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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
I'm restoring my 1963 Clausing 8520 mill ( pictures here if interested
http://gallery.intlwaters.com/thumbnails.php?album=323 ) and in the process am replacing the spindle bearings. I've read through many posts on the Yahoo Group and have just gotten more confused. Talked to a few bearing "engineers" (ya right) at SKF and they don't seem to have solid answers either. The spindle takes a pair of 7205 angular contact bearings that are held in place by a locking washer and nut. I was able to find on the MRC site that the torque on the nut should be 23-50 ft-lb. but can't seem to find answers to the following: Should the bearings be mounted "face to face" (where the contact lines of the bearings converge inward), or "back to back"? I can order bearings that are ground and sold as a matching set in either "b to b" or "f to f" that when mounted together and the retaining nut tightened give a "light preload". I can also order bearings that are not matched but are for "universal pairing" that are about half the cost and are made to mount either way. Some posts on the Yahoo Group mention that to apply a preload to these bearings a shim is needed between them either on the inner or outer race, others say none is needed. If the bearings are made to mount either way how can they be preloaded without the use of a shim? If needed how thick should it be? The machine came fitted with standard bearings and no shims so I can't go by what was there. Any experts here? Thanks in advance! |
#2
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
On Thu, 1 Dec 2005 09:20:18 -0500, "Terry Keeley" tkee(no spam)@(or
mail)rogers.com wrote: Greetings Terry, I assume you have contacted Clausing asking them how to mount the bearings. If not, try, maybe they can help. They helped me a few years ago with questions about an Atlas lathe. I have spoken with both SKF and NTN engineers. Both were helpful. But I also had to go through some younger engineers to finally speak to older ones with more experience. You need to be able to tell the engineer how the bearings are mounted. The mount limits the options. The lines converging or diverging regulate the stiffness of the assembly. Try SKF again and insist, politely, to speak to someone who really knows. ERS I'm restoring my 1963 Clausing 8520 mill ( pictures here if interested http://gallery.intlwaters.com/thumbnails.php?album=323 ) and in the process am replacing the spindle bearings. I've read through many posts on the Yahoo Group and have just gotten more confused. Talked to a few bearing "engineers" (ya right) at SKF and they don't seem to have solid answers either. The spindle takes a pair of 7205 angular contact bearings that are held in place by a locking washer and nut. I was able to find on the MRC site that the torque on the nut should be 23-50 ft-lb. but can't seem to find answers to the following: Should the bearings be mounted "face to face" (where the contact lines of the bearings converge inward), or "back to back"? I can order bearings that are ground and sold as a matching set in either "b to b" or "f to f" that when mounted together and the retaining nut tightened give a "light preload". I can also order bearings that are not matched but are for "universal pairing" that are about half the cost and are made to mount either way. Some posts on the Yahoo Group mention that to apply a preload to these bearings a shim is needed between them either on the inner or outer race, others say none is needed. If the bearings are made to mount either way how can they be preloaded without the use of a shim? If needed how thick should it be? The machine came fitted with standard bearings and no shims so I can't go by what was there. Any experts here? Thanks in advance! |
#3
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
Thanks Eric, you're right I'm sure, the person that was recommended at SKF
was on the road for the week so I asked if anyone else could help... Not sure about Clausing, posts on the Yahoo Group weren't too encouraging. "Eric R Snow" wrote in message ... On Thu, 1 Dec 2005 09:20:18 -0500, "Terry Keeley" tkee(no spam)@(or mail)rogers.com wrote: Greetings Terry, I assume you have contacted Clausing asking them how to mount the bearings. If not, try, maybe they can help. They helped me a few years ago with questions about an Atlas lathe. I have spoken with both SKF and NTN engineers. Both were helpful. But I also had to go through some younger engineers to finally speak to older ones with more experience. You need to be able to tell the engineer how the bearings are mounted. The mount limits the options. The lines converging or diverging regulate the stiffness of the assembly. Try SKF again and insist, politely, to speak to someone who really knows. ERS |
#4
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
In article , no spam says...
The spindle takes a pair of 7205 angular contact bearings that are held in place by a locking washer and nut. I was able to find on the MRC site that the torque on the nut should be 23-50 ft-lb. but can't seem to find answers to the following: Should the bearings be mounted "face to face" (where the contact lines of the bearings converge inward), or "back to back"? Just out of curiosity, were the originals bb or ff? My first take on it would be to replicate the original setup. I can order bearings that are ground and sold as a matching set in either "b to b" or "f to f" that when mounted together and the retaining nut tightened give a "light preload". I can also order bearings that are not matched but are for "universal pairing" that are about half the cost and are made to mount either way. Some posts on the Yahoo Group mention that to apply a preload to these bearings a shim is needed between them either on the inner or outer race, others say none is needed. If the bearings are made to mount either way how can they be preloaded without the use of a shim? If needed how thick should it be? If you do this without any shims the bearings will have way too much clearance I suspect. What bridgeport used to do was to grind the face of the bearing race to set this, rather than use shims, on the M heads. My first take would be to order the same type (bb or ff) as the original bearings, and purchase them as a true angular contact pair. Jim -- ================================================== please reply to: JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com ================================================== |
#5
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
In article ,
"Terry Keeley" tkee(no spam)@(or mail)rogers.com says... I'm restoring my 1963 Clausing 8520 mill ( pictures here if interested http://gallery.intlwaters.com/thumbnails.php?album=323 ) and in the process am replacing the spindle bearings. I've read through many posts on the Yahoo Group and have just gotten more confused. Talked to a few bearing "engineers" (ya right) at SKF and they don't seem to have solid answers either. The spindle takes a pair of 7205 angular contact bearings that are held in place by a locking washer and nut. I was able to find on the MRC site that the torque on the nut should be 23-50 ft-lb. but can't seem to find answers to the following: Should the bearings be mounted "face to face" (where the contact lines of the bearings converge inward), or "back to back"? Almost certainly back to back. I can order bearings that are ground and sold as a matching set in either "b to b" or "f to f" that when mounted together and the retaining nut tightened give a "light preload". I can also order bearings that are not matched but are for "universal pairing" that are about half the cost and are made to mount either way. Some posts on the Yahoo Group mention that to apply a preload to these bearings a shim is needed between them either on the inner or outer race, others say none is needed. If the bearings are made to mount either way how can they be preloaded without the use of a shim? If needed how thick should it be? You'll have to ask the bearing mfr for a definitive answer on the spacer thickness, but I wouldn't recommend this approach. A few tenths will make a big difference in the preload, possibly resulting in overheating or loss of rigidity, depending on whether the shim is too thick or too thin. Best to buy the proper matching set of bearings. A matched pair of precision 7207s should cost you around $275. Ned Simmons |
#6
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
..
Just out of curiosity, were the originals bb or ff? My first take on it would be to replicate the original setup. Thanks for the help but someone installed regular standard ball bearings so I don't have any history to go by. I can order bearings that are ground and sold as a matching set in either "b to b" or "f to f" that when mounted together and the retaining nut tightened give a "light preload". I can also order bearings that are not matched but are for "universal pairing" that are about half the cost and are made to mount either way. Some posts on the Yahoo Group mention that to apply a preload to these bearings a shim is needed between them either on the inner or outer race, others say none is needed. If the bearings are made to mount either way how can they be preloaded without the use of a shim? If needed how thick should it be? If you do this without any shims the bearings will have way too much clearance I suspect. What bridgeport used to do was to grind the face of the bearing race to set this, rather than use shims, on the M heads. My first take would be to order the same type (bb or ff) as the original bearings, and purchase them as a true angular contact pair. Jim Think this might be the way to go also but most don't seem to go this route... -- ================================================== please reply to: JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com ================================================== |
#7
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
In article , Ned Simmons
says... You'll have to ask the bearing mfr for a definitive answer on the spacer thickness, but I wouldn't recommend this approach. A few tenths will make a big difference in the preload, possibly resulting in overheating or loss of rigidity, depending on whether the shim is too thick or too thin. Agree. When I was doing this with non-setup bearings I was taking a tenth off the spacers at the end while doing trials. Jim -- ================================================== please reply to: JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com ================================================== |
#8
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
Terry,
When I replaced mine I bought the bearings from Clausing as a match set. There was no shim needed/supplied). When I installed them I realized there was two ways to do it. I mounted them so that when they were mounted on the spindle they were "tight". I don't remember if I ever figured out if this was the official direction or not, but I never had any problems. This way make since to me because the spindle nut has a locking feature, and the retaining nut does not. If the nut backs off, then you have lost the preload (bad thing). I did have a heating problem, but that was because I filled the bears completely with grease, and at the 2 highest speeds things over heated. Found out later that you should fill the bearings 1/3 rd with grease. Once I removed most of the grease it ran fine. You do this by filling 1/3 rd of the bearing 100% with grease, and then spinning the bearing around until it's even. Hope this helps, Vince Terry Keeley wrote: I'm restoring my 1963 Clausing 8520 mill ( pictures here if interested http://gallery.intlwaters.com/thumbnails.php?album=323 ) and in the process am replacing the spindle bearings. I've read through many posts on the Yahoo Group and have just gotten more confused. Talked to a few bearing "engineers" (ya right) at SKF and they don't seem to have solid answers either. The spindle takes a pair of 7205 angular contact bearings that are held in place by a locking washer and nut. I was able to find on the MRC site that the torque on the nut should be 23-50 ft-lb. but can't seem to find answers to the following: Should the bearings be mounted "face to face" (where the contact lines of the bearings converge inward), or "back to back"? I can order bearings that are ground and sold as a matching set in either "b to b" or "f to f" that when mounted together and the retaining nut tightened give a "light preload". I can also order bearings that are not matched but are for "universal pairing" that are about half the cost and are made to mount either way. Some posts on the Yahoo Group mention that to apply a preload to these bearings a shim is needed between them either on the inner or outer race, others say none is needed. If the bearings are made to mount either way how can they be preloaded without the use of a shim? If needed how thick should it be? The machine came fitted with standard bearings and no shims so I can't go by what was there. Any experts here? Thanks in advance! |
#9
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
Thanks for the help!
So when you put them on and tightened up the nut it applied the pre-load? I'd hear tat about the grease, thanks. "Vince Iorio" wrote in message ... Terry, When I replaced mine I bought the bearings from Clausing as a match set. There was no shim needed/supplied). When I installed them I realized there was two ways to do it. I mounted them so that when they were mounted on the spindle they were "tight". I don't remember if I ever figured out if this was the official direction or not, but I never had any problems. This way make since to me because the spindle nut has a locking feature, and the retaining nut does not. If the nut backs off, then you have lost the preload (bad thing). I did have a heating problem, but that was because I filled the bears completely with grease, and at the 2 highest speeds things over heated. Found out later that you should fill the bearings 1/3 rd with grease. Once I removed most of the grease it ran fine. You do this by filling 1/3 rd of the bearing 100% with grease, and then spinning the bearing around until it's even. Hope this helps, Vince Terry Keeley wrote: I'm restoring my 1963 Clausing 8520 mill ( pictures here if interested http://gallery.intlwaters.com/thumbnails.php?album=323 ) and in the process am replacing the spindle bearings. I've read through many posts on the Yahoo Group and have just gotten more confused. Talked to a few bearing "engineers" (ya right) at SKF and they don't seem to have solid answers either. The spindle takes a pair of 7205 angular contact bearings that are held in place by a locking washer and nut. I was able to find on the MRC site that the torque on the nut should be 23-50 ft-lb. but can't seem to find answers to the following: Should the bearings be mounted "face to face" (where the contact lines of the bearings converge inward), or "back to back"? I can order bearings that are ground and sold as a matching set in either "b to b" or "f to f" that when mounted together and the retaining nut tightened give a "light preload". I can also order bearings that are not matched but are for "universal pairing" that are about half the cost and are made to mount either way. Some posts on the Yahoo Group mention that to apply a preload to these bearings a shim is needed between them either on the inner or outer race, others say none is needed. If the bearings are made to mount either way how can they be preloaded without the use of a shim? If needed how thick should it be? The machine came fitted with standard bearings and no shims so I can't go by what was there. Any experts here? Thanks in advance! |
#10
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
Terry,
Ask to speak with Jo(lene) Olds at Clausing, if she is still there. She's been pretty helpful to me in the past. Mike "Terry Keeley" tkee(no spam)@(or mail)rogers.com wrote in message .. . Thanks Eric, you're right I'm sure, the person that was recommended at SKF was on the road for the week so I asked if anyone else could help... Not sure about Clausing, posts on the Yahoo Group weren't too encouraging. "Eric R Snow" wrote in message ... On Thu, 1 Dec 2005 09:20:18 -0500, "Terry Keeley" tkee(no spam)@(or mail)rogers.com wrote: Greetings Terry, I assume you have contacted Clausing asking them how to mount the bearings. If not, try, maybe they can help. They helped me a few years ago with questions about an Atlas lathe. I have spoken with both SKF and NTN engineers. Both were helpful. But I also had to go through some younger engineers to finally speak to older ones with more experience. You need to be able to tell the engineer how the bearings are mounted. The mount limits the options. The lines converging or diverging regulate the stiffness of the assembly. Try SKF again and insist, politely, to speak to someone who really knows. ERS |
#11
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
"Terry Keeley" tkee(no spam)@(or mail)rogers.com wrote in message .. . I'm restoring my 1963 Clausing 8520 mill ( pictures here if interested http://gallery.intlwaters.com/thumbnails.php?album=323 ) and in the process am replacing the spindle bearings. I've read through many posts on the Yahoo Group and have just gotten more confused. Talked to a few bearing "engineers" (ya right) at SKF and they don't seem to have solid answers either. The spindle takes a pair of 7205 angular contact bearings that are held in place by a locking washer and nut. I was able to find on the MRC site that the torque on the nut should be 23-50 ft-lb. but can't seem to find answers to the following: Should the bearings be mounted "face to face" (where the contact lines of the bearings converge inward), or "back to back"? I can order bearings that are ground and sold as a matching set in either "b to b" or "f to f" that when mounted together and the retaining nut tightened give a "light preload". I can also order bearings that are not matched but are for "universal pairing" that are about half the cost and are made to mount either way. Some posts on the Yahoo Group mention that to apply a preload to these bearings a shim is needed between them either on the inner or outer race, others say none is needed. If the bearings are made to mount either way how can they be preloaded without the use of a shim? If needed how thick should it be? The machine came fitted with standard bearings and no shims so I can't go by what was there. Any experts here? Thanks in advance! FWIW, the replacement bearings I ordered from Clausing a few years ago are Fafnir 7205WN SU. I haven't installed them yet, but it looks like it might be necessary pretty soon. There are one or two files in the Yahoo Clausing group that describe bearing replacement, I think. I've archived off two from there or elsewhere, complete with pictures. Email me if you can't find them at the Yahoo group. Following is the only info that Clausing could supply me on the spindle (note that no "sample" was attached): ASSEMBLING SPINDLE AND QUILL ASSEMBLY FOR CLAUSING MILL 1. Press 044-005 bearings one at a time on 701-004 spindle. Apply pressure on inner race only and use DB mounting as shown in instructions supplied with bearing - sample attached. 2.Slide 932-011 lock tab washer on spindle with inner tab in keyway. 3. Turn 537-020 nut on spindle and tighten securely against inner race of bearing. Bend a tab on the 932-011 lock washer into a matching slot of the 537-020 nut. 4. Place the spindle in the 631-001 quill - 044-005 bearings in the threaded end. 5. Press the 044-006 bearing on the spindle as far as it will go - apply pressure on inner race only and support spindle on nose only. 6. Assembly 708-001 oil seal in 641-008 retainer as shown in attached sketch. 7. Turn 641-008 retainer in quill -firm but not too tight. 8. Place M6-214 lead ball in threaded hole in quill and lock retainer with #10-32 x 3/16" socket set screw. INSTRUCTIONS FOR REMOVING NO.8520-25 V-MILL SPINDLE ASSEMBLY 1. Remove (2) 1/4" socket set screws from No.537-014 knurled nut located on top of spindle, then remove knurl nut from spindle. 2. Remove (4) 1/4" machine screws (2 on each side of guard) which screws guard No.342-020 to head casting. remove guard by pulling forward. 3. Remove (4) screws which screws plate No.386-009 containing pinion and compound gears. Tap plate lightly on edge while prying outward with screw driver to remove from dowell pins. 4. Remove socket set screw in No.233-001 dial and lift or pry up on stop screw No.696-007 until top of screw is against spindle pulley, push quill to bottom position. 5. Remove 1/4-20 socket cap screw holding stationary stop to face of quill. With stop removed, remove quill assembly from head, reverse procedure to install quill. Caution --be sure when installing spindle pulley guard that brake lever is engaged in brake ring slot. |
#12
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
Thanks Mike, she's off having a knee replaced. Lee is the gal replacing
her, she's semi-retired and good also but I didn't think they'd be good at this sort of thing... "Mike Henry" wrote in message ... Terry, Ask to speak with Jo(lene) Olds at Clausing, if she is still there. She's been pretty helpful to me in the past. Mike "Terry Keeley" tkee(no spam)@(or mail)rogers.com wrote in message .. . Thanks Eric, you're right I'm sure, the person that was recommended at SKF was on the road for the week so I asked if anyone else could help... Not sure about Clausing, posts on the Yahoo Group weren't too encouraging. "Eric R Snow" wrote in message ... On Thu, 1 Dec 2005 09:20:18 -0500, "Terry Keeley" tkee(no spam)@(or mail)rogers.com wrote: Greetings Terry, I assume you have contacted Clausing asking them how to mount the bearings. If not, try, maybe they can help. They helped me a few years ago with questions about an Atlas lathe. I have spoken with both SKF and NTN engineers. Both were helpful. But I also had to go through some younger engineers to finally speak to older ones with more experience. You need to be able to tell the engineer how the bearings are mounted. The mount limits the options. The lines converging or diverging regulate the stiffness of the assembly. Try SKF again and insist, politely, to speak to someone who really knows. ERS |
#13
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
Well those instructions kinda confirmed what I've been hearing from others
privately and also what an engineer at Barden said, it's back to back and there are no shims involved. Interesting they don't specify a torque rating for the locknut, I found that it's supposed to be 23-50 ft-lb. Thanks for the help! "Mike Henry" wrote in message ... "Terry Keeley" tkee(no spam)@(or mail)rogers.com wrote in message .. . I'm restoring my 1963 Clausing 8520 mill ( pictures here if interested http://gallery.intlwaters.com/thumbnails.php?album=323 ) and in the process am replacing the spindle bearings. I've read through many posts on the Yahoo Group and have just gotten more confused. Talked to a few bearing "engineers" (ya right) at SKF and they don't seem to have solid answers either. The spindle takes a pair of 7205 angular contact bearings that are held in place by a locking washer and nut. I was able to find on the MRC site that the torque on the nut should be 23-50 ft-lb. but can't seem to find answers to the following: Should the bearings be mounted "face to face" (where the contact lines of the bearings converge inward), or "back to back"? I can order bearings that are ground and sold as a matching set in either "b to b" or "f to f" that when mounted together and the retaining nut tightened give a "light preload". I can also order bearings that are not matched but are for "universal pairing" that are about half the cost and are made to mount either way. Some posts on the Yahoo Group mention that to apply a preload to these bearings a shim is needed between them either on the inner or outer race, others say none is needed. If the bearings are made to mount either way how can they be preloaded without the use of a shim? If needed how thick should it be? The machine came fitted with standard bearings and no shims so I can't go by what was there. Any experts here? Thanks in advance! FWIW, the replacement bearings I ordered from Clausing a few years ago are Fafnir 7205WN SU. I haven't installed them yet, but it looks like it might be necessary pretty soon. There are one or two files in the Yahoo Clausing group that describe bearing replacement, I think. I've archived off two from there or elsewhere, complete with pictures. Email me if you can't find them at the Yahoo group. Following is the only info that Clausing could supply me on the spindle (note that no "sample" was attached): ASSEMBLING SPINDLE AND QUILL ASSEMBLY FOR CLAUSING MILL 1. Press 044-005 bearings one at a time on 701-004 spindle. Apply pressure on inner race only and use DB mounting as shown in instructions supplied with bearing - sample attached. 2.Slide 932-011 lock tab washer on spindle with inner tab in keyway. 3. Turn 537-020 nut on spindle and tighten securely against inner race of bearing. Bend a tab on the 932-011 lock washer into a matching slot of the 537-020 nut. 4. Place the spindle in the 631-001 quill - 044-005 bearings in the threaded end. 5. Press the 044-006 bearing on the spindle as far as it will go - apply pressure on inner race only and support spindle on nose only. 6. Assembly 708-001 oil seal in 641-008 retainer as shown in attached sketch. 7. Turn 641-008 retainer in quill -firm but not too tight. 8. Place M6-214 lead ball in threaded hole in quill and lock retainer with #10-32 x 3/16" socket set screw. INSTRUCTIONS FOR REMOVING NO.8520-25 V-MILL SPINDLE ASSEMBLY 1. Remove (2) 1/4" socket set screws from No.537-014 knurled nut located on top of spindle, then remove knurl nut from spindle. 2. Remove (4) 1/4" machine screws (2 on each side of guard) which screws guard No.342-020 to head casting. remove guard by pulling forward. 3. Remove (4) screws which screws plate No.386-009 containing pinion and compound gears. Tap plate lightly on edge while prying outward with screw driver to remove from dowell pins. 4. Remove socket set screw in No.233-001 dial and lift or pry up on stop screw No.696-007 until top of screw is against spindle pulley, push quill to bottom position. 5. Remove 1/4-20 socket cap screw holding stationary stop to face of quill. With stop removed, remove quill assembly from head, reverse procedure to install quill. Caution --be sure when installing spindle pulley guard that brake lever is engaged in brake ring slot. |
#14
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
In article , no spam says...
Thanks for the help! So when you put them on and tightened up the nut it applied the pre-load? The true preload on the front pair is built in at the factory. The nut that tightens up the stack simply brings the inner races hard up against each other. The outer races have to be constrained to hard up against each other as well, this is typically done by placing them in a pocket with some kind of clamp ring that bears on the outer face of the outer bearing's outer race. The bearing manufacture has them ground such that, as long as all races are tight up against each other, the preload (or, tiny amount of clearance) will be exactly correct. This is why true angular contact pairs are so much more expensive. Jim -- ================================================== please reply to: JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com ================================================== |
#15
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
FWIW, the replacement bearings I ordered from Clausing a few years ago are
Fafnir 7205WN SU. Just curious, are those angular contact bearings? I can't find those numbers in the catalogue. The Fafnir numbers I'm getting are more like 2MM205WICRDUL, that's for a 25deg. Class 7 bearing. |
#16
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
In article , no spam says...
Well those instructions kinda confirmed what I've been hearing from others privately and also what an engineer at Barden said, it's back to back and there are no shims involved. Interesting they don't specify a torque rating for the locknut, I found that it's supposed to be 23-50 ft-lb. Thanks for the help! Once again, the torque on the locknut does NOT set the preload. It only assures that the preload that is built into the bearings is achieved, and stays in place. Those things don't have to be honkin' tight. Jim -- ================================================== please reply to: JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com ================================================== |
#17
Posted to rec.crafts.metalworking
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Clausing spindle bearings-help!
"Terry Keeley" tkee(no spam)@(or mail)rogers.com wrote in message ... FWIW, the replacement bearings I ordered from Clausing a few years ago are Fafnir 7205WN SU. Just curious, are those angular contact bearings? I can't find those numbers in the catalogue. The Fafnir numbers I'm getting are more like 2MM205WICRDUL, that's for a 25deg. Class 7 bearing. You've got me - I'm no bearing expert. Based on the info in this link: http://www.timken.com/industries/tor...nir/radial.pdf It looks like they are a light duty (72), 25 mm (05), angular contact (WN) bearing, external self-aligning (S) - but no mention of what the "U" might stand for. From the old Chaski group: "By what I can find in my Fafnir bearing book a 7205WN SU bearing is a : Single row angular contact bearing 7200 series .. Light 7205 is the bearing size (25x52x15mm) WN is 37* contact angle and heavy-duty retainer of bronze SU is flush ground bearings for back-to-back, face-to-face, or tandem mounting There is no description of this bearing being any type of precision (5, 7 or 9), the difference between this bearing and a standard 7205 bearing is the contact angle for combined thrust and radial loads. I would see no reason that these bearings should not be replaced with the orginal specifications (bearing class), but the angular contact and being flush ground I would think would be very important. I would be cautious about replacing with a standard 7205 ($5 bearing). " By someone else in response to a question about using standard 7205 bearings for the Clausing spindle. Mike |
#18
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Clausing spindle bearings-help!
On Thu, 1 Dec 2005 14:21:32 -0500, "Terry Keeley" tkee(no spam)@(or
mail)rogers.com wrote: . Just out of curiosity, were the originals bb or ff? My first take on it would be to replicate the original setup. Thanks for the help but someone installed regular standard ball bearings so I don't have any history to go by. Ive not removed bearings from your particular mill..but based on most angular contact bearings...they should be mounted like this " " With a hand snug preload. I recently got into a beef with a well known CNC lathe manufacture over angular contact bearings.. A brand new machine became noisy on the Z axis after about 6 hours use. I tracked the noise down to a thrust bearing between the ballscrew and the servo motor. Taking it apart...I found the bearings to be mounted . They were toasted..brinelled. The bearings and their housing came pre assembled from a major high quality bearing manufacture and not only did the machine become nosiy..but z repeatability was all over the map...up to .0035+ variations. The manufacture claimed it was the first time this was found..and frankly they didnt believe me...so they sent out a their own tech to check..and he replaced the bearing cartridge. Gee..suddenly it was quiet and most of the repeatability issues went away. 2 days later..I had to replace a ballscrew and thrustbearing on a much older machine made by the same manufacture. I pulled the bearing housing apart on a lark..and found the bearings to be I mentioned it to the customer..and he said he had always had an issue doing a back turn..... I suspect they really dont want to know about the second bearing I found ..as it may open a can of worms they dont want opened. Shrug. I figured that some gomer in Japan had too much saki and kereoki the night before and assembled em wrong. The second bearing means there are likely to be more bad ones out there.... All parties shall remain nameless. Gunner I can order bearings that are ground and sold as a matching set in either "b to b" or "f to f" that when mounted together and the retaining nut tightened give a "light preload". I can also order bearings that are not matched but are for "universal pairing" that are about half the cost and are made to mount either way. Some posts on the Yahoo Group mention that to apply a preload to these bearings a shim is needed between them either on the inner or outer race, others say none is needed. If the bearings are made to mount either way how can they be preloaded without the use of a shim? If needed how thick should it be? If you do this without any shims the bearings will have way too much clearance I suspect. What bridgeport used to do was to grind the face of the bearing race to set this, rather than use shims, on the M heads. My first take would be to order the same type (bb or ff) as the original bearings, and purchase them as a true angular contact pair. Jim Think this might be the way to go also but most don't seem to go this route... -- ================================================== please reply to: JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com ================================================== "Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules. Think of it as having your older brother knock the **** out of you for torturing the cat." Gunner |
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Clausing spindle bearings-help!
On Thu, 1 Dec 2005 13:52:36 -0500, Ned Simmons
wrote: In article , "Terry Keeley" tkee(no spam)@(or mail)rogers.com says... I'm restoring my 1963 Clausing 8520 mill ( pictures here if interested http://gallery.intlwaters.com/thumbnails.php?album=323 ) and in the process am replacing the spindle bearings. I've read through many posts on the Yahoo Group and have just gotten more confused. Talked to a few bearing "engineers" (ya right) at SKF and they don't seem to have solid answers either. The spindle takes a pair of 7205 angular contact bearings that are held in place by a locking washer and nut. I was able to find on the MRC site that the torque on the nut should be 23-50 ft-lb. but can't seem to find answers to the following: Should the bearings be mounted "face to face" (where the contact lines of the bearings converge inward), or "back to back"? Almost certainly back to back. I can order bearings that are ground and sold as a matching set in either "b to b" or "f to f" that when mounted together and the retaining nut tightened give a "light preload". I can also order bearings that are not matched but are for "universal pairing" that are about half the cost and are made to mount either way. Some posts on the Yahoo Group mention that to apply a preload to these bearings a shim is needed between them either on the inner or outer race, others say none is needed. If the bearings are made to mount either way how can they be preloaded without the use of a shim? If needed how thick should it be? You'll have to ask the bearing mfr for a definitive answer on the spacer thickness, but I wouldn't recommend this approach. A few tenths will make a big difference in the preload, possibly resulting in overheating or loss of rigidity, depending on whether the shim is too thick or too thin. Best to buy the proper matching set of bearings. A matched pair of precision 7207s should cost you around $275. Ned Simmons Call Alpine Bearing in Boston. Ask for JC..get his quote before buying from anyone else. Gunner "Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules. Think of it as having your older brother knock the **** out of you for torturing the cat." Gunner |
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Clausing spindle bearings-help!
On Sat, 03 Dec 2005 12:29:49 GMT, Gunner Asch
wrote: 2 days later..I had to replace a ballscrew and thrustbearing on a much older machine made by the same manufacture. I pulled the bearing housing apart on a lark..and found the bearings to be I mentioned it to the customer..and he said he had always had an issue doing a back turn..... I suspect they really dont want to know about the second bearing I found ..as it may open a can of worms they dont want opened. Shrug. Gunner: Since when has that ever stopped you? Here's a P-38 C-Rat Can Opener, go for it... :-P "Dumbth" needs to be stomped out wherever and whenever you find it. Even if you can't fix it, it's existence needs to become common knowledge so other people can spot and avoid it. But give the company a heads up, a chance to figure out there's a potential problem with their old machines and to issue a service bulletin about it - if you get up on a soap box, they're liable to take offense and sic a lawyer or three on you. A friend of mine (Not a FOAF) is a repair tech who found a repeatable flaw in an automated stage light - if you called for a certain combination of focus position, color filters and gobo screens, the whole light would lock up solid in whatever position it was in, and you had to remove power to get it to reset. If this happened in the middle of a show, it could be a big problem. The company's initial reaction was to deny there was any problem at all, there's no way that could happen, yatta yatta yatta. Or at least till they tried it themselves - then they got very very quiet... They have since revised the operating firmware on the PROM two or three times, and AFAIK they send them free to anyone who asks. -- Bruce -- -- Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop Electrician for Westend Electric - CA726700 5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545 Spamtrapped address: Remove the python and the invalid, and use a net. |
#21
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Clausing spindle bearings-help!
Terry Keeley wrote:
FWIW, the replacement bearings I ordered from Clausing a few years ago are Fafnir 7205WN SU. I have been following this thread with great interest, since I own the same mill (http://www.abrasha.com/studio.htm). I wonder, if I'll ever get to doing the same thing that you are doing. Your mill is going to be as close to "new" as possible when you are done. You even took the Clausing name plates on the side of the column off. Now that is dedication! And the added work you did by putting it all online is nothing to scoff at either. What a great job you're doing. BTW, I noticed in your images of the mill, that it does not have a motor mounted. If you are thinking of getting a new motor for it, I strongly recommend a new Baldor motor. Get a 3 phase, 3/4HP with RIGID base. Whatever motor you may get, do not get a resilient base motor for this mill. When I got my mill, it had some crappy Sears 1/2HP resilient base motor on it (the one in the picture on my site), and the mill was always dancing around the floor at the higher rpm's. Let me know, and I'll post the model number of my motor. Clausing still sells the rubber washers that go between the NEMA frame and the motor for mounting. Now, with my new motor properly mounted the machine is as rigid as it should be. If you are interested, I have a parts list with prices from Clausing of parts that are still available for this mill. The list is from the time that I got my mill, so it is most likely at least be partially outdated. I think that booklet also contained "exploded view" assembly drawings of the mill. At the time I got my mill I bought this list with drawings from Clausing for $10.00 after which I ordered several new parts. Among other things I got two new nuts for the lead screws for the X and Y axes, which brought the backlash down from around .020" to a more manageable .010". Still not great, but then again I am not machining parts for NASA. At the time new lead screws were also available, but they cost more than I paid for the entire mill, so I did not get those. And finally, I have printouts of the original owner's manual, that someone emailed me when I got this mill. That might have been Mike Henry, but I am not sure about that. I can no longer find the original digital files that were sent to me. But I think, that I still have those printouts somewhere, so if nothing else I can scan those and send them to you. Abrasha http://www.abrasha.com |
#22
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Clausing spindle bearings-help!
"Abrasha" wrote in message . .. Terry Keeley wrote: FWIW, the replacement bearings I ordered from Clausing a few years ago are Fafnir 7205WN SU. I have been following this thread with great interest, since I own the same mill (http://www.abrasha.com/studio.htm). I wonder, if I'll ever get to doing the same thing that you are doing. Your mill is going to be as close to "new" as possible when you are done. You even took the Clausing name plates on the side of the column off. Now that is dedication! And the added work you did by putting it all online is nothing to scoff at either. What a great job you're doing. BTW, I noticed in your images of the mill, that it does not have a motor mounted. If you are thinking of getting a new motor for it, I strongly recommend a new Baldor motor. Get a 3 phase, 3/4HP with RIGID base. Whatever motor you may get, do not get a resilient base motor for this mill. When I got my mill, it had some crappy Sears 1/2HP resilient base motor on it (the one in the picture on my site), and the mill was always dancing around the floor at the higher rpm's. Let me know, and I'll post the model number of my motor. Clausing still sells the rubber washers that go between the NEMA frame and the motor for mounting. Now, with my new motor properly mounted the machine is as rigid as it should be. If you are interested, I have a parts list with prices from Clausing of parts that are still available for this mill. The list is from the time that I got my mill, so it is most likely at least be partially outdated. I think that booklet also contained "exploded view" assembly drawings of the mill. At the time I got my mill I bought this list with drawings from Clausing for $10.00 after which I ordered several new parts. Among other things I got two new nuts for the lead screws for the X and Y axes, which brought the backlash down from around .020" to a more manageable .010". Still not great, but then again I am not machining parts for NASA. At the time new lead screws were also available, but they cost more than I paid for the entire mill, so I did not get those. And finally, I have printouts of the original owner's manual, that someone emailed me when I got this mill. That might have been Mike Henry, but I am not sure about that. I can no longer find the original digital files that were sent to me. But I think, that I still have those printouts somewhere, so if nothing else I can scan those and send them to you. It probably wasn't me that sent you the manual as Clausing only charges $10 for it and I feel that all but the most destitute owners should be willing to come with that much cash for a manual. I may have sent you copies of the test report from my mill, though, or maybe scans from an old brochure showing the few accessories they sold for these mills. If you've lost those, or just want them, email me for a copy. Mike |
#23
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Clausing spindle bearings-help!
Call Alpine Bearing in Boston. Ask for JC..get his quote before buying from anyone else. Gunner Thanks, I'll give him a try. I'm finding quite a variation in price for essentially the same bearings. The SKF bearings were quoted at $265 by Motion in Buffalo (or C$293 from Canadian Bearings here in Toronto) but the Bardens are around $320 or an incredible C$512 here. Must be using our old exchange rate of 60%! |
#24
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Clausing spindle bearings-help!
Ive not removed bearings from your particular mill..but based on most
angular contact bearings...they should be mounted like this " " With a hand snug preload. Are you sure that's right? That symbology is for "face to face" mounting and everyone I've talked to have said "back to back" is the way to go. |
#25
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Clausing spindle bearings-help!
Just curious, are those angular contact bearings? I can't find those
numbers in the catalogue. The Fafnir numbers I'm getting are more like 2MM205WICRDUL, that's for a 25deg. Class 7 bearing. You've got me - I'm no bearing expert. It looks like they are a light duty (72), 25 mm (05), angular contact (WN) bearing, external self-aligning (S) - but no mention of what the "U" might stand for. I'm actually finding that a 15degree contact angle might be better for a milling machine as it can take higher radial loads with less deflection, 25 degree and up are better for axial loads. |
#26
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Clausing spindle bearings-help!
I have been following this thread with great interest, since I own the
same mill (http://www.abrasha.com/studio.htm). I wonder, if I'll ever get to doing the same thing that you are doing. Your mill is going to be as close to "new" as possible when you are done. You even took the Clausing name plates on the side of the column off. Now that is dedication! And the added work you did by putting it all online is nothing to scoff at either. What a great job you're doing. BTW, I noticed in your images of the mill, that it does not have a motor mounted. If you are thinking of getting a new motor for it, I strongly recommend a new Baldor motor. Get a 3 phase, 3/4HP with RIGID base. Whatever motor you may get, do not get a resilient base motor for this mill. When I got my mill, it had some crappy Sears 1/2HP resilient base motor on it (the one in the picture on my site), and the mill was always dancing around the floor at the higher rpm's. Let me know, and I'll post the model number of my motor. Clausing still sells the rubber washers that go between the NEMA frame and the motor for mounting. Now, with my new motor properly mounted the machine is as rigid as it should be. If you are interested, I have a parts list with prices from Clausing of parts that are still available for this mill. The list is from the time that I got my mill, so it is most likely at least be partially outdated. I think that booklet also contained "exploded view" assembly drawings of the mill. At the time I got my mill I bought this list with drawings from Clausing for $10.00 after which I ordered several new parts. Among other things I got two new nuts for the lead screws for the X and Y axes, which brought the backlash down from around .020" to a more manageable .010". Still not great, but then again I am not machining parts for NASA. At the time new lead screws were also available, but they cost more than I paid for the entire mill, so I did not get those. And finally, I have printouts of the original owner's manual, that someone emailed me when I got this mill. That might have been Mike Henry, but I am not sure about that. I can no longer find the original digital files that were sent to me. But I think, that I still have those printouts somewhere, so if nothing else I can scan those and send them to you. Abrasha http://www.abrasha.com Thanks for the kind words, I've have two buddies that have this mill and know what it's capable of. When shopping I looked hard at the "china mills", including the RF45 but just couldn't do it, even though I would have paid about the same as for this 1963 Clausing. It's going to be pretty as well as functional soon. I've got a new Leeson 1/2 HP to go on it, woulda used a 3/4 HP but this one came cheap, not sure what you mean by a RIGID base but it has the standard mounting frame. Thanks for the offers on the parts lists but I ordered a manual and parts lists as soon as I got the machine. I'm replacing all the bearings, the gears for the knee and the "y" nut, plus a few other odds and ends. The dealer I bought it from (Dick Treimstra in Detroit) even supplied an original inspection report from another machine (might be Mike's) so I can check mine when I'm done. |
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Clausing spindle bearings-help!
Terry Keeley wrote:
I've got a new Leeson 1/2 HP to go on it, woulda used a 3/4 HP but this one came cheap, not sure what you mean by a RIGID base but it has the standard mounting frame. Check out this page: http://www.intea.hr/Baldor_pdf/ca453.pdf Go to page 7 of 16. The photo is of a resilient base motor. AS you can see, the base is a cradle that holds the motor around the shaft. On both ends the motor is mounted in a thick rubber rings, which allows for a certain amount of movement. This is a rigid base motor: http://tinyurl.com/8vgzc The base is welded to the motor. Or look here http://www.leeson.com/products/techref/mechanical.htm Read under: "Type of mounts" Rigid base Is bolted, welded or cast on main frame and allows motor to be rigidly mounted on equipment. Resilient base Has isolation or resilient rings between motor mounting hubs and base to absorb vibration and noise. A conductor is imbedded in the ring to complete the circuit for grounding purposes. Abrasha http://www.abrasha.com |
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Clausing spindle bearings-help!
On Sat, 3 Dec 2005 22:44:51 -0500, "Terry Keeley" tkee(no
spam)@(or mail)rogers.com wrote: Ive not removed bearings from your particular mill..but based on most angular contact bearings...they should be mounted like this " " With a hand snug preload. Are you sure that's right? That symbology is for "face to face" mounting and everyone I've talked to have said "back to back" is the way to go. Lots of recommendations on which way to mount the bearings but no input on why! As I see it, if the angular contact bearings are the only bearings on the shaft they should fit because that gives radial location, end thrust location and maximum resistance to angular misalignment of the shaft. By angular misalignment I mean the axis of the shaft shifting so that the shaft centre line traces out a double cone with the vertices located between the two bearings. An appropriate case for this pairing arrangement would be automobile front wheel bearings. If,as is common, on a Mill or a Lathe a third bearing is fitted well separated from the angular contact pair it is THIS bearing that provides the primary resistance to shaft angular movement. Any residual difference between this and the shaft angle defined by the angular contact pair results in the shaft being over constrained and generates large interbearing forces. This means that the angular contact bearings shoud be mounted to minimise the angular constraint - one way of visualising this is to realise that this is half way to the geometry of a self aligning bearing. I am not a bearing expert but I think this is a reasonable way of looking at it. Jim |
#29
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Clausing spindle bearings-help!
Oh, now see, don't think I've ever seen a resilient base motor, mines
definately a rigid base with the NEMA 56 frame. Thanks for the help! "Abrasha" wrote in message ... Terry Keeley wrote: I've got a new Leeson 1/2 HP to go on it, woulda used a 3/4 HP but this one came cheap, not sure what you mean by a RIGID base but it has the standard mounting frame. Check out this page: http://www.intea.hr/Baldor_pdf/ca453.pdf Go to page 7 of 16. The photo is of a resilient base motor. AS you can see, the base is a cradle that holds the motor around the shaft. On both ends the motor is mounted in a thick rubber rings, which allows for a certain amount of movement. This is a rigid base motor: http://tinyurl.com/8vgzc The base is welded to the motor. Or look here http://www.leeson.com/products/techref/mechanical.htm Read under: "Type of mounts" Rigid base Is bolted, welded or cast on main frame and allows motor to be rigidly mounted on equipment. Resilient base Has isolation or resilient rings between motor mounting hubs and base to absorb vibration and noise. A conductor is imbedded in the ring to complete the circuit for grounding purposes. Abrasha http://www.abrasha.com |
#30
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Clausing spindle bearings-help!
That's exactly the case with the 8520 spindle, they use a single bearing
near the top with a duplex pair at the bottom. Somewhere in my reading I recall that back to back mounting is a more rigid set-up. wrote in message ... On Sat, 3 Dec 2005 22:44:51 -0500, "Terry Keeley" tkee(no spam)@(or mail)rogers.com wrote: Ive not removed bearings from your particular mill..but based on most angular contact bearings...they should be mounted like this " " With a hand snug preload. Are you sure that's right? That symbology is for "face to face" mounting and everyone I've talked to have said "back to back" is the way to go. Lots of recommendations on which way to mount the bearings but no input on why! As I see it, if the angular contact bearings are the only bearings on the shaft they should fit because that gives radial location, end thrust location and maximum resistance to angular misalignment of the shaft. By angular misalignment I mean the axis of the shaft shifting so that the shaft centre line traces out a double cone with the vertices located between the two bearings. An appropriate case for this pairing arrangement would be automobile front wheel bearings. If,as is common, on a Mill or a Lathe a third bearing is fitted well separated from the angular contact pair it is THIS bearing that provides the primary resistance to shaft angular movement. Any residual difference between this and the shaft angle defined by the angular contact pair results in the shaft being over constrained and generates large interbearing forces. This means that the angular contact bearings shoud be mounted to minimise the angular constraint - one way of visualising this is to realise that this is half way to the geometry of a self aligning bearing. I am not a bearing expert but I think this is a reasonable way of looking at it. Jim |
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#33
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Clausing spindle bearings-help!
On Sat, 3 Dec 2005 22:44:51 -0500, "Terry Keeley" tkee(no spam)@(or
mail)rogers.com wrote: Ive not removed bearings from your particular mill..but based on most angular contact bearings...they should be mounted like this " " With a hand snug preload. Are you sure that's right? That symbology is for "face to face" mounting and everyone I've talked to have said "back to back" is the way to go. Hopefully, either the inner races _or_ the outer races are clamped together with a nut ant the other races are just located with a circlip, if at all. If so, this will define which way round to mount the bearings since the clamping _must_ set the preload. If both inner and outer are clamped with nuts, then you are back to the original confusion :-( Mark Rand RTFM |
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#35
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Clausing spindle bearings-help!
In article ,
says... When you preload Can you explain that notation, please? Your post makes sense to me if is face to face and is back to back, as illustrated here... http://www.koyousa.com/KoyoCatalog/C...&c=020-020-010 I don't recall ever seeing that notation and it seems backwards from the way bearings are usually drawn. Ned Simmons |
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Clausing spindle bearings-help!
The inner races are clamped together with a locknut, is that the proper
condition for back to back mounting? "Mark Rand" wrote in message news On Sat, 3 Dec 2005 22:44:51 -0500, "Terry Keeley" tkee(no spam)@(or mail)rogers.com wrote: Ive not removed bearings from your particular mill..but based on most angular contact bearings...they should be mounted like this " " With a hand snug preload. Are you sure that's right? That symbology is for "face to face" mounting and everyone I've talked to have said "back to back" is the way to go. Hopefully, either the inner races _or_ the outer races are clamped together with a nut ant the other races are just located with a circlip, if at all. If so, this will define which way round to mount the bearings since the clamping _must_ set the preload. If both inner and outer are clamped with nuts, then you are back to the original confusion :-( Mark Rand RTFM |
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Clausing spindle bearings-help!
In article , no spam says...
The inner races are clamped together with a locknut, is that the proper condition for back to back mounting? For angular contact pairs, whether back to back or face to face, the outer races and inner races *must* be clamped together. The inners via the spindle nut and whatever spacers stack happens to be there, the outers typically by clamping them in a bored recess with a clamp ring. In both ff and bb mounting, you will see that locknut. You cannot determine a priori one vs the other because of its presence. Jim -- ================================================== please reply to: JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com ================================================== |
#38
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Clausing spindle bearings-help!
Ned Simmons wrote:
In article , says... On Sat, 3 Dec 2005 22:44:51 -0500, "Terry Keeley" tkee(no spam)@(or mail)rogers.com wrote: Ive not removed bearings from your particular mill..but based on most angular contact bearings...they should be mounted like this " " With a hand snug preload. Are you sure that's right? That symbology is for "face to face" mounting and everyone I've talked to have said "back to back" is the way to go. Hopefully, either the inner races _or_ the outer races are clamped together with a nut ant the other races are just located with a circlip, if at all. If so, this will define which way round to mount the bearings since the clamping _must_ set the preload. In the arrangement being discussed, both the inner and outer races are clamped together. The nut does not set the preload, only clamps the inner races together. The preload is predetermined at the factory by grinding the faces of the races such that the faces are very slightly offset when the bearing is assembled with zero preload. The proper preload results from forcing the inner and outer races together. Ned Simmons If you are using ultra precision bearings, Ned's information will work fine. Also look for an identify mark on the inner and outer race of each bearing. The inner race marks should be lined up on the shaft and both outer marks should be lined up in the housing. The marks represent the out of roundness of the bearing and the two bearing should run with the out of roundness in the same position, to keep the run out errors to a minimum. Of course the out of roundness you probably cant even measure in most shops.( less than .0001) John |
#39
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Clausing spindle bearings-help!
Like most of you all, I save everything ...
Here are the bearing numbers I received when buying the bearings from Clausing several years ago (I still have the empty boxes). Two Fafnir 7205W SU bearings. The boxes were taped together and I believe they were the lower spindle bearing. Two Fafnir 9105KDD bearings. I believe these were for the front pulley. One Fafnir 204KDD bearing. I believe this was the upper spindle bearing. One CR Services 13548 Oil Seal. This is for the bottom of the spindle. As the directions posted by Mike says, the bearings are Back-to-Back. As I think back to when I was doing this, I recall putting them in backwards first. The advantage of the back to back configuration is when pressing the bearings out you are NOT reverse loading them. In the face to face configuration you are loading one of the bearings in the wrong direction when pressing them out. This might be a problem if the press is high, and you want to reuse the bearings. IAW my Fafnir catalog, the "SU" means the bearings are packaged singly, and can be used DB, DF or DT (Tandem). "DU" in place of "SU" means you will get 2 "SU" bearings in one package. Might be a price brake that way. There is a difference between the "W" and the "WN" that Mike quoted. I don't see a 7205WN in the catalog, just a 7205W. The "W" has a 20 deg contact angle, and the WN would have a 40 deg. It is only the smaller sizes that are "W", so I am guessing that they are to small to make with a 40 deg angle. FWIW, after I got the bearings from Clausing, I priced them out from a bearing house and they were about a 1/3 cheaper. Hope this helps. Vince Mike Henry wrote: FWIW, the replacement bearings I ordered from Clausing a few years ago are Fafnir 7205WN SU. I haven't installed them yet, but it looks like it might be necessary pretty soon. There are one or two files in the Yahoo Clausing group that describe bearing replacement, I think. I've archived off two from there or elsewhere, complete with pictures. Email me if you can't find them at the Yahoo group. Following is the only info that Clausing could supply me on the spindle (note that no "sample" was attached): ASSEMBLING SPINDLE AND QUILL ASSEMBLY FOR CLAUSING MILL 1. Press 044-005 bearings one at a time on 701-004 spindle. Apply pressure on inner race only and use DB mounting as shown in instructions supplied with bearing - sample attached. 2.Slide 932-011 lock tab washer on spindle with inner tab in keyway. 3. Turn 537-020 nut on spindle and tighten securely against inner race of bearing. Bend a tab on the 932-011 lock washer into a matching slot of the 537-020 nut. 4. Place the spindle in the 631-001 quill - 044-005 bearings in the threaded end. 5. Press the 044-006 bearing on the spindle as far as it will go - apply pressure on inner race only and support spindle on nose only. 6. Assembly 708-001 oil seal in 641-008 retainer as shown in attached sketch. 7. Turn 641-008 retainer in quill -firm but not too tight. 8. Place M6-214 lead ball in threaded hole in quill and lock retainer with #10-32 x 3/16" socket set screw. INSTRUCTIONS FOR REMOVING NO.8520-25 V-MILL SPINDLE ASSEMBLY 1. Remove (2) 1/4" socket set screws from No.537-014 knurled nut located on top of spindle, then remove knurl nut from spindle. 2. Remove (4) 1/4" machine screws (2 on each side of guard) which screws guard No.342-020 to head casting. remove guard by pulling forward. 3. Remove (4) screws which screws plate No.386-009 containing pinion and compound gears. Tap plate lightly on edge while prying outward with screw driver to remove from dowell pins. 4. Remove socket set screw in No.233-001 dial and lift or pry up on stop screw No.696-007 until top of screw is against spindle pulley, push quill to bottom position. 5. Remove 1/4-20 socket cap screw holding stationary stop to face of quill. With stop removed, remove quill assembly from head, reverse procedure to install quill. Caution --be sure when installing spindle pulley guard that brake lever is engaged in brake ring slot. |
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Clausing spindle bearings-help!
On Sun, 4 Dec 2005 17:29:16 -0500, Ned Simmons
wrote: In article , says... When you preload Can you explain that notation, please? Your post makes sense to me if is face to face and is back to back, as illustrated here... http://www.koyousa.com/KoyoCatalog/C...&c=020-020-010 I don't recall ever seeing that notation and it seems backwards from the way bearings are usually drawn. Ned Simmons As you will notice..angular contact bearings are essentally cone shaped in their bearing contacts. One side of the bearing has a wide gap around the race, the other side has a much narrower gap. They are designed to basicly be pushed from the wide..or thrust side, so the bearings are forced deeper in to the cone. Hence the being two cones facing each other with the thrust towards each other being applied by the shaft and lock nut that pulls them deeper into their respective cones. If you reverse the arraingment in a fashion..the shaft and nut Pulls the inner races away from the cone. Even with a preload cylinder between them..thrust makes the bearing move towards the wide end of the cone..away from full contact. \-----\ ----- thrust------ /___/ Even if the two cones are seperated by a short distance..they are pulled deeper in the races by the lock nut. I dont know the nomenclature for front and back..but only know them as thrust side and the other side G and the thrust side (often plainly marked as such) need to be on the outside of the bearing stack, and pulled together, then the entire bearing group held tightly in the housing. Ball screw thrust bearing (double bearing) packs have a removable "cover" that is held in place by bolts/screws that keep the outer races held rigidly in place.often with a very thin spacer that contacts only the facing faces G of the outer race. Hope that helped, not confused..and that diagram in your link..is as you indicated Gunner "Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules. Think of it as having your older brother knock the **** out of you for torturing the cat." Gunner |
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