Oregon bench grinder/disc size?

[buffalo606]

Just wondered what disc thickness is the right one for Oregon 75 chain (7/32" 5.5mm)? 

 

Can't find the old disc and can't make sense of the online charts.  

[Ian Clarke]

if you look on frjones you can find replacement discs quite easily and there is two to choose from. one for the bigger chains and one for the smaller ones. if you can wait another 24 hrs i will get the numbers off the disc at work when im bk in tomorrow.

 

[buffalo606]

if you look on frjones you can find replacement discs quite easily and there is two to choose from. one for the bigger chains and one for the smaller ones. if you can wait another 24 hrs i will get the numbers off the disc at work when im bk in tomorrow.
 

I was sure there was one size up from the 4.7 mm (making x3 sizes available?) but I'm probably wrong.

[Ian Clarke]

Standby caller. I'll check when at work. 

[GardenKit]

You need just 2 sizes to cover all common chains.

3.2 deals with 3/8 lp and .325

4.7 deals with 3/8 and .404.

Simples!

[Woodworks]

21 minutes ago, GardenKit said:

You need just 2 sizes to cover all common chains.

3.2 deals with 3/8 lp and .325

4.7 deals with 3/8 and .404.

Simples!

What's the problem with using the thinner discs on .404 chains. I can see you have less of a radius where the side plate meets the gullet but is this a problem?

[GardenKit]

3 hours ago, Woodworks said:

What's the problem with using the thinner discs on .404 chains. I can see you have less of a radius where the side plate meets the gullet but is this a problem?

It would be just like using too small a file Beau, and you would have less of a radius just as you say. Would this be problem? probably not, to be honest. But why not use the correct tool for the job?

[Woodworks]

1 hour ago, GardenKit said:

It would be just like using too small a file Beau, and you would have less of a radius just as you say. Would this be problem? probably not, to be honest. But why not use the correct tool for the job?

I see what your saying but a grinder is not quite the same as a file as the head of the grinder moves so most of the top plate and side plates bevels end up flat. Only the junction of the side plate to gullet gets the radius as opposed to using a file where all the top plates edge is concave to the files radius. It's a hassle changing discs when only doing a few chains of each.

Edited December 7, 2017 by Woodworks

[Ian Clarke]

https://www.frjonesandson.co.uk/products/oregon-grinding-wheel-for-standard-grinder/

 

There is the link to the frjones website and the grinder wheel. Just choose from the drop down menu. 

[buffalo606]

I see what your saying but a grinder is not quite the same as a file as the head of the grinder moves so most of the top plate and side plates bevels end up flat. Only the junction of the side plate to gullet gets the radius as opposed to using a file where all the top plates edge is concave to the files radius. It's a hassle changing discs when only doing a few chains of each.

Only problem I can think of is when you then need to sharpen up in the forest with say a 7/32" file the gullet will be a bit cramped?