Banana bars

[Mr Ed]

Its pretty easy to straighten bar without heating it. Worst thing for wrecking bars is cuttting Rhododendron or Laurel. The stuff grows in such odd circles, itt traps and twist the bars.We did a contract once, hand cut 22 hectares of big laurel - went through about 7 bars in 3 months.

[skyhuck]

Its pretty easy to straighten bar without heating it. Worst thing for wrecking bars is cuttting Rhododendron or Laurel. The stuff grows in such odd circles, itt traps and twist the bars.We did a contract once, hand cut 22 hectares of big laurel - went through about 7 bars in 3 months.

 

Good God! 22 hectares! :scared:more than 3 days on one site and i start to get fedup,that would have had me waking in the night with cold sweats.

[Marc]

Treediver? I thought this was started by Treebogan, I can't seriously believe you can't find a way to straighten a bar?? You've even got a press in your workshop.

[Lee Winger]

Don't know what you guys think , but I think todays bars are a lot easier to bend than say bars of 10 years ago, modern bars feel so light to me, they seem to wear quicker as well.

 

I would through out banana bars If I wear you treediver

[treediver]

Treediver? I thought this was started by Treebogan, I can't seriously believe you can't find a way to straighten a bar?? You've even got a press in your workshop.

 

Ive got a small vice which I sharpen n grind stuff on trouble is once the bars bent trying to straighten it usually makes it worse. What I need is a giant hydralic press which covers the entire length of the bars to squash them back into shape without destroying them.

[Marc]

Ive got a small vice which I sharpen n grind stuff on trouble is once the bars bent trying to straighten it usually makes it worse. What I need is a giant hydralic press which covers the entire length of the bars to squash them back into shape without destroying them.

 

I'm just yanking your chain mate, I did think you had a press though, could you not adapt that?

I've only ever managed to remove very slight bends, anything excesive and you end just making them worse like you say.

So maybe scrap metal is all there worth now.

[vduben]

Ive got a small vice which I sharpen n grind stuff on trouble is once the bars bent trying to straighten it usually makes it worse. What I need is a giant hydralic press which covers the entire length of the bars to squash them back into shape without destroying them.

 

that will not straighten it, yes it may go straight under the press but when the press is lifted there will still be a bend, the metal will have to be over bent the otherway to staighten it out. plus 9 times out of 10 it wont bend properly.....

just flash the cash:icon14:

[Old Monkey]

If they are bent length wise you can usually get them straight again. If they are cupped width wise it isn't worth trying. When I get enough I'll make a chainsaw bar adirondack chair.

[Arborist]

3.9.2 Straightening on a press

 

3.9.3 Opening the groove

 

 

 

/ STIHL guide bars are spring

hard. When bent slightly within their resilient range, as can

I occur during normal operation,

the bars spring back to their original shape. However, if force is applied a bar will remain permanently bent. If the defor¬mation is only slight, the bar can be straightened.

It is essential to first check the whole bar for any signs of cracks, especially at the point of deformation. The bar is un¬serviceable if cracks are found.

 

There are several ways of straightening the bar. If this is done in a press or a vice, the bar must be supported at two points equidistant from the cen¬ter of the bend. Pressure is then applied to the center of the bend until the bar is straight and re¬mains straight after pressure is released.

 

 

Finish straightening is per¬formed on a levelling plate with a hammer until the bar is per¬fectly flat in the rail area. The groove width is then checked by placing a piece of chain with the correct drive link gauge in the groove and pulling it around the bar. If the drive link tangs catch or stick at any point, the groove must be opened as necessary.

Once straightening has been finished the bar must again be checked for cracks which may have been caused by straightening. If any cracks are found the guide bar must not be used again even though so much time and effort has been invested.

 

 

A pinched groove can be opened by means of a groove drift which matches the speci¬fied groove width. This is done by clamping the guide bar in a vice and inserting the drift in the groove at an angle of about 45° at a point where the width is still correct.

A hammer is then used to knock the groove drift through the pinched portion of the groove. If the groove is badly distorted, it may be necessary to repeat this process several times until the chain can be pulled along the bar without resistance.

There is a risk of cracking the guide bar during this process, particularly at the nose of hard tipped bars. For this reason the guide bar must be examined for cracks after the groove has been opened. If any are found, the bar must not be used again!

[treediver]

Think i'll have a bash at whackin em straight, then when that fails i'll scrap em.