Bar's sprocket is freezing

[Husky77]

I was given a saw to look at, owner said chain wouldnt turn. Couldnt believe how tight the bar nose sprocket was. I said what you been cutting, hardwood blocks for firewood..... with a dull chain. It was so clogged with fine dust its a wonder the saw didnt blow up. After ten mins cleaning spraying and trying to get the sprocket to move I won. But never had a bar like it before or since, people just abuse tools

 

[coffeebrk]

I've purchased 2 bars since this thread started.

 

[pioneerguy600]

Bars last way more than a few chains.

You bet, I have original bars here that came on my 1957 Pioneer 600, it never seen bar oil as back then there was none at least where live, we used new crankcase oil W30 came in one quart cans and cost 36 cents a quart. Never used it in our automobile engines but it made good bar oil, the old bars had over 10 chains run through them , still in fine shape.

 

[lone wolf]

They probably do, mine normally go after user error - chipped or bent.

Stihl bars?

 

[Mad Professor]

If people cleaned the grooves and oiling holes in the bars regularly, and dressed the rails once in a while bars would last a lot longer too.

I've never had a tip go on a stihl bar, but have got them bound up with wood. Usually just running a chain against a stump by hand frees up that.

 

[stihltech]

1 bar will seem to last forever, 1will set the nose up quickly. That bar needs to be replaced. The aggravation will be put to better use in wood production.

 

[muddy42]

Stihl bars?

mostly stihl bars, yes.

 

[lone wolf]

mostly stihl bars, yes.

They usually hold up great, what are you doing pinching them at the base cut?

 

[SteveSr]

Keep in mind that it takes a while for the bar oil to get from the pump to the nose sprocket. The saw has to fill up the all of the oil passageways and the top bar slot before the drive links drag the oil to the nose. This applies for a NEW bar or one that you have just "cleaned" with WD40 or some other cleaner/solvent.

I burned up the nose sprocket of a BRAND NEW 20" Stihl bar because I didn't wait long enough for oil to get to the nose sprocket. Shame on Stihl for not putting any lube in there from the factory. Expensive lesson learned.

I did manage to replace the sprocket and bearings but it was difficult without a chain breaker.

https://www.arboristsite.com/thread...ip-sprocket-in-a-stihl-rollomatic-bar.368071/

 

[buzz sawyer]

Keep in mind that it takes a while for the bar oil to get from the pump to the nose sprocket. The saw has to fill up the all of the oil passageways and the top bar slot before the drive links drag the oil to the nose. This applies for a NEW bar or one that you have just "cleaned" with WD40 or some other cleaner/solvent.

I burned up the nose sprocket of a BRAND NEW 20" Stihl bar because I didn't wait long enough for oil to get to the nose sprocket. Shame on Stihl for not putting any lube in there from the factory. Expensive lesson learned.

I did manage to replace the sprocket and bearings but it was difficult without a chain breaker.

https://www.arboristsite.com/thread...ip-sprocket-in-a-stihl-rollomatic-bar.368071/

I never realized the top slot was "filled" with oil, I thought the drive links carried the oil to the nose rather quickly, assuming correct bar oil with tackifier is used.

 

[Mad Professor]

Keep in mind that it takes a while for the bar oil to get from the pump to the nose sprocket. The saw has to fill up the all of the oil passageways and the top bar slot before the drive links drag the oil to the nose. This applies for a NEW bar or one that you have just "cleaned" with WD40 or some other cleaner/solvent.

I burned up the nose sprocket of a BRAND NEW 20" Stihl bar because I didn't wait long enough for oil to get to the nose sprocket. Shame on Stihl for not putting any lube in there from the factory. Expensive lesson learned.

I did manage to replace the sprocket and bearings but it was difficult without a chain breaker.

https://www.arboristsite.com/thread...ip-sprocket-in-a-stihl-rollomatic-bar.368071/

Shame on you for not warming up your saws.

 

[SteveSr]

I never realized the top slot was "filled" with oil, I thought the drive links carried the oil to the nose rather quickly, assuming correct bar oil with tackifier is used.

Maybe "filled" was a bad word. However oiling is not instantaneous. The bar groove is significantly deeper than the drive links are long so it may be a while before the DL pick up oil. Also most of that oil may get flung off the nose as the chain circles around it and not soak in to the sprocket bearing. Once there is oil in the bar groove whatever doesn't get picked up by the DL is free to soak into the sprocket bearings.

 

[Chainsaw Pete]

From this discussion, @SteveSr, @Mad Professor, @buzz sawyer, it sounds like I should dip the tip of my new bar in barnchain oil first, then put the chain on. And maybe dribble some oil in the top slot - though that will probably flow out since the chain is not going into immediate service.

I wonder about just dipping the whole tip of the bar/chain in a cup of new motor oil the first time I use it. Bar and chain oil is pretty sticky and doesn't flow that well. Motor oil will flow into the sprocket's bearings and be displaced the first time the saw is run for any length of time by the b n c oil.

 

[Philbert]

As long as we are discussing bar and chain oil . . .

It’s not just for lubing the bar rails: it needs to get between all of the plates (cutters, tie straps, drive links), and very importantly, to the center portion of the rivets, which act as bearings.

No oil to the rivets creates ‘chain stretch’.



Philbert

 

[Chainsaw Pete]

Whenever I cleaned the bar, there was always some bnc oil in the slot when I was finished raking out the sawdust and crud. Only place that might have been oil starved was the sprocket since I use the pressure in a WD can to blow the dirt out. But then I usually dribble some real bnc oil in there before the chain goes on. Unless one uses a solvent or dips the whole bar in a grease cutter and water mix, it is virtually impossible to get all that sticky old oil off the bar's groove.

 

[SteveSr]

I wonder about just dipping the whole tip of the bar/chain in a cup of new motor oil the first time I use it. Bar and chain oil is pretty sticky and doesn't flow that well. Motor oil will flow into the sprocket's bearings and be displaced the first time the saw is run for any length of time by the b n c oil.

Bar oil is what is intended to be used in the sprocket bearing. Motor oil is too thin and while it will penetrate faster it will also get flung out faster as well. I would just angle the bar nose down and drip some bar oil in the bar groove and between sprocket teeth and let it sit a while... until it starts to run out the bottom.

 

[BrentStir]

I was given a saw to look at, owner said chain wouldnt turn. Couldnt believe how tight the bar nose sprocket was. I said what you been cutting, hardwood blocks for firewood..... with a dull chain. It was so clogged with fine dust its a wonder the saw didnt blow up. After ten mins cleaning spraying and trying to get the sprocket to move I won. But never had a bar like it before or since, people just abuse tools

More they just don’t know any better

 

[bwalker]

Dont they have needle bearings?

Roller bearings.

 

[bwalker]

When I have had tips fail they usually come apart, not seize.
It sounds to me like the tip is getting plugged up with dust. Which will happen with poorly sharpened chain and certain wood types.

 

[bwalker]

As long as we are discussing bar and chain oil . . .

It’s not just for lubing the bar rails: it needs to get between all of the plates (cutters, tie straps, drive links), and very importantly, to the center portion of the rivets, which act as bearings.

No oil to the rivets creates ‘chain stretch’.

View attachment 1194729

Philbert

The chain and the tip bearing is the main thing bar oil lubes. The rails don't get much oil, especially the underside. That's why the bar rails are heat treated such that they are much harder than the chain.