lorenzo
off to a rocking start
Member since July 2015
Posts: 12
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Post by lorenzo on Mar 15, 2018 13:31:29 GMT -5
I'm trying to build a simple grinding station so I can preform and do touch up on material intended for tumbling. My goal is to use a 5/8" shaft supported by pillow block bearings but I have read that standard pillow block bearings are only rated to about 650 rpms... not the 1700+ I'll be running. Has anyone had issues with the common/affordable bearings found on amazon or ebay? Thx!
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Post by johnjsgems on Mar 15, 2018 16:20:50 GMT -5
Highland Park used pillow block bearings on most of their equipment back in the day. A lot of that equipment is still running with original bearings.
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lorenzo
off to a rocking start
Member since July 2015
Posts: 12
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Post by lorenzo on Mar 15, 2018 17:00:59 GMT -5
Highland Park used pillow block bearings on most of their equipment back in the day. A lot of that equipment is still running with original bearings. Thanks! I understand they have been used in the past without issues in various lapidary applications. I can find brand name bearings which can surely handle the rpms... but they are like $70 each. My inexpensive grinder idea is quickly becoming expensive. I'm wanting to know if anyone has purchased and successfully used the more affordable 'chinese' bearings... which rarely mention an rpm rating. Such as these: www.amazon.com/UCP202-10-Pillow-Block-Bearing-Pieces/dp/B01IWGKNVEAm I overthinking this?
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Post by woodman on Mar 15, 2018 17:14:48 GMT -5
I think you are overthinking it, use the ones that you gave the link to, if they give out after 10 eyars, get some more. keep then greased.
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Post by toiv0 on Mar 15, 2018 17:40:48 GMT -5
I'm trying to build a simple grinding station so I can preform and do touch up on material intended for tumbling. My goal is to use a 5/8" shaft supported by pillow block bearings but I have read that standard pillow block bearings are only rated to about 650 rpms... not the 1700+ I'll be running. Has anyone had issues with the common/affordable bearings found on amazon or ebay? Thx! You get what you pay for. A friend been getting 10 dollar inserts on ebay and changes them out 2 or 3 times a year on one of his saws. Last go around he bought the 70 dollar ones, he just replaced with the good ones so I don't know yet how they will hold up.
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zarguy
fully equipped rock polisher
Cedar City, Utah - rockhound heaven!
Member since December 2005
Posts: 1,791
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Post by zarguy on Mar 15, 2018 17:58:12 GMT -5
lorenzo - I'm not sure the configuration of the grinder you're designing, but 5/8" might be undersized. Many machines have 1" shafts & bearings. Lynn
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Post by johnjsgems on Mar 15, 2018 19:12:08 GMT -5
When I worked commercial refrigeration/restaurant service Browning bearings lasted much longer than any import, lower cost choice. These were on hot, greasy exhaust fans that ran 24/7. I think with the intermittent use of lapidary equipment cheapos would be fine. Biggest killer of replacement bearings are installing on worn shafts and overtightening belts. Make sure your shafting is "cold rolled". 5/8" was commonly used on 6" units with 3 or 4 wheels. 8" wheels use 3/4" or 1" generally.
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lorenzo
off to a rocking start
Member since July 2015
Posts: 12
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Post by lorenzo on Mar 15, 2018 19:24:42 GMT -5
lorenzo - I'm not sure the configuration of the grinder you're designing, but 5/8" might be undersized. Many machines have 1" shafts & bearings. Lynn I'm trying to build a supergrinder using stacked diamond saw blades .... and if I'm feeling brave, I may try that 'tuck blade' that user jamesp has posted about in the past. A 5/8" arbor hole is common in those blades where as 3/4" and larger is not.
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zarguy
fully equipped rock polisher
Cedar City, Utah - rockhound heaven!
Member since December 2005
Posts: 1,791
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Post by zarguy on Mar 16, 2018 1:09:58 GMT -5
lorenzo Some 7" tile blades have a diamond shaped knockout, but it still accommodates a round shaft. I think it may be 3/4 or 7/8". If you're stacking a bunch of tile blades it's heavy, so the bigger the better. Lynn
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jm
having dreams about rocks
Member since October 2015
Posts: 56
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Post by jm on Mar 16, 2018 2:10:41 GMT -5
Highland Park used pillow block bearings on most of their equipment back in the day. A lot of that equipment is still running with original bearings. Thanks! I understand they have been used in the past without issues in various lapidary applications. I can find brand name bearings which can surely handle the rpms... but they are like $70 each. My inexpensive grinder idea is quickly becoming expensive. I'm wanting to know if anyone has purchased and successfully used the more affordable 'chinese' bearings... which rarely mention an rpm rating. Such as these: www.amazon.com/UCP202-10-Pillow-Block-Bearing-Pieces/dp/B01IWGKNVEAm I overthinking this? I used some of those cheap chinese imports on a 10" rock saw that I built a couple years ago. I run it at about 1700 rpm, sometimes for hours at a time if I'm cutting lots of rocks. Just tonight I had a chunk of pretty hard rock in there that took about 2 hrs to cut. I haven't noticed any problems with the bearings not being able to handle the speed. If you're looking to do this on the cheap, you can find those same bearings on ebay for a few dollars less than on amazon.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,159
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Post by jamesp on Mar 16, 2018 5:31:02 GMT -5
lorenzo - I'm not sure the configuration of the grinder you're designing, but 5/8" might be undersized. Many machines have 1" shafts & bearings. Lynn I'm trying to build a supergrinder using stacked diamond saw blades .... and if I'm feeling brave, I may try that 'tuck blade' that user jamesp has posted about in the past. A 5/8" arbor hole is common in those blades where as 3/4" and larger is not. I simply bought a tile saw for $99 and stuck that $20 1/4 inch tuck blade in it. It still a mean machine. It is the 3600 RPM of the tile saw that makes it such a rock eater. A lot of bang for the buck and only took changing from saw blade to tuck blade. I recently built an 8 inch flat lap(for finesse grinding) turning at 800 RPM and it is a joke compared to the tuck blade at 3600 RPM. ***warning - Make sure tile saw slot will accept tuck blade width of 1/4 inch. And always be careful with any speed of grinding equipment.
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Post by johnjsgems on Mar 16, 2018 10:31:17 GMT -5
I have an MK145 4" tile saw (5500 rpm) and MK101 10" tile saw (around 3000 rpm). Run both with good lapidary blades. Every time I pick up a really nice lapidary (belt driven) trim saw and consider keeping it for myself it doesn't get past the test stage and feel powerless. I am keeping a 6" and 10" Beacon Star saw but mainly because parts are available through Diamond Pacific and the 10" at least got rave reviews. Now if I can just get them both back together and cutting.
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