Grinder wheel vs round file size

[captain]

Just got a Maxx grinder and was wondering why the difference in grinding wheel size when compared to round file size. 3/8 chisel chain uses a 7/32 round file but a 3/16 grinding wheel, .325 chain uses a 3/16 round file and a 1/8 grinding wheel. Figured one would use the same size grinding wheel as round file.

 

[mtngun]

File size influences hook angle, but on a grinder, hook angle is determined by the grinder setup, not by the wheel diameter.

 

[captain]

Thanks mtngun, that sheds some light on it. I still find it interesting that one can use the same size wheel for two sizes of chain pitch (3/16 for 3/8 - .404 and 1/8 for .325-3/8 lo profile) Yesterday I saw a 5/32 timbertuff branded wheel at the store....wondering what pitch it is for being that it is between the 3/16 and the 1/8 size.

 

[blizake7]

How are you supposed to know the angle, wheel size, and depth that you need to cut at on a grinder? I just bought an Oregon 620-120 grinder and my head is spinning. Wtf am I doing!? lmao

 

[J D]

How are you supposed to know the angle, wheel size, and depth that you need to cut at on a grinder? I just bought an Oregon 620-120 grinder and my head is spinning. Wtf am I doing!? lmao

The chain manufacturer will list specs for sharpening their various chains by either grinder or hand file... Grinder is usually 55-50° cutting angle, 25-30° top plate angle, 1/8" wheel for smaller chain & 3/16" wheel for larger chain. Depth you set based on getting a good hook without over cutting it

 

[SimonHS]

How are you supposed to know the angle, wheel size, and depth that you need to cut at on a grinder?

Here is a chart that shows Oregon grinder settings for Oregon chain. You should be able to work out settings for other brands of chain using this chart as a starting point.

 

[Philbert]

wondering why the difference in grinding wheel size when compared to round file size.

Common question, and a good one.

I am not convinced that the reason is technical, vs practical. In other words, that a wheel 1/32 thicker, in between, would make much of a practical difference. But I am just speculating.

It is also possible to dress a grinding wheel down to a slightly smaller profile, if desired. Can’t do that with a file!


Philbert

 

[huskihl]

On a new chain, a wheel the same size as the recommended file will have a hard time getting under the cutter without taking off the top of the depth gauge. Once the tooth is worn down, that aspect doesn’t matter as much, but it will still be difficult to get enough hook without burying the wheel into the straps

 

[huskihl]

How are you supposed to know the angle, wheel size, and depth that you need to cut at on a grinder? I just bought an Oregon 620-120 grinder and my head is spinning. Wtf am I doing!? lmao

I have the same grinder. Once you get it set up so that your left and right cutters are the same length by adjusting the dial on the front, they do a really nice job. I use 25- 55 and 0 on the slide setting on bottom. I can’t tell much difference between using the slide and not using it, so I just omitted the hassle.

 

[thill]

When I got mine years ago, I just followed the existing angles of the blade. Took a little practice, but I loved that thing. Generally, the trick was to take only the tiniest bit needed to get sharp. Unless you really grounded the saw badly, then you have to do what you have to do.

You will soon get the hang of it, but having the initial settings will speed up the process.

 

[blizake7]

The chain manufacturer will list specs for sharpening their various chains by either grinder or hand file... Grinder is usually 55-50° cutting angle, 25-30° top plate angle, 1/8" wheel for smaller chain & 3/16" wheel for larger chain. Depth you set based on getting a good hook without over cutting it

So 3/16" is best for 3/8 050 chain..

 

[J D]

So 3/16" is best for 3/8 050 chain..

Correct