Crooked cutting chainsaw

[379hammerdown]

Hello,

I have a Husky Rancher 55 with a 20" Oregon bar on it that doesnt cut correctly. When I am cutting through a log... say 8" diameter or greater... the saw bar cuts into the log, then say maybe about half way through the log the saw bar takes a turn to the right, effectively pinching the sawbar and making it impossible to complete the cut. :angry2: I've been having to pull the bar out, and make stabbing cuts at the log with the tip to complet the cut. Big pain in the butt. Any suggestions? The Bar does not appear to be bent at all, and the bar calls for a 50gauge chain which it is indeed running a 50gauge chain.:greenchainsaw:

 

[West Texas]

Sounds to me like uneven wear on the bar rails. Take off the chain and dress the bar rails with a good file until they appear similar in appearance and give it a try. That usually works for me.

 

[Freakingstang]

if the bar is indeed not bent, then you need to wise up on your sharpening skills. A dull chain will banana one way or the other

 

[toolmaker]

Your chain might be sharper on one side than the other.
Your bar might be worn on one side.
Sharpen the chain correctly, have the bar dressed by a dealer.
A good idea for you after you correct this problem is to flip the bar over every time you sharpen or change chains, this will help to keep the bar wearing evenly.

 

[Crofter]

Flipping the bar only works if the side you flip it to does not have the same problem. If the chain has run crooked on the bar for any length of time one side of the chain rails as well as one side of the drivers will be worn uneven. The inside of the bar groove also gets wallowed out on one side. Merely squareing up the bar rails may not get it cutting straight again. Depends on how long it ran cahooie!

 

[tek9tim]

Madsen's has a good tech article about this very subject: http://www.madsens1.com/badbar.htm

In my experience, it has always been an unevenly sharpened chain that has caused the problem you speak of. Sometimes pretty radically, too.

 

[hoss]

If the guide bar is straight and the rails are even then it is definatley the chain. Look at the teeth, not just to see if they are dull but also check the angle each tooth is sharpened on and how it corresponds to the guide marks on the tooth. Another thing you will want to do is make sure that when you sharpen your chain that you are taking the same amount of material off of each tooth. If the teeth do not have the same amount of material on each tooth you will have to find the worst (dullest ) tooth and get it sharp,once it is done bring ALL the rest of the teeth to the same angle and size. I know this can take a lot of material off but it will make it right.

 

[buck futter]

to add to what tek said measure the tooth just don't eyeball it. If your bar looks to be ok maybe buying a new chain is a quick way to check if that is the problem, the down side is you will have a spare chain, so its a win win situation.
Also look how you hold the saw is there anyway you are putting even the slightest bias on the handles that could cause the saw to go to one side?

buck

 

[Patrick62]

My 2 cents worth

dress the bar, check if the chain is running worn drive links. Even sharpening helps bunches. If all else fails the 55 isn't antique, get a new bar and chain!

I have a antique that was real bad about going sideways. Rare chain and non-existant bar. I fixed it by correcting my sharpening, and then dressed the bar with a grinder. There was enough clearance to drop the drive teeth farther in where it isn't worn. Cuts straight and true (and quick for a antique).

-Pat

 

[Bad E]

Madsen's has a good tech article about this very subject: http://www.madsens1.com/badbar.htm

In my experience, it has always been an unevenly sharpened chain that has caused the problem you speak of. Sometimes pretty radically, too.

When I first started sharpening I had this problem. With more expeirience I overcame this problem.

 

[leweee]

make sure the chain gauge macths the bar gauge

I've seen .050 chain on .063 bars

 

[rjh245]

I worked at a Christmas tree farm and I was always cutting stumps flush to the ground. That would wear the bar's rails uneven in a short amount of time. It would also wear the chains. I had to watch to make sure the cutters were equally sharpened.
The boss threw away alot of bars that could have just had the rails ground even.
Rob

 

[Mr_Brushcutter]

Digital vernier calipers!

I have a set they speed up sharpening because your not constantly checking the calipers measurements. I sharpen my saw teeth to 0.05mm works well, they can also be used to check width/depth of guide rails. Oh get an engineers square too to check the rails are more or less square.

 

[clearance]

I say if the saw starts cutting funny all of a sudden and you have not just sharpened the chain, it is the bar. Check the bar with a 4'level, or a with a little bar like this against a framing square, anything that has a deadly straight edge. "Bar does not appear to be bent" was a clue, check it good. I say this because I have sharpened saws for people because it "isn't cutting good". After it is sharp it still don't cut good cause the bar is bent.

 

[buck futter]

Digital vernier calipers!

I have a set they speed up sharpening because your not constantly checking the calipers measurements. I sharpen my saw teeth to 0.05mm works well, they can also be used to check width/depth of guide rails. Oh get an engineers square too to check the rails are more or less square.

The DRO calipers is a godsent for actually getting the chain right. The biggest benefit is you can find what you believe to be the smallest tooth take a measurement and set the origin there, then go around the chain and see if they all are plus or if one is minus. If it is minus reset the origin to that tooth until you have the origin at the smallest tooth. Then sharpen that tooth measure again to reset the origin. now you have the length that you want all of your teeth set to. I have gone as far as keeping a tolerance of + - 2.5 thousands. After you have done all of the teeth you will need to reset your rakers. I set the rakers to 25 thou. and the top plate angle to 30 degrees for both 3/8 and .325. Of course I also clear the gullets down to the tie strap. they say it helps but I have never tested it out, so I do it in blind faith.


it may not a race chain but its quick smooth and straight as I can hold the saw.


Buck

 

[geofore]

banana cut

Things I would like to know. How old is the saw? When was the last time the sprocket was checked for wear? It may be worn enough to set the chain to one side and wear one side of the bar more than the other. A smiple thing to do when you put the saw in your vice to sharpen it and have a hard time reaching (using the same hand) the cutters when you turn the saw around after you sharpened the cutters on one side. Don't turn the saw around, flip the saw over in the vice to sharpen the cutters going the other way. If this is your first time flipping the saw to sharpen it, make sure the gas/oil caps are on and tight. They are easier to reach if you flip the saw over. You can now use the same hand and angle as before to get the cutters going the other way. This trick helps a lot of new guys sharpen chain and keep the cutter angles closer to the same angle. The worst saw/chain I fixxed last year was an electric Craftsman used to cut pallets at a warehouse, 22 degree angle on the cutters on one side and 45 degree on the other side. It couldn't be counted on to cut through a 4" round. One of the guys at the warehouse had put a file to it and it would cut no more. 2" into the wood the saw would slow down. 3" in it would stop. It had such a left hook it would stall the saw. Yes, having the cutter angles match makes a difference.