SJ-250 always out of round

[MerryMadMick]

Hello,

Recently I picked up an SJ-250 on sale.  When I first purchased it (new), it required truing and to be put into round.  About a week ago I pulled it off my storage rack (12mm peg), mounted it and it was out of round again.  Used the truing tool once again and got it perfectly round.  Mounted it this morning and was not surprised that it was out of round again.

Is gravity to blame here?

Thanks.

[MerryMadMick]

After some digging about, I was told that some users determined that the mounting hole is off-centre on some of the Japanese wheels which would probably explain the issue I'm having.

I'll return it to the store.

[cbwx34]

Hello,

Recently I picked up an SJ-250 on sale.  When I first purchased it (new), it required truing and to be put into round.  About a week ago I pulled it off my storage rack (12mm peg), mounted it and it was out of round again.  Used the truing tool once again and got it perfectly round.  Mounted it this morning and was not surprised that it was out of round again.

Is gravity to blame here?

Thanks.

After some digging about, I was told that some users determined that the mounting hole is off-centre on some of the Japanese wheels which would probably explain the issue I'm having.

I'll return it to the store.

Be curious where you read that some wheels come off center.  Part of the issue is they can't put a bushing in the SJ stone.  This tip might help...

A tip is when you mount the SJ wheel, always mount it so the label of the stone always shows "SJ-250" in level. The first time you might need to true it, but after that, it should be ok. Tighten the Ezy-lock harder by holding the honing wheel with your left hand and pull the stone towards you before you start the machine, tighten the Ezy-lock first,  this also straightens the stone a little.

SJ Wheel wheels rant

[MerryMadMick]

Thanks for the information.  I'll give it a try.  I have another week or so on my return window and I really like the finish this stone produces.

[John Hancock Sr]

I was watching a video the other day  - I think it was one of the Tormek videos - and they were saying that if the wheel is kept on the machine or stored vertical then the lower side of the wheel dries last. The trick is to let the wheel run in water for about 5 minutes before first use for the session. That way the wheel is evenly water soaked. The wetter side of the wheel is slightly softer and it can wear out of round when in use if the wheel is wetted unevenly.

The other thing they say is to always put the wheel on label up. Because the hole is always slightly larger than the shaft it rests very slightly off center so putting the wheel on label up ensures that it is centered the same each time.

[MerryMadMick]

Thanks John and cbwx34.

I rotated the wheel a few degrees at a time on the shaft, using label up as 0 degrees.  At 45 degrees past label up the wobble disappeared/diminished.  I've marked the wheel with an arrow and I'm hoping it remains true for the next few sharpening days.

Speaking of storage, what you say makes sense.  Is it best to store the stones flat?  And, in that case, after sharpening should I pull the wheel(s) and store flat?  I currently have 3 (SG, SB, SJ).

Thanks

 

[RichColvin]

This may be useful information for you. https://sharpeninghandbook.info/Grindstones-Affixing.html

[Ken S]

I rarely use my SJ, so I claim no special expertise. I would suggest emailing support
(support@tormek.se). I would also suggest returning the SJ. I leave the choice up to you whether to request a refund or another SJ.

Ken

[John Hancock Sr]

And, in that case, after sharpening should I pull the wheel(s) and store flat?

I don't. Just let it rotate for a few minutes before starting your sharpening.

[MerryMadMick]

I would also suggest returning the SJ.

Returned it today.  Thanks Ken.