Used T-4: Grinding wheel issues

[eld0n]

Dear Tormek community,

I just bought a used Tormek and mounted the wheel. It has noticeable radial wobble and is out of square (see attached pictures). The seller claims the wobble is due to the relative position of the stone on the axle. I have not received an answer on the fact that the stone is out of square yet.

Edit: I have tried changing the position of the stone on the axle, but that does not seem to do anything; in fact, the high spots do not migrate as I change the position of the grinding wheel.

When I take off the stone and turn the machine on, the axle seems to run perfectly true. The motor sounds fine, with an even sound.

It looks like the stone has not been taken proper care of. The machine itself seems OK, but I am worried it may have hidden defects as well. I have about 20 hours to decide whether or not to return the machine.

My questions are the following: What do I need to do to make sure the machine is healthy? Is it worth truing the stone? The outer diameter is about 189mm, while the diameter on the machine side is 186mm.

Many thanks in advance!
Julius

[Ken S]

EldOn,

I suspect your problem is the grinding wheel being worn out of true and not properly maintained. If so, after the wheel is properly trued, all should be well.

You should email Tormek support. (support@tormek.se) You should also contact the seller for information about the original purchase. You may be able to transfer any remaining warranty time. Support can assist you with your issue and also walk through registering your T4. Support is very helpful; they will gladly answer any of your questions.

You will need a TT-50 Truing Tool. It was redesigned in 2019. You will want the redesigned version. It is essential.

Good luck, and keep us posted.

Ken

[Sir Amwell]

It sounds like the machine itself is running ok.
If you are buying it at a bargain price then go ahead. You can true the wheel as Ken suggests. Or buy a new wheel? ( cost of truing tool?). If you anticipate lots of use on the sg stone then you are going to need a truing tool at some point.
If it's only a slight bargain then think again. If a truing wheel is in the price and the machine is ok ( they are robust machines)  go for it. Just maybe anticipate a new wheel somewhere down the line.
Don't know what the T4 retails at now. But say it's half the price of a new one then go for it. You won't regret it.

[Ken S]

The present price of the TT-50 seems to be $108 USD. It is essential with the SG and SJ wheels.

The second hand market for Tormek has been very strong. I leave it to you to decide if the savings of a used Tormek justifies not buying new. For me, a large factor would be warranty transference.

Ken

[eld0n]

Dear Tormekeers,

many thanks for your quick and helpful replies!

The seller says he bought the T-4 at a local store 3 years ago and does not have the receipt. Since the photos looked as thought the machine was hardly used (as he claimed in the description) and Tormeks have a reputation of being bombproof, it felt it was a good offer still. I am getting in touch with Tormek support as per your suggestion, Ken S.

Concerning the price, the machine came with a nice package of jigs, including the revised version of the TT-50. That places it about 2/3 of a new T- 4;including the jigs it is the best price I have seen on the local market for used Tormeks in over 6 months.

What puzzles me is that the seller claimed to have sharpened only a few kitchen knives and trued the wheel once, taking off less than 1mm. That obviously does not check out, hence I am worried something else might be off with the machine.

Any additional thoughts would be much appreciated!

Best,
Julius

[Ken S]

Julius,

Most of the questions on the forum concerning used Tormeks are about vintage SuperGrind models. While these venerable machines are bombproof, they can be expensive to bring up to date. A three year old T4 has all the latest technology already built in. My guess would be that if you patiently retrue your grinding wheel (not difficult, in fact, enjoyable) you should be good to go.

I have owned a T4 since it was introduced in 2014. I really like it; you will, too. It was a substantial redesign over the T3, and these innovations were later incorporated into the T8. It is a rugged, reliable machine. I especially prefer it over my T8 when I have to carry it. At half the weight of the larger machines, it is a joy to transport!

Do keep us posted.

Ken

[Ken S]

.
Julius,

I would like to share some brief thoughts on truing. When I started with the Tormek, I was reluctant to use the truing tool for quite a while. (I suspect this is a common reluctance.) It is best cured through actual use.

Here is a link to a Tormek online class covering the TT-50. (It is the first part of the class.)

Do not hurry with the truing. Go slowly and take very light cuts. Advancing the microadjust just half a number is a good starting point. Moving ninety seconds to cross the grinding wheel is a good speed. Better several light passes than one heavy pass. Your eyes and ears will tell you how much of the wheel is cut with succeeding passes.

Frequent, light truing is the way to go. You will soon be truing like an old pro.

Ken

ps If, by chance, your TT-50 is the pre 2019 model, do not worry. Most of them work fine.If you happen to have one which chatters, the forum has discovered a very easy, inexpensive fix using small electrical ties.

[eld0n]

Ken,

many thanks for your kind and helpful replies. When confronted with the fact that the wheel was substantially more worn than advertised, the seller offered to refund me the value of a new SG-200 grindstone. That lowered the overall price of the T-4 with all jigs to less than half that of a new machine, so I decided to keep it. Many thanks for your encouraging remark, which was seconded by the Tormek support. However, the support restated that the warranty is only valid with the original receipt. I do not think this will be an issue down the road, as the machine and motor seem perfectly healthy.

It is funny how psychology works: now I regard the installed grindstone as a practice piece, so I was not afraid to begin truing it straight away. I have to admit that I followed common sense more than instructions; I had watched some videos on the subject in the past, though. It worked out fine, and the stone now runs true, although I ran into some minor issues.

First, the truing jig that came with the T-4 is indeed the new model. However, it chatters quite horribly when engaging with the center portion of the stone. This has left a very uneven,chipped surface. I did start at the highest spots, shaving off the high spots and then gradually lowering the tip with every other pass. On the first runs, the tip engaged the stone evenly; then, it started to chatter towards the middle. The part holding the diamond tip seems to brace against the universal support, yet there is some play nevertheless. Is that OK? At any rate, I suspect that user error may play the largest part here. I did take my time for every pass (will watch the clock next time) and lowered the tip ever so slightly with every other pass (will watch the digits next time). My suspicion is that I might have been too aggressive in setting the diamond tip in the first place, because it engaged with the grinding wheel on two passes without lowering it (hope this makes sense). This notwithstanding, the play in the jig itself has me worried a bit.

Anyway, I was able to restore two horribly mis-ground plane irons and a 1/4" chisel with a chipped edge. I had been eager to do so for months, and I felt an exuberant joy at finally being able to grind my tools on my own Tormek. The chipped portion in the center of the wheel was slightly annoying when grinding the narrow chisel, but hardly noticeable with the wider plane blades.

Since the machine immediately saw some serious use, I was confronted with an unexpected question: what to do with the water trough while the machine cools down after the 30-minute intervals? Is it OK to just leave the stone soaking? I made sure to turn the wheel manually every once in a while so the stone would not soak unevenly. Is that even necessary?

Thanks a lot for your help in getting acquainted with the T-4. Judging from my first experience with the machine, I think this is the beginning of a beautiful friendship.

Best,
Julius

[Ken S]

Julius,

The dreaded "thirty minute cooling limit" with the T4 was corrected during the redesign of the T4 from the T3. The T3 had an all plastic housing which tended to retain the heat of the motor. There was the possibility that this heat could melt some of the plastic housing. The new zinc top not only improved the accuracy of the machine; it also acted as a radiator and dispersed the heat. Here is a link to the online class where Wolfgang and Sebastien answer a viewer question about this starting at minute 25. (I was the viewer who asked the question):

https://youtu.be/tXO6YejYdck

You as the machine operator will need a rest long before your T4!

Chisels are wonderful learning tools. With only one straight bevel, large enough to examine visually, they are the easiest tool to sharpen. I have around a dozen 3/4" Irwin (formerly Marples) Blue Chip chisels. They are long enough to be useful. They have a proper flat back with no radiused edges. They are reasonable quality steel at a very reasonable price. The 3/4" bevel is large enough for useful naked eye examination. Having several makes it easy to compare scratch patterns from various parts of the sharpening process. Two or three of the same size is a good learning kit.

Your seller sounds like a fair minded guy. You are off to a great start. Your T4 will give you many years of yeoman service.

Ken