# Surface grinder wheel hub



## Ian Moss (Jul 9, 2022)

Bought a collection of tools that included a surface grinder wheel hub that fits my SG spindle, but the wheel securing nut has a right hand thread rather than the left hand thread of all my other hubs. I know the R and L hand threading is to keep the nut from loosening when torque is applied to the spindle, but the washer between the nut and the stone has two key tabs to keep it from rotating. I doubt that the starting torque would enough loosen the nut, especially since I do a soft start with my VFD. Would I be taking a foolish risk to use this RH hub on my LH grinder??


----------



## Susquatch (Jul 10, 2022)

Ian Moss said:


> Bought a collection of tools that included a surface grinder wheel hub that fits my SG spindle, but the wheel securing nut has a right hand thread rather than the left hand thread of all my other hubs. I know the R and L hand threading is to keep the nut from loosening when torque is applied to the spindle, but the washer between the nut and the stone has two key tabs to keep it from rotating. I doubt that the starting torque would enough loosen the nut, especially since I do a soft start with my VFD. Would I be taking a foolish risk to use this RH hub on my LH grinder??



I am reluctant to provide advice contrary to a manufacturers advice. I'm guessing you already know that the safest thing to do is to not use it. 

Consider selling the hub to someone with a grinder that takes a RH hub and buy a proper hub for your grinder. Who knows, your RH hub might be rare enough to command a much better swap value.


----------



## Dabbler (Jul 11, 2022)

[edit I should read better]  Does your nut for the hub have a key slot?  If not, you can make one.  Some manufacturers made their hubs for a key washer, which usually got lost in time.  

[edit] If the washer is keyed to the shaft, and then to the nut, after tightening it will hold the wheel just fine....  The washer has a keyway molded into it, with 7-9 external leaves for folding over.  I have seen this in one British surface grinder I've used, but not North American ones.  The brit common taper is 3.5 inches per foot, as opposed to the US 3 inches per foot...

My SG is running on a VFD, so I use the soft start to eliminate similar worries.

if this helps...


----------



## Susquatch (Jul 11, 2022)

Dabbler said:


> The washer is keyed to the shaft, and then to the nut, after tightening. The washer has a keyway molded into it, with 7-9 external leaves for folding over. I have seen this in one British surface grinder I've used, but not North American ones. The brit common taper is 3.5 inches per foot, as opposed to the US 3 inches per foot...



I think you are caught in the same rabbit hole that I was in when I first saw the question. I think the nut in this case isn't the spindle nut (which is independent of the hub and cannot be swapped left/right) it's the big circular hub nut. I'm not sure it should really be called a nut though. 

I did think about ways of doing something similar to that nut though if it were mine.


----------



## Dabbler (Jul 11, 2022)

[edit]  is this the type of washer that holds the wheel to the wheel adapter?


----------



## Ian Moss (Jul 11, 2022)

No, the washer just has two tabs on the ID that engage two slots on the hub. I am leaning to the removable loctite approach, as I expect that I may never have to remove the nut once I true and balance the wheel.


----------



## Susquatch (Jul 11, 2022)

Ian Moss said:


> No, the washer just has two tabs on the ID that engage two slots on the hub. I am leaning to the removable loctite approach, as I expect that I may never have to remove the nut once I true and balance the wheel.



Good stuff Ian. I have come to understand that there are many ways that these hubs are configured. Therefore much of what I said might not make sense for your situation. 

Hubs for small wheels for my grinder are fairly low cost on Amazon. I just wish I could get bigger hubs for bigger wheels at a reasonable price too.


----------

