Repairing trem knife edges - Trem on my JS1000 will not retu

[Jason Stone]

I figured this would be useful for all. *I looked in the old forum for something addressing this directly but couldn't find anything.

The lo pro edge on my JS1000 refuses to return to zero after use. *It either leaves the strings slightly sharp or slightly flat. *The guitar is only 3 or 4 months old, but*I have a feeling the knife edges are not as sharp as they should be. *I seem to remember Rich telling me that some trems left the factory without properly sharpened edges. *The most obvious sign on my JS1000 is that the trem actually pops off the post on the treble side when the bar is depressed as far as it can go. *No, the trem doesn't actually come off the posts completely, but you can hear an audible "pop" once the bar is down far enough. *You can also feel something move if you put your finger on the post when you do this. *I think the edge is actually coming out of the groove in the post. *I've taken the trem off the guitar and compared it to the trem on my JEM7VWH (which doesn't have this problem and returns to zero every time) and I can't really see much difference between the knife edges on each. *However, because of the popping noise just described, I am convinced it is either the knife edges on the trem or the posts themselves that are causing this problem. *BTW, the posts are not loose and are properly locked down with the small screw on the inside.

So the question is: *what is the best way to sharpen the knife edges on the trem? *Is there a particular kind of file I need to buy? *What angle do I need to sharpen at? *How do I know when the edges are sharp enough (other than by reinstalling the trem and testing)? *You get the idea.

Any advice is most appreciated.

Thanks!

Jason

[jemsite]

OK, i think a nice writeup was lost when the forum crashed a while back.

You will need two FINE files.
* One round one. Mine are 7/32" diameter
* One flat (mine is a 3-sided) about 5/16"

Obviously, the round file is for the curved tremolo knife edge, the flat file for the flat knife edge. The files usually are bi-directional, like a saw. You will have to stroke the file in ONE DIRECTION, utilizing the blades to smooth not rip the metal edge. See the crude diagram below:

[font=courier]
--->file direction--->
<<<<<<<<<<<<&l t;<<< (knife edge)
\\\\\\\\\\\\\\\\ (file blade orientation)[/font]

Ensure that you hold the file at the angle that would fix the edge/burr. You're looking at about a 45-degree angle or less but eyeball it to follow the existing knife edge.

I'll have to take some pics but in the meantime common sense should prevail. Use the full length of the file with long, steady strokes. Repeat a few times and reexamine visually to see if more is needed.

Again the goal is to make the knife edge crisp instead of being dull, blunt or burred.

The last step is to replace the tremolo posts. Makes sense to start with new ones if possible. Good luck... glen


(Edited by jemsite at 10:38 am on April 30, 2001)


(Edited by jemsite at 10:39 am on April 30, 2001)

[mikek]

before u start filing away (on the tremolo, that is

replace the tremolo posts first, they are pretty cheap - and tighten the toplock (2 screws in the back of the neck) REAL good, and I really mean you have to tighten it alot!!.

I had the problem myself, changed the tremolo system/tremolo posts (to a edge) - STILL had the problem - then I SUPER tightened the nut - and it now comes back to zero 100%.