Drill a small-diameter pilot hole, THEN a large-diameter finished hole? Or not?

[Jim Becker]

Given you'll be using a DP and clamping the bassword body to the DP table for the task, you do not really have to drill a pilot, IMHO, if you use a sharp drill bit for the work. I tend to use Forstner bits for this kind of thing. The advise to very carefully mark "the spot" with a center punch is spot-on. It doesn't need to be deep but it will serve as the spot you need to line up your drill bit before clamping and doing the deed. A dimple is easier to do that with than just a pencil mark, IMHO. But again, not deep...just enough to show the spot clearly.

BTW, I've been really happy using basswood for guitar bodies. It cooperates really well and is fine grained. While I cut on my CNC, any hand work with sharp tools subsequent to that work has been a pleasure. The price is pretty decent, too.

[Bill Dufour]

A aircraft type stepped drill would work. But the plot point is not much smaller then the main body portion. Good practice is the pilot should be no larger the the diameter of the web of the bigger drill.
Bill D

https://www.ustoolandfastener.com/3-...SABEgLobvD_BwE

[Tom Burgess]

Given you'll be using a DP and clamping the bassword body to the DP table for the task, you do not really have to drill a pilot, IMHO, if you use a sharp drill bit for the work. I tend to use Forstner bits for this kind of thing.

I just tried the 3/8" Forstner in an inconspicuous section of the basswood body. Too tight, so my only option looks to be the 25/64" twist drill.

The advise to very carefully mark "the spot" with a center punch is spot-on. It doesn't need to be deep but it will serve as the spot you need to line up your drill bit before clamping and doing the deed. A dimple is easier to do that with than just a pencil mark, IMHO.

Agreed. In my 3/8" Forstner experiment, I did dimple the center point as you suggest, and was surprised at how easy it was to align the Forstner center spur with that dimpled centerpoint. I guess I've had problems with that because I typically use larger Forstner bits; all that 'diameter' gets in the way of seeing exactly where that spur is in relation to the centerpoint dimple.

BTW, I've been really happy using basswood for guitar bodies. It cooperates really well and is fine grained. While I cut on my CNC, any hand work with sharp tools subsequent to that work has been a pleasure. The price is pretty decent, too.

I bought two inexpensive Chinese Stratocaster clones. Excellent value, but some dimensions are out of spec. For example, I have to slip the bolt-on neck away from the body because the scale length is too short. Can't intonate properly unless I extend the scale length to the correct 25.5 inches.

So I converted the four neck-screw holes to short slots last night. Had everything lined up perfectly, with the body clamped firmly to the drill press table. My 3/16" twist drill entered the workpiece exactly where I intended, right next to each existing 3/16" hole. BUT...when I unclamped and flipped the body/workpiece, those new holes were not aligned properly at their exits. And each wandered in a slightly different direction. Had to clean things up with a coping saw. But as you say, the basswood was easy to work with hand tools.

[Tom Burgess]

A aircraft type stepped drill would work. But the plot point is not much smaller then the main body portion. Good practice is the pilot should be no larger the the diameter of the web of the bigger drill.
Bill D

https://www.ustoolandfastener.com/3-...SABEgLobvD_BwE

That stepped drill looks great. I've never seen one before, but I see it's part of the Kreg line. I just found out that 3/8" is too small a hole, so thank you, but I'm going to have to go to 25/64" and that's an unusual size. So it looks like a twist drill in that size is my only option.

And thanks for the rule of thumb regarding maximum size for the pilot hole. That'll be a problem for me in this case, because I don't have long bits in small diameters. I hope it's not a hard and fast rule.

[Jim Becker]

Bummer that the kits had the scale incorrect...that's a bear to adjust when a trem is involved. Hardtail...you could have just moved the bridge. Trem...you gotta do the neck dance and then deal with the gap at the heel.

I encourage you to build your own, too. We have a nice Musical Instrument forum here at SMC where a number of guitars have been featured. I'll also recommend the TDPRI forums, specifically the "Tele Home Depot" discussion area. Nice folks like here with a focus on guitar building, and not just Fender designs. Several of us are members both here at SMC and there at TDPRI.

[Kevin Jenness]

It will be more accurate to drill the larger hole first, as it will be less likely to deflect than the smaller drill. It is relatively easy to find the center of the larger hole, even with a twist bit. For a cleaner entry you can get a 25/64" brad point. https://www.leevalley.com/en-us/shop...s?item=07J0225

[John K Jordan]

I've had good success by starting the holes in wood with either a center bit or a starter bit, both used in machining. This assumes using a drill press to constrain the bits and clamp the work, of course. An x/y table for the drill press can help with precise positioning.

For precision if possible I always use shorter bits rather than long jobber bits. Screw machine bits are perfect - stubby and won't flex. Or you can cut a long bit shorter and resharpen if you have that ability.

A good drill press and chuck with no slop is important if a precise hole size is needed. Even better, if you have or know someone with a milling machine you can make holes as precise as you'll ever get, both in position and hole size. Align the wood with the axis of the work and use the X/Y cranks to position precisely in angle and distance. Can use a center-cutting end mill that will make a plunge cut but a good drill bit held in a collet should be as precise. A quality Jacobs chuck will work too but if hole diameter precision was needed I'd test it with a drill rod and a dial indicator. I use a laser center finder to align the axis with the marked position then swap it out for the bit. I use the laser center finder on my drill press too. I bought this one:
https://littlemachineshop.com/produc...ProductID=2604

I don't see you mention where you live - there may be people reading with scrap basswood near you. I keep basswood in 12/4 to 16/4 planks up to 12" wide. (I use it to make woodturnings with chip carving.)

chip_carved_goblet_c.jpg

JKJ

[David Buchhauser]

For the most accurate work, use metal working tools. Start with an optical center punch. Then if you will use a pointed drill, drill with that. If you use a twist drill, use a center drill.

I agree on the "metal working tools". My first thought (if I were tasked with doing this) would be to fixture this guitar body to the table of my Bridgeport milling machine with digital readout. Then I would either drill, mill, or some combination to produce accurate round holes in the desired locations.
David

[Keith Westfall]

I just tried the 3/8" Forstner in an inconspicuous section of the basswood body. Too tight, so my only option looks to be the 25/64" twist drill.

I'd drill it with the Fostner bit first and then ream it with the 25 /64. It should/will follow the hole for a clean out, rather then rely on the 25/64 to drill the hole first. Fostner bits don't usually wander to far a stray!

[Clint Baxter]

It will be more accurate to drill the larger hole first, as it will be less likely to deflect than the smaller drill. It is relatively easy to find the center of the larger hole, even with a twist bit. For a cleaner entry you can get a 25/64" brad point. https://www.leevalley.com/en-us/shop...s?item=07J0225

FWIW Lee Valley has brad point bits in both 25/64 and 10mm sizes. They also have a 10mm forstner bit for $10.50, much cheaper than the Bosch bit you referenced in an earlier post. More options to consider.

Clint

[Walter Plummer]

I just became aware of these bits a while ago. I have not used one yet but I like the idea. The tips are like small step drills to start the bit. https://www.norsemandrill.com/Vortex...-Mechanics.php. KBC tools sells them. https://www.kbctools.com/customer/do..._SaleFlyer.pdf Page 5 of flyer.

[ChrisA Edwards]

Tom, I have loads of offcuts of basswood, what size pieces do you need?

Basswood is very light in weight.

I'd be happy to send you some for the cost of shipping.

[Ole Anderson]

Mission critical? Construct a steel drill guide first. That way there is no chance for the drill to follow the grain and wander.

[Jim Becker]

Mission critical? Construct a steel drill guide first. That way there is no chance for the drill to follow the grain and wander.

"Enquiring Minds" want to know...what that actually is. . And it it applicable for use on a drill press like the OP is doing?

[Brian Holcombe]

A drill guide is helpful if you are doing multiples of this work.