My biggest tree to tackle yet - monster white oak

[Yellowbeard]

Been reading how much grinders cost so I think I figured out this answer...

 

[rarefish383]

Yellowbeard, the one good thing about good students, is they drag the rest of the class along with them. Thanks for the questions, I learned a bit too, Joe.

 

[BobL]

So I guess you were a physics teacher then? What level?

I taught high school for 7 years and then left and did a doctorate. After 7 years in research I taught university level for 23 years.

Also, why not this? http://www.madsens1.com/bnc_teeth_types.htm

Well, as expected Madsens have to make money to stay in business.

Yellowbeard, the one good thing about good students, is they drag the rest of the class along with them. Thanks for the questions, I learned a bit too, Joe.

I forget which Apollo astronaut it was but when some journalist interviewed one of his college teachers, the teacher said the astronaut/student always seemed to ask pretty obvious and easy questions that the teacher knew the astronaut/student already knew the answers to. After a while the teacher realised the astronaut/student was doing that because the teacher had either not really explained the concept etc clearly enough or had maybe gone too fast or whatever.

 

[Yellowbeard]

I taught high school for 7 years and then left and did a doctorate. After 7 years in research I taught university level for 23 years.

Wow. This is my 7th year teaching high school (science and then engineering). I'm currently applying to a PhD program. Now, to be fair, I did several other things (software instructor, communications director for a transportation research center, construction manager, land planner) before I went to teaching but... Wow. Small world. My dad and brother were both physics majors.

Yellowbeard, the one good thing about good students, is they drag the rest of the class along with them. Thanks for the questions, I learned a bit too, Joe.

Wow. Thanks Joe. I consider that a real compliment. I'm still blown away by how much I learned. I talked about this experience today in class with me in the role of student and BobL in the role of teacher. I was discussing what had been motivating me (different than my students, as I had a real problem I wanted solved) and showed how basically BobL had given me homework, then marked some of my answers wrong and then I had finally learned the lesson. So that was worthwhile too.

This is the reason the internet is the world's most powerful tool.

 

[BobL]

Wow. This is my 7th year teaching high school (science and then engineering). I'm currently applying to a PhD program. Now, to be fair, I did several other things (software instructor, communications director for a transportation research center, construction manager, land planner) before I went to teaching but... Wow. Small world. My dad and brother were both physics majors.

Small world indeed.

I was discussing what had been motivating me (different than my students, as I had a real problem I wanted solved) and showed how basically BobL had given me homework, then marked some of my answers wrong and then I had finally learned the lesson. So that was worthwhile too.

Learning from mistakes is critical andI don't think teachers encourage students enough for trying and making a mistake.

 

[Yellowbeard]

I always tell them that I learn far more from my mistakes than from my successes.

 

[Tree Ninja]

I've been working in the tree industry for 14 years and always thought I could sharpen a chain. I realize it's a bit different between cross cutting and milling but this has been a fascinating read for me. Gives me something to aim for when I start milling in the next few weeks. Thanks for the info Bobl and keep up the good work Yellowbeard!

 

[SeMoTony]

The cutters look much better but the rakers do need dropping to at least 6.5º


Shark fin is a good description - not quite sure about the rest but maybe it doesn't matter.

Check these out - this is super nerdy stuff so apologies for those that wanna "just flog a saw and make some noise" .

Just a reminder to others that "raker top angle" is not the same as the "raker angle" -

The "raker angle" is that angle shown in YBs photo below as 5.1º.
The raker angle is formed between lines made by
a) the line starting out at the tip of the cutter and parallel to the bar
and
b) the top of the cutter and the point at which a straight line from there touches the top most part of the raker - this may not be the back of the raker but closer to the front of the raker especially if the raker is flat, by which I mean parallel to the bar.

Note: In YBs photo because the top black line is not parallel to the top of the pink box so the raker angle is less that that indicated.
Before I measure/calculate the angle in photoshop using pixel counts I rotate the image so that the bar is exactly horizontal.
View attachment 531610
OK see the line on the raker marked with the red arrow above, that should the minimum slope of the raker top, and the min angle that raker grinders and files should generate for a basic raker shape.

But many aficionados finesse that even more.
This is Mtngun's raker shape - totally flat but seriously sloped. I'm pretty sure he use a grinder.
View attachment 531613
It's not visible in this photo but he ended up using a lot of hook and a high raker angle (remember this is not the angle on the top of the raker - see above).
The combination of all this was his cutting speed was consistently one of the fastest reported on AS for softwoods back when he was posting.
This will be super grabby so be prepared for more vibe and wear and tear.


Finally this one

The orange line (raker top flat and parallel to the bar) will have the least penetration into the timber - more dust
The green one follows the slope of the guide line marked on some rakers - this should be better but may not be severe enough especially in softwoods.
The brown line is Mntguns and also what another member "Sawchain" used - serious penetration and as said above, be prepared for serious vibe.
I prefer using the blue or red lines and putting more raker angle on as this combo maintains a reasonable cutting speed and does not generate too much vibe.
View attachment 531609



Cheers YB
BTW I have seen very few "horrible" students in my time. Most learning and teaching problems comes from a failure of the teacher and the student to understand where each of them are coming from and where they want to go.

Much gratitude, once again to BobL for so freely sharing in even more/different perspective. Traumatic Brain Injury makes brain function slower & understanding improved by bombardment a bit at a time over a long time to get my thinker attaining sharping get it's for my milling

 

[Dbodave]

wow