Woodworking Q: Enlarging A Drilled Hole?

Discussion in 'Project Depot' started by glasshand, Jul 16, 2019.

  1. glasshand

    glasshand Well-Known Member

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    So I want to replace the tremolo studs in my Peavey body with the Gotoh studs. This will mean enlarging the holes, from about 7mm to 10mm. What's the best way to do this? I'm being very cautious because mounting the bridge is really the single most critical thing, IMO, and the hardest to fix if you get it wrong. The current placement of the holes is fine, I just need them to be larger. I guess if the answer is "fill and redrill" I can live with that.
     
  2. STACKS

    STACKS Well-Known Member

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    That's what I would do. Probably the best/easiest way to make sure you have the bridge in the correct place
     
  3. mozz

    mozz Well-Known Member Supporting Member

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    If you are making the holes bigger, why would you fill?
     

  4. honyock

    honyock Well-Known Member

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    if you have an appropriately sized drill press, you could mask the current hole to prevent tear out. Then use the current sized bit or even chuck up the anchor to line it up and then remove the bit (or anchor) from the hole when it the body is aligned and locked into place somehow.

    Then install the correct sized forstner bit or reverse drill with the correct sized jobber bit and you'll get damn close to a centered hole...
     
  5. rrobbone

    rrobbone Well-Known Member

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    In replacing a stud with a larger diameter stud, the pivot point of the trem on those studs will be moved back ever so slightly because the pivot point is on the edge of the stud, not the center. It would probably be just fine because you could likely re-adjust the saddles to account for the difference. The biggest issue there is that you lose that tiny bit of space for intonation as it would shorten the area available for travel by the saddles.

    If you want to retain the same amount of adjustment area for the saddles, then fill and redrill is the way to go. I would suggest this because going from 7mm to 10mm diameter is a big difference when talking about those studs. That might cause an issue in terms of a guitar's scale length. I would imagine this would make intonation still possible, but more difficult than is necessary. If there's room to fill and redrill, that's what I do. It'll make certain the guitar will intonate properly, and if it's done correctly it will also strengthen the area of stress in the wood around the studs.
     
  6. Rollin Hand

    Rollin Hand Well-Known Member

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    Not being argumentative, but the Gotoh studs that I have are the same diameter at the pivot point as a Floyd stud. The base and the bushing are larger by comparison.

    Still, to add Floyd studs to my 5150 project, I was told a fill and redrill were necessary, if only to keep the bit from wandering.
     
  7. jam

    jam Well-Known Member

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    Holy crap! Talk about over thinking it. If the current holes are in the right place, the new ones will be too. Just go incrementally through drill sizes up to where you need. The drill bits will be pretty much self-centering.
     
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  8. rrobbone

    rrobbone Well-Known Member

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    No argument here! I welcome the discussion.

    You make an excellent point. I assumed that since the studs were larger diameter at the base, then they'd naturally be a larger diameter at the pivot point as well. I agree it may not be the case. G-hand needs to measure that.

    If the Gotoh studs are the same diameter as the original studs at the pivot point, then all that needs doing is making those stud holes larger in diameter. The placement would be fine where it sits under these circumstances. The scale length measurements would be the same.

    However, I'd still go ahead and re-fill and drill as was recommended to you - if for no other reason than to strengthen that stud hole.

    Well caught.
     
    Last edited: Jul 17, 2019
  9. jwguitar

    jwguitar Well-Known Member

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    Fill the holes and redrill using a drill press. That way you get an straight hole and that will assure you the studs are not tilted.
     
  10. mozz

    mozz Well-Known Member Supporting Member

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    10mm hole needed, so to drill and refill you need a fairly large dowel, at least 14mm if not bigger to gain any strength. That's gonna show up pretty ugly.
     
  11. nomadh

    nomadh Well-Known Member

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    I am mystified as to why anyone would possibly fill and redrill. Isnt there a bit with steps to it. Line up the step in the hole. Drill down to the next step or 2. Finish with the correct size now you have a good guide hole. Other wise if that bit doesnt exist line it up on a drill press. You'll be within 1/2 mm. Isnt that what intonating bridges are for? Id think the biggest issue would be finish cracking or tearout. Just make sure to use a brand new $40 bit and go slow.
     
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  12. honyock

    honyock Well-Known Member

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    even a decent (new sharp) 10mm forstner bit should not tear out if you mask it well. I've done this upsizing tailpiece bushing to 1/2" on multiple import guitars now.

    Reverse drilling will use the bit like a rasp and also prevent tear out, as long as you go slow, but they tend to wander more easily than a forstner bit due to length.

    Sent from my SM-G955U using Tapatalk
     
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  13. Rollin Hand

    Rollin Hand Well-Known Member

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    Thanks. I was going to use the Gotoh studs on my project, but the bushing is so wide that it would impact the structural integrity of the holes. Not good.

    I should have just had the thing drilled for Floyd studs in the first place. Penny wise, ound foolish.
     
  14. Pratteman

    Pratteman Well-Known Member

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    Use a step drill

    Sent from my Pixel 2 XL using Tapatalk
     
  15. jam

    jam Well-Known Member

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    Is this because the holes from the bushings/inserts would impinge on the trem cutout?
     
  16. andrewsrea

    andrewsrea Well-Known Member

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    For enlarging holes: reamer
     
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  17. Rollin Hand

    Rollin Hand Well-Known Member

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    Yeah, pretty much. That is why I bought the Flod posts/bushings -- better metal equals more sustain and better performance. The posts that came with the kit don't give me that confidence, and the Gotoh bushins look to be too big for my application.

    Then I just have to find the time to finish the damn thing.
     
  18. jam

    jam Well-Known Member

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    For me, that's always the hardest part!
     
  19. Rollin Hand

    Rollin Hand Well-Known Member

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    Tell me about it. I am weighing selling a body I have (2-piece lightweight ash mighty mite body) becasue I have had it for years and haven't gotten to it. I have a couple of other guitars that could use a titch of love that I don't have time to give -- they may go on the block. Then I might be able to finish the 5150 and Project Sustained Effort, which could esily be named Project Intermittant Effort At Best.
     
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  20. Chocol8

    Chocol8 Well-Known Member

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    I would absolutely NOT refill unless the the center needs to move more than 1.5 mm.

    Use a drill press. Clamp the body in place with the center of the hole lined up and drill.
     
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