grinder wheel sharpening

[minilathe22]

Hello everyone. I have a cheap grinder with one very large grey wheel on a worm drive which turns very slowly and one thinner white grinding wheel running at higher speeds on the other side. I paid £20 or so for the white wheel. I am often disappointed with the sharpness of my chisels, it seems to vary how sharp they are after coming off the wheel. Sometimes they feel razor sharp to the touch and other times I don't feel I have made any improvement.

I have a diamond dresser block that I run back and forth across the wheel surface to redress it. I have noticed when sharpening that almost immediately some metal from the tool gets embedded in the wheel surface. Is this normal? Should I redress the wheel as soon as this happens? It does seem to clog very quickly.

 

[Paul Hannaby]

Is the large wheel supposed to run in a water trough?

The wheels will need dressing occasionally but not as soon as you notice some metal particles. As particles build up and the sharpness of the surface grit on the stone deteriorates, sharpening will become slower and more hear will be generated so experience / trial and error will show you when you need to dress the wheel.

Perhaps the inconsistent sharpness after grinding is due to changing the angle of the grind? You may be grinding some of the bevel but not actually refreshing the edge. One tip to try is to colour the bevel with a marker pen before grinding. You can then see immediately where you are removing metal so you can see if you have ground in the right place to affect the edge.

 

[Dalboy]

the grinder Paul is referring to that runs in a water bath looks like THIS and yes you can sharpen tools on it but it can be a little slow I have THIS one and find it does a great job with the aid of jigs to get a consistent grind. many people like the Robert Sorby system but that is expensive.

 

[minilathe22]

Yes the larger wheel has a trough you can fill with water, but the sides are plastic so I am never sure how I am supposed to hold the tool at a specific angle securely. I only use the other smaller wheel.

Having thought about my setup I think perhaps the toolrest is a bit flexible, and during grinder it might be bending slightly. This cannot be helping. The record power grinder Dalboy linked to looks like it has much more secure toolrests and a wider wheel. I will consider upgrading.

 

[Dalboy]

Yes the larger wheel has a trough you can fill with water, but the sides are plastic so I am never sure how I am supposed to hold the tool at a specific angle securely. I only use the other smaller wheel.

Having thought about my setup I think perhaps the toolrest is a bit flexible, and during grinder it might be bending slightly. This cannot be helping. The record power grinder Dalboy linked to looks like it has much more secure toolrests and a wider wheel. I will consider upgrading.

You could always make an independent jig to rest the tools on.

On my grinder I removed my tool rests and use a Robert Sorby Jig like THIS one on the white wheel you can also make your own jigs as I did as seen in the photo before I brought the Sorby one