T8 Drive wheel issue - confirmation?

[Mitch]

Hi team,

Hope you're all doing well. I think I have the drive wheel issue that has been talked about here in a few other threads. Anyone able to watch this video and confirm it for me before I contact the dealer I bought the T8 from?

I tried sanding the rubber which helped *marginally* - it at least took down the thin rubber strip from the center which can't have helped things. But I think the wheel is actually buckled, judging from the side to side play.

https://vimeo.com/621320233

What do you guys think?

[micha]

Hi Mitch,

I'd contact Tormek support and send them the link to the video. The drive wheel indeed seems to have some imbalance in more than one dimension.Is ist just me or does the motor sound quite coarse, too?
Anyway, that's one for the support guys at support@tormek.se - they'll ask the right questions and find the most expedient solution.

[Mitch]

Thanks for the reply Micha.

I've e-mailed Tormek Support, depending what happens I'll try and update this thread with the result and any replacement I end up doing personally so others can see the process.

[Ken S]

Mitch,

Micha's recommendation of contacting support is very wise. The support staff are experienced old Tormek hands who are eager to help.
Please keep in mind that support works Monday through Friday.

Keep us posted.

Ken

[Mitch]

I've tried using load to center the rubber, didn't help. Feels as though the rubber is thicker on one side. I turned the rubber around and mounted it backwards w which helped a little, the contact between the motor and wheel is steady now (movement is down to about 1mm back and forth) but didn't fix the issue. Still makes a clicking sound.

The supplier said they checked 2 machines and neither had any wobble, so they're going to send me another drive wheel.

Here's a video showing the only way I could think of to test if the zinc wheel is buckled.

https://vimeo.com/626184700

I'll update with a before/after video assuming the new wheel is the fix.

[Mitch]

Okay, so the driveshaft was bent, I believe it was mostly limited to the honing wheel side, sleeve only - not the thicker section running on the bushings. I am getting a tiny amount of movement in the grindstone which I may attempt to fix with this trick, but that side is what I'd call within tolerance. This solution isn't elegant, and unless someone here with experience of the machine thinks it's reasonably safe, I don't recommend it to others. This post is simply to put a bookend on the problem. I was frustrated and didn't want to have the machine in at the dealer's for several weeks.

My solution:

1. With the machine running, butt the edge marker horizontally against the front of the plastic handle at the top. This will put the tip level with the top of the zinc wheel's inside rim. Slowly move the marker in and aim for the very top of the rim until you get a thin black line around part of the wheel.

2. Stop the machine. Turn the drive wheel so that the very middle of the black line is facing upward (I used a finger on each end of the black line to get the center of the line pointing straight up.

3. Now the top of the drive wheel needs to be forced outward carefully, so brace the bottom with your hand and push the top of the wheel from the inside. Use your judgement here, you'll make several adjustments so don't over do it.

4. To check your work, repeat the marker trick. If you've made a difference, the next line that you mark on the rim should be longer (the shorter the line, the more acute the bend is in the driveshaft).

5. Repeat this as many times as is needed to start getting a solid line at least most, if not all the way around the wheel. I started with a line around 90 degrees of the wheel, to 120, to 180. If you've made a few lines you may need to use a rag and solvent to carefully remove the marker lines - DON'T rub it into the rubber wheel.. I can't imagine anything good coming from that.

[Ken S]

Mitch,
Instead of all this, why don't you email support (support@tormek.se)?
Ken

[Mitch]

They keep saying that this is within tolerance, it's just the rubber moving and not the zinc wheel (see my final Vimeo video), and it'll come right.

The dealer appears to be on the case now, I'll see how that goes.

[RickKrung]

Please forgive my denseness...  But, what is the functional problem that you are trying to solve?  That is, what is the effect on grinding or honing?  I ask because: 1) I have not read where you say what it is and 2) when I look at the videos, while I do see a little bit of wobble, it doesn't appear to me as an issue of its own.  In the second video, I hear a ticking, which would annoy the heck out of me, but is it (or whatever) causing a problem with how the machine functions in grinding or honing?  In the first video, I see the motor drive shaft moving in & out with the surface of the rubber wheel. Mine does that too and I don't see how that is a problem. 

Please elaborate? 

Rick

[Mitch]

The honing wheel was riding up and down, and jerking left and right, which made it really disconcerting to have the blade pressed up against it. I've just started the second leather wheel I bought with the machine after reading a good thread about correctly oiling and impregnating the leather. Between that and the correction to the shaft, it's running beautifully now, results on the knife I did last knife confirm that.

The clicking is the motor's contact with the rubber, having to compensate in and out for what the wheel was doing every revolution. That's cleared up now.