Hi folks!
That was new to me.
The SJ-250 has to be mounted only with writing upwards.
If you do not so the rotation of the dics is not correct.
That´s the info from Tormek Customer Service.
For me that´s trash. So my next wheel is a CBN with 6µ.
Pietje
Pietje,
REGULATION:
Definitions
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noun
1.
a rule or directive made and maintained by an authority.
I believe we may have different ideas about the word usage. Tormek will not confiscate your SJ if you mount your wheel with the writing upwards. The Japanese water stone has a softer material than the harder SG wheel. Therefore, it is more prone to having the bore wear. Mounting your SJ wheel is a suggestion to enhance the trueness.
Switching to another kind of wheel will not necessarily guarantee increased wheel trueness. Many third party wheels sold for use with the Tormek have larger diameter bore, typically 5/8" or 1". These are primarily designed for higher speed dry grinders. They may have well machined reducing bushings or, more typically, a set of plastic bushings or a loose fitting stainless steel bushing. Both of these options can introduce a sloppy fit.
Mounting the wheel with the writing upwards is a very simple procedure to maximize accuracy. It should be a habit with all of your grinding wheels, either Tormek or third party.
The difference between a Tormek wheel (SJ, SG, or SB) and either CBN or diamond is that the trueness can be refined on the Tormek wheels with a light pass with the TT-50 truing tool. With CBN or diamond wheels, your degree of trueness is limited to whatever the factory or reducing bushings produce produce added to the wear of the grains.
If you are truly particular about wheel trueness, the most accurate choice is a freshly trued Tormek grinding wheel. Always mounting writing up minimizes the amount of truing needed.
Ken
Pietje,
I explained why that is in this note: https://sharpeninghandbook.info/Grindstones-Affixing.html (https://sharpeninghandbook.info/Grindstones-Affixing.html).
Rich
Further to what Ken and Rich said:
Most of my wheels are trued and installed with the writing up the same each time they are installed (SG-250 and Stun Tiger #800). However as Tormek acknowledges, the SJ-250 has looser tolerances than the SG, SB or diamond wheels. I therefore found that to get the least "lateral wobble" with my SJ-250 stone, I actually had to use trial and error to find the "best position" for that particular stone. As it turns out that ended up being with the 9 o'clock position actually configured at what would be the 12 o'clock location. This gave me the least wobble, so I marked that location with a sharpie marker, and that wheel I trued to that position and always re-mount at that position. Listen to what Sebastien says at t=20min 3 seconds of the Tormek Live tips and tricks linked below. This worked well for me to get the least wobble on my SJ stone.
https://youtu.be/0htKSoTBjoI?t=1184 (https://youtu.be/0htKSoTBjoI?t=1184)
Beaker.