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I don't have experience with the SVH-320 on a T-4, but I do own a T-4 and chose it specifically for its size and portability over the T-8.

The higher price of the T-8 was not a factor for me, since I feel that it's very clear what you're getting extra for the price difference. Usually, I go for the absolute best, but I realized that I just don't have the space for a T-8, and will be using the T-4 only casually. To me, it sounds like you are a more dedicated hobbyist woodworker, and would possibly be benefiting from a T-8, also given the tools that you mention. Note that the T-8 should come with a water chute for long tools (convenient when sharpening your planer blade), has a magnet in the water trough to catch metal particles and comes with both a TT-50 and SE-77 in the box, in addition to the advantages already mentioned in this thread. I had to buy the TT-50 (mandatory purchase) and SE-77 accessories separately which brings the price difference between the T-4 and T-8 (at least in my country) to an acceptable €160, which IMHO is completely worth it.

Hello all, I wanted to let you know that my trusted Tormek reseller (a premium web shop with a brick-and-mortar visiting location) has investigated the grind stone thoroughly in my presence.

They performed various tests including multiple runs of my stone on a brand new T-4 machine, running a brand new stone on my machine, evaluated left-to-right wobble on a new T-4 machine with another new stone and looked at the wobble on a known-good T-7.

Admittedly, no machine was entirely without wobble, but it was apparent that the wobble I experienced was out of spec, that getting the stone to mount right was not the intended care-free operation, and also that the arbor hole in my stone was significantly larger compared to the other stones.

In short, they found my stone to be defective, and exchanged it for a new one that sits much more snug on the axle. I'm happy with the service and the result!

[simultaneously]

First of all, thanks for all your help and comments!

@Ken S: Correct, I used the TT-50 to dress/true the grinding wheel to remove an up/down wobble. I did this when I finally managed to mount the wheel with acceptable left/right wobble.

Fortunately, this evening, I finally had some quiet time to really take a good look at the problem and establish what is happening by measuring the stone's position on the axle as (sort of) suggested, and I think I know now for sure what's going on. Since I could not find my plumb line or a true level surface, I settled for relative measuring of the stone's angle using a square resting on the USB.

I started with a known good position with minimal left/right wobble, and put the long end of the square against the side of the wheel. There was a very small gap between the square and the bottom of the stone, but rotating the wheel did not cause any change, so this told me that my USB is almost parallel to the axle.

Then I took the EZYLock nut off the axle. With the stone against the washer but free on the axle, it turns out that the stone tilts to the right quite a bit. There was now a significant gap between the long end of the square and the bottom of the stone. I tightened the EZYLock nut again per the manual. This did not correct or change the tilt of the stone at all. When I rotated the wheel, I immediately faced a massive left/right wobble. I repeated taking off the nut and fastening it again a couple of times, each time with the washer, axle and stone in different positions, each attempt resulting in the same severe wobble (which is ~2.0mm left + 2.0mm right of the centerline).

This confirmed my hunch that the washer and EZYLock nut (maybe especially the grabby plastic one) are very good at what they do, clamping the stone, even when it's not 90 degrees to the axle; they don't care! This inspired me to try wiggling the stone from the left to the right while simultaneously tightening the EZYLock nut. This makes all the difference. I can tighten the nut ~10-15 degrees further until I can no longer wiggle the wheel, and this approach completely corrects the tilt of the wheel on the axle. I can get consistent results regardless of the position of the wheel, axle and washer, and the stone runs without significant left to right wobble, probably as little as 0.1-0.2mm, which is well within Tormek's tolerances I believe.

So based on the above, if the general experience here is that your stones are square to the axle before tightening the EZYLock nut, I think the stone's arbor hole must indeed have some defect and is too wide overall or widens towards the label side. This may be amplified because the SG-200 stone is 37.5mm wide and the machined part of the axle supporting the stone is only 32.5mm long before the threading starts, I don't know. It may also be amplified if the working surface is not perfectly level. Even the difference between the T-8 and T-4 nut could be a factor, where perhaps the small plastic ledge of the T-4 nut grabs the stone more aggressively compared to the solid and smooth surface of the stainless steel T-8 nut. Other components are just not suspect, the thickness of the axle of my machine is dead-on 12.0mm and the washer is perfectly flat (I checked).

Since my T-4 is only two weeks old, I will avoid implementing measures that might void the warranty. I've had one excellent experience with Tormek support in Sweden already, and I'm confident either Tormek or the reseller in my country will resolve any justifiable issue. I'll probably contact my reseller first and support my case with this thread.

Hi jeffs55, I like your suggestions! Did you mean that I remove the axle/shaft from the machine and affix the wheel then? I probably could also use the USB as a reference for the square. I'm also curious if the slant is caused by tightening the nut, or that the slant is already present.

Please allow me to further follow up on your suggestions tomorrow, it's almost bedtime for me.

Both of you, thank you so much for your response!

It is an interesting phenomenon for sure.

I realise from viewing the video myself again that it may not entirely be clear what I'm doing to demonstrate the issue, so I'll try to explain the steps. My first attempt is fastening the nut per the instruction manual, hand tight and the torque of the motor should do the rest. The second attempt includes loosening the nut by turning the stone slightly, but not much, and then using much more force trying to hand-tighten the nut again. The third attempt also includes a slight turn of the wheel in order to loosen the nut, but in addition to hand-tightening the nut again, after that I also turn the wheel to apply extra force indeed. I tried to keep washer, wheel and axle in the same position in all attempts as much as possible. In later attempts (not recorded on video) I ensured even much better alignment (marked the three components) with same results.

What seems to be happening over and over again is that the stone is clamped firmly between the washer and nut in an already slanted position, which is sometimes only corrected with applying more force by turning the wheel. This is however absolutely not a guaranteed way to prevent the issue from happening.

I checked the washer for potential small debris sticking to it, but found nothing there. It also appears nice and flat when checked with an engineer's straight edge. Maybe I'll run the washer over a Japanese water stone to see if there are low or high spots, but I wouldn't expect variances in that order to be able to cause such a big wobble to be honest.

Hi everyone,

I'm a hobbyist woodworker and knife enthousiast from the Netherlands, and long-time lurker of this forum. After years of deliberation, I've finally decided to invest in a Tormek T-4 and the HTK-706 hand tool kit, and have already beautifully sharpened some chisels and knives.

However, I'm dealing with huge wobble and eccentricity of the grindstone 19 out of 20 times after taking it off and attaching it again. The axle seems straight and the bushings are fine and well lubricated with the white lithium EP2 grease I purchased.

I've already read a lot about possible issues and beginner mistakes and resolutions. For example, I marked the position of the washer, stone and axle when I get nearly perfect behavior. However, I'm not able to repeat this success with everything aligned identically. I've dressed the stone and even flattened the stone on the washer-side using the grading stone, but I still run into issues. The problem was less noticible in the beginning and while the stone was still factory-dry, but after having used the machine and taken the stone off for a couple of times, I'm afraid the problem is getting worse. I'm afraid the cause might be the arbor hole that is too large.

Below is a OneDrive link of a video of me demonstrating the problem as it was when I just got the machine. Notice that where I tightened the wheel an extra bit by hand, it caused much less wobble in this instance. Increasingly, I'm not that lucky anymore...

https://1drv.ms/v/s!Au1g8fW6BaQzh8YFPyS_NRI9mXKh_A

I would appreciate your insight and opinions on this!