Premature bar wear mystery on new MS 661 C-M

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Hmmm. I wasn't aware that the Laws of Physics were a theory.

The Dunning Kreuger Effect is in full force tonight.
Haha...another spin Dr.
I guess when you can't back up your alligator mouth..I guess there's always the ol' deflection.
I made myself clear.
I don't believe anyone is saying expansion & contraction of metals was not proven.
I'm talking about 2 expanding parts and with the bar expanding at a greater rate. The chain is spinning so it's going to cool off some.
The chalkboard theory was them saying the chain will tighten on the crank as it cools.
That's a laugh. it will go slack once all parts cool.
 
Gee, you mean the problems Einstein encountered?

Nothing compared to the average 661 owner.

So at the moment...

A chain could expand if it gets hot.

A bar could expand if it gets hot.

More oil could keep both from getting as hot.

If more oil was applied which of the two would expand less?

Why does the bar need to be replaced?

If the bar needs to be replaced, why not the chain?

If Epstein did not kill himself who did kill himself?

Relatively sure this is all Einstein’s fault. Of course there is no physical evidence of this so it is just a theory.
 
Nothing compared to the average 661 owner.

So at the moment...

A chain could expand if it gets hot.

A bar could expand if it gets hot.

More oil could keep both from getting as hot.

If more oil was applied which of the two would expand less?

Why does the bar need to be replaced?

If the bar needs to be replaced, why not the chain?

If Epstein did not kill himself who did kill himself?

Relatively sure this is all Einstein’s fault. Of course there is no physical evidence of this so it is just a theory.
It is all relative.
 
Man, I’m really curious what you guys that don’t see a chain go slack after cooling down do for a living. It doesn’t even make it into a discussion in any full time sawing environment. It just is. Why they would say the opposite is true is beyond me but I’ve never heard or seen it be anything but what I have witnessed. So believe what you read but run the sh*t out of a saw, lots of oil, little oil, sharp chain, dull chain. The dam chain is going to have some slack when it cools. If you say anything different than I don’t believe you have any real experience. Good grief lol
That's just it, they obviously don't have any experience. F*en rookies!
 
What is Coefficient of Thermal Expansion? How to measure it?


Not meaning to fuel this debate...

Linear expansion is directly related to the original length. That is, a 36” bar will have increased in length by twice as much as an 18” for a given change in temp. Really long bars in big wood get hot. Bars being essentially the same width and thickness see similar increases in those dimensions But, longer bars get disproportionately longer than they do wider or thicker. Chains will dissipate energy via oil, chips and the heat sink of the bar. Bar gets longer than the chain and it runs tight. On bars with inadequate oiling or dull AF, the chain heats up faster than the bar and loosens momentarily. But, that is usually how most homeowners run ‘em. Line up some small wood and lean on it. Sizzling hot, tighten it up. Repeat.
 
What is Coefficient of Thermal Expansion? How to measure it?


Not meaning to fuel this debate...

Linear expansion is directly related to the original length. That is, a 36” bar will have increased in length by twice as much as an 18” for a given change in temp. Really long bars in big wood get hot. Bars being essentially the same width and thickness see similar increases in those dimensions But, longer bars get disproportionately longer than they do wider or thicker. Chains will dissipate energy via oil, chips and the heat sink of the bar. Bar gets longer than the chain and it runs tight. On bars with inadequate oiling or dull AF, the chain heats up faster than the bar and loosens momentarily. But, that is usually how most homeowners run ‘em. Line up some small wood and lean on it. Sizzling hot, tighten it up. Repeat.
I'll let you guys in on a few little secrets, this little thing called linear expansion is caused by temperature, the chain is a little over twice the length of the bar , so it will expand twice the distance the bar will at the same temperature, the chain produces the heat from friction on the bar , the pins & cutting edges, the bar body can never get hotter than the chain, the two are in constant contact, it absorbs heat from the chain friction. Some of you chaps are claiming the opposite happens, I'd like to know how that is possible?

Also if someone hadn't sharpened a new chainsaw after a couple of days of use, I'd expect it to start cutting around corners.
 
Man, I’m really curious what you guys that don’t see a chain go slack after cooling down do for a living. It doesn’t even make it into a discussion in any full time sawing environment. It just is. Why they would say the opposite is true is beyond me but I’ve never heard or seen it be anything but what I have witnessed. So believe what you read but run the sh*t out of a saw, lots of oil, little oil, sharp chain, dull chain. The dam chain is going to have some slack when it cools. If you say anything different than I don’t believe you have any real experience. Good grief lol

What do I do for a living? For the last 38 years I’ve cut and forwarded saw logs and pulp. Don’t believe me? R.I. woods operator # 21-31, arborist lic # 403, Ct supervising harvester lic # 001052. Unlike you I don’t hide behind a screen name and sling BS as sport.
 
What is Coefficient of Thermal Expansion? How to measure it?


Not meaning to fuel this debate...

Linear expansion is directly related to the original length. That is, a 36” bar will have increased in length by twice as much as an 18” for a given change in temp. Really long bars in big wood get hot. Bars being essentially the same width and thickness see similar increases in those dimensions But, longer bars get disproportionately longer than they do wider or thicker. Chains will dissipate energy via oil, chips and the heat sink of the bar. Bar gets longer than the chain and it runs tight. On bars with inadequate oiling or dull AF, the chain heats up faster than the bar and loosens momentarily. But, that is usually how most homeowners run ‘em. Line up some small wood and lean on it. Sizzling hot, tighten it up. Repeat.
When properly operated the bar gets no hotter than the chain and often is cooler . The rail isn’t the whole bar. The whole bar would have to get hotter than the chain and that doesn’t happen. Put your hand on the center of the bar and you’ll find it’s much cooler than the rail. Without the bar center being hot your example isn’t applicable.
 
The chain is a little over twice the length of the bar , so it will expand twice the distance the bar will at the same temperature,
the bar body can never get hotter than the chain, Some of you chaps are claiming the opposite happens, I'd like to know how that is possible?
I chopped out the obvious and as well, the condescending nonsense.

Firstly: I offered a possible explanation as to why...
I am not "claiming" as you said. Personally, I don't NEED to know why. That's really not the focus of my first post.

Secondly: They are different metals with different shapes and functions.
Ones in motion, ones stationary.
Would every 50mm piston tested in the same saw, heat transfer equally providing all else was the same besides the piston?
No! Most you could run until the rest of the saw has 'had it' and some I could melt in one good sized tree.
Fact.
 
Keep it up guys, this is WAY better than the boring oil threads. I'm going to get out my propane torch and start heating up some bars and chains, guess the chains will have to be spinning or results will be questionable. I've always thought the "loosen chain or bend crank" thing was a lot of hooey.
 
The last thing I did yesterday was spend 1/2 an hour cutting and bucking a dead white oak in the landing, then I trimmed the log pile. Without any adjustment my chain is at least as tight, if not tighter this morning than when my saw went in the truck box yesterday afternoon. when was the bar and chain hotter, when I put the saw away or this morning?
 
Anyhoo. It does not look as though the side plates are resting on the bar rails on the top of the bar in the photos. Might be crap in the groove, I suppose it could be hammered out already.

It does look like the side plates have taken a beating.

The wear pattern on the bar looks typical from running a dull chain with very little oil.

If the groove on the bar is no longer deep enough to provide clearance, replace it. If it is deep enough grind the rails, hammer them tighter if needed and get back to work.

If you are running carbide chain on the 026, get some for the 661. Otherwise sharpen the chain as soon as its performance drops off.

Do the Oiler mod.
 
Do the Oiler mod.
It ain’t a mod. You push in a factory installed limiting pin so you can get full travel out of the adjustment.

The owners manual instructs you to for more oiling. He’s questioning his oil flow test and only has the Oiler turned up half way, if that.
 
We got metal expanding when it’s cold, oilers that aren’t outputting enough but only turned up halfway, chains tensioned properly with drive links almost completely out of the bar groove, recommendations for carbide chain to buck up a blowdown, pistons melting down as comparisons, train track pictures.

What a **** show. Lmao!
 
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