Measure Hook Angle

[WolfMann]

How do you guys measure the hook angle on your chains? I'm looking for a tool like in the pic below (not sure what it's called), but also thinking I could just print a small protractor, put it on cardboard and use that. Wanted to see what you guys are doing?Thanks in advance.

 

[Philbert]

Some angles are hard to measure accurately, without precision machinists' tools. Also, remember that most guide bars are curved, not flat, so you need some type of frame of reference.

If you mount the chain into a chain grinder, and adjust the head tilt to match the slope/hook angle, you can read an approximate value off of the angle scale on the grinder.

Philbert

 

[WolfMann]

Thank you Philbert, don't have a grinder yet, I do have a Granberg 106b. That's a good point about the curve on the bar. I'll be sure to remember that.

 

[HarleyT]

In the screenshot, can someone explain what we are looking at?
And what/where it is trying to measure?

 

[HarleyT]

I mean, this chain is a mess. And it is not apparent what this gauge is measuring.

 

[HarleyT]

Looks like a chain hand sharpened by someone that doesn't know what he is doing.

 

[Mad Professor]

Eye use my eyeballs and fingers.

I freehand filed for 10 years before I used any sort of holder. I don't think the holder makes my chains sharper, just makes me being less of a craftsman.

 

[HarleyT]

Holder?

 

[WolfMann]

HarleyT, the screenshot came from Will Malloff's book Chainsaw Lumbermaking, it's a modified ripping chain for cutting with the grain.

 

[HarleyT]

Well the angles/hook/ etc of the right/left cutters shown, tells us that the guy that sharpened that chain did chitty work.

 

[WolfMann]

What he's done is take a full comp, round ground chisel chain, file it straight across at 0° and lowered hook angle to 50°-45° (grinder vs hand file). I don't know if you've done much alaskan milling but this guy wrote the book on it.

 

[HarleyT]

It had to be a "before" pic!!!

 

[WolfMann]

It's a ripping chain, not for cross-cutting.

 

[HarleyT]

So the next cutter has a different top plate angle, and no hook? Is that how they sharpen their chains up there?
Cut around corners?

 

[HarleyT]

Or is this a pic of a chain that is "halfway" done?

 

[HarleyT]

Or is this a pic of a chain that is "halfway" done?

That is more likely.....

I am guessing....

 

[WolfMann]

I would reckon he modified that first cutter, then someone took a pic with the protractor plate to emphasize the point of lowering the hook angle, but I don't know for sure, I wasn't there when they wrote the book.

 

[HarleyT]

Shouldn't the angles on each side be somewhat close?

 

[HarleyT]

Lol. Just asking.....

 

[WolfMann]

Heres some more pictures.