Tonebar screw stripped, suggestions?

[tape_hiss]

I'm in the process of replacing all of the tone bars on my Mark 1 and I've come across a few whose screws have been stripped - the 5/16" hex bolt that attaches the tine to the tone bar is no longer, well, a hex and is almost completely rounded over on a few of them.  Anyone have any suggestions as to how I can remove that little bolt?

[BerneseMtnDog]

You could start by using a fine metal file to create some opposing flats on the bolt head and then try to grab it with a vice grip.

Steve

[Tine-E]

I've always used the cutting disc with my Dremel to cut/etch a slot deep and wide enough for your screw driver to fit. Never fails.

[Tim Hodges]

I've always used the cutting disc with my Dremel to cut/etch a slot deep and wide enough for your screw driver to fit. Never fails.

Exactly what I do.

[pianotuner steveo]

And I agree with that method also. If the head snaps off, and you can't remove the rest of the bolt, you will have to replace the tine. Drilling out the broken piece will likely ruin the threads.

[voltergeist]

And I agree with that method also. If the head snaps off, and you can't remove the rest of the lot, you will have to replace the tine. Drilling out the broken piece will likely ruin the threads.

I've had a few of those screws break (due to the considerable torque from the impact driver, it's easy to overdo it), and every time I've needed to I've gotten the screw out of the tine by drilling a small hole in the broken screw and taking it out with a screw extractor.  Sometimes that's not even necessary, since the screw is loose enough to twist out by hand.

[Alan Lenhoff]

It's worth mentioning that the archives of this group are full of (bad) advice that you really need to crank down those screws hard. Others have pointed out that the factory spec was 35 inch pounds of torque. That's not very tight.

Borrowing from an old post:

" If you use a wrench and exert force on it at a point 6 inches away from the bolt, you'd be about right if you pushed it with six pounds of force. I'd think the force you can exert with three straight fingers pushing the wrench ought to do the job."

"So, if you're using a long wrench, or you're pushing from your shoulder, or leaning your body weight on it when you tighten, or leaving a "Craftsman" imprint in your palm when you push, you're probably about to have an "Oh crap!" moment."

Alan

[bumpyrhode]

These are available from many suppliers. One end is a left handed drill bit and the
other is the extractor. Use the smallest size first. Don't drill to far into the head
because that might cause you to shear the head off. Best used with a drill that has
a slip-clutch chuck set at a low setting. Or when extracting put the bit in a 1/4"
interchangeable screwdriver handle. If you go the slot cutting method for a flat
screwdriver, try to use one that has a hex shank so you can put a wrench (spanner)
on it. Hold pressure down on the screwdriver handle and turn with the wrench.


http://www.lowes.com/pd_299780-41877-8430P_4294607735__?productId=3031513&Ns=p_product_qty_sales_dollar|1&pl=1&currentURL=%3FNs%3Dp_product_qty_sales_dollar%7C1&facetInfo=

[voltergeist]

It's worth mentioning that the archives of this group are full of (bad) advice that you really need to crank down those screws hard. Others have pointed out that the factory spec was 35 inch pounds of torque. That's not very tight.

Borrowing from an old post:

" If you use a wrench and exert force on it at a point 6 inches away from the bolt, you'd be about right if you pushed it with six pounds of force. I'd think the force you can exert with three straight fingers pushing the wrench ought to do the job."

"So, if you're using a long wrench, or you're pushing from your shoulder, or leaning your body weight on it when you tighten, or leaving a "Craftsman" imprint in your palm when you push, you're probably about to have an "Oh crap!" moment."

Alan

Fair enough, but I bet there are 100 tines that get put on too loose for every screw that gets broken.  The sound is dependent on the mechanical coupling between the tine and the tonebar, so there is really no such thing as too tight- there is only too much torque for the screw to withstand.

[pianotuner steveo]

My post should say "rest of the bolt" not "rest of the lot"

Stupid auto correct strikes again....

[voltergeist]

It's worth mentioning that the archives of this group are full of (bad) advice that you really need to crank down those screws hard. Others have pointed out that the factory spec was 35 inch pounds of torque. That's not very tight.

Borrowing from an old post:

" If you use a wrench and exert force on it at a point 6 inches away from the bolt, you'd be about right if you pushed it with six pounds of force. I'd think the force you can exert with three straight fingers pushing the wrench ought to do the job."

"So, if you're using a long wrench, or you're pushing from your shoulder, or leaning your body weight on it when you tighten, or leaving a "Craftsman" imprint in your palm when you push, you're probably about to have an "Oh crap!" moment."

Alan

Fair enough, but I bet there are 100 tines that get put on too loose for every screw that gets broken.  The sound is dependent on the mechanical coupling between the tine and the tonebar, so there is really no such thing as too tight- there is only too much torque for the screw to withstand.

I should add that either Ken Rich or Retrolinear (I forget which) has switched to socket head cap screws that can handle more torque for tighter coupling in the assembly. 

[Tim W]

Just for the record- we (Retrolinear) do not use socket head cap screws on Rhodes pianos. 
I spoke with Ken Rich and he does not either.

In a situation like this we would put the assembly in a vise, drill the head off the old screw, remove the remaining threaded part of the screw from the tone generator assembly and replace it with a spare.

[voltergeist]

Just for the record- we (Retrolinear) do not use socket head cap screws on Rhodes pianos. 
I spoke with Ken Rich and he does not either.

In a situation like this we would put the assembly in a vise, drill the head off the old screw, remove the remaining threaded part of the screw from the tone generator assembly and replace it with a spare.

My apologies.  I wonder where I saw that done, then?

Do you agree that there is theoretically benefit from using a stronger screw for tighter coupling? 

[Alan Lenhoff]

(The late) Steve Hayes of Speakeasy Vintage posted here some years ago that he used cap screws and lock washers to achieve a tighter bond. 

I have no idea whether that's a good idea or not.

Alan