es.Good thing a broom dont need no power.

[Mic6]

The newer machines heads are held up by the Z servo. Not sure exactly when they started doing this.

[Chris Rizzo]

Somewhere around the 03-04 era Haas got rid of the nitrogen charged Monroe-Gas-o-Matic-Delux-Ride shocks, and switched to using the z motor. This was of course after the initial switch from Chamberlain (or was it Genie?) garage door springs to said shocks.

 

It was always amusing having power outages with a whole shop of spindles running and see which one has the longest coast-down time. I was always a bit concerned from lack of cooling though.

[GoetzInd]

quote:

---

It was always amusing having power outages with a whole shop of spindles running and see which one has the longest coast-down time. I was always a bit concerned from lack of cooling though.

---

I was just thinking the same thing. Sounds like a 747 spooling down on the tarmac.

 

MIke

[Jmick]

Early power detection can be installed by Haas after the machine is on your floor. It doesn't eliminate all drop but it only drops about .01. We installed it on our machines that are 2003 or newer. We also top off our nitrogen on the older machines every year.

[Superman]

It would probably be good to see what your machine does do when the power goes out, with no tools and no part.

 

Dial indicator (plunger type) onto the spindle face, and power down.

 

At least you'll have some sort of idea of how you stand