1996 4020ht - new to me, much maintenance required

Just picked up a 1996 4020 with 28inch z axis.
We brought it without been able to power it up but the price was right so worth the punt.

The good
Ways look good
Electrically runs fine
1400-5 cpu (upgraded according to the parameter sheet ment to have 1400-4)
-5 axis cards
Turcite on x axis looks good from the little I can see.

The bad
Hasn't been running for near 3 years
Backlash numbers are high z=20 y=25 x=30
After running a dti along the screw I have z.02mm x0.05mm y0.025mm thrust bearings and couplings require replacement and/or inspection.
Y thrust bearings are noisey as and you can feel them through the table so need to be replaced.
Spindle is very noisey just trying to track down if it is coming from the spindle (likely) or the motor(unlikely)
The spindle chiller has been completely disconnected.
55k power on hours
18k cutting hours

The plan of attack
First thing is the replace the y axis thrust bearings and coupling then remeasure backlash. Hopefully the numbers will drop considerably. Then move to the other 2 axis.

Does anyone have any tips for thrust bearing replacement especially y axis as that will be the first on the list.
Cheers

You can order the thrust bearing and seal kits from several sources like ITS or FadalCNC for around $90 per axis.
The ones I just got from ITS were NSK bearings and had the preload shim with the kit, and all the required seals.

I just did all mine this week and it's pretty simple, especially for me because I removed all my screws to be reworked so my bearing carriers were already off.
Just make sure the thrust bearings are face to face, in other words, the thick side of the inner races will face each other. The shim goes between the faces.

Make sure you get the correct kits. There is one from metric screws and then inch screws. With yours being a 1996 I would imagine they are metric.

Richard

Cheers.
We are in Australia so getting gear from the states is time consuming and costly. Will pull it apart and try to source parts locally.
Can the bearings be replaced without pulling the bearing block off?
My screws need attention also. What did you get done to yours? A reball or replace?

After removing the y axis servo , coupling and mount I can't for the life of me undo the nut that holds the thrust bearings.
Looks like I am about to do what I never thought I would and that is take an impact gun to the ball screw

Would you like the numbers for the metric bearings and seals? I still have the boxes. You could probably reuse your old shim.
I also used an impact to remove the stop nuts on the end of the screws. I used short quick burst and they came right off.

On the ball screws and nuts, it's supposed to be a total rework. Regrind and rebuild.
They guarantee, it will be as good or better than new. I guess we will see how good of a job they do.

That would be great thanks. Part numbers are gold.
Impact gun it is .
Cheers

3 of SKF Seals 12360 (Inside block coolant seals)
1 of SKF Seal 11138 (Seal for thrust retainer to screw seal adapter)
2 of NSK Angular Contact Bearings 7304BYGUG2 - NB5F 20mm x 52mm x 15mm

1 of preload shim 0.875" ID x 1.375" OD x 0.001" thick

Bloody champion thanks

Seems the bearings are ex production so no stock within nsk worldwide.
Looks like they will need to come from the states or I can change to a proper ball screw support bearing and go away from the angular contact but they are pretty expensive at about $200 a bearing.
Will shoot off an email to the fadal parts places and see what shipping cost and time I can expect and make my decision from there.

Quote:

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Originally Posted by Deano7/11

Seems the bearings are ex production so no stock within nsk worldwide.
Looks like they will need to come from the states or I can change to a proper ball screw support bearing and go away from the angular contact but they are pretty expensive at about $200 a bearing.
Will shoot off an email to the fadal parts places and see what shipping cost and time I can expect and make my decision from there.

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I order them from Misumi for very cheap. They do international shipping I’m pretty sure. Any 7304 bearing should work.

Download for free All Fadal Manuals do not pay for them several places https://flintmachine.com/fadal.php or Fadal Manuals | ItsCnc.com parts manual, maintenance, troubleshooting etc. etc.

Oh and by the way many of the small components (belts, air valves , relays etc.) on the fadal can be bought from https://www.mcmaster.com/