Chatter marks on SG-250 wheel using TT-50 Truing Tool

[Thy Will Be Done]

I have run into an issue with this that is constant and cannot seem to overcome it.  I have a newer T8 machine that I have used somewhat heavily, I've gone through almost half the life of the SG-250 stone.  I have trued often with the TT-50 but now I cannot get a flat surface and have also ran into issues of the surface being cupped horizontally AND the surface on the outer side of the stone begins to chatter and cut chatter marks into the stone that look similar to an all terrain tire tread but they are very shallow.  I've tried coming from both sides of the wheel with the TT-50. 

A call to Customer Support lead me to believe I need a new TT-50 exchange tip but I don't believe this is what is causing it.  I noticed the tip has a slight tilt where it is not sitting perfectly level on the stone surface because I've always trued from the outside to inside of wheel.  The CS person told me that I should always go both ways and that this likely caused the tip to go out of flat.  I don't see why this would matter.  I also suspect I may have a problem with the nylon bearing/bushings as I went far longer than I should have without cleaning and regreasing the main shaft.

Anybody care to weigh in before I go play whack a mole with changing components and hoping it helps?

[cb200t]

Can you try rotating the diamond cutter so a different part of it is exposed and doing the cutting?

For the shaft, can you use a micrometer and check the runout where the bushings contact it?

[Ken S]

This is a puzzle for me. I have never experienced the problem, which does not mean that it is not a problem.

Your problem may well be the nylon bushings or the diamond tip. However; before replacing these, I would try cleaning and regreasing the shaft and bushings. If the diamonds on the tip look uneven, I would try loosening the tip with an Allen wrench and rotating it.

Is your TT-50 the modified 2019 version? (If so, it will look like the current photos.) It was redesigned to lessen chatter. If you have the older TT-50, you can modify it yourself with some electrical ties.

I approach truing very gingerly, some might say too gingerly. I set my cut depth to just a fraction of a microadjust number and cross the grinding wheel very slowly, taking at least two minutes. I always get a dead flat surface without chatter. I am not saying my method is the best or only way. It is the slowest way, and it works for me.

Ken

[Thy Will Be Done]

Can you try rotating the diamond cutter so a different part of it is exposed and doing the cutting?

For the shaft, can you use a micrometer and check the runout where the bushings contact it?

I would do both but I do not have a micrometer or even understand what you mean to check runout.  Another thought was that the washer which is just behind the large plastic hand tightened nut that snugs the honing wheel may have been loose.  I will tighten this and see if it matters.

I would try turning the diamond tip but do not have a metric wrench set and it doesn't fit any SAE allen wrenchs that I have so I assume metric.  The recommendation to replace the tip sounds strange because I can see plenty of visible diamonds and they are cutting.  The problem is the inconsistency of depth of cut.