Thread: Scheppach tiger grinder wheels off centre

All grinding stones need to be 'trued up' when first installed. They are effectively a moulded mixture of abrasive and binder and can be out a little bit from the moulding process. I am not familiar with your Tiger, but have dealt with other similar lower end (compared to Tormek) units. Every one that I have seen the stone has been out about as much as yours out of the box. They generally have a fairly large mounting bore with a number of extruded plastic sleeves ganged up to reduce the bore to match the machine. A single sleeve normally doesn't throw things out a lot, but ganged sleeves often do. It is sometimes possible to rotate or otherwise adjust individual sleeves in the gang to get a better initial run from the stone, but it would still need truing on the circumference to get to a viable situation.

Precision grinders have hubs that are mounted into the stone for life, and the stone is then trued. That way stones can be interchanged and expected to remount in a reasonably condition only requiring a light truing to get them spot on, but basic freehand or simple jig based grinders don't run to that. I suggest that time spent trying to come to grips with the sleeves may be better spent than time truing, given the very low speed the unit operates at makes initial truing a long and tedious task.

Originally Posted by malb

All grinding stones need to be 'trued up' when first installed. They are effectively a moulded mixture of abrasive and binder and can be out a little bit from the moulding process. I am not familiar with your Tiger, but have dealt with other similar lower end (compared to Tormek) units. Every one that I have seen the stone has been out about as much as yours out of the box. They generally have a fairly large mounting bore with a number of extruded plastic sleeves ganged up to reduce the bore to match the machine. A single sleeve normally doesn't throw things out a lot, but ganged sleeves often do. It is sometimes possible to rotate or otherwise adjust individual sleeves in the gang to get a better initial run from the stone, but it would still need truing on the circumference to get to a viable situation.

Precision grinders have hubs that are mounted into the stone for life, and the stone is then trued. That way stones can be interchanged and expected to remount in a reasonably condition only requiring a light truing to get them spot on, but basic freehand or simple jig based grinders don't run to that. I suggest that time spent trying to come to grips with the sleeves may be better spent than time truing, given the very low speed the unit operates at makes initial truing a long and tedious task.

Extremely delayed response but I realised I never thanked you for the response. It was reassuring to know this is pretty standard and while I am still yet to true it to the level of precision I want with the right tool, I checked that it does not have ganged sleeves and so am confident that if it proves to be a problem with some of my more precision tools I'll be able to true it perfectly and it'll stay true.

Thanks! Great to have forums where you can ask advice on such niche subjects