Stihl FS45 string trimmer bump knob - cannot remove

Fish

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I'll take some better pics here in a minute....
 

Fish

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This is what the cutting head sits on.DSCN6217.jpg
 

Fish

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This is the mating side view of the cutting head, it has the nut shaped hole to fit on the shaft end.DSCN6216.jpg
 

Fish

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Now, they put this hole here so you might put a pin or nail in to hold the head while you try to loosen the nut.

DSCN6215.jpg
 

Fish

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And inside the plastic nut is just a regular Stihl bar nut.


DSCN6218.jpg
 

dukerocks

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Thanks for the EXCELLEXT pics. I used a ice pick through that hole but it would not engage into any hole in the backside of the cutting head - I spun the cutting head slowly while pushing on the icepick. Even if I prevent the cutting head from turning this will not keep the flex cable from turning while I try to turn the nut. I have got to prevent the flex cable from turning while trying to twist off the nut. Thanks
 

Fish

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It sounds like the black plastic cutting head has rounded out, the hex headed hole should lock on the end of the shaft and it should turn only when the shaft turns.
 

dukerocks

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It did not round out - I do have the bare exposed nut. It does not have any plastic around it - the bump knob has been completely cut offf. I need to keep the flex drive cable from turning!!!! Bob
 

dukerocks

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I am attaching pics of what I am working on, just to show you where I am at with this project. As I say, I completely have the bump knob cut away showing the bare nut.
 

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Fish

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If you literally clamped the whole black cutting head in a big vise so it couldn't move at all, and turned the nut to the left, what would happen?

Would the drive cable still turn?
 
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