Dull chains...does it really kill saws....how?

[Mattyo]

Redbull, for the 15th time, I'm not arguing that cutting with a dull chain is a good thing, I'm simply trying find the mechanism of saw death DUE TO a dull chain.

 

[Mattyo]

Also, @Redbull661 ... since you do so many comparisons... and are good at graphs and stuff, would you be willing to take the mantle of running a dull chain vs sharp one and checking exhaust temps? ...

 

[jakethesnake]

It's a fun question Mattyo. I think it's a combination of all this stuff.

 

[Redbull661]

Also, @Redbull661 ... since you do so many comparisons... and are good at graphs and stuff, would you be willing to take the mantle of running a dull chain vs sharp one and checking exhaust temps? ...

how dull? like chain on backwards dull ?

if I can get my thermocouple figured out. Then yes, I suppose I could.

 

[Dub11]

how dull? like chain on backwards dull ?

if I can get my thermocouple figured out. Then yes, I suppose I could.

While your at it can you test a flux capacitor to see if you really need to hit 88mph?

 

[angelo c]

I got no scientific data to support my "facts" but here they are anyway:

Most the of the saws I repair are( Stihl) trashed from a tree service that a local buddy runs. when I first started doing their saws I was troubled by the amount of times I was seeing the same saws for rebuilds...My immediate thought was fuel/mix related. So I bought them some measured jugs and taught the foreman to mix ONLY complete cans and ONLY with measured amounts of oil. DO NOT fill a 5 gallon jug unless it is EMPTY and then only with this amount of oil in this CAN ....

Cut down on the rebuilds measurably...but was still getting saws in for rebuilds...

so I spent a few days on the job with them to learn how they actually use them in the field...
was shocked by some of the experienced climbers ability to look like they were "filing" but rarely got the chain "sharp" ...it would cut but not what I could produce with a grinder...and I stink.

so what I surmised after watching the crews is that most saws are damaged before lunch or at the end of the day...chain is dull, guy is late for date, tree is still being bucked up and we gotta push. cant stop to file....gotta get done....push, lean, do whatever ya gotta do to get done....the next day the saw won't start....I don't wonder why anymore.

One time I dropped by a job to pick up some rounds and was shocked by the chips the 460 was NOT spitting out...I went over to the guy and asked him if he had another saw/chain to finish with...I'd file this one in the meantime....the other one was dull too and they did NOT have a raker file ON THE JOB AT ALL ? I had to borrow a rat tail file from the homeowner to get the rakers down enough to finish up....the guys were pissed at me for stopping the job.

so in summary: excessive heat is tough on air cooled machines.

 

[cus_deluxe]

this is literally happening outside my house right now.

 

[cus_deluxe]

good thing its an 028, it cant be killed.

 

[Dub11]

this is literally happening outside my house right now.

So you live next door to WranglerStar?

 

[redtractor]

Get out a heat gun, I will bet $ to donuts that a dull chain will increase the temp at the exhaust port, cause the saw is working harder to pull a dull chain through wood, and that will increase the chance of a heat failure to the piston.

I have to point out that part in bold letters as not right in this instance as a dull chain isn't going through the wood. A sharp chain would grab into the wood and make the engine work harder.

 

[cus_deluxe]

So you live next door to WranglerStar?

haha now thats funny!

 

[cus_deluxe]

so what can we agree on? Longer cut times at higher rpms combined with higher temp due to excessive heat buildup from bar and chain soaking into case, bearings top end etc?

 

[Mattyo]

I have to point out that part in bold letters as not right in this instance as a dull chain isn't going through the wood. A sharp chain would grab into the wood and make the engine work harder.

I'd definitely buy that an engine works harder by pulling a sharp chain through wood... hence the bog. A motor at screaming at high RPM because of a dull chain can't be a good thing likely because the lube can't keep up, nor can the air flow around the fins...hence scoring?

 

[MustangMike]

I have to point out that part in bold letters as not right in this instance as a dull chain isn't going through the wood. A sharp chain would grab into the wood and make the engine work harder.

I will respectfully disagree. Many times they will just dog the saw in harder to make it cut. Adds lots of extra stress.

Admittedly, their may be times when either scenario plays out.

 

[Mattyo]

well, we also have to define saw death.... scored/siezed top end? even J mentioned oil lines that were melted... even though the saw might be still running, doesn't mean its a usable piece without bar lube

 

[cus_deluxe]

i think we should diferrentiate between a chain with depth gauge issues and cutter issues. depth guages to0 high will lead to a screamer. poor cutting tooth and proper depth gauge is whats goin on in my video above. 2 different things goin on

 

[MustangMike]

(Response to Matt)

All of the above! Heat is the enemy, and a dull chain will produce it in many ways.

Fines clogging your filter also has to be a major contributor, which is also why milling is so tough on saws.

 

[danimal]

A saw is normally tuned so it cleans up under load. If the chains dull it never cleans up, so it's basically screaming all day. Boom.

A guy gave me a plastic poulan a couple of years ago, he said it runs fine but it won't cut at all. I'm getting a new one, tired messing with it.

He was right. And it cut fine after I turned the chain the right way round

Like Forrest Gump said.
Ya cant fix stupid. . .

 

[danimal]

While your at it can you test a flux capacitor to see if you really need to hit 88mph?

I BE WANTS TO HOOK ONE UP TO A 288.
FUTURISTIC PORT JOB I BET. . .

 

[Wolverine]

was shocked by some of the experienced climbers ability to look like they were "filing" but rarely got the chain "sharp" ..
so what I surmised after watching the crews is that most saws are damaged before lunch or at the end of the day...chain is dull, guy is late for date, tree is still being bucked up and we gotta push. cant stop to file....gotta get done....push, lean, do whatever ya gotta do to get done....the next day the saw won't start....I don't wonder why anymore.

I think this is probably more common than we'd imagine. I know an arborist and he's pretty much the same. Not real savvy on saws and mechanics, but loves the climb.
I attributed this scoring to the chain that was on the saw when I bought it. I'm sure it was on its way to a worse state. Running a saw with that chain is almost like piss revving down through the cut.