Spindle Tolerance Ring

[SharonB]

On a CarveWright 'B' machine, that I acquired last year, I found a spindle tolerance ring wrapped around a front post. The machine does have a CarveTight spindle. Is this something I can fix myself or does the spindle have to be removed and sent back to LHR? If I can re-insert the ring is there any schematics showing how the ring is to be installed?83062

[bergerud]

The tolerance ring cannot really be replaced without removing the spindle. I have taken spindles in and out many times. If it was my machine I would whip out the spindle and replace the ring. If you want to do that I can advise you. Otherwise I think you will have to send your truck to LHR.

[SharonB]

Dan... I think I'd like to give it a try to replace it myself. Any help you can give would be greatly appreciated. If, after your suggestions, I feel it is beyond my ability I will certainly send it to LHR. I gather I would have to take the track off either way.

[bergerud]

You do not have to take the truck off but it would sure make it easier. With it off, you can use a vise to press out the spindle. Come back when the truck is off.

[SharonB]

Thanks Dan, I'll try and attack that job tomorrow. Don't suppose there is any information out there on taking the track off. But I'll go check right now.

Ok, I found the information on removing the Y-track. Right now I know I'm going to hate this job....mainly when it comes to putting the Y-track back on and adjusting the roller bearings.

[SteveNelson46]

Sharon,

Dan is talking about the Y-Z TRUCK. Not the track rails. Use wrenches to loosen the eccentric bearings that are on one side of the truck. It sounds easy but the nuts/screws are very difficult to loosen. Doing this from memory as I haven't taken the truck off in awhile but I think there is a special flat wrench that will fit between the truck and the bearing or you can just grind down one yourself.

[SharonB]

Steve... I have a several of the original wrenches. Hopefully one of these will work.
Is there any literature on removing this track. All I have is removing the Y-track.

[bergerud]

There is a pdf and a video which might be useful. You only have to take off the z truck.

http://www.carvewright.com/assets/service/Service_instructions/CarveWright_service_replace_z-truck.pdf

http://support.carvewright.com/carvetight-installation-and-use/

[SharonB]

Thanks Dan for the links. I thought I had all the Repair Manuals downloaded but did not have the "Replacing the Z-truck." I remember taking the Z-truck off years ago on my A machine. So, using the video as a reminder I'll try removing the Z-truck tomorrow.

[bergerud]

You should first make sure you can release the z truck rollers. You should be able to do this without having to loosen the screws. The screws and the eccentrics should rotate without the screws coming loose.

If releasing the rollers turns out to be a problem (do not even think about drilling out the screws), you may want to rethink removing the truck and instead think about making a spindle puller.

[SharonB]

Dan.... No problem removing the the Z track. And I think I see where the ring goes. Would it be easier to chat on the phone about re-installing the ring? If so, please PM me with your phone number.

[bergerud]

Would it be easier to chat on the phone...

No, I am a phoneaphobic!! Besides, this way we leave information on the forum for others who may need to do the same. I think you should post some pictures of pressing the spindle out and in again. It would be nice to show people that it is not so hard.

[SharonB]

I see no problem with pressing the ring in. I plan on putting the split towards the back. And since I don't see any difference in which side needs to go in first I'll head out to the shop and try my luck. Will see about photos.

[bergerud]

I would think about using some Loctite or contact cement on the ring. Something to increase the friction. It came out once, it could work its way out again. Stick it to the truck somehow. (I recall that I bent out small parts of the ring edge so it would bite into the aluminum.)

If you have not yet pressed out the spindle, note that the big bearing comes out with the spindle. The problem is only to press the top out of the small bearing. Make sure nothing is in the way of the big bearing as it must come out with the spindle.

[bergerud]

I got your pictures. You are right, that was too easy! The spindle and lower bearing have to come out of the truck. You have to take off the top hat and remove the clip on the top of the spindle. Now you have to press the spindle out of the truck. Really you only have to press the top of the spindle out of the top bearing. Try tapping on it with a wooded block and a hammer. If it moves, you may be able to tap it out. If it is tighter than that, you will need to use a vise. With a small socket (or facsimile) on the top of the spindle and a big socket or pipe on the bottom of the truck. Remember there needs to be room for the big bottom bearing to come out with the spindle.

You might read my old post on "spindle puller" to get a better idea of what is involved. http://forum.carvewright.com/showthread.php?18052-Spindle-Puller&p=152135#post152135

[SharonB]

Dan.... I liked my way better... even if it was wrong. Ok, back to square one. Will tackle it again tomorrow.

[bergerud]

Your way might work if you use Loctite and find just the right size tool to gently tap in it.

[SharonB]

Dan.... Yes, I think my way would have worked if, like you said, if I'd have used Loctite. Doing it your way the hardest part was getting the Snap Ring off. Had to go borrow pliers to do that. With a block of wood and a punch the spindle came right out, with just a few tips of a sledge hammer (smile). Now that it is apart I don't really see what would hold the tolerance ring in place any differently than putting it in from the bottom.
Like you stated maybe crimping the edges slightly and/or using Loctite on the outside of the ring might be the answer.

Now the fun part is getting it all pressed back together. I think pressing it together is going to take a clear mind. So, I'm out of the shop for the evening, fixing myself a toddy (this so I can brave the evening news)...not because I had a hard day.

[Digitalwoodshop]

GREAT JOB so far.... I tucked one back in once in 2008 without removing it from the machine and it popped back out next carve... Good Luck !!!

Ended up replacing the truck.

AL

[bergerud]

Now that it is apart I don't really see what would hold the tolerance ring in place any differently than putting it in from the bottom.


There is a difference. Like Al said, his just came right back out. I had thought before that when the ring goes in first, the bearing pushes it up tight to the top of the hole. There is then some stress holding it to the top and no "wiggle" room for it to vibrate and move.

A little Loctite cannot hurt in either case.


(LHR should use tolerance rings with tabs: http://www.bearings.saint-gobain.com/solutions/rencol-hvt-style )

[SharonB]

Well, the track is back on the machine at the moment. Just need to attach wires and put the cover on the machine. Will give it a try tomorrow. Guess the worse thing that can happen is the ring coming back out. I really don't see much that holds the ring from dropping out. But here is what I did today. Please comment if you see something I should have done differently. Will try to put all pictures on one reply.... it might take two.
It does take two.... see next post.

[SharonB]

Last set of pictures.....

[bergerud]

Looking good. Nice job. Your pictures will surely help others to follow your example!

[henry1]

have to agree with Dan nice job

[normrichards]

Thank you so much for sharing your pictures and instructions for doing this. It makes a huge difference for others with the same or similar issues.

[DocWheeler]

I've never done that, but have a question. Is it possible to peen the casting edge so it holds the ring in place after it is installed?

[bergerud]

I've never done that, but have a question. Is it possible to peen the casting edge so it holds the ring in place after it is installed?


I think that would work just fine.

[Mugsowner]

Awesome job with the photos. Does LHR offer these as a replacement part? If not maybe they should. I was not sure what SharonB had here, but the pictures told the story. I can see that ring taking a lot of abuse. I like the idea, saves the housing from abuse from all the vibration. That being said the ring itself will deform over time form said abuse from vibration and drop out because of a lack of tension. This should have been a very tight tolerance press fit.As the chuck does it's thing, the ring is taking pressures and heating up slightly , as we all do under pressure.

[SteveNelson46]

Sharon,
Thank you very much for the pictures. They explain just how easy it is to disassemble the CT spindle.

Dan,

I think you have posted this before but what size bearings did you use to replace the spindle bearings and where do you recommend buying them.

[bergerud]

Sharon,
Thank you very much for the pictures. They explain just how easy it is to disassemble the CT spindle.

Dan,

I think you have posted this before but what size bearings did you use to replace the spindle bearings and where do you recommend buying them.

The bearings are the same for QC and CT. NSK 6002VV for the bottom and NSK 6000DDU for the top. The top bearing is standard and easy to find. The bottom is a little harder to find. The V stands for non contact seals. It is a high rpm bearing.

(One should note that it may not be so easy to get the spindle out. Some, I think, are tighter than others. It is possible to damage the top bearing pressing the spindle out.)

[SharonB]

Dan is right that all shafts might not come out as easy as mine did. I don't think I taped on the shaft more than half a dozen times and it dropped right out. And it slipped back in by what I would consider fairly easy. Getting the top bearing pressed back down past the snap ring slot was probably the hardest and not damage the bearing.

But I would never have tackled the project without Dan and Steve's encouragement. Thanks guys

[Mugsowner]

The shafts should not come out easy. If they do, there is more clearance than normal, which is why I feel the ring should be replaced. Taking apart as SharonB did is a good way to exposing components. However Ball bearing are harder then the races that hold it all together. Hitting a bearing causes small dents in the races, under high rpms will cause vibration. I would recommend changing bearings when you pull the shaft. This unit would take a certain assembly order and method to insure long life. Don't get me wrong SharonB fix is great, but I do feel it is more of a patch then a repair. Pressed bearings do not like be taken apart and stress are put on areas where they should not be, so it is very hard to take apart without causing some bearing damage even if it is slight. The proper method to install these bearing and shaft can be done in the shop with a couple pressing fixtures.

[bergerud]

The shafts should not come out easy. If they do, there is more clearance than normal, which is why I feel the ring should be replaced. Taking apart as SharonB did is a good way to exposing components. However Ball bearing are harder then the races that hold it all together. Hitting a bearing causes small dents in the races, under high rpms will cause vibration. I would recommend changing bearings when you pull the shaft. This unit would take a certain assembly order and method to insure long life. Don't get me wrong SharonB fix is great, but I do feel it is more of a patch then a repair. Pressed bearings do not like be taken apart and stress are put on areas where they should not be, so it is very hard to take apart without causing some bearing damage even if it is slight. The proper method to install these bearing and shaft can be done in the shop with a couple pressing fixtures.

I agree that the top bearing can easily be damaged by tapping or pressing the spindle shaft out. On the other hand, the top bearing is a common, easily replaced bearing. The bearings are not held very tight by the tolerance rings, and so, pressing the bearings in and out of the tolerance rings does not damage the bearings. The procedure causes no damage to the all important and special lower bearing.

[normrichards]

Both my carvewrights tolerance ring has fallen out as well as a friend of mines in a nearby town. It seems pretty common to me. On both machines we put them back while bending the depressions a little bit more out to hold tighter. On my machine it has lasted over 5 years without falling out again or any issues with the bearings. My son in law owned the machine back when it happened and I have had it about 3 years and it has never come out. I guess someone could damage the bearings and I tapped my shaft out and pressed it back with a vise but I was as careful as I could be and had no problems.

[SharonB]

Well, it DID NOT WORK. It ran a project for about 25 minutes and then sound changed and the picture below shows the results. Does anyone know if I send this back to LHR if they will repair it or do I have to invest in a completely new track?

[bergerud]

I am surprised by that. Many others have put the rings back in and had no further problems. I wonder if it a symptom of something else. Is there some excessive vibration? How was the lower bearing? Maybe it is out of grease and producing high frequency vibration. In that case, the bearing will rotate in the tolerance ring. I use smaller bearings on my ER20M spindles, and before I started using ceramic bearings, I had a few tolerance rings come out as the bearings started to fail. I have been using the same tolerance rings over and over again, and so, I do not think it is the fault of the tolerance ring.

It is too bad your efforts were in vain, I do not know what to say at this point. If you still want to play, tap out the spindle and check the bearing. (No need to remove the truck, just put a wooden block under the truck and tap it out from above.)

[SharonB]

Dan... All seemed to be running fine. The temperature never got hot on any part of the casing, CT or top hat. What it did carve was as it should be. I will investigate more tomorrow. It probably won't hurt to see if I can find bearing locally and just replace them too. If I have to take it apart this might be the way to go.

A note on the project that was carving.... After deleting the part of the pattern that had carved, I transferred the sled to my old reliable "A' machine and finished the carve. Couldn't believe how close the carving matched up. Very minor sanding required. Wish my other machines worked as will as that 'A' machine.

[SharonB]

Still working to get the z-track spindle reassembled. Found the screws in the adjustable bearings of the z-carriage could be removed with just a screwdriver thus allowing them to back out. Evidently, the original Red Loctite was not holding anymore. The track wasn't too loose and I don't know if this caused the tolerance ring to come out or the tolerance ring caused the screws to loosen. But either way this lead to replacing both bearings on the spindle (as a precaution). Having new adjustable rollers and screws I will start mounting the rest of it back together, just as soon as I go into town and purchase some Red Loctite.

The trip to town might take a day or so as the snow has started coming down and it is supposed to snow all night.... if you believe the weather people. Just hoping we only get a light dusting this time around.

[bergerud]

Did you find that there was anything wrong with the lower bearing? Was it running dry? (I assume you replaced it with an NSK 6002VV, right?)

[SharonB]

Dan... I didn't really see anything thing wrong with the bottom bearing. But since I was able to buy the bearings locally and had everything apart it just seemed to be a good idea to replace both of them. Yes, I was able to get both NSK 6002VV and NSK 6000DDU. It is not a job I'd like to repeat very often....hopefully never again.

Now that I see how easy the screws came out of the Roller Bearings it certainly had to cause or contribute to the problem. Will report later on how the machine runs once I buy some Loctite.

[bergerud]

It is hard to know if a bearing which spins at 20 000 rpm is bad or not. I hope the new bearings fix the problem.

Note that the top bearing has a wave washer under it. Although feeble, it is supposed to push the outside race of the top bearing up to take out the slack in the bearings. When you push the top bearing down into the tolerance ring, only push it down enough for the clip to snap in. What I do is push the bearing down using the clip. For example, put the bearing and clip on the spindle above the slot and then, using the old bearing on top of the clip, slowly press until the clip snaps in.

[SharonB]

Did a one hour carve today with the tolerance ring re-installed with new bearings. All went well and temperatures were in the normal range. Of course, I will be keeping a good eye on things for awhile. It certainly was a learning experience. Thanks gang for all the advice and encouragement.

[SharonB]

Oh well. That fix didn't work. Tolerance ring came out again today. Guess the next step is to get a whole new unit or just set the machine aside for the time being. Not a happy camper this evening.

[bergerud]

That was a good effort Sharon. Too bad it worked out again. I guess the only part left to blame is the tolerance ring itself. Strange.