Machine Vibration

[marhk]

My machine has a great deal of vibration at times when grinding chisels or plane irons. Pushing down on the outer end of the support helps some but not completely. This is at times a very coarse vibration!

What other measures can I take?

[Jeff Farris]

Are you talking about a noise, or a vibration that you can feel?  A noise or buzz is usually something loose on the machine.  Often, it is the AngleMaster or Turning Tool Setter -- if you reposition them, it will stop.  Sometimes the locking knobs on the horizontal base will vibrate, as well.  

I would suggest that you remove your grindstone and lubricate the two plastic bushings that support the main shaft. Use a Teflon? based spray lubricant or a very small amount of waterproof grease. Reassemble and make sure that all accessories and locks are secured.  That should stop the vibration.

[bulerias1981]

I just bought a new T3. I have a bit of a wobble problem as well I believe. If you stare hard enough you can see the honing wheel wobble, and when it does, it makes a sound. I find it harder to see the grinding wheel wobble. But I can tell when I'm sharpening my plane iron as the wheel makes its revolution, you can hear a slightly louder distinct sound. I've pulled the drive shaft apart to see if I could find any irregularities. I didn't notice a lot. Cant say I know 100% of what I was looking for. I put it back togather and same issue.

Also, I'm wondering if its causing another problem I'm having.. When I sharpen my plane iron, it comes out a few degrees skewed. This is not good for obviously reasons. I did all the standard checks. Checked if it was aligned in the jig correctly. Checked that it was torqued down evenly. I'm not sure what to do. Its been this way out of the box.

[Jeff Farris]

At the low speed of the Tormek, any side to side deviation is noticeable, where on a high speed machine, you would never see it.  The Owner's Handbook lists allowable run out tolerances for the grindstones.

The sound variation per revolution is caused by a slight inconsistency in the grindstone.  It is nothing to be concerned about, and is not the cause of your problem with getting a square grind.

On a plane iron, which is almost invariably wider than the grindstone, grinding time and pressure are very critical to getting a square grind, and unfortunately cannot be controlled by anything except the operator. The only way to get a square grind on a plane iron is to jig the tool up as carefully as you can, work with a stone that is true to Universal Support, and MOST IMPORTANTLY work with a try square next to your Tormek.  Check the tool frequently and correct any skew by concentrating the grinding time and pressure on the longer side of the angle.

[bulerias1981]

I did check that the pressure was distributed evenly. I am using the SE-76 jig for a Lie-Nielsen no.6 Bench plane blade. Is that jig suitable? I see there is SVH-60, is that better in solving this uneveness issue?

Also it seems that its rocking possible more than 1mm. But I have no way of measuring.

[Jeff Farris]

You're using the right jig.  It would be virtually impossible for anyone, no matter how experienced, to grind an iron perfectly square without checking for square and regrinding the side that is too long.  There's nothing wrong with your machine or your jig selection.  Just concentrate the grinding for a few seconds on the long point, then make a few even strokes across the stone.  Then check for square again.  Repeat as needed.

[bulerias1981]

I have taken a couple of videos of the machine. You can see it wobbling here both ceramic wheel and honing wheel in unison. Which makes me to believe theres something wrong with the drive shaft.

http://www.youtube.com/watch?v=riUhG9qQQ10

In the next video I removed all the hardware and extras. The water tray the support, the tightening knobs for the support. And if you stare at the wheel and the honing wheel enough youll see it swaying. Looks maybe more than 1mm. Please tell me if this is normal. This machine is 3 days old.

http://www.youtube.com/watch?v=jciTLQ6BRTw

[Jeff Farris]

The video is a little shaky, and you're not holding on one section very long.  I certainly see the movement, but I don't see any movement that is outside of tolerance.  Please clean your grindstone with the SP-650 Stone Grader, and try the recommendations I've given your for achieving square grinds.  The machine you have in your shop is capable of delivering square grinds if you follow the suggestions I've given you.

[bulerias1981]

Jeff,

I have tried the recommendations. It still is producing erratic cuts on my plane blade. I'm afraid to sharpen anything that requries squareness. I had to fix my plane blade on a flat stone, which now its square and perfect. I don't trust this wobbling. Did you see the 2nd video? You said video as in singular. There is a second video that I made the camera stationary. I think the second video is more clear.  Look at the edge of the stone, it seems obvious.
http://www.youtube.com/watch?v=jciTLQ6BRTw

As a violin-maker I need to join two pieces of wood perfectly with a dead straight and square blade. I'm just too nervous to put a blade back on there like this. Its a lovely machine, but I've had it only 3 or 4 days now.

[Jeff Farris]

I did look at both videos.  Did you purchase the diamond truing tool for the Tormek?  The movement of the stone that could cause a problem is the up and down movement, not the side to side movement.  The up and down movement is a result of the stone wearing unevenly, and being now out of round. That would be removed by truing the grindstone. 

Where did you buy your machine?  You may be looking for a level of performance that cannot be delivered by the T-3.  Did you consider the T-7?  It is a considerably more robust machine. 

Do your planes not have lateral adjustment? 

[bulerias1981]

I bought the machine from Woodcraft in Norwalk, CT. I'm not sure if I should bring it back or what I should do. I love it, just need a perfect edge on my plane blades.

[boehme]

I have used a Tormek for more than seven years and from your descriptions of the problems that you are having, I would definitely say that the wheel is out of round.  Have you used the diamond truing tool to get the stone perfectly round, yet?  That is an important step in getting your machine set up to run true.  Just as most cutting tools are not sharp when you buy them, the grinding stone is not perfectly round when you buy it -- but, even if it were, it has to be trued up to match your particular machine because the guide bar will have a slightly different alignment on every machine -- even though it is just a very small fraction of a degree of alignment difference, you still must tune the stone to your machine.  The fact that you are getting skewed bevels on plane irons is pretty clear evidence of that unless you are not squaring the end of the iron first and then mounting it correctly in the fixture before beginning.

Once the outside of the stone has been trued, what difference does it make that the side had a slight side-to-side movement?  The stone is not loose -- it is just the slight angular misalignment of the bushing through the stone that produces the eccentric motion, but it has nothing whatsoever to do with the grinding surface where you sharpen the planar blades.

As far as the very slight side to side misalignment of the leather honing wheel is concerned -- that is even less significant than your concern about the grinding wheel because the leather surface is soft and compliant so that it will deform under the pressure of the edge being honed.

By the way, if you do the trigonometry, you will find that even with a slightly out of round stone with an eccentricity of 1 mm, the effect that it has on the tool bevel angle is unmeasurable without laboratory instruments capable of measuring at the milliradian level.

BTW, the poor quality of the videos especially being out of focus and not using a tripod with the camera jerking all around makes it impossible to ascertain anything useful from them.

[bulerias1981]

I haven't trued the stone yet as I haven't purchased the jig. This machine is only a few days old. As I mentioned, the wobbling seems to be in unison with both wheels acting together. The wobbling is more side to side as in x-axis. So I'm not sure what truing would do for that.

[Jeff Farris]

Here's a quick way you can determine if the side to side run out is coming from a problem with the shaft.  In the first place, that is highly unlikely, however, this process will determine if it is.

The run out on the grind stone comes from the stone not being perfectly perpendicular to the shaft.  This is caused by the fit between the stone, the inside washer, and the shoulder of the main shaft.  Loosen the nut that holds the stone.  Turn the inside washer about 1/4 of a revolution, making sure that the stone does not move with it.  The side to side run out should now change.  It could be more, less, or the same but with  different points of the stone representing the apexes of the travel.  If the same points of the stone continue to represent the apexes, the stone is warped.  If the same points of the shaft represent the apexes, there is a problem with the shaft.

The stone truing tool is an essential tool for the kind of precision you're looking for.  It is not included in the T-3 because it isn't required for normal household tools like scissors and knives. I suggest you purchase the truing tool or possibly exchange the T-3 for a T-7.

[boehme]

Machinists use a calibrated granite block to check for straightness and flatness, but if you have granite counter tops or other counter tops that you trust to be very flat then you can remove the shaft and roll it gently on the flat surface to see if it is straight.  If you have a high quality straight edge such as a Starrett ground straight edge you could also use that, but it would be more difficult to keep things lined up correctly.  As Mr. Farris said, a crooked shaft is highly unlikely.  But, even with a perfectly straight shaft, the bushed hole through the stone is not absolutely perpendicular to the side.  Since none of the jigs are designed to sharpen anything against the side of the stone, there is no reason anyway for the sides to run perfectly true.  Regardless of how close to perfectly perpendicular the alignment of the side of the stone, once you true the grinding surface (i.e., the outside diameter of the stone) using the diamond truing tool, the grinding surface will then run perfectly smoothly without any bumps or weaving.  I think that you may possibly have gotten fixated on what is going on with the side of the wheel, but it has no relationship to the perimeter surface that is used for tool sharpening (for that matter, it could be scalloped or fluted or just rough and uneven since it is not even a part of the big picture).  Sometimes this point is hard to envision for those who are not familiar with machining or who are not woodturners.  But, first true up the stone if it needs it and then give it a try and I think you will see this a bit more clearly as reading text in a forum posting are often inadequate to explain complex things sufficiently.

If you have a dial indicator, you could attach it to one of the fixtures that mount on the guide bar and then take readings at various wheel rotation angles and at different points across the grinding surface of the stone (Just make sure that you lift the indicator from the stone when rotating it  ).  For sharpening plane irons and other wide cutting edges like that, the most important parameter is the side-to-side variation so that the tool doesn't develop a skew angle.  But, as I mentioned previously, slight eccentricity in the wheel diameter is much less of a problem.  Both of those issues are resolved by using the diamond truing tool on the stone.

I have sharpened everything from planer and jointer blades to scissors, knives, plane irons, chisels, and woodturning tools.  About the only thing that I have not sharpened is carving tools -- yet -- but, I have started carving so it won't be long until I do that too.  I am very meticulous about getting tools sharpened exactly right and the Tormek has worked extremely well for me.  Did I mention that I can see a very slight amount of weaving on the side of the stone on my machine?  It doesn't make any difference in its performance.  The only things that I do on the outside flat surface of the stone is lap the faces of tools like chisels, plane irons, and woodturning scrapers before I sharpen them.  The outside face is as flat as you could expect to find on any grinding stone -- and since I am hand holding the face of the tool against the stone as it turns, the fact that it is moving about a millimeter side-to-side doesn't make any difference.