4020 spindle rebuild

[Roy's cnc]

Need advice on rebuilding the spindle on a 93' model 4020. Can I do this ? If so, parts costs and how to do help. We have bearing noise, but machine is operating. Has 6 belt hi lo auto, new belts and idler wheel bearings. Seems to be top spindle bearings.

[StealthDumpKits]

Check with Fadal on prices for a new or rebuilt spindle cartridge. That's the quickest way to get back online.

[gotis]

Depends on how the spindlehousing is mounted in the machine, the spindles I have rebuilt usually have a housing of their own and that is then bolted to the machine.
the bearings are usually slide fit, not press or shrink, one very important factor is the preload, and that the bearings outer and inner markings line up, not to forget the correct lube at the correct amount.

The last spindelset I rebuilt have been working at 6000 rpm for 24 hours a day 8 months now and still "rocks" they get up to around 60 degrees celsius, and these puppies take a royal beating every cycle (about 1500 a day)

check your spindlebearing dimensions, I might have a set for you.

[AndyB]

Are Fadal 10k rpm spindles that easy to rebuild? Has anyone else done it with good success?

[DareBee]

6 belts?
my 94 only has 2.
My spindle from a couple of weeks ago was 3300 USD.
A good Fadal tech will easily change it out in less than 4 hours.
This swap requires a couple of special tools and can be tricky to set it up and shim correctly.
The parts for rebuild run about $1000 if you undertake the job, but you will probably need a couple days down time.
I feel the extra money spent is worth having warranty and the knowledge that it was rebuilt be people that do it everyday, a little piece of mind for when you are in the middle of a big job and your DIY spindle rebuild might crap out.
Don't get me wrong I have rebuilt spindles before (not Fadal) with no problems at all, but we all know how valuable experience is especially on a needed piece of equipment.

[Roy's cnc]

I just thought $ 2000. + seemed to be a bit much as the parts are around $1000. What special tools are needed?

[nervis1]

you can change out the spindle yourself.

Pull the z cover, pull the drawbar and washers, belts off, heat the spindle pulley with a propane torch for about 3-4 min turning the spindle around, it should slide off

undo the SHCSs on the spindle face, R+R the spindle.

reverse to re install.

Might as well replace the drawbar, retainer and washers at this time as well.

You need a bar to place between the casting and pulley to get the offset right, 4020 may be 2", not sure, a call to Fadal will solve that one.

The only other tool you need is the compression tool for the drawbar you can get that from CNCpros or Fadal for under 30 bucks.

You can tram the spindle just like any mill just use shims between the casting and spindle to get it right.

Just make sure you install the right number of spring washers in the spindle pocket, the Fadal maintenance manual has a list of how many each spindle takes. Mine was 2 washers short when I changed it out, would have never known if I had not looked at the list in the manual.

Darebee, the Fadal tech milked that visit, it's a 2 hr job max.

[Roy's cnc]

Thanks Nervis1, this is the kind of info. i'm looking for . Please explain [ tram the spindle] in more detail, preload etc.

[melzer]

first buy the bearings there are 4 of them in 2 sets
the type of them is
1.ANGEL THRUST BEARINGS FAFNIR 2MM9112W1 DUM
OR NSK 7012CTYDUMP A7
2. ANGEL THRUST BEARINGS FAFNIR 2MM210W1 DUM
OR NSK 7210CTYDUMP A7
second befor removing the pully look for bar that fit under the pully
be aware how the bearing set inside the housing
the preloads need to be 0.02 - 0.04 mm by pushing the spindle at 1500 PSI
if you need more help post it here
you can buy REM at CNCPROS or at KMAC price are around 3000
or at FADAL i think price are around 4000

[nervis1]

A. you are not going to rebuild the spindle, (unless you are into self abuse I guess) you are going to buy a rebuilt one and exchange your old one or get a new one. Preload is already set, no need to worry about it.

(BTW if you don't know how to tram a spindle, rebuilding a spindle is not something I'd tackle at least right now. Again...just get a rebuilt one)

The spindle cartridge is just that, a tube , with a CAT taper on one end, with mount bolts on the bottom, tube at the top that takes the pulley as a shrink fit. Slide the old one out put the new one in.

Tram. Make sure all of the old shim stock is out of there...Stick a .0001 indicator in the spindle on an arm, sweep the table (I use a 123 block on the table because of those little bumps on the fadal table) look to get it within .0002, tech told me thats as good as it gets on a Fadal.

You figure out where the spindle is out and start sliding shim stock between the casting and spindle in whatever direction is appropriate until it's in there. It will help to lightly stone the casting and spindle mating surafaces before doing this, get rid of any burrs etc.

[StealthDumpKits]

Whats the grease specifications for rebuilding the cartridge on your own?

[HuFlungDung]

I kind of shudder a wee bit when I hear of guys "shimming the spindle into tram". Is the factory so incompetent that they cannot even cut that surface correctly?

Might be a better time to relevel the table and see if the need for shimstock can be eliminated, since the shimming is going to be kind of crude at best since you are trying to create a wedge effect.

I'd also be hesitant to expect anyone but me to do the very best job on a rebuild. I've hired too many experts who did a half-a$$ job that I could have done myself without even trying hard. I'm not saying that there are no good experts out there, but they are difficult to get hold of, IMO.