Chatter in dry hard eucalyptus (Oz wood thread)

[rogue60]

What top plate angle are you running? back it off to 25-20 degrees on chisel if it's really hard timber.
What chain are you running just Oregon? It's too soft of a chain in my experience get Stihl chain it holds an edge way longer.
Cleaning out the gullet as you have in above pics don't do it the timber is too hard to be packing with chips. Not doing it makes the chain smoother cutting in hard hardwood in my experience.
Do you own any saws with balls and not just revs and chain speed if so run Stihl .404 and 7pin. 3/8 is fine it just dulls faster.
Chisel is very good in clean wood semi chisel if timber is contaminated with dirt/ sand. Oh I will add If running RS give the file 10 down.
And regardless of what the internet says round filed is more than adequate.

 

[Wilhelm]

Host a GTG and enjoy watching others trashing their chains while demolishing Your logs!

 

[rogue60]

 

[Benwa]

A slower moving chain has more time to take and keep a bite in hard wood.
A fast moving chain will "slip" over the grain rather than take a proper bite.
A slow chain will pull a continuous wood chip in hardwoods, a fast chain will chatter resulting in an interrupted cutting performance.

I mostly buck turkey oak, it is a dense and hard wood species - I prefer a moderate chain speed.
Even in hardwoods I prefer full chisel chains.

For comparison, beech is butter soft compared to turkey oak.

Take a butchers knife and smash it continuously into a bunch of meat, it will take a long time to get dull.
Take the same butchers knife and smash it into an aluminum block, it will dull noticeably faster.

Both the meat and the aluminum are softer than steel, but they'll dull the steel at a different pace.

The difference in hardness and density of different wood species will result in unequal chain dulling.

Well, that's my theory regarding this particular topic!
I may be looking at it the wrong way, but I am fairly certain that I am not.

Cheers

Okay I think we are missing each other a little bit. I follow you in regards to a slower chain taking a full bite and producing a smoother cut in hardwoods. I can understand why you would much prefer the slower chain speed and smooth/ good cutting performance over poor. I also completely understand that for a given wood hardness/species/condition, one will dull a chain faster than another. I agree with you absolutely 100% on these statements.

The question at hand is "does faster chain speed dull a chain faster"........ the response, by more than a few people I gather, is that yes it does. So, my question is, why? Other than the fact that the cutter is hitting the wood more times in a given amount of time over a slower chain speed, is there another reason it dulls faster? Do the forces caused by the chattering chain skipping over the wood, effect the leading edge of the cutters differently, resulting in a chain that dulls faster?........... If this is the case, can a chain not be sharpened in a manner that it can be run at a faster chain speed AND pull a full chip in hard wood? Therefore not chattering, resulting in a cutter that dulls, at or close to the same rate as a slower chain? Other than the obvious fact that a cutter is in the wood more times in a given time frame with a faster chain speed, I can't wrap my head around why faster chain speed ITSELF would dull a chain quicker. I'm hoping someone can enlighten me. Now, if it IS the chatter that dulls the cutter faster, I would think that filing styles/preferences would come into play. Then again, maybe it doesn't matter what way you file it. A faster chain speed will always chatter in hardwoods no matter how its filed, therefor dulling a chain faster. I honestly have no idea, but it intrigues me and there has to be an explanation out there somewhere. If not, well, maybe it's one of those things that "just is." In which case, I digress. I also have a screwy brain and maybe I'm just reading way too far into this question. It's been known to happen a time or two

 

[rogue60]

I don't have anything to add as far as does faster chain speed dull a chain faster in hardwood probably ?
For me high chain speed in hardwood is not my pick for setup it's hard on gear in long term work type scenario.
Take .404 it takes more power to pull it the harder the timber gets I've tried 8 pin a few times yeah no thanks a stock 661 feels about maxed out running 25inch bar 7pin .404 in some of the hard hardwoods with 8pin the saw is getting hot over working instantly stalling the chain if you don't feather it lightly would smoke the clutch in no time.
Vibration and chattering is just part of cutting hard hardwoods sometimes. You get a lot of feed back as to what your chain is doing then going back to softer hardwood everything is back to nice and smooth.
Generally speaking it's best to cut Aussie hardwoods green the drier they get the harder they get but this doesn't mean you can't cut it it's just harder on gear the drier it gets.

 

[Wilhelm]

Why does sap bake onto a chain?
Heat!

The chains cutters leading edge will generate the most heat, ergo the leading edge will dull faster due to heat build up.
The higher the chain speed, the more heat is generated.

Lets be honest, it doesn't take much for a chain sharpened to specs to stop self feeding.
Just because the chain still cuts while being forced through the log utilizing humongous bucking spikes doesn't make it a sharp chain.

On a drill press I can feed a sharp drill bit fast with next to no force, but I can also feed the same DULL drill bit in the same material "fast" utilizing a 20+" pipe on the drill press's lever.
While at drill bits, slow rpm's will feel slower feeding but keep the drill bits edge sharp longer and the generated chips thicker, higher rpm's will feel like feeding faster FOR A WHILE but quickly fry the drill bits leading edge and generate dust.

In dry hard eucalyptus I'd want a full chisel chain on an old school slow rpm chainsaw - 090G for example.

I must point out that I have never encountered eucalyptus, but I work with hard metal on a daily basis - the physics are the same and one can't go against physics.

 

[Maintenance Chief]

Why does sap bake onto a chain?
Heat!

The chains cutters leading edge will generate the most heat, ergo the leading edge will dull faster due to heat build up.
The higher the chain speed, the more heat is generated.

Lets be honest, it doesn't take much for a chain sharpened to specs to stop self feeding.
Just because the chain still cuts while being forced through the log utilizing humongous bucking spikes doesn't make it a sharp chain.

On a drill press I can feed a sharp drill bit fast with next to no force, but I can also feed the same DULL drill bit in the same material "fast" utilizing a 20+" pipe on the drill press's lever.
While at drill bits, slow rpm's will feel slower feeding but keep the drill bits edge sharp longer and the generated chips thicker, higher rpm's will feel like feeding faster FOR A WHILE but quickly fry the drill bits leading edge and generate dust.

In dry hard eucalyptus I'd want a full chisel chain on an old school slow rpm chainsaw - 090G for example.

I must point out that I have never encountered eucalyptus, but I work with hard metal on a daily basis - the physics are the same and one can't go against physics.

That makes sense to me, after all a thermostat is installed in a engine to slow the coolant down so the radiator has time to cool it.
Theoretically a slower chain speed would give the cutting edge more time to cool between friction generated heat.
The solution would be a tiny fan (in the clutch cover) or cool oil mist on spray on the chain to keep it from tempering. Haha that would be fun to keep clean!

 

[Wilhelm]

Oregon had (maybe still has) a water soluble emulsifying B&C oil advertising it as featuring superior cooling of the bar and chain.
This makes sense, evaporating water equals heat transfer.
By the time mineral oil evaporates the B&C are already burning hot.

 

[Wonkydonkey]

Wow three good poasts in a row.


I totally agree , but that’s not that I have any experience in Aussie hardwoods.
The faster the chain In the wood the more heat is generated and the more chatter there is as the tooth dolphins shallower through the wood.
., as Wilhelm says the same with metal, heat will dull the cutting edge. And I know that’s why they use cutting fluids to keep it cool, the tool as well as the material being cut (work hardening).

you could change the cutting edge so it would not dull as quick and cut a bit slower. (We know this by changing the top plate angle from 30 or 35 to 25 depending on soft or hard wood being cut) but we can’t really change the tooth cutter angle, other than the size of the file used or holding it higher/lower. Unless you use a grinder

So as wilhelm says, speed is the key thing and we find hard to know And how do we try to keep consistently slower

Also rogue60 says changing the rim to an 8 don’t work, I’m wondering if we could get a 6 pin rim to try an even lower speed chain with even more torque, like the older saws.
I know of 6 pins for the smaller homeowner saws but not the bigger saws.


We also know full chisel is fast at first but the semi chisel is faster in the long run (In some woods)
So it’s really panning out as slower is better and keep the chips big.

oh and one last thing, this reminds me of the rabbit and tortoise race story.

 

[davidwyby]

I’m wondering if this is a good excuse to get a 3120... @Flying_Dutchman


I wonder if chatter dulls because the harder wood grabs and rocks the cutter link harder and the wood pulls across the cutter vs. being cut? Hard to explain.

If you watch high speed video of machining chatter, you can see how it would dull things...

 

[Wilhelm]

I’m wondering if this is a good excuse to get a 3120...


I wonder if chatter dulls because the harder wood grabs and rocks the cutter link harder and the wood pulls across the cutter vs. being cut? Hard to explain.

If you watch high speed video of machining chatter, you can see how it would dull things...

3120 is fairly modern and can probably still be considered a fast saw.

Chatter is impact, the cutters get hammered and the entire chain gets shock loaded.

I don't think there are large spline 6 tooth sprockets, the spline size can't fit 6 3/8" teeth.

 

[Wilhelm]

Get a cheap generic china made chainsaw, they tend to run 8000rpm max no load - that would indicate they'd run 5-6k under load.
The 52cc ones also often sport a 6 tooth sprocket.

Alternatively, tune one of Your stock saws rich to decrease in cut rpm's.

 

[walkdog]

The couple experiences I’ve had cutting dry Eucalyptus have been so demoralizing that I pretty much refuse to touch it :/

Recently turned down some red ironbark logs, which make for some of my favorite timber on earth, because the resins were starting to solidify after less than 6 months of being down. Logs also hadn’t been sealed, and were starting to check badly, but that wouldn’t have stopped me if they hadn’t started to go rock solid.

You’re definitely going to see more chatter with the tip of the bar buried. I wonder if you might be able get some mileage out of having an assistant dump bar oil into the kerf as you are grinding through that stuff?

Also, while I know it doesn’t look cool and can feel cumbersome, I strongly recommend that you consider donning a proper respirator or at least a N95 mask while cutting that stuff. Cumulative exposure to fine particulate/VOC clouds is no joke.

 

[Wilhelm]

Now I want a go at eucalyptus!

The hardest wood species I ever encountered is cornelian cherry.
Fun stuff, tasty fruit.
I have two small ax handles made out of it.

 

[davidwyby]

This guy has fun with it too.

 

[huskyboy]

I don't have anything to add as far as does faster chain speed dull a chain faster in hardwood probably ?
For me high chain speed in hardwood is not my pick for setup it's hard on gear in long term work type scenario.
Take .404 it takes more power to pull it the harder the timber gets I've tried 8 pin a few times yeah no thanks a stock 661 feels about maxed out running 25inch bar 7pin .404 in some of the hard hardwoods with 8pin the saw is getting hot over working instantly stalling the chain if you don't feather it lightly would smoke the clutch in no time.
Vibration and chattering is just part of cutting hard hardwoods sometimes. You get a lot of feed back as to what your chain is doing then going back to softer hardwood everything is back to nice and smooth.
Generally speaking it's best to cut Aussie hardwoods green the drier they get the harder they get but this doesn't mean you can't cut it it's just harder on gear the drier it gets.

Careful there. You might offend some people videoing there hot rods showing a tach reading 13,000 rpm self feeding in the wood cutting soft pine/poplar. Lol

 

[Benwa]

Why does sap bake onto a chain?
Heat!

The chains cutters leading edge will generate the most heat, ergo the leading edge will dull faster due to heat build up.
The higher the chain speed, the more heat is generated.

Lets be honest, it doesn't take much for a chain sharpened to specs to stop self feeding.
Just because the chain still cuts while being forced through the log utilizing humongous bucking spikes doesn't make it a sharp chain.

On a drill press I can feed a sharp drill bit fast with next to no force, but I can also feed the same DULL drill bit in the same material "fast" utilizing a 20+" pipe on the drill press's lever.
While at drill bits, slow rpm's will feel slower feeding but keep the drill bits edge sharp longer and the generated chips thicker, higher rpm's will feel like feeding faster FOR A WHILE but quickly fry the drill bits leading edge and generate dust.

In dry hard eucalyptus I'd want a full chisel chain on an old school slow rpm chainsaw - 090G for example.

I must point out that I have never encountered eucalyptus, but I work with hard metal on a daily basis - the physics are the same and one can't go against physics.

Thank you boys for all the awesome feedback! That was my first thought in the original post

"I'm truly interested in reasoning/logic behind it, &/or why it would dull quicker at a faster speed............ heat?.......... or the pure fact that at a higher speed it's chewing through MORE wood in a given amount of time?.......Thanks for any input guys."

I'm thankful for the time all you guys took to elaborate on this matter for me. It is truly appreciated! I can calm my brain now haha. I'm always down to learn new things, thanks for being willing to contribute!

 

[Benwa]

Oregon had (maybe still has) a water soluble emulsifying B&C oil advertising it as featuring superior cooling of the bar and chain.
This makes sense, evaporating water equals heat transfer.
By the time mineral oil evaporates the B&C are already burning hot.

@davidwyby is this what you've been looking for?!

 

[davidwyby]

@rogue60 nice! Thanks!

I will be running my 395...maybe a 3120.

 

[rogue60]

@rogue60 nice! Thanks!

I will be running my 395...maybe a 3120.

The 395 should be plenty enough saw I wouldn't bother with a 3120 myself unless you plan on running longer bars in .404 or milling.