Why grind rakers with 60deg 1/4" wheel

[hokiebob1]

Why does Oregon suggest dressing the 1/4" stone parallel to the chain while the wheel is at 60 degs, then grinding the rakers? Is this simply to give a wider grind surface to clean up the rakers and bumper straps, or is there some other reason. For a simple raker on a non-safety chain, seems like you could just use a 90deg stroke with a standard "square" 1/4" wheel.

thoughts?
b

 

[tawilson]

Never noticed that. The NT grinder manual says do it at 90.

 

[zemmo]

Why does Oregon suggest dressing the 1/4" stone parallel to the chain while the wheel is at 60 degs, then grinding the rakers? Is this simply to give a wider grind surface to clean up the rakers and bumper straps, or is there some other reason. For a simple raker on a non-safety chain, seems like you could just use a 90deg stroke with a standard "square" 1/4" wheel.

thoughts?
b

I dressed the wheel as the Oregon manual recommends, but I don't see why, except for the greater surface area you mention, which shouldn't matter except on really BIG depth gauges. Watching a roadrunner glean cool stuff from my yard as I type...

 

[PA Plumber]

I just learned recently that a flat raker/depth gauge is incorrect. Maybe the angle will allow for the taper needed on the leading edge of the raker.

 

[zemmo]

I just learned recently that a flat raker/depth gauge is incorrect. Maybe the angle will allow for the taper needed on the leading edge of the raker.

The manual suggests dressing the wheel until you're presenting a wheel surface parallel with the chain, so you'd still have to hand taper the rakers...

 

[PA Plumber]

So go through, remove .025 below cutters, then go back through and take off the leading edge? Would be nice to do that in one pass.

 

[hokiebob1]

I suppose in theory you could do as Oregon suggests, then change the angle on the grinder from 60 deg to say 50 or 40 deg.....this should taper the raker like it should be, although the trick would be to get the depth set correctly in the first place.

For that matter, you could take the square 1/4" wheel and angle it to 80 deg or 70 deg and accomplish the same thing--assuming the surface area of the wheel contacts the entire raker to eliminate having to move the chain slightly to finish it up.

 

[tawilson]

Methinks that doing depth gauges is a two step process. Get em down where you want them, then round off the front.

 

[hokiebob1]

I just did a set with the wheel at 80 degs and a square 1/4" wheel--I'll tell you what--they sure turned out perrtty. I think I'll keep doing them that way--I may play with the angle a bit more depending on how far down on the raker you are, but it sure worked well. The key is to keep the leading edge of the raker below the high point.

 

[tawilson]

Gee, seeing as I bought two grinders, I got a 1/4" wheel hanging on a nail doing nothing. Might have to give it a whirl. I'm learnable.

 

[olyman]

tom--actually--its fun with the learning curve on these grinders--we all learn from one another--cool--

 

[Tree Sling'r]

I can set my angles on my raker machine and I have gotton better cutting results with a slight hard angle on the rakers.
Don't know the number, but angle is def. better than flat.