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Do Robodrills leak continuous air around the spindle ?
- Thread starter Milacron
- Start date
- Replies 25
- Views 7,463
machtool
Diamond
- Joined
- Jun 22, 2004
- Location
- Melbourne Australia
Perfectly normal. That's the spindle air purge. Its most important when the spindle is stopped. When they are spinning, the labyrinth seals will fling coolant off.
Regards Phil.
Regards Phil.
jCandlish
Titanium
- Joined
- Jun 1, 2011
- Location
- Oberaargau, Swizerland
Can't say how it works on a Robodrill, but on my machine the spindle air purge is only active during the tool change cycle.
You could check for the spindle air solenoid signal in the machine ladder for its actuation timing.
In my experience, I would not say that the leakage is perfectly normal.
More like perfectly normal wear.
The tiny gaskets inside the pneumatics go to heaven. See => http://www.practicalmachinist.com/vb/cnc-machining/norgren-valve-island-40-series-v-09-a-284037/
In retrospect having spares for the critical pneumatic components is not a bad idea, because the lead times can be very long if the item has been obsoleted.
.
You could check for the spindle air solenoid signal in the machine ladder for its actuation timing.
In my experience, I would not say that the leakage is perfectly normal.
More like perfectly normal wear.
The tiny gaskets inside the pneumatics go to heaven. See => http://www.practicalmachinist.com/vb/cnc-machining/norgren-valve-island-40-series-v-09-a-284037/
In retrospect having spares for the critical pneumatic components is not a bad idea, because the lead times can be very long if the item has been obsoleted.
.
machtool
Diamond
- Joined
- Jun 22, 2004
- Location
- Melbourne Australia
Thats not air purge, thats taper cleaning.
Good one Bro. Lets hear all about your experience on one only machine in your garage.
Simple fact of the matter, most all good manufactuers pressurise the nose labyrinth. Air going out equal's coolant mist not coming in. Thats why it important to have purge while the spindle is cooling down, and contracting air space.
jCandlish
Titanium
- Joined
- Jun 1, 2011
- Location
- Oberaargau, Swizerland
Tonytn36
Diamond
- Joined
- Dec 23, 2007
- Location
- Southeastern US
Most have 0.5bar positive pressure. Should be a regulator for it (possibly a fixed regulator) Don't need a lot of pressure, just need it higher than ambient. Almost all of our spindles have this feature.
machtool
Diamond
- Joined
- Jun 22, 2004
- Location
- Melbourne Australia
Rule of thumb was always half an atmosphere. 7 p.s.i. That goes back to what I called a "Red head"Heald were famous for them. But dedicated to production lines. There used to be dozens of them on an auto production line. That was the Spec in the 70's. It hasn't changed since. I still see modern Japanese machines call out 50 kPa. Thats remarkably about the same.
Adjustment could be anything depending on manufacturer. But generally, they dont use an air service unit / pressure regulator, due to the low pressure. Because the clearance between the spindle and the spindle nose does'nt change. It's normally just a needle valve flow restrictor. Thats set at the factory. I have an ultra low pressue gauge, I couple in line if I ever have to tune one. I think it only reads 1 atm / 14.7 p.s.i. Mid gauge is good. Lots of Japanese manufacturers, will drop in a tiny little disc, with a pissy liitle oriface, under a BSP fitting. Dont ask me how I know that.
Regards Phil.
Just in summary, I've read here and other places, about turning the air off when the spindle stops. Worst possible time to do that. If air is bubbling out, moisture isn't trickling in.
For us intermitent users with tiny air compressors it would be nice if they at least included a timer to shut the air off after 30 minutes or whatever....suppose I could retrofit one..
As Phil mentions, Mr. Conclusion Jump, this is air coming from vents that surround the spindle cartridge, not the internal air purge during a tool change (meant to blow any chips off the taper of the tool). I'm tempted to say this is necessary due to the 10,000 RPM spindle but come to think of it, my old Makino FNC 60 VMC had the same feature and it only went to 6,000 RPM (and had a separate spindle chiller to boot) Why the FNC 60 needed that even with a spindle chiller is beyond me.
jCandlish
Titanium
- Joined
- Jun 1, 2011
- Location
- Oberaargau, Swizerland
So you were already familiar with spindle pressurization? Why then ask about the "leak" unless it is something remarkably different to what you are already familiar with?
The way your question was posed it was not clear if the leak was an 8 bar blast or a 1.5 bar puff. Just that there was a "leak", which in itself refers to a malfunction, as opposed to say the word "flow".
.
Note the "come to think of it" comment... I'm getting old, been thru so much iron here over the years, I forget stuff...
and I guess "leak" is easier to spell than "spindle pressurization"...(plus that's not what it is either) 
Jez, funnin' with ya <jbc>... as Butch says to Marsellus... so, we cool ?
jCandlish
Titanium
- Joined
- Jun 1, 2011
- Location
- Oberaargau, Swizerland
Sure. With my Bro machtool too.
TeachMePlease
Diamond
- Joined
- Feb 11, 2014
- Location
- FL
Dangit Teach, we were just about ready for a group hug
and here you go stirring the pot again 
Scruffy887
Titanium
- Joined
- Dec 17, 2012
- Location
- Se Ma USA
Got air purge on my Mazaks, put a valve on to shut it off when not needed. Turns off all air so impossible to forget to turn on.
And why are we friggin posting on July 4th??
Monsoon rain here is SE Mass, sitting at kitchen island eating Sea Salt Carmel gelato. Swordfish for lunch.
And why are we friggin posting on July 4th??
Monsoon rain here is SE Mass, sitting at kitchen island eating Sea Salt Carmel gelato. Swordfish for lunch.
steve_p
Aluminum
- Joined
- Mar 5, 2014
- Location
- Southeast Massachusetts
Scruffy887
Titanium
- Joined
- Dec 17, 2012
- Location
- Se Ma USA
Do you know the name of the capitol of Freetown? Ever hear of a Chuckit?
steve_p
Aluminum
- Joined
- Mar 5, 2014
- Location
- Southeast Massachusetts
Capital of Freetown, you mean Assonet?
We actually started in east Freetown.
Never heard of a chuckit until i just googled it. The dog ball launcher thing?
Scruffy887
Titanium
- Joined
- Dec 17, 2012
- Location
- Se Ma USA
Hey Ernie, what's that in the back of your pickup truck? Dunno, found it off the highway. Fixin to chuck it in my yard.
I am minutes from 24.
Went to the Mattapoiset Inn with friends for brunch a very long time ago. Ug! This orange juice has gone bad. No John, that's Mimosa with Champaign in it.
The air purge on my Brother costs me about $200/mo in electricity when running the machine 24/7 (I have two units, so I get two power bills, and the air compressor is on one side and the Brother on the other). I was going to put a timer after the spindle turns off to turn a solenoid off, but after reading this thread I'll just leave it. We're pretty good about turning the valve on the back of the machine off when it's not being used. I probably need to get a screw compressor now... can't stand my reciprocating compressor going off every 15 minutes.
Matt
Matt
