Loose Chain

[psc1947]

Did the Bar move?
30 yrs in industrial maint: = "It's usually the simplest thing."
Set the saw up, Scribe at the bar cover,
If the chain gets loose and the mark doesn't move, that's one thing eliminated.
Still could be a bar problem but it's not because the bar's moving.
If the top part of the scribe disappears The bar was sagging when it was tightened.

 

[Czed]

Check for wear on the sprocket and bar rails sometimes they'll pinch
I flip my saw upside down and adjust the chain.

 

[TheJollyLogger]

Chains stretch... scribing the bar is worthless

 

[psc1947]

Chains stretch... scribing the bar is worthless

It is worth knowing if your bar has actually moved.

I has a Husky brought to me with chronic loose chain problems.
By using a scribe I pinned it down to the bar.

The problem was that the chain was chronically loose, not because it had stretched but because the Husky tooless adjuster would not hold even if you took a pair of Channel Locks to it. Two flare nuts fixed the problem, worthless scribbing "identified" the problem.

When you have a problem with a saw it is because something has changed. We need to know what changed and why.
If doing something worthless identifies the problem then it isn't worthless.

 

[The Shooters Apprentice]

Did the Bar move?
30 yrs in industrial maint: = "It's usually the simplest thing."
Set the saw up, Scribe at the bar cover,
If the chain gets loose and the mark doesn't move, that's one thing eliminated.
Still could be a bar problem but it's not because the bar's moving.
If the top part of the scribe disappears The bar was sagging when it was tightened.

generally if the bar sags the chain gets tighter, and if the bar is lifted the chain gets looser which is why you lift up on the bar when tightening the chain before snugging up the bar nuts.

 

[psc1947]

Did you miss this part of my starting post?
"If the top part of the scribe disappears The bar was sagging when it was tightened?"

If the bar is lifted from downward pressure during use this often functionally rotates the bar upward counter clockwise and changes the position of the bar up to the position is should have been in during tightening.
If the scribbed line was very tight against the cover then the movement of the bar will rotate and the part the scribbed line at the top will move toward the side cover while the scribbed line between the cover and the lower part of the bar will move and leave a gap.

Of course yu are right in that "if the bar is lifted the chain gets looser." Whch is why I pointed out the sagging bar---"If the top part of the scribe disappears The bar was sagging when it was tightened."

 

[sean donato]

Can't believe you needed to make a scribe mark to figure it out. The tool less tensioner are widely know for being junky. Change out to a standard cover (if possible) and move on with lift.