Do chains stretch???

[Philbert]

On a longer bar, you might have enough range of adjustment to start with a slightly smaller chain loop, so that you can compensate for stretch. On smaller saws this is not always the case.

I have an Echo that takes 57 drive links and will absolutely not accept a new 56 DL chain. But I am told that it may accept a 'stretched' 56 link chain. Of course, an outboard clutch makes fitting a tight chain more difficult compared to an inboard clutch.

Philbert

 

[Hddnis]

The biggest problem with chain stretching, is a dull chain and the heat that builds up, taking the temper out and heat will make them stretch. Bar wear and chain wear will also make the chain get loose, along with sprocket wear. Adjusting the chain too tight will make them stretch and not enough bar oil or the wrong bar oil.
Proper adjustment, the rite oil, and stopping when the chain gets dull will go a long way in the life of a chain.
Also filling the rake’s to the proper depth will help.
It’s a constant maintenance on a saw chain that will produce the best results.

Keep them sharp, and the rake’s at the rite depth and lots of good oil will help the most.

If your chain gets hot enough to lose it's temper you could be lighting your wood on fire.:msp_scared:

As a rule of thumb steel won't be failing under design loads till 650°f. The alloy used in chains is far more heat resistant than that, I don't know the specific temps due to not knowing the alloy, but saw chain would not see heat related failure till the vicinity of 1000+°f

Do chains ever get that hot?

Sadly yes, far too often in fact. I've seen pros pull their saw out of a stump and the paint was buring off the bar, the oil was smoking off the chain, and the sprocket tip was flaming. "Hard working" guys seem to be the worst at it, they like to get things done and they lose sight of taking care of machines. Constant maintenance is very true.

Imagine how much heat a really hot chain transfers to the saw powerhead, you can kill a saw from chain heat. Of course any conditions that are hard on a chain are also hard on the powerhead, running for long periods under heavy load is just a saw killer.

If a chain ever gets smoking hot I believe it should be thrown away. My experience is that it will be nothing but a problem after that.

Mr. HE

 

[Kevin in Ohio]

Imagine how much heat a really hot chain transfers to the saw powerhead, you can kill a saw from chain heat. Of course any conditions that are hard on a chain are also hard on the powerhead, running for long periods under heavy load is just a saw killer.

Mr. HE

Imagine how much heat would be transferred to the powerhead if a saw was having gas/oil mixture ignited thousands of times a minute. Whoops.

 

[Hddnis]

Imagine how much heat would be transferred to the powerhead if a saw was having gas/oil mixture ignited thousands of times a minute. Whoops.

Very true, but the saw is designed to deal with that heat. A saw is not designed to have a smoking hot chain under the clutch cover. Whoops.


Mr. HE

 

[Philbert]

These must be the 'hot saws' I hear people talkin' about!

(Of course, this one does have very good chip flow around the sprocket!)

Philbert

 

[Hddnis]

That is ugly!:msp_scared:

Run with the brake on?

Cutters look kind of rounded, but that may just be the pic. I'm guessing the heat was not chain induced because the bar doesn't look like it got hot enough.

What did the internals look like? Oiler? Clutch side seal? Clutch side bearing? Just curious.:msp_biggrin:



Mr. HE

 

[Kevin in Ohio]

Very true, but the saw is designed to deal with that heat. A saw is not designed to have a smoking hot chain under the clutch cover. Whoops.


Mr. HE

In all seriousness, When your chain has a 1/2" stretch in 1 ft of chain it is ready for the scrap pile. That info comes direct from the Oregon Rep at a class my Dad went to.

Over the years when working on others saws you see a lot of, shall we say, interesting things. You tend to make the mistake of assuming someone has common sense on why things are happening. Like when a guy wanted his new chain replaced because it wouldn't cut like the old one. I looked at it and asked if he wanted me to install his chain this time since he had it on backwards.

 

[Hddnis]

In all seriousness, When your chain has a 1/2" stretch in 1 ft of chain it is ready for the scrap pile. That info comes direct from the Oregon Rep at a class my Dad went to.

Over the years when working on others saws you see a lot of, shall we say, interesting things. You tend to make the mistake of assuming someone has common sense on why things are happening. Like when a guy wanted his new chain replaced because it wouldn't cut like the old one. I looked at it and asked if he wanted me to install his chain this time since he had it on backwards.

Yep!

I subbed out a big tree removal job to a friend of mine, he used a lot of non-english speaking labor.

I watched his crews:

1. Light the debris around a ceder stump on fire by overheating the chain, this just feet away from the building and then they ignored it. I stomped that out and then ran the sprinklers later that night.
2. Run the bar into a big rock next to another stump, not move the rock, and then try to keep cutting the stump with the same saw and chain, again it got smoking hot.
3. Put chains on backwards.
4. Fill saw with fuel a few times, but not bar oil.
5. Use steel shovels and pitchforks to push brush into the chipper.
6. When told not to do above, they climbed into the infeed chute and used their legs to push the brush! :msp_scared: That earned a stop work order from me. I'll let 'em wreck equipment, but I was not going to watch a guy go legs first through the chipper!

This was during the building boom. Labor was hard to come by and anyone with any skill at all had his own company. I talked to my friend and he tried to keep a closer eye on them, but he was running a big stump grinder elsewhere on the job. We both made money of course, even though I hadn't planned to be there the whole time, but I told him to get a better crew before I sent more work his way. He did and I continued to hire him for jobs large and small. In fact, with a bit of effort he had some top notch guys that really could get some good work done fast.

Anyway, just one example that came to mind of a day where common sense was nowhere to be found. I kept waking up that night with nightmares of the building catching fire or the chipper eating someone.



Mr. HE

 

[jthornton]

I swapped chains on my little Stihl 021 once and lent it to my neighbor... he was back in 30 minutes. I asked him if he was done? He said no, your saw don't cut worth a crap! I'm going to town and get a new chain for mine. A few days later I went to use my saw and dang right off the bat I saw that I had put the chain on backwards...

John

 

[blades]

Backwards chain - happens to everyone sometime, and usually not just once in a lifetime either.

 

[haveawoody]

Got to admit i have put a chain on backwards more than once.
Long days cutting make for speedy chain changes so i bet it has happened to most of us.

 

[sb47]

If your chain gets hot enough to lose it's temper you could be lighting your wood on fire.:msp_scared:

As a rule of thumb steel won't be failing under design loads till 650°f. The alloy used in chains is far more heat resistant than that, I don't know the specific temps due to not knowing the alloy, but saw chain would not see heat related failure till the vicinity of 1000+°f

Do chains ever get that hot?

Sadly yes, far too often in fact. I've seen pros pull their saw out of a stump and the paint was buring off the bar, the oil was smoking off the chain, and the sprocket tip was flaming. "Hard working" guys seem to be the worst at it, they like to get things done and they lose sight of taking care of machines. Constant maintenance is very true.

Imagine how much heat a really hot chain transfers to the saw powerhead, you can kill a saw from chain heat. Of course any conditions that are hard on a chain are also hard on the powerhead, running for long periods under heavy load is just a saw killer.

If a chain ever gets smoking hot I believe it should be thrown away. My experience is that it will be nothing but a problem after that.

Mr. HE

I’m not sure what parts of a chain saw chain is tempered and what is not, maybe every part is tempered, I don’t know.
When I was a newbie and didn’t know better I would run a chain till it got hot enough to smoke the oil that was on it. And they never stayed sharp after that. They would dull in minutes after being so hot and re sharpened.

Now that I have been cutting foe some 20 years, I have learned a lot of things; some were learned the hard way and some I’ve learned from other people.

I can now run a chain till the teeth are worn down so much they start to break off before I run out of adjustment.

If I have to put any pressure at all on the saw for it to cut, its time to stop for a sharpening.
The saw should pull itself through the wood with no pressure at all.

Most people over look the rakes and never check to see if there set rite.
The rakes determine how much wood is cut, so there very important to keep at the rite depth.

Keep them sharp and the rakes set properly, the rite tension on the chain and you should have no problem.

 

[Philbert]

That is ugly! . . What did the internals look like? Oiler? Clutch side seal? Clutch side bearing? Just curious.

I should have clarified - this was not my saw. I think that I picked the photo up here on A.S. some time back.

But I would love to see the Craig's List ad: 'light darkening of the plastic, but mostly cosmetic . . . '

Philbert

 

[GVS]

FoxFire mentioned your Drive Sprocket. It will wear grooves in the Spurs, and the chain becomes loose.
View attachment 278586

That image presents the perfect case for rim drive!

 

[sb47]

That image presents the perfect case for rim drive!

It also wears the chain drive links Themsleves as well as the sprocket.

 

[Tree Feller]

I did to . But why doe.s the chain has to be loose when cold ?

So when it shinks when it cools down it don't put pressure on the sproket and bearings!

 

[sb47]

If I can see my chain is loose when I stop and there plenty of slack in the chain, then it will be fine when it cools down.
But if its tight then I’ll loosen the bar nuts and that usually puts enough slack in the chain so when it cools down, there no pressure on the drive sprocket.
I’ve never seen damage to the drive line due to excessive pressure form a tight chain, but I suppose it could happen.

 

[bentring]

I swapped chains on my little Stihl 021 once and lent it to my neighbor... he was back in 30 minutes. I asked him if he was done? He said no, your saw don't cut worth a crap! I'm going to town and get a new chain for mine. A few days later I went to use my saw and dang right off the bat I saw that I had put the chain on backwards...

John

That was just your subconscious not wanting him to use your saw.

 

[Arbonaut]

Count the drive links. You might go up to the next size sproket, take up the slack and increase your saw's performance.