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Results 16 to 21 of 21
Thread: Max spindle rpm for Hafco AL960B
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1st September 2013, 12:23 AM #16
Chief Swarf Maker
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- Aug 2013
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See, i wanted a spindle brake but my lathe doesnt have one. I had rough plans to fit a small disc and caliper, but a bit of work involved.
I wanted more speed, so the VFD seemed to kill 2 birds with 1 stone. I have since discovered the Chinese vfd doesnt actually have provision for a braking resistor, they just tell you it does. I was hoping the drive could be used to stop the machine like a brake, but i have to settle for a reduced spin-down time instead.
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1st September 2013, 12:32 AM #17
Chief Swarf Maker
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I meant to ask about heat. Cutting with cermet produces a LOT of it (the more the better), and on long runs this inevitably ends up soaking into the headstock. It gets warm-hot to the touch after some hours, at which point i give it a rest.
At what (approximate) point does the temperature start to adversely affect bearing life? I would have a stab in the dark and say the MAX they would ever see is 60 or 70c. I assume they are meant to run in environments hotter than this?
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1st September 2013, 01:06 AM #18
GOLD MEMBER
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- Oct 2010
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- melbourne, laverton
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brake
maybe a brake motor would work for you they are only on off type thing no more control than that.
5 5 KW Electric Motor With Brake in Illawarra, NSW | eBay
i don't think 70 deg would be an issue.
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1st September 2013, 10:18 AM #19
Senior Member
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- Feb 2011
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If you're up for a bit of reading and a little math#http://nachi-tool.jp/bearing/pdf/Tech.pdf
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2nd September 2013, 12:04 AM #20
Member
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- Oct 2011
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- queensland
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Yes I have felt in that reservoir to slow the release of oil, on mine it came with what looked like a piece of surgical gauze which was completely useless, the oil would drain in less than 5 minutes.
EP additive, Extreme Pressure, something like like molybond 2.5 is good, about $16 at Bolts and Industrial if you have one of those stores near you.
Garry
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5th September 2013, 12:56 PM #21
Chief Swarf Maker
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- Aug 2013
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I had a bad run with motors and my lathe was offline for 2 weeks which killed me, i'm not rooting around changing it again lol. Plus i like that variable speed, and 5.5kw is a bit excessive, they come with 1.5 standard
slhouette thanks for the link, if i get a spare minute ill crunch some numbers but i would have to "decode" the gearbox first and work out all the various shaft speeds and bearing sizes etc.
I think the speeds and temps i am playing with are well within the envelope from the brief reading i've done of other bearing literature.
Garry, where do you get the felt from? I will sus out some EP additive next time i'm at the bearing shop. Any downsides from this stuff?
Thanks for the help lads.