Chainsaw cutting curves...but this is different

[singinwoodwackr]

This has “defective or mislabeled bar and/or chain” written all over it. Nearly 40 yrs of cutting…each time this type of thing occurred the bar rails were out of true or a mismatched bar/chain with a wider kerf bar using a narrower DL chain Was the culprit.
mic the drive links and the bar slot. I‘d bet a saw they are not correct, or, that new bar is not ground correctly.

grind the bar rails with a perfectly square 1” belt sander or specific bar dressing grinder. I bet the problem stops.

 

[JRenna]

Is it possible you are torquing the saw slightly as you push the handle down. Try some cuts with the bar level. Try some with it dogged in. I’d think a small bar could have the same effect as a coping saw. Just brainstorming.

 

[sofasurfer]

I finally found my micrometer. The bar groove measures .058" and the chain measures .052".

 

[singinwoodwackr]

I finally found my micrometer. The bar groove measures .058" and the chain measures .052".

Bet the bar was ground out of square. Rare, but I've seen it in brand new. Same symptoms...cuts fine in small stuff but curves in larger diameter wood.

 

[Philbert]

. . . cuts fine in small stuff but curves in larger diameter wood.

Maybe it’s a special carving bar?

Philbert

 

[JRenna]

I’ve never personally measured a drive link with a caliper but your measurements seem reasonable - .003 on each side of drive link plus oil. Chains are not a close tolerance fit. I will measure mine tomorrow and see what sort of tolerances the chains have relative to the bar.

 

[JRenna]

Here are some pics of a .050 gauge bar and chain to show the tolerance between the two. The bar is considerably wider than the chain.

 

[singinwoodwackr]

Here are some pics of a .050 gauge bar and chain to show the tolerance between the two. The bar is considerably wider than the chain.

View attachment 991543View attachment 991544

I just measured 2 brand new bars...
.050 bar is .052

.063 bar is .065
That's what I would expect from a new bar.
Stihl and Jonsured bars

 

[singinwoodwackr]

I finally found my micrometer. The bar groove measures .058" and the chain measures .052".

Mic may be off. Chain Guage should be exact, ie, .050 or .063.
Bar groove should be larger.

 

[JRenna]

My bar and chain is used so it might be a little oversized. However, .002” over is an awfully tight fit. That’s like close tolerance aircraft hardware tight. It would be a pain to get the chain in the groove. Regardless, I think the OP’s bar and chain combo is adequate. Rather good in my opinion.

 

[singinwoodwackr]

My bar and chain is used so it might be a little oversized. However, .002” over is an awfully tight fit. That’s like close tolerance aircraft hardware tight. It would be a pain to get the chain in the groove. Regardless, I think the OP’s bar and chain combo is adequate. Rather good in my opinion.

I imagine there is an industry tolerance, just don’t know what it is.
and, trying to mic that narrow a grove with a basic gauge is iffy, imo.
my mic is probably off
or, I’m measuring paint as well

 

[kevin j]

Use feeler gauges on the bar groove

 

[sofasurfer]

I tool the saw back to TCS. They gave me a new one. First thinh I noticed is that, as with the first saw, the chain is so tight from the factory that I couldn't budge it. Had to readjust it first thing. I guess this is how they ship them but I think they should have a tag on the saw saying that it should not be run until chain is readjusted (just sayin'). I took the bar off and checked the numbers. All exactly the same as the first saw. Then I measured the bar and chain. There was a .002" difference between the bar and chain. There was significantly less wobble of the chain in the bar groove. HOWEVER!!! The saw still cut a curve, although not a bad as the first one.
I'm taking it back tomorrow and getting a refund. I am going to spend my money on a older saw, probably a McCulloch, not sure. I'll look around a while and see whats available.
I tried calling Poulan and the recording said they don't accept phone calls. Their website said to visit an authorized repair center. Their website lists a bunch of local repair shops who have no special connection to Poulan. Pretty good for a company thats an offspring off one of the supposedly best chainsaw manufacturers (Husqvarna). I also called Husqvarna. They don't take calls either. Impressive!

 

[singinwoodwackr]

IMO, The bars are not ground true. Most likely a bad batch.

 

[ValleyForge]

I tool the saw back to TCS. They gave me a new one. First thinh I noticed is that, as with the first saw, the chain is so tight from the factory that I couldn't budge it. Had to readjust it first thing. I guess this is how they ship them but I think they should have a tag on the saw saying that it should not be run until chain is readjusted (just sayin'). I took the bar off and checked the numbers. All exactly the same as the first saw. Then I measured the bar and chain. There was a .002" difference between the bar and chain. There was significantly less wobble of the chain in the bar groove. HOWEVER!!! The saw still cut a curve, although not a bad as the first one.
I'm taking it back tomorrow and getting a refund. I am going to spend my money on a older saw, probably a McCulloch, not sure. I'll look around a while and see whats available.
I tried calling Poulan and the recording said they don't accept phone calls. Their website said to visit an authorized repair center. Their website lists a bunch of local repair shops who have no special connection to Poulan. Pretty good for a company thats an offspring off one of the supposedly best chainsaw manufacturers (Husqvarna). I also called Husqvarna. They don't take calls either. Impressive!

Just skip all the intermediate and box store saws and go get a Stihl….

 

[JRenna]

Yep, for just $1000 more you can cut a straight line!

 

[scottr]

The chain on the saw is stamped with "oregon 91" (suprised its Oregon) which https://www.oregonproducts.com/en/p...ght-saw-chain/c/finding-the-right-saw-chain-s says is .050". The bar is stamped with "18-91-62-y8" which I assume means .062".

The 62 is for 62 drive links of oregon 91 chain on your 18" bar .

 

[Squareground3691]

Just skip all the intermediate and box store saws and go get a Stihl….

Better yet get some me of these

 

[Bearcreek]

I tool the saw back to TCS. They gave me a new one. First thinh I noticed is that, as with the first saw, the chain is so tight from the factory that I couldn't budge it. Had to readjust it first thing. I guess this is how they ship them but I think they should have a tag on the saw saying that it should not be run until chain is readjusted (just sayin'). I took the bar off and checked the numbers. All exactly the same as the first saw. Then I measured the bar and chain. There was a .002" difference between the bar and chain. There was significantly less wobble of the chain in the bar groove. HOWEVER!!! The saw still cut a curve, although not a bad as the first one.
I'm taking it back tomorrow and getting a refund. I am going to spend my money on a older saw, probably a McCulloch, not sure. I'll look around a while and see whats available.
I tried calling Poulan and the recording said they don't accept phone calls. Their website said to visit an authorized repair center. Their website lists a bunch of local repair shops who have no special connection to Poulan. Pretty good for a company thats an offspring off one of the supposedly best chainsaw manufacturers (Husqvarna). I also called Husqvarna. They don't take calls either. Impressive!

Poulan isn't an "offspring" of Husky. Husky bought the company year ago and now assembles some of their low end saws at a former Poulan factory. Husky makes good saws. They also make "homeowner" saws, which is what you have.

 

[mbrick]

Buy a good saw from Stihl, Husky, or Echo.