Broken Bolt / Anti-Vibe

[No_Bivy]

Broke a bolt on the upper vibe mount on a 046. It is the "lag thread" . I have tried drilling the screw.....no avail. Maybe my drill bit sucks? Is there a better way to get it out?. The part it is screwed to is plastic. "easy out" ? or craftsmen type?

 

[GASoline71]

An easy out should do the trick... but ya have to get a small hole drilled in there... a sharp drill bit is the key.

Wow John... that saw has seen better days...

Gary

 

[No_Bivy]

Wow John... that saw has seen better days...

Gary

it's just dirty.......runs great. I just re-built the other 46 I have....seems to be good

 

[lumberjack]

Slow speed, down pressure, and a lubricating oil cuts better than spinning the bit at 3krpm, burning the tip of the bit.

 

[NeTree]

Slow speed, down pressure, and a lubricating oil cuts better than spinning the bit at 3krpm, burning the tip of the bit.

Yup.

 

[Al Smith]

By "lag bolt " I assume you mean it has threads like woodscrew .Those things are hard as a rock .

What you might try is an old toolmaker trick of "pecking " it out .Take an old drill bit and sharpen it to a fine point about like an awl tip . Use this like you would a prick punch to back out the bolt .Don't ask me why those old farts always used a drill bit ,don't know they just always did . I might add though that this about the only method I know of removing a broken grade 8 short of drilling it out using a solid carbide bit .

What ever you do though take caution you don't heat the broken screw stub enough to melt the plastic .Not good .

 

[sotc]

left hand drill?

 

[Al Smith]

Well ,a lefty is an idea but that's not the problem .That bolt is harder than Kelsey's nuts . If you get to drilling away with a high speed steel bit chances are all you are going to do is heat the thing up and make it harder and in the process melt the plastic .

It's going to take a hard bit ,solid carbide I imagine . Flood the thing with water as it's drilled .Water is a much better coolant than oil .Oil has a tendency to trap in the heat rather than carry it way .I learned that lessen while trying to turn some Thomson shafting .It got so hard I couldn't cut it with carbide ,that's hard .

 

[TheTreeSpyder]

That is tough stuff, and a tough location too. Prolly not best location for heating it up. i've had some luck with if there is / or is maid a shelf from center to outer and you can set a screw driver to catch on it, then drive it around with hammer

 

[No_Bivy]

By "lag bolt " I assume you mean it has threads like woodscrew .Those things are hard as a rock .

What you might try is an old toolmaker trick of "pecking " it out .Take an old drill bit and sharpen it to a fine point about like an awl tip . Use this like you would a prick punch to back out the bolt .Don't ask me why those old farts always used a drill bit ,don't know they just always did . I might add though that this about the only method I know of removing a broken grade 8 short of drilling it out using a solid carbide bit .

What ever you do though take caution you don't heat the broken screw stub enough to melt the plastic .Not good .

I don't quite understand Al..I have never heard of a prick punch, how do they work?

 

[SkwerI]

John, use a small chisel or sharp punch. Find a bump or ledge on the broken surface of the bolt to hit against, and then use the chisel and hammer to tap the bolt in a CCW direction and spin it out. It's slow but if you can get a bite then you can spin the bolt a little bit at a time.

 

[Al Smith]

A side comment .For reasons unknown to me it seems that the bolt in question is always the one that gives you the most grief .

I've seen them break or strip out on several Stihl models no matter if it were a plastic suspension system or metal . On the metal housings they often sieze up due to galvanic action and are nearly impossible to remove .

 

[woodworkingboy]

Get a headache just thinking about ones like that....

Being a chainsaw, there is probably oil down on the bolt, but putting in some penetrating oil might make it easier to loosen up. It's hard to tell in the pic if the broken bolt is flush to the surface, but if the methods suggested don't work, as a last resort, you might grind a slot in the bolt and if it won't back out with a regular driver, an impact driver will probably turn it. Be as delicate as you can when banging on it, don't want to crack the case.

 

[Al Smith]

The "woodscrew" threads used in plastic don't actually bind up like the bolts threads used on metal housings . Plus they actually hold pretty well .

A slot might just works as well as the other methods suggested .

 

[Cobleskill]

A Dremel tool with a cut-off wheel is a good way to make a slot. A pneumatic die grinder works good too.

 

[JIML]

I would always just dig a little plastic out around those and get a pair of pliers on them. Plenty of material to work with there. Probably dug 20 of those out when I worked in the shop, on 44,46,66.

 

[No_Bivy]

PRESTO!!!...better drill bit, and very gently used an easy out. Now all I have to do is put er back together....

 

[Al Smith]

Oh goody ,get 'er done ,go cut wood .

 

[No_Bivy]

finally, all saws back in action.......knock on wood

 

[Al Smith]

Well then ,go cut wood . See you learned something .It's all good .

 

[No_Bivy]

Well then ,go cut wood . See you learned something .It's all good .

thanks yall',... all of you have helped me save some $$$ on saw repair. I really appreciate it.

 

[GASoline71]

Cool beans!!!

Gary