Saw Cutting Crooked

[IanB22]

Take a pair of callipers and measure each tooth. I almost guarantee that one side of teeth will be longer than the other. If they are different in length they will cut wrong. Forget what the guy said, and measure with callipers the tooth length.

 

[Wood Doctor]

Take a pair of callipers and measure each tooth. I almost guarantee that one side of teeth will be longer than the other. If they are different in length they will cut wrong. Forget what the guy said, and measure with callipers the tooth length.

But, once again it's the clearance between the cutter edge and the raker that is causing it. The longer cutter has more bite because the raker is allowing it. The shorter cutter has an edge that has dropped down further. If the rakers are high enough, you'll be producing powder on a chain that is razor sharp.

If I run into a sharp chain that pulls right, I take it off, mark it with a note, and replace it with another. When I get back to the shop, I drop the left-side rakers down. The next time I install that chain, it usually cuts true.

 

[dl5205]

It would seem that the OP has abandoned this thread. That is a shame, because I was curious if a NEW bar and a NEW chain had fixed the issue, or if it was still an actual mystery.

When cutting 40" wood with a 20" bar, it's easy to cut a spiral, even if your equipment is true.

 

[dl5205]

Chris-PA , I see you responded with a 'like' on my prev. comment. Is there a TERM for the Technique necessary to cut a tapered column so that when it was set on its base on a horizontal plane, its centerline would be perpendicular to that plane?

 

[Chris-PA]

Chris-PA , I see you responded with a 'like' on my prev. comment. Is there a TERM for the Technique necessary to cut a tapered column so that when it was set on its base on a horizontal plane, its centerline would be perpendicular to that plane?

Gee, I'm not really sure what you're looking for. How about a circular Conic Section?:

 

[flyboy553]

Just to let you know, I fixed the bar yesterday. I took it to a machine shop and put it on their precision grinder, something the saw shop doesn't have. Using precision measuring equipment(also something a saw shop doesn't have), we found one side of the bar to be .003 to .005 higher than the other. Once ground down to dead even on all parts, it cuts straight. Hard to believe that little bit would do it, but it did.
So, you guys who said bar issue were right. Always seemed logical to be that, but after measuring with a machinist's square and looking flat, was hard to accept.

The measuring was done on an inspection table using height gages I think they're called. It's on a stand, has a needle like end on it with a dial indicator.
Thanks for the input!

Ted

 

[Philbert]

1. Glad you were able to fix it.

2. Thanks for sharing the results - I think most of us learned something from this thread.


Philbert

 

[dl5205]

Gee, I'm not really sure what you're looking for. How about a circular Conic Section?:

Circular Conic Section. That'll do until something better comes along.

THANKS!

 

[dl5205]

You could see that if you started a cut perpendicular to one side of the cone, using a 'too short' bar, by the time you got to the other side, the cuts wouldn't line up.

 

[Gypo Logger]

Sometimes a 058 will fit in a 050 bar that's worn.Flipping the bar often ensures square rails. Low oil delivery compounds toboggan cuts, as does worn sprockets and too many drive links.
John

 

[rwoods]

1. Glad you were able to fix it.

2. Thanks for sharing the results - I think most of us learned something from this thread.


Philbert

It got me to thinking. I re-squared my grinder (easier said than done on my old Bel-saw) and cleaned up some bars today. I discovered part of what I had attributed to internal wear of the bar was actually the chain although I couldn't see it. The drive links must be worn on one side since the chain would tip to one side with thumb pressure but not to the other side. Reversed the chain and the tilt reversed. Just guessing here but given the consistency of the result over the years and the only constant being my bar dressing, I would hazard to say that among other things I haven't squared the grinder as close as it should be squared before grinding the bar.

Ron

 

[mike047]

As I have read this discussion, I wondered, at what point is a bar beyond spending time and money on? I realize that many in business try to save money as well as the homeowner. An 18" Stihl bar goes for around $40, at what point has one gotten their money's worth from it? How much is a reasonable investment[in time or money] to keep using a $40 bar.

I do realize that a long expensive bar, that the professional use, would be worth more maintenance in time and money.

I personally don't saw enough with one particular saw to wear a bar out. I do turn them over periodically and ensure the groove and nose sprocket are cleaned frequently.
I also ensure that the bar gets enough oil.

I also know that there are many puzzles that we will go to extreme length to solve...just because

 

[flyboy553]

A bar is worn out when the drive links hit the bottom of the rail. You can tell when that happens, among other things, the inside of the rail will be shiny from them hitting. If there is gunk in the rail, then it isn't hitting.

I turn my bar about once a week. I cut at least 5 days a week, sometimes seven.

Ted

 

[Philbert]

. . . at what point is a bar beyond spending time and money on?

That's really up to the individual. Do you have to pay an employee to do it, or do it in your own, 'free' time? What is the additional cost in downtime, or in trips to the store, if your saw/sprocket/bar/chain is not cutting at it's best?

Some of us enjoy and receive satisfaction from repairing and maintaining tools (and from 'scrounging'/saving/rescuing items not worth it to others).

One of the take-aways from threads like this is understanding what might be going on; what types of maintenance might prevent these problems; and what repairs might involve; so that you can decide if it is worth it to you personally or not.

Philbert

 

[IanB22]

10$ to square a bar at the 'good' saw shop in my area. Old timers still run it and they have no problem taking my 10$ once a season to square up my 25+ yr old canon 42" bar. FWIW, I like keeping the 'old' but serviceable equipment going. It's part of the hobby in my opinion.

 

[Redbug]

But, once again it's the clearance between the cutter edge and the raker that is causing it. The longer cutter has more bite because the raker is allowing it. The shorter cutter has an edge that has dropped down further. If the rakers are high enough, you'll be producing powder on a chain that is razor sharp.

If I run into a sharp chain that pulls right, I take it off, mark it with a note, and replace it with another. When I get back to the shop, I drop the left-side rakers down. The next time I install that chain, it usually cuts true.

You hit the nail on the head...most of the time that's the cause. I found that out by the school of hard knocks.

 

[SS Sniper]

Is there a bur on the edge of the bar?

 

[singinwoodwackr]

Is there a bur on the edge of the bar?

that wouldn't cause the problem

see #47

 

[StihlFroling]

Your welcome on the bar remedy. Luckily our Stihl shop has a bar trueing device and I already went thru this issue with all the guessing. Glad you have it fixed

 

[fearofpavement]

Whenever I get in a saw in that I'm going to flip, I service the bar by truing and deburring the rails. I use a 12" disc sander for the truing and a 6"x48" belt sander for the deburring. It takes between 4 and 10 minutes per bar. I also sharpen up the chain and take down the rakers if necessary. Often that takes 20 minutes depending how bad of shape it's in. Most chains are pathetically dull when received.
At any rate, when someone tries out a saw, it cuts fast and straight. Many people's chains are dull even when they think they're sharp. I can guarantee that if someone doesn't file their chains and only has them sharpened at a shop, most of the time they have a dull chain. Using a chain that's dull requires a lot more force for it to cut wood and puts a lot of additional wear on the bar rails. I quite often get homeowner type saws that have bars that are completely ruined. (worn beyond repair)
Keeping chains sharp is probably the single most important aspect of saw maintenance.