Shaft thread wears bushing

[Sharpco]

Every time a stone is replaced, the thread of the shaft wears the bushing of the stone. This is an anxiety because I replace the stone very often. SJ is more worried because there is no bushing.

[Ken S]

Sharpco,

I shall pay special attention in the future. I generally remove my grinding wheel at the end of a sharpening session. I have two suggestions:

First, cup your hand under your wheel before you remove it and take the weight off the shaft.

Second, when the thread wear starts to be a problem, contact support. Your new Tormek warranty covers even commercial use for seven years. I do not speak for Tormek, however, I would be very surprised if they did not send you a new replacement shaft.

Keep us posted.

Ken

[Sharpco]

Sharpco,

I shall pay special attention in the future. I generally remove my grinding wheel at the end of a sharpening session. I have two suggestions:

First, cup your hand under your wheel before you remove it and take the weight off the shaft.

Second, when the thread wear starts to be a problem, contact support. Your new Tormek warranty covers even commercial use for seven years. I do not speak for Tormek, however, I would be very surprised if they did not send you a new replacement shaft.

Keep us posted.

Ken

Ken.

I have been careful that the weight of the stone does not push the shaft. Nevertheless, it was difficult to avoid the wear of Bushing.

And what I worry about is not the wear of the shaft, but the bushing is worn to affect the rotation of the stone.

When I contacted Stig, he says it would be OK, but I am still worried.

[cbwx34]

I wonder if the bushing is put on the coarse stone to protect the shaft from the coarse stone... and not needed on the fine stone?

How much wear are you seeing on the bushing?  (And do you see any wear on the fine stone?)

A search didn't bring up anyone reporting the bushing on a wheel wearing (or a fine stone)... so that's a plus.

But you do bring up some interesting points.

[Sharpco]

I wonder if the bushing is put on the coarse stone to protect the shaft from the coarse stone... and not needed on the fine stone?

How much wear are you seeing on the bushing?  (And do you see any wear on the fine stone?)

A search didn't bring up anyone reporting the bushing on a wheel wearing (or a fine stone)... so that's a plus.

But you do bring up some interesting points.

I can not see the wear of bushing with my eyes. However, the powder created by the wear of the bushing always exists on the thread.

[cbwx34]

I can not see the wear of bushing with my eyes. However, the powder created by the wear of the bushing always exists on the thread.

So, the next question (should've asked in the last post).... how much has your stone worn?  (Just trying to get an idea of if the stone would wear out before the bushing wear became noticeable?)

[RickKrung]

I can not see the wear of bushing with my eyes. However, the powder created by the wear of the bushing always exists on the thread.

There is dust everywhere on my machine, including the shaft and threads, which is the residue from grinding distributed by spilled tank water. So, at first I thought that was what it was rather than wear of the bushing. But, then I looked at the back side of the bushing and there were chips out of the edge of the bushing bore.  At first glance, I didn't see any chips on the threads, but it seemed logical there could or should be.

So, I used a marker to blacken the chipped corner of the bushing, plus a little on the bore and outer flat and then put the wheel on and off again a couple of times.  Sure enough, where were additional chips out of the bushing and chips on the threads. 

There is not much clearance between the bushing bore and threads so I tried to think what could go on the threads to protect the bore and prevent breakout.  Teflon plumbers tape is the thinest I could think of, that I have.  Tried that and still there were chips on the threads and breakout, but it was less. 

Tried a single layer of blue painters tape and there was still some, but much less. 

Perhaps Sharpco could post some pix of what he is describing as the issue, especially if what I have pictured is not what he is experiencing. 

At this point, I only have one wheel, so this is not much of an issue for me, but if changing wheels often, I can see why there is concern.

Rick

[cbwx34]

Some interesting testing Rick.

Here's what I see.  I took a couple of pictures of my stone... it's currently at approx. 218mm.  It has gotten switched a lot between it and a Japanese waterstone.



I tried to snap a photo with light to the side to show chipping (top photo), then a picture with a flash to show the "bore" (bottom).  Similar to Rick, you can see chipping around the edge, but the bore looks fine.  I didn't take a picture of the shaft because frankly I don't see anything to take a picture of.

I don't see the chipping around the hole to be an issue at all.. since the bore itself isn't affected.  And since the stone rides against a washer that is at least 6mm beyond the edge of the chipped area (rough measurement)... the chipping won't affect the stone in that regard either.

So, while at first glance it appears to be an issue, I'm probably over 1/2 the stone's life, and don't see how it could affect anything... unless I'm missing something? 

[RickKrung]

Some interesting testing Rick.

Here's what I see.  I took a couple of pictures of my stone... it's currently at approx. 218mm.  It has gotten switched a lot between it and a Japanese waterstone.

I tried to snap a photo with light to the side to show chipping (top photo), then a picture with a flash to show the "bore" (bottom).  Similar to Rick, you can see chipping around the edge, but the bore looks fine.  I didn't take a picture of the shaft because frankly I don't see anything to take a picture of.

I don't see the chipping around the hole to be an issue at all.. since the bore itself isn't affected.  And since the stone rides against a washer that is at least 6mm beyond the edge of the chipped area (rough measurement)... the chipping won't affect the stone in that regard either.

So, while at first glance it appears to be an issue, I'm probably over 1/2 the stone's life, and don't see how it could affect anything... unless I'm missing something? 

I actually agree with you, CB, that the chipping is not likely to be a problem over the life of the stone.  Like you, I see that the stone is held by shouldered washers against the outer surface of the stone (light colored area on the side of the stone just outside the dark, recessed area of the bushing more easily seen on all my photos of that area).  And that the bore is wide enough and largely unaffected that even if the chipping erodes a few mm, there is still plenty to align the wheel and that chipping in the recessed area has no direct bearing on wheel alignment. 

I was more exploring the question for myself, as at first I didn't get what the problem was. 

[Sharpco]

I can not see the wear of bushing with my eyes. However, the powder created by the wear of the bushing always exists on the thread.

So, the next question (should've asked in the last post).... how much has your stone worn?  (Just trying to get an idea of if the stone would wear out before the bushing wear became noticeable?)

Good point, CB. 

Actually, SG is not a big problem. There is only a slight possibility. Because, as you say, it is okay if the stone wears up to 200mm before the bushing wears and causes problems.

The real problem is SJ. It is a stone with very little wear. I used it for nearly a year, but the diameter is still 242mm. But I can feel that the hole is wider than at the beginning. SJ has no bushing.

[cbwx34]

Good point, CB. 

Actually, SG is not a big problem. There is only a slight possibility. Because, as you say, it is okay if the stone wears up to 200mm before the bushing wears and causes problems.

The real problem is SJ. It is a stone with very little wear. I used it for nearly a year, but the diameter is still 242mm. But I can feel that the hole is wider than at the beginning. SJ has no bushing.

Hmmmm.  I guess if it wore to the point you couldn't use it... maybe a warranty claim?  Since the design is now to allow the easy switching between stones of different types... I would think the design should support it.

Maybe a little more input from Tormek is needed here.... 

[Herman Trivilino]

And that the bore is wide enough and largely unaffected that even if the chipping erodes a few mm, there is still plenty to align the wheel and that chipping in the recessed area has no direct bearing on wheel alignment. 

This is what I was thinking, too. Perhaps this is what Stig meant when he said it's not a problem.

[Ken S]

Sharpco, CB, and Rick,

I have noticed some slight chipping on my wheels. I just thought it was "normal wear and tear". My attitude toward my Tormek has changed over the years. First, my Tormek was stolen and never recovered. Then my (replacement) Tormek was used heavily for a weekend as a demonstrator, including a lot of prep duty. Over the years, I have done a lot of testing for the forum. As much as I still value my Tormek, it has become a useful tool instead of a precious tool.

CB, you make an interesting point about Tormek making the grinding wheel interchangeable. That is a possible stress area the older Tormeks did not have. I always welcome input from Sweden.

Stig has told me about an American knife sharpener named Terry. I forget the vast number of knives Terry has sharpened over the years. What is even more amazing is that Terry bought his Tormek used, several years used. His venerable SuperGrind is still going strong! My grandfather's 1891 Stanley jack plane still works great, even with a broken frog, however, that is with very light use. Terry's SuperGrind gets day in day out commercial use.

I totally believe the wear posts, however, I have to believe that, wear and all, the Tormek is a very tough, long lasting machine,

Ken

[cbwx34]

Stig has told me about an American knife sharpener named Terry. I forget the vast number of knives Terry has sharpened over the years. What is even more amazing is that Terry bought his Tormek used, several years used. His venerable SuperGrind is still going strong! My grandfather's 1891 Stanley jack plane still works great, even with a broken frog, however, that is with very light use. Terry's SuperGrind gets day in day out commercial use.

Terry is in this video...

Tormek Sharpens 30,000 knives

[SharpenADullWitt]

Stig has told me about an American knife sharpener named Terry. I forget the vast number of knives Terry has sharpened over the years. What is even more amazing is that Terry bought his Tormek used, several years used. His venerable SuperGrind is still going strong! My grandfather's 1891 Stanley jack plane still works great, even with a broken frog, however, that is with very light use. Terry's SuperGrind gets day in day out commercial use.

Terry is in this video...

Tormek Sharpens 30,000 knives

Since Steve has retired, I would love to meet this guy and take some training from him.  I can see this as a retirement gig.