Newbie- Air storage tank?

[jkinz56]

Hello everyone,
My company just purchased 2 used Partner 6's at auction.
The machines were hooked up to a 120 gallon air storage tank that had a low pressure alarm on it, unfortunatley this tank did not get sold with the machines.
My question; Is this tank necessary? If so, does it really need to be 120 gallon?
Thanks,
Jeff

[mholden]

No you do not need it. They only use air at tool change they must have had air volume problems in there shop

[jkinz56]

OK,
Thanks for responding.
Jeff

[Wcarmn]

I use an air tank with one of my Milltronics machines. I have several Milltronics, but only do this for one. I do not have an air volume problem, but the tool change would occasionally give an error when in the process of rapiding up for a tool change.

One of the reasons I say I do not have an air volume problem is that I have about 25 cnc machines, and have never had any issue with air, except this one.

A small 5 gallon tank solved the problem.

Milltronics are good machines with a great control.
Regards,
wcarm

[AMCjeepCJ]

Originally Posted by mholden No you do not need it. They only use air at tool change they must have had air volume problems in there shop

I know you work for Milltronics but I disagree in part. My machine changes tools fine but with the setup we had, it was possible for me to use to many air nozzles (hand operated for cleaning parts,) and it did the equivalant of an E-stop on my machine causing MUCH damage to my parts and tooling. I had it occur twice on custom wheels, pissing me off to no small degree since I didn't realize what the problem was at first plus it scared the crap out of me when everything exploded when I hit the air gun those couple of times.

I simply went into the software and shut off the sensor that watches the air pressure. I think it is simply stupid to shut off the machine mid cycle if there is a drop in air pressure. I cannot for the life of me understand why anyone would think this is a good idea. I love my machine except for a few things and that was a HUGE one for me besides the crappy seals on the cabinets that leak everywhere. If this software problem has not already been fixed, it needs to be addressed immediately. This is not simply an inconvenience, it is thoroughly dangerous to the operator having it setup like this. A much better way would be to have the machine 'park' at the next tool change and wait for pressure to be restored instead of killing the machine during a cut~

You yourself stated they only use air during a tool change so why on Earth do they shut off their drives mid cut if they won't even care if their is low pressure until it needs to change another tool?

If you don't want to EVER risk breaking your stuff, ruining your parts or getting injured then leave the sensor ON and install an air tank. It's cheap, works and depending on your parts, WILL pay for itself sooner or later if you ever have the pressure drop for any reason during a cut.

[moldcore]

My VM24 needs air to assist the Z axis and purge the spindle bearings. The newer machines don’t need it on the Z, not sure about the bearings. It won’t boot up without the air up to pressure. After ten years this machine keeps going and going without having to replace the bearings unlike my older partner 1 that has no air purge spindle and has been replace 3 times but it will run just fine without air.
We had to replace the original regulator on the machine last year and replaced it with a digital one that keeps it at a very even keel. If your air is dropping when you use an air gun perhaps you need a regulator on the tank. Our tank is at 140 psi minimum and the shop air is set to 110 psi with a regulator, machine regulator is set to 90 psi. Never had any problem with the air pressure dropping, even when using two a three hoses at the same time.

[AMCjeepCJ]

Originally Posted by moldcore We had to replace the original regulator on the machine last year and replaced it with a digital one that keeps it at a very even keel. If your air is dropping when you use an air gun perhaps you need a regulator on the tank. Our tank is at 140 psi minimum and the shop air is set to 110 psi with a regulator, machine regulator is set to 90 psi. Never had any problem with the air pressure dropping, even when using two a three hoses at the same time.

I had a bad setup using regular airlines for that end of the shop. What was happening is the hoses would expand ever so slightly and if the right combination of tools were used at exactly the same moment, the hoses would shrink that tiny little bit and the mills pressure would drop enough to kill it. It was definitely my fault on the airline setup but I couldn't for the life of me figure out why my machine was crashing. I obviously read the red warning message but it happened so suddenly it scared me pretty bad. When you say it purges the spindle bearing, is that the noise you sometimes hear when it is sitting at an idle when you manually shut the spindle off?? I have an 05' VM22. Any idea if mine has an air purged bearing??

[moldcore]

Originally Posted by AMCjeepCJ Any idea if mine has an air purged bearing??

Yours should have that feature. Even the new ones listed on their web site say “Five-bearing spindle with air-purge seal”. I thought it was standard the past 8 years or longer. Your machine should have an air line oiler and filter on the regulator that helps keeping the bearing and tool carousel air lines clean. When the spindle is on there should be a hissing sound coming from the spindle even when not turning. This keeps coolant from getting into the bearings but does draws down the air tank causing frequent compressor cycles when the machine is running. It’s a good idea to turn on the spindle (but set rpm to zero) when hosing down the machine to prevent coolant from getting into bearing.

[AMCjeepCJ]

Thanks for the info, I appreciate it. I always wondered what that noise was~

[Tim Horgan]

FYI,

The spindle air purge runs for 15 minutes after the spindle shuts off. This is to prevent coolant/dust from getting sucked up as the spindle cools.

When the control sees low air pressure it waits half a second and then checks the pressure a second time before estopping the machine. This is to prevent estops from "short" drops in air pressure.

[MangooLeaf]

Hey, Im going to be out of the sport for 3 months due to travels, and I wondered if it is okay to keep pressure in my air tank for that time. I bled it out at the field last week, but one of my teammates refilled it for me without knowing that I had wanted it empty.

Currently it would be really inconvenient to empty it so I just wondered if it will be safe to leave it as is for 3 months?