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  #1  
Old 02-21-2021, 09:03 AM
cheer tunes cheer tunes is offline
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Default Step bit recommendation (for drilling end pins)

Hi, I'd like to start drilling out my own end pins today for pickup installs. SO I need the hole to be 1/2 inch. Several of my instruments already have the smaller hole that will just need to be enlarged.

Can you recommend a step bit to use in my drill? I know stew mac has an end pin reamer that is $90. Will something from Home Depot work just as well?

Thanks!!
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Old 02-21-2021, 10:02 AM
Rudy4 Rudy4 is online now
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I glue in a short length of dowel into existing holes and use that as a firm and solid place to put the starting point of a 1/2" Forstner bit. The dowel only needs to be about 1/4" long because the Forstner self-centers after the outer spurs start cutting the bore. I cover the end pin location with wide painter's tape as added insurance against any damage to the existing finish.

Last edited by Rudy4; 02-21-2021 at 10:14 AM.
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Old 02-21-2021, 10:06 AM
Mandobart Mandobart is offline
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I've used this stepless drill bit set from Harbor Fright. The hex shaft of course fits in a drill, but I've also used it in my cordless driver and a hand driver, depending.

I als forstner bits.
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Old 02-21-2021, 10:07 AM
RoyBoy RoyBoy is offline
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I just went to Harbor Freight and bought a set (they only had them in sets of three) for under $20. The longest/skinniest of them goes by increments of 32nds which makes it track into a smaller hole really well. I drilled into the tail of the guitar up to the next to the last step 15/32" and from there switched to a regular 15/32" drill bit to finish the hole. 15/32" is actually the hole size you need for those end pin jacks, but 1/2" works fine I'd imagine.
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Old 02-21-2021, 10:08 AM
charles Tauber charles Tauber is online now
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This has been asked, and answered, many times. Essentially, any standard method to drill or enlarge a hole has been successfully used by those reporting their methods.

You can,

  • use a standard step drill
  • use an inexpensive standard (sheet metal) reamer
  • use an expensive wood reamer, such as sold by luthier supply houses
  • use a series of progressively larger standard twist drills
  • use brad-point drills bits
  • use spade bits
  • use Forstner bits
  • plug the hole first
  • not plug the hole first
  • enlarge an existing hole
  • put tape around the hole to protect the finish
  • not put tape around the hole to protect the finish
  • use the bit rotating "forward"
  • use the bit rotating "backward"

Any or all of these can be made to work and have been used. The choice of which to use is up to the individual and what he or she believes give the best result for him or her, or best fits his or her budget and/or available tools.

About the only thing you can't do is use a spade bit with an existing hole, since there is nothing to centre/guide the bit.

Last edited by charles Tauber; 02-21-2021 at 10:14 AM.
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  #6  
Old 02-21-2021, 10:16 AM
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Frank Ford Frank Ford is offline
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IRWIN UNIBIT, available in hardware stores, etc. Get the one with 1/16" steps.

Looks nasty, but is safe, clean, easy, self-centering.
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  #7  
Old 02-21-2021, 03:43 PM
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Victory Pete Victory Pete is offline
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Quote:
Originally Posted by charles Tauber View Post
This has been asked, and answered, many times. Essentially, any standard method to drill or enlarge a hole has been successfully used by those reporting their methods.

You can,

  • use a standard step drill
  • use an inexpensive standard (sheet metal) reamer
  • use an expensive wood reamer, such as sold by luthier supply houses
  • use a series of progressively larger standard twist drills
  • use brad-point drills bits
  • use spade bits
  • use Forstner bits
  • plug the hole first
  • not plug the hole first
  • enlarge an existing hole
  • put tape around the hole to protect the finish
  • not put tape around the hole to protect the finish
  • use the bit rotating "forward"
  • use the bit rotating "backward"

Any or all of these can be made to work and have been used. The choice of which to use is up to the individual and what he or she believes give the best result for him or her, or best fits his or her budget and/or available tools.

About the only thing you can't do is use a spade bit with an existing hole, since there is nothing to centre/guide the bit.
I like this approach. I always start by using a reamer to get through the finish and the side wood to ensure no chipping, then I improvise depending on mood.
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Old 02-22-2021, 11:24 AM
John Arnold John Arnold is offline
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I start with a utility reamer, then finish with successive drill bits. Reaming the hole to the finished size on the outside helps prevent chipping with the drill bit. Spinning the bit backwards also prevents chipping.
When I do enlarge them, I drill them 15/32", because that is the size of the jacks. IMHO, drilling a 1/2" hole makes for a very sloppy fit.
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  #9  
Old 02-22-2021, 12:00 PM
Howard Klepper Howard Klepper is offline
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Quote:
Originally Posted by Frank Ford View Post
IRWIN UNIBIT, available in hardware stores, etc. Get the one with 1/16" steps.

Looks nasty, but is safe, clean, easy, self-centering.
the 4-12 mm one is even better for this job, since 12 mm is all you need, and 1/2" is a bit oversized. You can go all the way through the block with the last 12mm step. Also the segments are longer than with the one that goes in 1/16ths, which makes it a little smoother to use.

It is very hard to chip out anything with the Unibit. I've tried, but couldn't make it mess up.
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  #10  
Old 02-22-2021, 07:00 PM
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bnjp bnjp is offline
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Yes, use the Unibit, 1/8" to 1/2" but don't get the one with like 12 different steps, get the one that's more like six steps. You'll have to chuck it out on your drill a little so it'll drill all they way through the tail block.

This one:
https://www.amazon.com/Irwin-Tools-1...4041916&sr=8-5

EDIT: the reason I say to get the one with fewer steps (opposite of what Frank said) is because I also use it to drill out electrics that need import holes drilled out to 3/8" CTS pots. The steps on the other one aren't deep enough to go through the guitar top.
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Last edited by bnjp; 02-22-2021 at 07:05 PM.
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  #11  
Old 02-22-2021, 07:01 PM
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bnjp bnjp is offline
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Quote:
Originally Posted by Howard Klepper View Post
the 4-12 mm one is even better for this job, since 12 mm is all you need, and 1/2" is a bit oversized.
This is true, actually. I have a 12mm one too. But usually use the 1/2" one
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