cinci milacron arrow 1250 - gas bottle

[m@chinist]

Hello,

I'm the new one here and i have a new toy also ;] - cinci milacron arrow 1250.
The problem is when power goes off - then Z axis falls down a bit.
There is a bottle with some kind of gas behind the column (You can see it looking down behind the column from the top of machine) and the bottle is empty. I asked the service already for the help - but looks like they are not interested.
My question is - is it really the gas to keep Z axis in position when power falls down or the gas is for something different?
And what kind of gas should i use to refill ??

Thanks for help.

[mike_Kilroy]

I dont know what that is because I don't know anything about that stuff, but I know the Z servo motor has a failsafe 24vdc brake on it that is to hold Z from falling when the servo is not on. Might your brake pad be worn out? I know Cincinnati Machine service group can repair those if you want......

[Jaxbubba]

Just guessing, and the Service people should help you. I would guess the bottle is for storing Nitrogen for the counterbalance cylinder. Haas machines use the same setup. Servo motors are not strong enough to hold the weight of the ram when the power goes off. Check with the service people, but this is my guess from being an old timer.

[m@chinist]

Hello,
we asked the service already. they were busy....

i spoked with a mechanical guy who knows cincinatti a bit and he says:
- possible that gas is still inside in spite of manometer shows zero
- possible that there should be an oil also.

am a bit confused now... is it like a hydro/gas accumulator ?

[MKC]

First, your machine does have a counterbalanced spindle and it sounds like its either low on gas or empty. In that condition the Z axis servo brake will hold the spindle up, but it IS a failsafe brake only.
During controlled machine shut down the spindle shouldn't fall, your control should be engaging the brake before releasing the servo motor. During a power chop without shut down what your seeing is normal in this circumstance.

The power goes away and there's a tiny lag time between the servo losing power and the springs on the brake slamming it shut so you see some drop on the column.

Regards,
Chris

[m@chinist]

MKC - yes, it is like You say, with controlled power off nothing happens.

Can You explain a bit more - it is a missing gas problem only or it is a system which has gas working together with oil ?

[MKC]

For your machine I would recommend getting in touch with MAG Maintenance Technologies support. Its my understanding that this is an air over oil system however that could be wrong.
I've always had good luck at MAG with machine specific problems, I myself specialize in the Kollmorgen/Vickers drives and motors so your counterbalance really isn't my area of expertise.

[m@chinist]

to get in contact with service was our first choice. they are not interested in help / too busy now. so, thats why wy try to figure it out by ourselves.
maybe i can find a maintenance manual for this (or similar) machine somewhere over the web ?

[MKC]

Sent you a PM

[mike_Kilroy]

sent you a pm.

[m@chinist]

thanks.

[scudzuki]

to get in contact with service was our first choice. they are not interested in help / too busy now. so, thats why wy try to figure it out by ourselves.
maybe i can find a maintenance manual for this (or similar) machine somewhere over the web ?

That is odd, the folks at MAG have spent plenty of time helping me out either on the phone or via email, most times with little or no likelihood of my buying something from them for their efforts. Maybe a time zone conflict?

Joe