2005 Fadal VMC 3016 and 10k RPM (Spindle Chiller?)

Hi guys,

My small company recently bought our first mill and yours truly is in charge of getting it set up (and in way over my head!). We made the smart move and brought in a CNC specialist to run me through loading coolant, setting height offset, zeroing XYZ etc. I've done all these before but on a very different 2013 Haas VF1. I was super excited for the 10k RPM of this 2005 Fadal; the 2013 Haas could only go up to 8k. But he said I was missing a spindle chiller and that without it I can only safely go up to 7kRPM.

Now I'm confused. I called the used CNC seller we bought it from and talked to their tech, he told me he thought the spindle chiller was built in. I've looked online for replacement spindle chillers, just so I can see what the part looks like and whether it's on the back of my machine or not. I haven't found much and I haven't been able to find a picture of a fadal vmc 3016 spindle chiller. Maybe the specialist was mistaken? I do see what looks like a black and white pump with tubes coming out (the specialist pointed this out to me). Is there a separate chiller unit that is missing? If so, where would its coolant go and how can I find a replacement? I've attached a few pictures of the mill.

Advice appreciated, thanks!

Looks like you are missing the whole chiller cabinet. Doesn't look like it was ever there.

The original is nothing more than a soda fountain pump on 1/3 hp motor or something stupid like that.. It
goes through some kind of half assed AC unit. A lot of them also had chilled ball screws, which was nothing
but rusted thrust bearings waiting to happen, and if a Mazak can move at double the speed and accelerations
as a Fadal without cooled ball screws, what the hell does a Fadal need them for??

Just mickey mouse some shit up.. A pump and a heater core, some type of anti corosion stuff.. Trust me, straight
water turns to rust really fast, which turns into a new pump, and then from all the rust left over, most likely
another pump, and then possibly one more .. Factory Fadals use "Dow Frost", I don't know what the hell it is, but
its not pocket killing.. All the Fadal places used to have it in 3 gallon jugs..

The "chilled" side of it, I believe is overkill.. You aren't trying to make ice cream, just trying to not get too hot...
Had one years ago that the thermostat was busted on.. The chiller never shut off and sometimes you would get ice around the
spindle taper, and also got a lot of condensation..

If I was actually worried about a functioning spindle chiller.. I already said, pump and heater core.. I wouldn't want it running
ALL the time. Probably find a way to wire it into the waylube circuit, which I believe stops pumping after I think 7 minutes of no
movement.

In all honesty, if you aren't running balls out all day long, you'll be fine without a chiller. I remember reading somewhere that the spindle is
100% duty cycle at 8k.. I've run mine without a functioning chiller for quite some time (actually unplugged because they get noisy and annoying)
I haven't blown one up yet, and there are some days where they are close to flat out all day.

7k limit??? Its not like if you turn it on at 10k it instantly goes to 400 degrees.

You could also pull a Haas and plumb some of your coolant through the chiller lines. Actually using the coolant and a seperate
pump wouldn't be the worst idea in the world. Just turn it on when you need it.

See you're telling me what I want to hear but I'm worried it's going to get me in trouble. This machine is going to be running, in comparison to a big machine shop, veeery infrequently (an hour a day? maybe every other day?) and on top of that I'm going to be machining aluminum most of the time. So I want to say "eh" to the chiller and run at 10k RPM to my heart's content, but I sure don't want to end up with a busted spindle either.

Maybe I'll work with the CNC Specialist to get a semi decent external chiller solution up and running, something that I can turn on and off with a simple relay or external switch. Or hell, power it/unplug it externally. Just so I'm not worried about hurting my "new" CNC mill.

An hour a day.. I wouldn't even worry about it, or think about it... 14 hours a day, 24/7, that's when you start to
worry about it.

Go put a tool in the spindle and run it at 10k for an hour, and see how hot it is... I'd be surprised if
it was much over 115 degrees.

DO NOT go up to a cold machine and type S10000M3 [green button].... Warm her up a bit, and you aren't actually
warming, you are just redistributing the grease in the bearings.. I like S800.2 Motor spinning 400, spindle
spinning at safe speed, and high gear is quieter at low revs.

The duty cycle on the old 10k machines is 5 hours at 8k+, off for 30 mins IIRC.

Hi Perry, would you mind explaining what you mean by duty cycle? Still relatively new to this. Does this mean you were supposed to have the machine off for 30 minutes for every five hours you had it running at an 8lk+ spindle speed? Do you know if this duty cycle was calculated assuming one had a functioning spindle chiller?

http://www.fadalcnc.com/media/pdf/tech_docs_1/Maintenance_Manual/Spindle_Drive_and_Motor.pdf

Page 317

Spindle Duty Cycle

It is the recommendation of the Engineering Department in conjunction with the
bearing manufacturers that the following procedures be followed to increase
spindle life under extreme operating conditions.

Spindles operating under 8,000 RPMs need no cool down period regardless of on time or load to the tool.

Fadal recommends that Spindles operating at over 8,000 RPMs for extended
periods of time should be shut down for a period of at least 20 minutes after
every 5 hours of continuous operation. This will allow cooling of the races and
re-lubrication of the grease lubricated bearings. The actual load to the spindle
is not a factor a these higher RPMs. The time period should be monitored as
closely as possible to increase spindle life.

I disagree with the "shut down" part of the statement above. I would run the spindle at minimum RPM to ensure the grease is distributed evenly in the races. Their theory is that the grease is being displaced by the balls and it needs to "fall down" into the bearing again after running at high speed for extended periods.

The worst thing you can do to a high precision bearing is to allow it to cool down quickly, you should perform a cool-down cycle for 20 minutes at the end of a long 10k shift, allowing the bearings to return to ambient temp over a long period of time. 20 minutes at no load should be sufficient time for the chiller to return the temperature to ambient.

Bobw, does the data sticker on the chiller unit state a BTU rating? I'm curious what kind of heat dissipation they offered.

No Idea, I'm not seeing a sticker on either of them.. ITS says its 21amps at 110v if that helps.

If you do it the way the factory did it, Chiller, pump, pump motor, control card, relays.. Your going to
be almost a $new$ $pindle into it by the time your done.

I'm doing it similar to how they did it back in the day. I picked up a new 3/8" outlet 1/8HP coolant pump off eBay and I'm going to drop it into a ~5gal coolant tank and run the return flow through an automotive trans cooler. The cooler has 2 5" muffin fans that are connected to a 12v power supply. I'd like to hook those up to a thermostatic switch that turns them on when the coolant warms up.

The chiller system operated at around 30 degrees IIRC, so they were pumping below ambient coolant into the spindle housing and screws to remove heat from them and try to bring them down below ambient.

I have a feeling the numbers were chosen for a couple reasons. First, they assume ambient is 20degC or 68degF. The liquid flowing through the spindle is not very efficient at pulling heat out of the cast iron (thermal growth in the YZ plane), so a reduced temperature liquid will help to offset the lack of thermal efficiency of the heat exchanger.

The ballscrews are gun drilled, so while the channel is as long as the screw, they too are not terribly good at transferring heat. Clearly they are trying to fight thermal growth of the screw and the subsequent pitch error.

I wonder if larger screws, better PEC, and temperature feedback would have been a better solution than a fragile gland interface to the ballscrew?

HAAS was able to do YZ temp compensation around the same time as Fadal was building stuff, and they were pretty dead simple designs, but still held Fadal like tolerances (maybe better). I had a 1993 VF0 for a while and it would make good parts.

Highly doubt that's a 10K rpm spindle. If it was they configured spindle chilling 2 different ways.

1. Big spindle chiller 20x28x10 hanging off the back that used dowfost coolant
2. Spindle coolant pump with mesh screen filter that used a pump and dump and machine coolant as the spindle coolant

That machine has a hose to an auxiliary spray wand but no 2nd pump for the pump and dump. Its most likely a 7500rpm spindle non cooled which were most common in L machines. But open up the back side of the pendant and look at the options for yourself. Or go to command mode and type in SETP and scroll through the menus. Looks like someone just put a decal on there to make it look like a 10K rpm spindle. Fadal spindles were built using a 12K RPM bearing. If the chiller was good they needed zero cool down and could run almost indefinitely. But like anything...the moment you turn it on is the moment it starts to wear out.

We don't even use our chiller. I have never felt the spindle get particularly hot, and yes we rut it between 8-10k regularly. Of course it sucks with any cutter above 3/8" diameter because it starts tossing coolant out the top of the machine so I tend to run 1/2" tools with coolant 6k or lower.