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Thk slides
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wdavis364
I bought a pair of THK SR15 slides off a Ebay and one of the blocks is
slides is moving rough as though it is missing some of the ball bearings. Can I reload the bearings here? I've seen ball bearing on sale for reloading. Is there info on how to do this? If this is doable, where can I look for this information and where to buy these ball bearing? thanks bill |
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Bill,
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Rough running may indicate corrosion or debris in the bearings. If you look at the travelers from the bottom up, you should be able to see if there are gaps between the balls. If there are no major gaps, then the roughness is probably not due to missing balls. You may have to remove the travelers and clean them in kerosene before repacking them with clean grease. You will have to measure one of the bearing balls that you already have with a micrometer to get the size. Bearings are easily available from eBay or McMaster-Carr, and many other suppliers. They come out a whole lot easier than they go in! Reloading the bearings it lotsa fun. I scrapped some assembly machinery over the past 2 years and found to my chagrin that many of the linear bearings were not captive, so I've had more practice than I care to admit. Turns out that it was only the caked on grease and grime that held the bearing balls in the travelers. I have seen some new bearings that come with a blue plastic loading fixture, but have never had one to work with. Before you start, put a tie-wrap or piece of wire through one of the mounting holes at the far end of the rail so your "other" bearing doesn't slide off while you work on your end. (You can probably figure out why I suggest this!) I use a magnetized Allen key a bit smaller than the diameter of the bearings to pick up and manipulate the balls. I slide the partially loaded traveler to the open end of the rail, with the rail on top, and the traveler on the bottom, and pick up a bearing at a time with the Allen key, and push it into the ball channel between the end of the traveler and the rail. I use a wood dowel to push the bearing balls off the Allen key. When the race gets nearly full, bearings will start to push out of the recirculating channel as you push new ones in. Then you should run the traveler back and forth to take up slack space between the balls, until there is no more room to insert more balls, and your done. Checking from underneath the traveler will indicate whether there are still gaps in the stack of balls. It can be surprisingly difficult to get the empty spaces out from between the balls in the circuit. HTH, Dave wdavis364 wrote: I bought a pair of THK SR15 slides off a Ebay and one of the blocks is slides is moving rough as though it is missing some of the ball bearings. |
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Bill Davis
Well Dave, you're scaring me. These Slides were represented as never used. When I got them, they looked to be in original package. It took me a while to clean what looks to be amber colored sticky substance. The package has been open (maybe to photograph for selling. I'm thinking either the bearing came off the rail and maybe some ball bearing escape or what ever the substance that I had to clean may ended up in side the bearings. Maybe I should do what you suggested in the first paragraph first. Do you know if the THK SR15 bearing have a way holding the ball bearing in place whenever I remove them from the rail?
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thanks bill ----- Original Message -----
From: David Speck To: CAD_CAM_EDM_DRO@... Sent: Thursday, August 24, 2006 4:47 PM Subject: Re: [CAD_CAM_EDM_DRO] Thk slides Bill, Rough running may indicate corrosion or debris in the bearings. If you look at the travelers from the bottom up, you should be able to see if there are gaps between the balls. If there are no major gaps, then the roughness is probably not due to missing balls. You may have to remove the travelers and clean them in kerosene before repacking them with clean grease. You will have to measure one of the bearing balls that you already have with a micrometer to get the size. Bearings are easily available from eBay or McMaster-Carr, and many other suppliers. They come out a whole lot easier than they go in! Reloading the bearings it lotsa fun. I scrapped some assembly machinery over the past 2 years and found to my chagrin that many of the linear bearings were not captive, so I've had more practice than I care to admit. Turns out that it was only the caked on grease and grime that held the bearing balls in the travelers. I have seen some new bearings that come with a blue plastic loading fixture, but have never had one to work with. Before you start, put a tie-wrap or piece of wire through one of the mounting holes at the far end of the rail so your "other" bearing doesn't slide off while you work on your end. (You can probably figure out why I suggest this!) I use a magnetized Allen key a bit smaller than the diameter of the bearings to pick up and manipulate the balls. I slide the partially loaded traveler to the open end of the rail, with the rail on top, and the traveler on the bottom, and pick up a bearing at a time with the Allen key, and push it into the ball channel between the end of the traveler and the rail. I use a wood dowel to push the bearing balls off the Allen key. When the race gets nearly full, bearings will start to push out of the recirculating channel as you push new ones in. Then you should run the traveler back and forth to take up slack space between the balls, until there is no more room to insert more balls, and your done. Checking from underneath the traveler will indicate whether there are still gaps in the stack of balls. It can be surprisingly difficult to get the empty spaces out from between the balls in the circuit. HTH, Dave wdavis364 wrote: > I bought a pair of THK SR15 slides off a Ebay and one of the blocks is > slides is moving rough as though it is missing some of the ball > bearings. > Can I reload the bearings here? I've seen ball bearing on sale for > reloading. Is there info on how to do this? If this is doable, where > can I look for this information and where to buy these ball bearing? > thanks > bill |
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BRIAN FOLEY
Hi, first try is to clean the bearing and see if you can get some dirt out
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of the bearing. it might also be grease hardened up in the ball races. time and mineral spirits usually will help loosen the grease. cul brian f. ----- Original Message -----
From: "wdavis364" <wdavis@...> To: <CAD_CAM_EDM_DRO@...> Sent: Thursday, August 24, 2006 5:10 PM Subject: [CAD_CAM_EDM_DRO] Thk slides I bought a pair of THK SR15 slides off a Ebay and one of the blocks istimg@... Moderator: pentam@... indigo_red@... davemucha@...[Moderators] URL to this group:aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble. sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........ bill |
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Bill,
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Sounds like the bearings were shipped in Cosmolene, a preservative coating (in)famous in the military world for the difficulty involved in removing it. It should come off with any hydrocarbon solvent, like kerosene or mineral spirits plus a generous application of elbow grease. Work outdoors with good rubber gloves away from sources of ignition. If you have removed the coating, have you repacked the bearings with new grease? A liberal coat of new lithium grease should smooth things out dramatically if the bearings are in good shape. I would think that the coating might make the bearings stiff, but I wouldn't expect them to run rough unless the ways were corroded or contaminated with dirt. Shouldn't be the case if the bearings are new. I guess the question would be how old they are, and whether they were corroded. In any case, inspect the bearings from the bottom and see if the line of balls is visible from the underside. There should be no gaps larger than one ball diameter in the line of balls. However, on the units that I have reassembled, even 3 or 4 missing balls didn't make the travel detectably rough. I don't know anything about the specific model THK bearing you refer to, though I disassembled a great many different models in the machines I salvaged. Most turned out to not be captive ball systems. Google is your friend -- perhaps the pertinent spec page indicates it the balls are captive on your model or not, but I'd assume the latter. If you take the travelers off the rails, do it over a big clean container, or else be prepared to crawl around on the shop floor with a flashlight for a long time. It's really amazing how far ball bearings bounce when dropped on a concrete floor, and they have an uncanny ability to find expansion joints and floor drains from 15 feet away =:^o Dave Bill Davis wrote: Well Dave, you're scaring me. These Slides were represented as never used. When I got them, they looked to be in original package. It took me a while to clean what looks to be amber colored sticky substance. The package has been open (maybe to photograph for selling. I'm thinking either the bearing came off the rail and maybe some ball bearing escape or what ever the substance that I had to clean may ended up in side the bearings. Maybe I should do what you suggested in the first paragraph first. Do you know if the THK SR15 bearing have a way holding the ball bearing in place whenever I remove them from the rail? thanks |
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When the race gets nearly full, bearings will start to
push out of the recirculating channel as you push new ones in.Then you should run the traveler back and forth to take up slack space betweenthere are still gaps in the stack of balls. It can be surprisinglydifficult to get the empty spaces out from between the balls in the circuit.Ball screws may be easer then. I found the recirculating tubing to be a half tubing that would lift out ever-so-slightly and then open like a clam. You had mentioned that balls are available in different places. McMaster has 1/8" balls in three grades, plain, chromed and ground, but only in 1/8". I would like to get sizes around that,some smaller, some larger, to allow me to adjust a ball screw. Any ideas where to get some that are off-size ? Dave |
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Bill Davis
Dave, It been a long time since I've seen comolene. I really think the cosmolene was on the rail it self and not in the bearings as much, though with me running the bearing back and forth on the rail it may of pick up some of it. The cosmolene wasn't laid on thick like you see in the military, more like a thin layer of paint.
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While running this one bearing if I put pressure on it, it seems to run smoother. the problem is when I change directions, it seems to hang up momentarily. I'm thinking I'll put both bearings on end of the rail and stick in a bucket cleaning solution and let soak. Maybe with a brush and little air pressure may solve the problem. Thanks bill ----- Original Message -----
From: David Speck To: CAD_CAM_EDM_DRO@... Sent: Thursday, August 24, 2006 5:56 PM Subject: Re: [CAD_CAM_EDM_DRO] Thk slides Bill, Sounds like the bearings were shipped in Cosmolene, a preservative coating (in)famous in the military world for the difficulty involved in removing it. It should come off with any hydrocarbon solvent, like kerosene or mineral spirits plus a generous application of elbow grease. Work outdoors with good rubber gloves away from sources of ignition. If you have removed the coating, have you repacked the bearings with new grease? A liberal coat of new lithium grease should smooth things out dramatically if the bearings are in good shape. I would think that the coating might make the bearings stiff, but I wouldn't expect them to run rough unless the ways were corroded or contaminated with dirt. Shouldn't be the case if the bearings are new. I guess the question would be how old they are, and whether they were corroded. In any case, inspect the bearings from the bottom and see if the line of balls is visible from the underside. There should be no gaps larger than one ball diameter in the line of balls. However, on the units that I have reassembled, even 3 or 4 missing balls didn't make the travel detectably rough. I don't know anything about the specific model THK bearing you refer to, though I disassembled a great many different models in the machines I salvaged. Most turned out to not be captive ball systems. Google is your friend -- perhaps the pertinent spec page indicates it the balls are captive on your model or not, but I'd assume the latter. If you take the travelers off the rails, do it over a big clean container, or else be prepared to crawl around on the shop floor with a flashlight for a long time. It's really amazing how far ball bearings bounce when dropped on a concrete floor, and they have an uncanny ability to find expansion joints and floor drains from 15 feet away =:^o Dave Bill Davis wrote: > Well Dave, you're scaring me. These Slides were represented as never used. When I got them, they looked to be in original package. It took me a while to clean what looks to be amber colored sticky substance. The package has been open (maybe to photograph for selling. I'm thinking either the bearing came off the rail and maybe some ball bearing escape or what ever the substance that I had to clean may ended up in side the bearings. Maybe I should do what you suggested in the first paragraph first. Do you know if the THK SR15 bearing have a way holding the ball bearing in place whenever I remove them from the rail? > thanks > bill > ----- Original Message ----- > From: David Speck > To: CAD_CAM_EDM_DRO@... > Sent: Thursday, August 24, 2006 4:47 PM > Subject: Re: [CAD_CAM_EDM_DRO] Thk slides > > > Bill, > > Rough running may indicate corrosion or debris in the bearings. If you > look at the travelers from the bottom up, you should be able to see if > there are gaps between the balls. If there are no major gaps, then the > roughness is probably not due to missing balls. You may have to remove > the travelers and clean them in kerosene before repacking them with > clean grease. > > You will have to measure one of the bearing balls that you already have > with a micrometer to get the size. Bearings are easily available from > eBay or McMaster-Carr, and many other suppliers. They come out a whole > lot easier than they go in! > > Reloading the bearings it lotsa fun. I scrapped some assembly machinery > over the past 2 years and found to my chagrin that many of the linear > bearings were not captive, so I've had more practice than I care to > admit. Turns out that it was only the caked on grease and grime that > held the bearing balls in the travelers. I have seen some new bearings > that come with a blue plastic loading fixture, but have never had one to > work with. > > Before you start, put a tie-wrap or piece of wire through one of the > mounting holes at the far end of the rail so your "other" bearing > doesn't slide off while you work on your end. (You can probably figure > out why I suggest this!) > > I use a magnetized Allen key a bit smaller than the diameter of the > bearings to pick up and manipulate the balls. I slide the partially > loaded traveler to the open end of the rail, with the rail on top, and > the traveler on the bottom, and pick up a bearing at a time with the > Allen key, and push it into the ball channel between the end of the > traveler and the rail. I use a wood dowel to push the bearing balls off > the Allen key. When the race gets nearly full, bearings will start to > push out of the recirculating channel as you push new ones in. Then you > should run the traveler back and forth to take up slack space between > the balls, until there is no more room to insert more balls, and your > done. Checking from underneath the traveler will indicate whether there > are still gaps in the stack of balls. It can be surprisingly difficult > to get the empty spaces out from between the balls in the circuit. > > HTH, > Dave > > wdavis364 wrote: > > I bought a pair of THK SR15 slides off a Ebay and one of the blocks is > > slides is moving rough as though it is missing some of the ball > > bearings. > > Can I reload the bearings here? I've seen ball bearing on sale for > > reloading. Is there info on how to do this? If this is doable, where > > can I look for this information and where to buy these ball bearing? > > thanks > > bill |
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Bill Davis
Brian, I think you're right, I need to stick the bearing in cleaning solution and let it soak a while.
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thanks bill ----- Original Message -----
From: BRIAN FOLEY To: CAD_CAM_EDM_DRO@... Sent: Thursday, August 24, 2006 5:28 PM Subject: Re: [CAD_CAM_EDM_DRO] Thk slides Hi, first try is to clean the bearing and see if you can get some dirt out of the bearing. it might also be grease hardened up in the ball races. time and mineral spirits usually will help loosen the grease. cul brian f. ----- Original Message ----- From: "wdavis364" <wdavis@...> To: <CAD_CAM_EDM_DRO@...> Sent: Thursday, August 24, 2006 5:10 PM Subject: [CAD_CAM_EDM_DRO] Thk slides > I bought a pair of THK SR15 slides off a Ebay and one of the blocks is > slides is moving rough as though it is missing some of the ball > bearings. > Can I reload the bearings here? I've seen ball bearing on sale for > reloading. Is there info on how to do this? If this is doable, where > can I look for this information and where to buy these ball bearing? > thanks > bill > > > > > > Addresses: > FAQ: > FILES: > Post Messages: CAD_CAM_EDM_DRO@... > > Subscribe: CAD_CAM_EDM_DRO-subscribe@... > Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@... > List owner: CAD_CAM_EDM_DRO-owner@..., wanliker@..., timg@... > Moderator: pentam@... indigo_red@... davemucha@... [Moderators] > URL to this group: > > OFF Topic POSTS: General Machining > If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble. > > > I consider this to be a sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list. > > NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........ > bill > List Mom > List Owner > > > Yahoo! Groups Links > > > > > > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.405 / Virus Database: 268.11.5/426 - Release Date: 8/23/06 > > |
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BRIAN FOLEY
dont be affraid to work em back and forth. and same when you put grease to
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them work it in good..cul brian f. ----- Original Message -----
From: "Bill Davis" <wdavis@...> To: <CAD_CAM_EDM_DRO@...> Sent: Thursday, August 24, 2006 8:05 PM Subject: Re: [CAD_CAM_EDM_DRO] Thk slides Brian, I think you're right, I need to stick the bearing in cleaningsolution and let it soak a while. thanksout of the bearing. it might also be grease hardened up in the ball races.time and mineral spirits usually will help loosen the grease. cul brian f.if you have trouble.for OT subjects, that are not allowed on the CCED list.THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........8/23/06 >timg@... Moderator: pentam@... indigo_red@... davemucha@...[Moderators] URL to this group:aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble. sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........ bill |
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--- In CAD_CAM_EDM_DRO@..., "Bill Davis" <wdavis@...>
wrote: solution and let it soak a while. thanks Bill: Run the bearings back and forth while "painting" on Mineral Spirits with a brush. While soaking them will help, it won't wash the junk out of the bearings. Once they start to free up you can switch to WD40 (more as a cleaner than a lubricant). Another more aggressive approach that I sometimes have to use on my slides is brake cleaner from the auto store. Works wonders on waxy or junked up surfaces but will attack some plastics so be careful. |
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caudlet wrote:
--- In CAD_CAM_EDM_DRO@..., "Bill Davis" <wdavis@...> wrote:Another thing that works to clean Cosmoline is WD-40. When I bought my ballscrews, I basically wrapped them in paper towels soaked in WD-40. I got a plastic tablecloth from the dollar store, and wrapped the whole thing in that. After a day "infusing", the cosmoline just wiped off with a rag. I also had a problem with the ballnuts feeling "scratchy", and it was entirely due to the cosmoline. Once I ran it over the screw several dozen times, cleaning and soaking with WD-40, they were smooth as silk. - Steve |
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Here's an article that describes a method of removal. It was a link on
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wikipedia. I looked it up because you guys got me curious. (Nothing like those hexapods, though.) At the end is a list of cleaners including EZ Off Oven Cleaner. That stuff is straight lye -- I'd avoid it if I had cleaners that weren't rated for turning flesh into soap. Speaking of the hexapods (yeah, I know I'm a broken record sometimes), I've been thinking about those ball and socket joints they use. What do you guys think of using a couple of milled halves of delrin clamped around a ball as a bearing? Or better yet, casting it into some graphite doped epoxy (great idea, whoever you were.) On 8/25/06, Stephen Wille Padnos <spadnos@...> wrote:
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Bill Davis
thanks tom, I'll try it. It seems every time I work with it it seems to get a little better. What ever it is that on the bearings is got to be tough stuff.
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thanks bill ----- Original Message -----
From: caudlet To: CAD_CAM_EDM_DRO@... Sent: Friday, August 25, 2006 7:14 AM Subject: [CAD_CAM_EDM_DRO] Re: Thk slides --- In CAD_CAM_EDM_DRO@..., "Bill Davis" <wdavis@...> wrote: > > Brian, I think you're right, I need to stick the bearing in cleaning solution and let it soak a while. > thanks > bill Bill: Run the bearings back and forth while "painting" on Mineral Spirits with a brush. While soaking them will help, it won't wash the junk out of the bearings. Once they start to free up you can switch to WD40 (more as a cleaner than a lubricant). Another more aggressive approach that I sometimes have to use on my slides is brake cleaner from the auto store. Works wonders on waxy or junked up surfaces but will attack some plastics so be careful. |
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