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bent bar

Started by propster, February 01, 2012, 12:47:23 AM

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propster

Another newbie question. Can a bent bar be salvaged, or not worth it? Does it need to be done professionally? Thanks guys

mad murdock

Couple ?'s is it a solid bar, or laminated? Where is the bend and how sharp is the bend? A pic is worth a thousand words. BTW welcome to the forestry forum propster, I think you will enjoy it here!
Turbosawmill M6 (now M8) Warrior Ultra liteweight, Granberg Alaskan III, lots of saws-gas powered and human powered :D

T Welsh

propster, Welcome,Yes bar,s can be bent back into shape as long as they where not kinked in the rail,s. the best method is an arbor press using a machinists straight edge. I have had good luck with bars up to 24" after that not such good luck with 36" and 48",they are a lot less forgiving in a long cut,I use the longer bars for felling and bucking only. Tim

propster

Appreciate the welcome guys. Not kinked at all to my knowledge, more of a gradual or slight bend - enough that it won't cut straight through a log. One is the original bar ('00 55 Rancher), and the other is a replacement Pro Lite by Oregon, which I understand Oregon makes most or many of the Husky bars. I knew I did it on the second one when I hung it up, the other seems like it happened ever so gradually over time, or at least I didn't experience a single event that I can say "that's when it happened". I believe they are both laminated, but not sure. What is the best way to tell?  The bar is 18". I'll see if I can get pics up.

Al_Smith

You can straighten them most of the times .I get a few bars from a tree service I help out with .Those guys seem to think a saw bar and a crowbar are one in the same for some reason .Even if they get a twist in them a 36" aluminum pipe wrench and a big vise and some elbow grease will get it straight again ---most of the time

John Mc

Can you actually see the bend, or are you just assuming it's bent by the fact that it won't cut straight? There are other things that will make a bar not cut straight besides a bent bar. Rails worn unevenly is one. A chain that was not sharpened correctly could be another. Both are easily fixed. We can go into more detail if you think it could be some other issue.

John Mc
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

propster

I can see the bend. If I try to straighten, how will I know if I accomplished the goal - just a visual and then try cutting with it it? I used to straighten aluminum arrows by hand - lots of trial and error but then you could spin it to make sure you got it. Not sure how I'd tell on a bar.

sawguy21

Lay it on a flat surface.
old age and treachery will always overcome youth and enthusiasm

HolmenTree

If its a solid body bar [not laminated] it can be hammered straight with about a 2 lb hammer, I use a brass hammer but steel works fine. Lay the bar on a heavy flat piece of steel with the bend up, and hammer in the center of the bar where the bend is. Eye ball down the length, hammer until straight.

I tighten up my rails the same way but make sure you have a shim of proper thickness between the rails at the point where the hammer hits. A Oregon bar cleaner hook works good as a shim for the .050 bars.
Making a living with a saw since age 16.

John Mc

When you say to hammer the bar "with the bend up", are you saying to lay it down with the ends up, or the middle up (so it looks like an "n" or a "U") ?  If I didn't put much thought into it, I'd lay it down like an "n" and try to pound it flat, but I'm thinking that may not work. You might be able to focus the unbending better the other way.

I've never tried it, but it seems it's worth the gamble if it happens to me in the future.
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

Al_Smith

I've had good luck if it's just a warp by using a 4 pound dead blow hammer and blocks .It's just like auto body work except the material is thicker .

Now don't anybody get the bright idea of heating the bar up with a rosebud .Not good you'll just turn it into junk .

beenthere

When you hit steel with a hammer, the metal will expand.
That is how you true up a steel carpenters square and how they hammer a circular saw blade.

Seems hammer blows on bar would be on the under-belly side of the bow. They would expand the steel and cause the bar to straighten.

Or put the bar in a press and press the hump down.
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

JohnG28

I could see a brass hammer maybe, as it is softer than steel.  It shouldn't do much to the steel's properties, I don't think.  I have bent a bar before, but not to the point that a hammer was required to fix.  A little pressure in the opposite direction of the bend about did it.  Unless this is something like a 6" bar I would think that would be do-able to most bars, right?
Stihl MS361, 460 & 200T, Jonsered 490, Jonsereds 90, Husky 350 & 142, Homelite XL and Super XL

Ohio_Bill

I have straighten several bars by putting them in a vice and just pulling on them . I don't know if that is right way to do it, but seems to work. 
Bill
USAF Veteran  C141 Loadmaster
LT 40 HDD42-RA   , Allis Chalmers I 500 Forklift , Allis Chalmers 840 Loader , International 4300 , Zetor 6245 Tractor – Loader ,Bob Cat 763 , Riehl Steel Edger

HolmenTree

Quote from: John Mc on February 07, 2012, 09:34:48 AM
When you say to hammer the bar "with the bend up", are you saying to lay it down with the ends up, or the middle up (so it looks like an "n" or a "U") ?
Sorry I should have explained it a little better. "bend up" like a "n". First you have to see where about in the length of the bar where the bend is. When you find it mark the peak or center of bend with a chalk,with the bar laying on a flat anvil or what have you, hammer the area back and forth in left and right direction from the center mark[ tail to nose]. Don't hammer near the rails, only in the center of the bar. 2 - 3 inches each way from chalk mark should be enough to straighten it. This technique brings back the "memory" of the original flat surface.
Just keep eye balling down the bars length to check straightness. To tighten up the rails as I said earlier both sides of the bar rails have to be hammered.
Works like a charm, part of my regular maintenence for the past 38 years.
Making a living with a saw since age 16.

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