CBN Wheel for RSBG8 Grinder

[Turner Tim]

Afternoon all,
I've got one of the older style 8" grinders (pre 2018) and I'm about to look to replace the 40mm white wheel and started to think about a CBN replacement. Being realistic, I don't need the new wheel to be 40mm wide, just turning tools being sharpened, but the variety out there in the big world is slightly confusing so I'm just looking for any advice/guidance as to various options for sources to get a suitable wheel from please?

Many thanks
Tim

 

[deema]

May I ask, why do you want to change the white aluminium oxide wheel?

 

[Paul Hannaby]

bear in mind that the spindle length on the RSBG8 grinder is designed for 25mm wheels. The 40mm wheels Record install are dished in the centre so they are only 25mm wide where they attach. IF you get a CBN wheel, make sure the centre boss is configured likewise.

 

[Sideways]

It's not uncommon for cbn wheels to be made with an oversize bore and paired with thick machined flanges to reduce them down to fit different spindle sizes.
I have a 40mm Axminster wheel on a 25/40mm post 2018 RSBG8 grinder and it just fits (but properly).
That wheel and its flanges are wide and it took some hunting to find the grinder to fit it.
The wheel was on sale and came first in my case.

 

[graduate_owner]

I bought an xminster 40mm CBN wheel. I had to buy inserts to match the grinder shaft, about £20 extra, but worth every penny I think. They sharpen my turning tools really quickly with very little heat generated, and I don't need to bother with a shield (just protective glasses) because they can't disintegrate, so it's easier to see what I am doing.

K

 

[Mike Fletcher]

I'm getting into woodturning and was told sharp chisels are essential for successful projects and dull chisels can be dangerous. I have to agree. I bought a Record Power grinder with a wet stone wheel. Although it works well, I'm already tired of flattening the wheel after shaping a few chisels. I'm spending more time flattening than I am sharpening! A few questions:

Does the rotation of the wheel make any difference. I have read that some use the grinder with the wheel rotating into the chisel and some say to have the wheel rotating away from the chisel. Is there a right or wrong way or is it just personal preference?

CBN vs diamond wheels. Are they worth the money? Do you need water for these wheels?

Edge angles. I have some friends who are into woodturning and each one uses a different angle on their chisels. Again, is this personal preference? Are some angles easier to use than others? From my limited experience, I'm struggling with the skew chisel. Some say to increase the angle some say to reduce the angle.

Confused and trying to stay safe!

 

[Sideways]

I'll answer one of the above.
Diamond is twice as hard as CBN.
CBN is fifty times more conductive of heat than diamond.

So, if you want to sharpen tungsten carbide tips (most people don't) or you are using a slow, water cooled wheel like a tormek, diamond is your choice.

If you want to sharpen typical high speed steel turning tools on a standard bench grinder with no water and minimal fuss, CBN is ideal for this. It cuts fast and cool.

Both are long life. Both tend to be solid wheels with the abrasive applied to the edge. This makes then inherently safer than a traditional wheel as they should not shatter. Value to you depends on how much you value ease of use. They are far more expensive but they are convenient.

 

[Robbo3]

I'm getting into woodturning and was told sharp chisels are essential for successful projects and dull chisels can be dangerous. I have to agree. I bought a Record Power grinder with a wet stone wheel. Although it works well, I'm already tired of flattening the wheel after shaping a few chisels. I'm spending more time flattening than I am sharpening! A few questions:

Does the rotation of the wheel make any difference. I have read that some use the grinder with the wheel rotating into the chisel and some say to have the wheel rotating away from the chisel. Is there a right or wrong way or is it just personal preference?

CBN vs diamond wheels. Are they worth the money? Do you need water for these wheels?

Edge angles. I have some friends who are into woodturning and each one uses a different angle on their chisels. Again, is this personal preference? Are some angles easier to use than others? From my limited experience, I'm struggling with the skew chisel. Some say to increase the angle some say to reduce the angle.

Confused and trying to stay safe!

Water stones tend to rotate away from the tool, possibly because a dig in could ruin the stone, whilst the norm, even for belts, is to rotate towards the tool.
Don't worry about angles, just copy what is already there - with the proviso that someone hasn't previously put their own grind on the tools. Your body will adjust to allow the tool to cut. If it's tiring or awkward a slight adjustment of the toolrest height can often make things work.

 

[Turner Tim]

Sorry, didn't mean to post and run, but I'm away from home for a family medical emergency and will do a "proper" reply at the weekend.

Cheers Tim