T-4 Arbor run out

[helldan211]

Hello Everyone,
First let me say that as a new Tormek owner, I am in love!  I apologize if this has been covered already, but I didn't find the answer I was looking for when I searched.  I bought a t-4 second hand and it seemed to be working great.  I then noticed that the stone was hopping up and down a little bit so I used the TT-5 and graded it.  I thought that corrected the issue, but I noticed again that it was hopping up and down.  I bought a new SJ 200 wheel and am now noticing the same thing.  I'm thinking the shaft may be bent.   The hop is much more noticeable on the outer edge of the wheel and not the inner edge.  Am I doing something wrong? 
Here is a link to the video:  https://drive.google.com/file/d/1XoFQvyOXGkKPe1iYfEAQzFKZGsiiN86c/view?usp=sharing

Thank you all very much for your help and expertise

Dan

[Ken S]

Welcome to the forum, Dan.

I would be surprised if your shaft is bent, especially with a T4. The shaft of the T4 is just as beefy as the T8 shaft. The only difference is that the T4 shaft is slightly shorter.

Your best bet is to contact support (support@tormek.se). While problems with Tormeks are rare, support will troubleshoot, repair, or replace many more problems than we will ever see. Based on numerous posts, you will be pleasantly surprised with how customer friendly Tormek is. You may also be covered by the warranty.

Keep us posted.

Ken

[helldan211]

Thank you very much.  I will do that.  I'll let you know how it goes. 

Dan

[RickKrung]

...snip...   The hop is much more noticeable on the outer edge of the wheel and not the inner edge.  Am I doing something wrong? 
Here is a link to the video:  https://drive.google.com/file/d/1XoFQvyOXGkKPe1iYfEAQzFKZGsiiN86c/view?usp=sharing
...snip...

Interesting.  I do see the eccentricity on that hub/washer, which seems it maybe should not be doing. 

Is that surface, between the stone and the case, which is fluctuating as it rotates, the hub of the shaft (integral with the shaft) or a washer?  Could make huge difference.  If an integral shaft, it would indicate some form of shaft runout.  If a washer, it could only be slop between the washer and the shaft. 

I don't recall the impetus, but quite a while ago there was a discussion of a process for ensuring concentricity of trued stones that are removed and returned to the machine.  It involved maintaining the rotational location of the stone on the shaft when returning it.  This was an attempt to compensate for slight eccentricities, whether real or perceived, in the shaft and play/slop between the shaft and bore of the stones. 

I began doing this when I just had the SG, SB and SJ stones.  I marked the end of the shaft and the outer surface of the washer (between the shaft hub and stone) with a center-punch, and marked the label of each stone with a sharpie.  I true them in this alignment and align all of these when mounting each stone thereafter. 

If you were to try this with your stone and shaft, you may be able to minimize/eliminate any eccentricity in your shaft.  If you can eliminate all or most the wobbling by doing this, you may have a solution and it may reveal a problem with the shaft.

In order to ensure the stone is truly repositioned, I position stones slightly clockwise on the shaft from what I want the final position to be.  And then, in tightening, I rotate the stone counterclockwise to tighten it and with practice, it ends up in the rotational position that I want.  This may be a procedure that is mentioned in the manual for tightening, rather than just trying to tighten the nut.  I think something similar, for loosening stones is discussed, which is to hold the leather wheel with one hand and rotate the grindstone clockwise (in concert with the loosening direction of the left-hand thread).  The tightening procedure is just the opposite. 

Rick

[John_B]

Rick, I also adopted the practice of marking my stones position when I trued it for the first time. It was so easy to do; so why not?

I have not had any issues with concentricity so I am satisfied.

Dan do you happen to own a dial indicator that you can use on the shaft to measure any run out?

[RickKrung]

Rick, I also adopted the practice of marking my stones position when I trued it for the first time. It was so easy to do; so why not?

I have not had any issues with concentricity so I am satisfied.

Dan do you happen to own a dial indicator that you can use on the shaft to measure any run out?

Yes, so easy to do, so why not...

Good question about the dial indicator.  Or a test indicator.  Either would work.  Setting them up would be the challenge. 

Rick

[RickKrung]

I meant to suggest in my reply about marking the shaft/washer/wheel, to

1) align things and mark them, similarly as described,
2) true the stone in that position,
3)verify there is no runout in the wheel surface (visually would do),
4) loosen the stone and rotate it 180º while ensuring the shaft does not also rotate (hold the leather wheel), and
5) check to see if there is noticeable rounout. 

If there is a lot, similar to what you are experiencing, then there may be a problem with the shaft.  Also, check that thing about the surface of the stone being higher at the outer edge than the inner edge. 

Rick

[helldan211]

I do not currently own a dial indicator, but maybe I will order one.  I will try all of the things you have mentioned and get back to you.  I didn't hear back from the tech support department.  Maybe I will send a follow up later today. 

Thanks!
Dan

[helldan211]

I would like to add that I just sharpened a kitchen knife today.  When the blade was contacting the stone closer to the outer edge, the wobble is very noticeable. I can feel the stone pushing the blade up and down.  when the contact area is on the inner side of the stone, it's not wobbling at all. 

[helldan211]

First of all, thank you for the suggestions. 

I used a punch to make a reference point on the washer and on the shaft.  I marked the end of the shaft and the stone and started to grade the stone.  I am sharing 3 videos of what is going on when I true the stone.  Please let me know if something does not appear to be right.  It just seems wrong.  I'm just chewing through these stones.


Video 1:beginning of the first truing.   https://drive.google.com/file/d/1TC1S6JnczyF-029Urx8HhPSCUidjKgya/view?usp=sharing
Video 2: beginning of the third pass. https://drive.google.com/file/d/1XBG2b6uQJjFtocuJiZH59AdHEX6hvRfJ/view?usp=sharing
Video 3: end of the third pass https://drive.google.com/file/d/1XugW_JfhtHRliEBswsJzQ0TmmrkiOPcZ/view?usp=sharing

[RickKrung]

First of all, thank you for the suggestions. 

I used a punch to make a reference point on the washer and on the shaft.  I marked the end of the shaft and the stone and started to grade the stone.  I am sharing 3 videos of what is going on when I true the stone.  Please let me know if something does not appear to be right.  It just seems wrong.  I'm just chewing through these stones.

Video 1:beginning of the first truing.   https://drive.google.com/file/d/1TC1S6JnczyF-029Urx8HhPSCUidjKgya/view?usp=sharing
Video 2: beginning of the third pass. https://drive.google.com/file/d/1XBG2b6uQJjFtocuJiZH59AdHEX6hvRfJ/view?usp=sharing
Video 3: end of the third pass https://drive.google.com/file/d/1XugW_JfhtHRliEBswsJzQ0TmmrkiOPcZ/view?usp=sharing

Nothing is really jumping out at me, other than the sound of vibration.  You are going to have to tell us what you think is not right about it. 

Did you have some problem with the truing process or the results?  The wheel appears to be running true after it was all done.  Is the surface of the trued stone uniform, or does it have striations or an angular regular pattern, likely at the outer edge? 

Rick

[helldan211]

It is getting closer to true.  I trued it two weeks ago.  While truing it there was an angular pattern for the first third of the stone and then the pattern was up and down for the rest.  With the last pass it seems to have lessened.  Maybe a few more passes with the grader will sort that out.  I also have been taking  the stone off to measure it because I have been using the grind angle software.  I was not paying attention to indexing if the stone as the earlier posters had mentioned.  I've only had the machine for a month and have had to remove a lot of material to keep it true.  I will now do my best to keep the stone indexed to the markings that I had made to see if that makes a difference going forward.  I'm new with this and maybe I need more time.  I'll make a few more passes tomorrow as the vibration is very loud and my 20 month old goes to sleep in a little bit. Thank you all for your help, but it seems like I might just need more time with it.

[John_B]

It also could be that the previous owner never bothered to true the stone and it got more out of round than we would expect. I know many people are unnecessarily concerned about wear and they are reluctant to use the grader. I saw definite improvement by your 3rd video.

[RickKrung]

It also could be that the previous owner never bothered to true the stone and it got more out of round than we would expect. I know many people are unnecessarily concerned about wear and they are reluctant to use the grader. I saw definite improvement by your 3rd video.

Good thought. 

I agree with your two points, one about being overly concerned about consuming wheel when it comes to truing.  Truing is a vital and necessary "expense", as Ken S. says frequently, a consumable, like brake shoes.  And I also saw definite improvement at the end of the third pass.  What I saw was a wheel in a usable condition, for trueness. 

Rick

[helldan211]

Thank you very much.  I still have a lot to learn and am loving every minute of it.  Mods, you can take this down if you like.  Unless you think it will be helpful to others.