Mazak SQT Spindle bearing life expectancy

Have some questions about SQT spindle bearing life and maintenance.

Looking at SQT - 10 2001 to potentially buy,it was a production machine that was set up to run 2 or 3 shifts daily making small parts ,for 20 years, auto loaded and unloaded.

Very low load machining,and according to operators - never crashed, but many hours machining.

Given the hours and conditions,would the spindle bearings still have much life left in them ?

The price to replace in about 10K AUD.

The spindle sounds ok and ive used a few of these machines when new over the years to compare

Do the SQT spindles need maintenance ? or just repaired when noisy ?

Need some info from experts on here to assist with decision to purchase or not to purchase.

Thanks in advance.

10k aud to replace the bearings sounds very cheap. The super quick turns have integral spindle motors that make it a bit difficult to switch bearing like a typical lathe. The spindle do come out as cartridges though.

I had a very tired 1996 sqt18 and the spindle was perfectly fine on it. That machine had a lot of hours and it was ok. I imagine if you check the run out and the axial/ radial stiffness of the spindle if that all checks out good and it sounds good you’ll be fine for a while of light use.

Ianagos said:

10k aud to replace the bearings sounds very cheap. The super quick turns have integral spindle motors that make it a bit difficult to switch bearing like a typical lathe. The spindle do come out as cartridges though.

I had a very tired 1996 sqt18 and the spindle was perfectly fine on it. That machine had a lot of hours and it was ok. I imagine if you check the run out and the axial/ radial stiffness of the spindle if that all checks out good and it sounds good you’ll be fine for a while of light use.

Click to expand...

Thanks for reply,the 10K price was for cartridge bearing replacement.

What are you planning on doing with it?

A 20 year old machine is a 20 year old machine, and something, perhaps expensive, may die.

If you plan on putting 5000 hours a year on it, it may be a reason to pause

If you going to put 200 hours a year on it, it may not be a big worry

I plan on doing jobbing work and small batch production, aprox 10 hours per week.

The best indicator of the bearings is simply the sound of the spindle at different speeds.

If the spindle sounds good now, barring a crash or bearing contamination, it should keep sounding good for a long, long time.

The SQT spindles like the machines were beasts...

ToolCat

Thanks for that info, the spindle was very quite at 5000rpm, no problem there.
The machine is in poor condition, albeit it has a good spindle.
The ball bearing slides are pitted as are ball screws, and the guy wants top dollar for it [ Dealer ]
So I will keep looking.

I have only had 1 spindle need rebuilt out of 6 SQT's, 1994-1998. The one that needed rebuilt runs a job that ramps up to 5000 RPM(still too slow) and had a1 minute cycle. That is the hardest on these spindles, crashing being the exception to this. This job will run for about 2 weeks like this. When it was time to rebuild, I pulled it and sent it out. I think it was $7-$8k for a rebuild, but that is probably higher now. I run a job on a different SQT 3:30 cycle to remove 11 pounds of 1018. The 3:30 includes finish pass. The rougher is pulling 70% spindle load and I have not had any problems with that one. Like the cat man said, If the spindle sounds good now, it should be fine.

thanksFMS Controller Version E