used 462 acquired, curve on the bar

[schreib69]

I just bought a used 462C Stihl and now find the 32" bar is slightly curved:
When the bar is laid flat on my table saw top(iron and flat) the tip angles up about 1/16" at the tip from the table top when I hold down the mount end.
I have not yet run the saw and am a bit worried this is a problem. My 362 and its 20" bar lay dead flat but I figure a long bar is a LOT more likely to not be as able to stay perfectly straight with use.
Your thoughts?

 

[ElevatorGuy]

You may be able to space up the other side with the curve up on the other end and put some weight on it to straighten it. Stihl bar? I wouldn’t run it bent, just going to bind and possibly throw the chain.

 

[sean donato]

Throw it out and buy another bar. Not worth the agitation to try and straighten it. All it's gonna do is wear out your chains faster and possibly cut crooked. Not worth the effort to deal with.

 

[nedsim]

I just bought a used 462C Stihl and now find the 32" bar is slightly curved:
When the bar is laid flat on my table saw top(iron and flat) the tip angles up about 1/16" at the tip from the table top when I hold down the mount end.
I have not yet run the saw and am a bit worried this is a problem. My 362 and its 20" bar lay dead flat but I figure a long bar is a LOT more likely to not be as able to stay perfectly straight with use.
Your thoughts?

With a little planning and patience you can probably straighten it. Long machined parts that warp as a result of removing stressed material are routinely straightened to within a couple thousandths.

If you decide, as others have indicated, that it's too curved to us as-is, and the bar is OK otherwise, what do you have to lose by trying? I've designed and built straightening presses up to 250 tons force with associated gaging devices for parts up to 8 inches diameter. You can do the same for something as small as your bar with a setup as simple a stiff beam and a stout c-clamp. A hydraulic press will make the job even easier.

 

[computeruser]

What’s your time worth?

 

[schreib69]

thanks for all your replies. Hopefully, the Ebay seller will offer compensation or credit. . . We will see!

With a little planning and patience you can probably straighten it. Long machined parts that warp as a result of removing stressed material are routinely straightened to within a couple thousandths.

If you decide, as others have indicated, that it's too curved to us as-is, and the bar is OK otherwise, what do you have to lose by trying? I've designed and built straightening presses up to 250 tons force with associated gaging devices for parts up to 8 inches diameter. You can do the same for something as small as your bar with a setup as simple a stiff beam and a stout c-clamp. A hydraulic press will make the job even easier.

Sounds like a decent plan. If you have any detailed pointers I would be "up for it"! I have done this sort of thing before. I have found that it is good to try to "over" bend just a bit in order to get something flat otherwise it retains some of the original curve.
Here are more details I learned today:
-- when flipped onto the bowed side, shim stock measurement of the gap shows the gap is about 2/3 of the way from the "flat" end(driven end) and is about 0.020" off my cast iron table saw top.
-- when laying on the curved side the tip pops up about 0.060"(about a 1/16")
-- the tip has thin rivets protruding preventing the face of the bar from falling totally flat regardless of which side it rests on; probably less than 0.01"

If I were to try to bend this, my 1st thought is to place a fulcrum at the point just before the bar starts curving "up" nearer the tip end. I would probably guess at a shim on the order of 1/16" to start with, then, small increases as I find it tests out to come closer to dead flat. I would plan to just press down with my hand to deflect it across the fulcrum.

What would YOU suggest?!

 

[schreib69]

What’s your time worth?

I'm retired, so, NOT much!
By the way the Ebay seller is being very supportive and is open to adjustment. I am being reasonable also. Not trying to screw anyone.

 

[singinwoodwackr]

I just bought a used 462C Stihl and now find the 32" bar is slightly curved:
When the bar is laid flat on my table saw top(iron and flat) the tip angles up about 1/16" at the tip from the table top when I hold down the mount end.
I have not yet run the saw and am a bit worried this is a problem. My 362 and its 20" bar lay dead flat but I figure a long bar is a LOT more likely to not be as able to stay perfectly straight with use.
Your thoughts?

If you have a good vice a small bend like that is a 5min fix. I’ve done dozens in worse shape. Heck, at only 1/16” you done need a vice.

 

[TheJollyLogger]

Wow... just wow... I have no words...

 

[trains]

Only 1.5mm off from end to end ? 1/ 16" ?, you dont mean 3/16 or more do you ?

This bar was bent and at least 1/2" or 12mm over the length of the 36" bar, including twisted 1/3 along its length too by 5mm took the worst of the bend out, then flattened its twist and then finished the bend.





now it lays flat on a true flat surface.
but for 1.5mm along its length as you mentioned, I would just find the point where its not quite right and bend it back, but have seen bars running fine with more than that in them.

 

[ElevatorGuy]

I'm retired, so, NOT much!

Retirement time is the most valuable, Enjoy every minute of it.

 

[rwoods]

If it were mine, I would run it with only 1/16” on a 32” bar. If it is worrisome then go Trains’ route. Chains and bars are very forgiving.

Ron

 

[trains]

yeah, when using the saw with the longer bar, it moves more than that anyway, thus asking if there was a typo and it was meant to be 3/16

 

[lone wolf]

Throw it out and buy another bar. Not worth the agitation to try and straighten it. All it's gonna do is wear out your chains faster and possibly cut crooked. Not worth the effort to deal with.

THIS.

 

[nedsim]

thanks for all your replies. Hopefully, the Ebay seller will offer compensation or credit. . . We will see!

Sounds like a decent plan. If you have any detailed pointers I would be "up for it"! I have done this sort of thing before. I have found that it is good to try to "over" bend just a bit in order to get something flat otherwise it retains some of the original curve.
Here are more details I learned today:
-- when flipped onto the bowed side, shim stock measurement of the gap shows the gap is about 2/3 of the way from the "flat" end(driven end) and is about 0.020" off my cast iron table saw top.
-- when laying on the curved side the tip pops up about 0.060"(about a 1/16")
-- the tip has thin rivets protruding preventing the face of the bar from falling totally flat regardless of which side it rests on; probably less than 0.01"

If I were to try to bend this, my 1st thought is to place a fulcrum at the point just before the bar starts curving "up" nearer the tip end. I would probably guess at a shim on the order of 1/16" to start with, then, small increases as I find it tests out to come closer to dead flat. I would plan to just press down with my hand to deflect it across the fulcrum.

What would YOU suggest?!

Trains' setup is how I would go about it. The usual procedure is to set the supports relatively close together, perhaps 6" in this case, and shuffle the bar along perhaps 3-4 inches at a time, straightening at those short increments. Use a straightedge as long as the distance between the supports to gage the straightness between the supports as you move along. A long straightedge, or your table saw top, to assess your overall progress. Avoid bending near the roller tip. It'll probably take a couple passes, depending on how quickly you zero in on the amount of overbend required to bend the bar and how fussy you are about the final result.

 

[woodfarmer]

#1 I probably never would have even noticed it or laid it on a flat surface.
#2 If you haven‘t even used it I would go and try it first.
#3 remember you are buying used and the seller may not have ever noticed it.

 

[old guy]

That is an easy one, I use a block of white oak and a heavy hammer, just put a small piece of wood under one end of the bar on the block.

 

[Stihl Learning]

If you do not have a vise use a couple of 2x4 scraps underneath and a rubber mallet or dead blow hammer. Just do a little bit at a time and check as you go. It is not an exact science, have fun and take your time. I have done many of them. Check straightness like a gun sight down the groove like a previous poster pictured.

 

[schreib69]

If you have a good vice a small bend like that is a 5min fix. I’ve done dozens in worse shape. Heck, at only 1/16” you done need a vice.

I took the saw out and cut a stump off with it, no problems at all. I did not push the seller for ANY compensation and will just live the minor bow in the bar. It worked just fine. Regardless, when I get a chance I will bend it back flat if possible. Besides, I have no need for a saw that long. I plan to buy another 20" bar and chain and use that while hanging the 32" bar on the wall for that one "big" tree!
Thanks all for your suggestions.

 

[schreib69]

Only 1.5mm off from end to end ? 1/ 16" ?, you dont mean 3/16 or more do you ?

No, I really meant only 1/16". If you read the details not that when I flip it over so the bowed side is DOWN I can only get a 0.020" shim in the gap. It is negligible. Based on its performance on the stump(see earlier post. . .), your response, and others, I will leave well enough alone. Thanks to you and the rest for your input.