Replace the bearings in the ZX45 spindle
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- Опубликовано: 23 июн 2022
- Because I am an idiot, I need to replace the bearings,
A guide to design machine spindles are from page 57 and onward is the linked document
www.skf.com/binaries/pub12/Im... 
Наука
watching you dismantle the spindle of a precision machine with a screwdriver and a hammer, reminded me of my younger days
my first car (1956 Holden) had a screwdriver and a hammer in its factory toolpouch
Stavros
Next time you need to pull out a Tapered Bearing Race, try using a metal cutting disc on a Dremel or similar. Cut a groove in the race across the thickness, and split it with a hammer and chisel. The metal is hard so it will give in to this. We did this all the time for bearings and racing in the rebuild shop.
Not quite a robrenz spindle rebuild but it definitely was as interesting and informative. You have checked off two machining video standards: replace bearings and getting a shop press. Thanks for posting
Snyggt jobbat + grattis till nya verktyget i verkstan som du kommer att ha nytta av. Glad midsommar!
It probably was stuck from too much preload. When you need a press to install the upper bearing i don't see a way to loosen the preload other than thermal contraction (or hammer blows).
Taper roller bearings are fine for normal precision spindles and make cheap arrangements possible. I doubt you could use the advantage of p3/p4 AC bearings with chinesium bearing seats.
One of the few Ruemema machines is a Leinen super precision lathe which uses taper roller bearings like a wheel bearing. It's not generally a bad design.
you need to put on a winch for the table on the press now it makes changing the height of the table so much easier
Enjoy ALL MM journeys! Thank you for bringing me along.
The recommended grease fill is only something like 20-25%, so I suspect this is why your bearings got so hot. IIRC, there's info about that in the SKF / HSK / FAG etc app notes. You can damage them by overfilling but I doubt it in this case!
It's not a bad idea to move all the hammers from the workshop to an adjacent room.
did you make that encoder setup for the spindle?
I wonder if YT lets me add that Gamet has been manufacturing tapered roller bearings for spindles for quite some time. I've already got 4 comments trying to say the same.
I want to see some chips flying! :)
Uhh ohh. It should not heat up so much at low rpm, high chance its not heat from grease, but heat from too large preload from tightening (which leads to bearing expanding, which in turn leads to more preload which can quickly destroy the bearing).
Mind if you got it to now run at max rpm without heating it might have just been the grease.
He packed so much grease in the lower bearing that - even though it wasn't confined by design - it's no surprise that it got hot until the rotation worked the excess grease out of the bearing.
I would be afraid to damage/bend the spindle after so many whacks! Is it still reasonably concentric? I mean, it might be beefy enough to survive all the impact force, but it is a bit sketchy.
I've caused a fair bit of runout on my first experimental spindle by making this sort of shortcuts, but the spindle shaft was only 12mm diameter (Aliexpress "collet extension"), so it wasn't very strong to begin with.
If you put too much grease bearings, it's raise up temperature
many shortcuts makes for lots of editing for youtuber. not so many yaks to shave for you though.