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Why can't I cut straight?

Started by ksks, November 13, 2013, 07:35:24 PM

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ksks

Casual cutter here...

Seems like I always tend to fade when cutting.  Today I was way off.  Was cutting a log about 1 1/2+foot diameter.  I ended up 4" off center to the left at the bottom. 

Today's wood was some unknown, floated in, half rotted junk.  It was soft.  But even in oak I drift.

I am learning to sharpen chains and that may have been some of the problem today (my first chain), but I seem to do it with a professionally sharpen chains too.

I have the typical grip.

I can't figure out how I'm guiding the bar to not go straight. 

Any insight would be helpful.

Thanks,

ksks
Striving to be average!

JByrd

In my experience, this is usually caused by a worn out bar.  The groove gets too wide and lets the chain tilt to one side as it cuts.  Try flipping the bar over, to see if the top side is worn as bad.  If that doesn't work, you need a new one.
JByrd

Ward Barnes

Thanks JByrd:  I had not considered the bar as the problem.  It does make sense.  Anytime I had the problem it was my poor chain sharpening skills (I'm much better now).   :snowball:
7 year old Stihl MS 390.  New Stihl trim saw MS 250.  Kubota BX 2200 tractor.  2005 F150 4X4.
Dull chains cause accidents.  Accidents cause shorter life spans.
You don't sharpen a chain when it gets dull.  You sharpen a chain to keep it from getting dull.

bigsbetter

Definitly could be the chain being sharper on one side or a bar issue. Take the chain off and look closely at the bar. See if it has a worn edge on top or bottom where the chain rides. Sometimes they need a flat file to them to file off the worn edge.  My 8 year old son wants me to put a smilely in here.. >>>>8> >>>>8>
Work Hard...Then Play Hard!

double clutchin weasel

Let's cover the obvious first. Don't take any offense.
The aforementioned worn bar groove.
Wrong gauge chain (0.050 chain in an 0.058 bar, for instance).
Cutters longer on one side of chain. Saw will cut toward side with longer cutters. Often, someone will keep "sharpening" the other side, thinking those are dull, making them shorter & aggravating the problem.
Drags (or rakers or depth gauges) uneven. Saw will cut toward side taking the larger bite.
Drags too high, requiring excessive force to cut, combined with the natural off-center grip of the saw. Will cause the to tilt, and cut to one side.

Keep working on the sharpening technique! It's one of the most crucial skills.to successful sawing.
Eagles may soar, but weasels don't get sucked into jet engines.

thecfarm

In my more than 30 years of running a saw,when it starts to cut crooked it's because of my filing. Most times I can sharpen it with the motor on the right and I'm good to go.
Model 6020-20hp Manual Thomas bandsaw,TC40A 4wd 40 hp New Holland tractor, 450 Norse Winch, Heatmor 400 OWB,YCC 1978-79

Ianab

A good way to check the bar is to take it off and try and stand it on edge on a flat surface. A nice even bar should balance on the edge (that supports the chain). If it keeps falling over (in the same direction) then the rails are uneven, hence the chain is uneven, hence it cuts in a circle.

There are other reasons like uneven sharpening, but if it's happening on all your chains, even professionally sharpened ones, then that's the first place to look. Easy enough to check, and if the bar is worn unevenly, nothing else you do is going to fix the problem.

If you haven't flipped the bar over, do that. Both sides are the same, and the "top" shouldn't have much wear. If both sides are worn, then it's usually possible to "Dress" the bar with a file or grinder. This works a few times,until you have worn away too much steel, and it's time for a new bar.

Ian
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

ksks

Thanks for all the info!  Good ideas here.

Don't worry about me taking offense.  I'll take all the help I can get.

I have heard about filing the bar. 
  - Is that just filing both sides flat? 
  - Is that something that would be better for a shop to do?  For safety sake.

I will try balancing the bar to see if its tipsy, and flip it over.

Thanks for the good, and kind, help!

ksks
Striving to be average!

Ianab

You can buy a file / guide for dressing the bar.

http://www.baileysonline.com/Chainsaw-Bars/Repair-Maintenance/Edge-Files-Sharpeners/Pferd-Universal-Edge-Sharpener.axd

It's faster to dress it with a bench grinder and guide plate, which is probably what the shop will do. But you can't get into too much trouble working on it yourself with a hand file and guide   ;)  5 mins with that file and your should have the bar reasonably true again.

Ian
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

SLawyer Dave

I was always taught that every time you sharpen or change to a new chain, that you should also flip, (reverse) the bar.  This way you tend to spread the wear evenly amongst the bar, and increase its lifespan.  If you are fading in the cut, flip the bar, and see if that changes the cut.  If you dive the other direction, chances are it is a bad bar.  If you still fade in the same direction, than it is most almost assuredly a dull mis-filed chain.

I was cutting with a friend of mine last year.  He was doing fine, but got the tip in the dirt for just a second after a cut.  Could not cut a straight cut after that, as the dirt had dulled one side of the chain, and it kept pulling it sideways through the cut.  Took 20 minutes, resharpened the chain, and he was back to cutting no further problems.  It doesn't take much of a problem to pull the cut out of square.

shootingarts

What bar and chain are you running? Dual dogs or single? I had been unable to run a saw for years and when I started back a few months ago the only thing I had was a toy saw from a big box and of course the nothing chain. Couldn't cut straight no matter how hard I tried having to force that thing through wood.

I found a Makita 6401 about a week or so ago.(Dolmar 6400) Much stouter bar and dual dogs. Even with garbage chain I was cutting straight as a die instantly. Put some full comp chisel chain on it and the saw glides through big logs on a chalk line.

Just some things to consider too. Like everyone else, I think it is more likely to be an equipment problem than operator issues.

Hu

ksks

Quote from: shootingarts on November 14, 2013, 10:47:38 AM
What bar and chain are you running? Dual dogs or single?

haha, no idea what you just said!
Striving to be average!

Philbert

As noted, several possibilities.

Most guys who hand file are 'stronger' on one side, so they end up with different angles or cutter lengths on R and L sides. If you are aware of this you can look for it and adjust/compensate.

Bar wear can take on different forms. If one rail is lower than the other, the rails need to be filed or ground square.

But the inside groove can also wear, allowing the chain to rock from one side to another. Hold a straight edge (vertically) flat against the side of the bar; the cutters should prevent the straight edge from touching the bar. If the cutters move away, allowing the straight edge to touch the bar, the bar groove is probably worn. Some guys will try to close a worn bar groove with a special tool but it's really time to think about a new bar

Philbert

shootingarts

Quote from: ksks on November 14, 2013, 10:52:40 AM
Quote from: shootingarts on November 14, 2013, 10:47:38 AM
What bar and chain are you running? Dual dogs or single?

haha, no idea what you just said!

Dogs are the pointy things with the red arrow pointing at them. Despite the way they look in the picture they are exactly even with each other and dead level across. Makita calls them spike bars but what the hell do they know? My daddy and my daddy's daddy called them dogs, course they never come when called so it don't matter noway!

Gotta remember your talking with a south Louisiana country boy. It ain't rexactly a furrin language but I rarely meet anyone from anywhere else that don't talk funny!

Hu



 

Philbert

Called 'dogs' (or 'dawgs') ' cause they bite into the wood!

Philbert

shootingarts

About the dogs, if you are running slow cutting chain it is easy to lean on things a bit. Do that with a single dog and limber bar and the pressure you are putting on the saw and the single anchor point causes a curve.

Uneven rail height, all the other things mentioned by others, can cause you to run crooked too but sometimes it is just a simple thing. I couldn't cut straight with a toy saw, soon as I grabbed up the Makita I could make cuts that looked like they were ready to plane for lumber.

Hu

beenthere

I just have single "dawgs" on my Stihl and have no problem cutting straight. So don't think they are by themselves what is the aid, or the problem of curved cutting.

Only time I've ever witnessed a curve in my cut was when the chain was rocked and I didn't do a sufficient job of filing the teeth equally on both sides. Thought a shortcut would work. But it didn't.

Dawgs are not needed for most sawing if the chain is sharp. They do aid in making some cuts when felling and about the only time I use them.. possibly a few times bucking if in a tight spot or big diam. log.
Maybe on short bars they could be handy.
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

SawTroll

Quote from: doubleclutchinweasel on November 13, 2013, 08:54:25 PM
Let's cover the obvious first. Don't take any offense.
The aforementioned worn bar groove.
Wrong gauge chain (0.050 chain in an 0.058 bar, for instance).
Cutters longer on one side of chain. Saw will cut toward side with longer cutters. Often, someone will keep "sharpening" the other side, thinking those are dull, making them shorter & aggravating the problem.
Drags (or rakers or depth gauges) uneven. Saw will cut toward side taking the larger bite.
Drags too high, requiring excessive force to cut, combined with the natural off-center grip of the saw. Will cause the to tilt, and cut to one side.

Keep working on the sharpening technique! It's one of the most crucial skills.to successful sawing.

Cound be all or any of that - but it also could be an AV mount that is broken or isn't working properly....
Information collector.

Philbert

Quote from: SawTroll on November 14, 2013, 04:10:25 PMCound be all or any of that - but it also could be an AV mount that is broken or isn't working properly....

That's a very interesting idea!  Not something I would normally think of.

Philbert

turnkey

Quote from: thecfarm on November 13, 2013, 09:21:01 PM
In my more than 30 years of running a saw,when it starts to cut crooked it's because of my filing. Most times I can sharpen it with the motor on the right and I'm good to go.

Same here.  90% or more of the time a crooked cut is due to a chain needing sharpening or one that has been poorly sharpened.

Yes, _occasionally_ it is the fault of the bar but first and foremost suspect the chain.

Harry K

turnkey

Just a tip for handsharpeners if you haven't heard it befoe :).

I mount the saw in the vice upside down.  That allows me tosharpen both sides right handeded. Stand facing the saw to do one side, stand by the power head to do the other.  I saw that tip on another site way back when and have used it ever since.  It eliminates the "strong hand" problem of uneven sharpening.

Dunno how It would work for lefties though.

Harry K

Terry Syd

Ditto on all the mechanical stuff.

You wrote "Seems like I always tend to fade when cutting." - That happens to me also (I'm 66) and my cuts can get off line because I'm fading.

I have to imagine a chalk line on the wood and focus on the line - works for me.

ksks

Thanks for the replays.

First today I will try flipping the bar without sharpening.

I have another chain professionally sharpened so that will be my next step.

I did order the bar file.

I have only one dog.

Striving to be average!

motard

Sharpen your chain.

Yes if that fails get a B&C combo.

7sleeper

And to make Philbert happy  ;D I will mention that many people use those el cheapo HF grinders to grind both sides equal again. And yes they will make a nice sharp chain so that you don't need to send it out again and can be sure of your own quality.
Here is a link on how to use one of those.
youtube.com/watch?v=f3m_ErOrzHY

7

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