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View Full Version : Can I pick your brains? How would you solve this puzzle....

HankMcSpank
09-09-2011, 11:25 AM
Hiya,

Long time no speakee...i have a challenge & you guys popped straight into my non engineering mind!

I seek to be able to drill a hole about 4mm diameter, very accurately (ie no divergence) all the way along a 450mm long guitar neck...

http://img98.imageshack.us/img98/5528/6512string.jpg (http://imageshack.us/photo/my-images/98/6512string.jpg/)

....so that the resulting bored hole runs just beneath the fretboard (the fretboard is the 3mm veneer dark wood on top of the neck ie where where the guitar puts his fingers)

Two problems...

1. What kind of custom rig would be in order (I'm thinking any drilling bit/rig would need to 'hang' vertical so gravity doesn't 'pull' on the bit, causing it to diverge)

2. Where on earth could I buy a drill bit just 4mm diameter and 500mm long! (or how would you approach making one?!). I have found places that sell 500m bits, but they start at 6mm diameter, which is excessive for my needs.

Things to consider....

No snappage - it would be catastrophic to have the bit snap half way along

Really accurate - it would be even more of a tragedy to see the drill bit surface out of the guitar's fretboard at the end of its travel!

repeatability - I'd like to do this to a few necks!

Many thanks,

Hank.

Robin Hewitt
09-09-2011, 11:35 AM
Hi Hank

Perhaps you need a gun drill. You blast air through to clear the chips so they don't push you off course. (Oil or oil air mix if drilling guns)

You spin the wood. The axis of rotation defining a straight line through the part where the wood is moving slowest. IIRC the gun drill shies away from the faster cut and automatically centres itself on the axis.

I have some long gun drill bits if you want pics.

Knowlege exhausted

Robin

EDIT: PS: Suggest, drill the hole, cut the neck around it

Ricardoco
09-09-2011, 12:15 PM
Hiya,

Long time no speakee...i have a challenge & you guys popped straight into my non engineering mind!

I seek to be able to drill a hole about 4mm diameter, very accurately (ie no divergence) all the way along a 450mm long guitar neck...

http://img98.imageshack.us/img98/5528/6512string.jpg (http://imageshack.us/photo/my-images/98/6512string.jpg/)

....so that the resulting bored hole runs just beneath the fretboard (the fretboard is the 3mm veneer dark wood on top of the neck ie where where the guitar puts his fingers)

Two problems...

1. What kind of custom rig would be in order (I'm thinking any drilling bit/rig would need to 'hang' vertical so gravity doesn't 'pull' on the bit, causing it to diverge)

2. Where on earth could I buy a drill bit just 4mm diameter and 500mm long! (or how would you approach making one?!). I have found places that sell 500m bits, but they start at 6mm diameter, which is excessive for my needs.

Things to consider....

No snappage - it would be catastrophic to have the bit snap half way along

Really accurate - it would be even more of a tragedy to see the drill bit surface out of the guitar's fretboard at the end of its travel!

repeatability - I'd like to do this to a few necks!

Many thanks,

Hank.

Hi. so the picture below is what you would like to achieve but after the neck is constructed??

4493

I did always wonder how they did it...

blackburn mark
09-09-2011, 12:15 PM
i allways assumed the tension rod ran down a slot that you would cut into the neck face and cover with the fret board ?
wouldnt work if your just adding a veneer as the fret board

i would s**t myself trying to drill over that distance:wink:

you have got me thinking now!!

if the standard is to bond your fret board over the slot then it would be easy .....

iv just measured one of mine.... the fret board is 5mm deap, rose wood i think

blackburn mark
09-09-2011, 12:18 PM
you beat me to it rick..... they are just slotted buy the look of them :)

Ricardoco
09-09-2011, 12:26 PM
i would s**t myself trying to drill over that distance:wink:

And you beat me to that!!!

I'm not joking they were the exact words i thought when i read the post!!!:rofl:

blackburn mark
09-09-2011, 12:32 PM
And you beat me to that!!!

I'm not joking they were the exact words i thought when i read the post!!!:rofl:

hahahaha!!! i reckon you owe us a cake hankmcspank for saving you the nightmare:lol:

HankMcSpank
09-09-2011, 01:06 PM
no it's not for a truss rod - it's for wires (LED fret markers).

Agreed, it's an onerous task, but believe me, I'd sh*t myself more by way of heating the fretboard with steam, prizing it off with lever, routing some wire channels, sanding the glue off the fretboard and neck, and then putting it all back together and then aligning it back up - ie aka this guy's way...

....drilling a hole down the neck is the way to go!

I've knocked up a small 12 led (10 channel) led chaser & want to fit some LEDs in the fretmarkers of my cheap guitar as an experiment.

blackburn mark
09-09-2011, 01:25 PM
WHAT???? you mean no cake???? downer!!!.....

it makes some sense now.... id be tempted to explore the posibility of drilling side on under the frettboard to the truss rod cavity
and pray there is enough room in there for your wires

can you still get the truss rod out ?

HankMcSpank
09-09-2011, 01:31 PM
can you still get the truss rod out ?

Not understanding the question, I've not done anything yet, I'm at the preliminary stage asking for ideas/info how to drill a long thin hole :naughty:- where does the truss rod fit into this line of thinking?!

Rogue
09-09-2011, 01:44 PM
Not understanding the question, I've not done anything yet, I'm at the preliminary stage asking for ideas/info how to drill a long thin hole :naughty:- where does the truss rod fit into this line of thinking?!

I'd guess the question relates to making use of what is already there - there might be a way of using the existing hole and extending it enough to fit the wires?

I have this mental image now of trying to thread a wiresaw down the truss hole in order to cut a small v-notch for the wires, and I'm breaking a sweat just thinking of all the horrible ways that could go wrong :confused:

blackburn mark
09-09-2011, 01:48 PM
Not understanding the question, I've not done anything yet, I'm at the preliminary stage asking for ideas/info how to drill a long thin hole :naughty:- where does the truss rod fit into this line of thinking?!

Errrrm? i may be missunderstanding what you are trying to do.... i was assuming you where looking for a way to run your wiring from your fret inlayed LED lights to your guitar body and im thinking you already have a cavity in the neck running its full length directly under you fret inlays except for your 12th fret, im also assuming that the cavity is a U shape because of the way its manufactured and just maybe ther is enough room to run your wiring alongside the tension rod

HankMcSpank
09-09-2011, 01:55 PM
You're understanding my final goal ....but I didn't understand your question about me having access to the truss rod (which suggested I already had my guitar here in pieces) ....I was talking in general - obviously there's a truss rod in every guitar neck, but not being a truss rod expert (or neck expert), I have no idea how much space there is between the top of it (assuming the guitar is lying on its back) & the fretboard rear 'face'.

Does anyone know if there's typically a 'void' there already? (ie a gap between the truss rod & the fretboard)...these would be thin wires, though quite a few of them - about 11 wires in fact)

blackburn mark
09-09-2011, 02:10 PM
You're understanding my final goal ....but I didn't understand your question about me having access to the truss rod (which suggested I already had my guitar here in pieces) ....I was talking in general - obviously there's a truss rodd in every guitar neck, but not being a truss rod expert (or neck expert), I have no idea how much space there is between the top of it (assuming the guitar is lying on its back) & the fretboard rear 'face'.

im no expert on them myself.... my understanding has it that the slot will have been cut with a ball nose type cutter and the truss rod will be a pretty snug fit except that when you add the fret board there will be some space left in the two upper corners of that U shaped slot that the fret board now covers

the reason i asked if you could still get the truss rod out is if there is enough room you will still have the problem of threading those wires, if the rod comes out it should be possible

HankMcSpank
09-09-2011, 02:39 PM
I thought a typical truss rod could only be removed by taking off the fretboard? (which is what I'm trying to avoid doing)

blackburn mark
09-09-2011, 02:54 PM
I thought a typical truss rod could only be removed by taking off the fretboard? (which is what I'm trying to avoid doing)

iv an acoustic that looks like its non removable and iv a jackson with a straight through neck, iv not explored how thats done

im pretty sure (if my memory serves me) i had a jap strat that had a stopper nut at one end and was ajusted at the machine heads so im pretty sure that one would have come out

its worth exploring though if your going to make a few.... im pretty sure it would save some serious heart ache if you could find a way around drilling the full length

HankMcSpank
09-09-2011, 03:03 PM
Truss rods are quite often fairly embedded in the neck,

http://www.youtube.com/watch?v=UrK-DVFFw4g (a series of 8 videos how to repair a broken one!)

but I concur, that if I can utilise any opportunities that existing channel presents, it's gotta be the way to go

Ricardoco
09-09-2011, 03:07 PM
iv an acoustic that looks like its non removable and iv a jackson with a straight through neck, iv not explored how thats done

im pretty sure (if my memory serves me) i had a jap strat that had a stopper nut at one end and was ajusted at the machine heads so im pretty sure that one would have come out

its worth exploring though if your going to make a few.... im pretty sure it would save some serious heart ache if you could find a way around drilling the full length

Now i may be way off here but a distant memory 20yrs + (When i was the Owner/Proprieter of workhouse rehearsal and recording studio.) I saw a truss rod taken out and i remember asking why it was bent, and was told that some are as it puts a spring in it.. so maybe that is why it is hard to remove when the tension is off??

And no i dont know anything about music as i didnt need too!!

Rick

blackburn mark
09-09-2011, 03:53 PM
Truss rods are quite often fairly embedded in the neck,

http://www.youtube.com/watch?v=UrK-DVFFw4g (a series of 8 videos how to repair a broken one!)

but I concur, that if I can utilise any opportunities that existing channel presents, it's gotta be the way to go

you learn something every day :) i allways assumed the truss rod was a single rod.... youve got your work cut out there trying to work around one of those in the video :(

i think i would sooner make a neck from scratch than go through all that pain of stripping one... now the drilling looks a bit less desprate:redface:

i think i would still try my best not to drill... what about removing the frets and cutting a funky (strategic) pattern in the fretboard and bonding the wiring behind an inlay ??

can LEDs be run in series ? how thin could you go with wiring ?

im going to have nightmares about drilling tonight:lol:

HankMcSpank
09-09-2011, 04:08 PM
can LEDs be run in series ? how thin could you go with wiring ?

Neither! I'm running out to 12 leds individually (this allows for some funky VU meter & knight rider type patterns!) ...the wire will be very thin though.

Jonathan
09-09-2011, 04:14 PM
Neither! I'm running out to 12 leds individually (this allows for some funky VU meter & knight rider type patterns!) ...the wire will be very thin though.

Er, surely for 12 individual LEDs you need 13 wires? Or are you multiplexing them? Wiring the LEDs in a 3x4 array gets the wire count down to 7. Five wires is possible, depends what you are controlling them with? You can get some very very thin wire, can't remember the name of it at the moment. I've got plenty of 8 core 'alarm cable' if that's any use to you...

HankMcSpank
09-09-2011, 04:22 PM
Er, surely for 12 individual LEDs you need 13 wires? Or are you multiplexing them? Wiring the LEDs in a 3x4 array gets the wire count down to 7. Five wires is possible, depends what you are controlling them with? You can get some very very thin wire, can't remember the name of it at the moment. I've got plenty of 8 core 'alarm cable' if that's any use to you...

there are actually 10 frets with 'fret markers' along the neck (some guitars only have 9 frets with markers), but two of the frets along the neck actually have two fret markers (which would be 2 leds that light up together, so only one 'feed' wire shared between them), so it's actually 10 fret positions, plus a return wire.

re the alarm cable...thanks but I've cable aplenty this end!

blackburn mark
09-09-2011, 04:29 PM
Neither! I'm running out to 12 leds individually (this allows for some funky VU meter & knight rider type patterns!) ...the wire will be very thin though.

ahhh... sorry man, i didnt twig untill id posted.... if your going to the trouble of putting them in you have got to get some of that old "night rider" poshness going on :)

HankMcSpank
09-09-2011, 04:44 PM
ahhh... sorry man, i didnt twig untill id posted.... if your going to the trouble of putting them in you have got to get some of that old "night rider" poshness going on :)

Hehe, cheesy, uneccesary...but justifiable nevertheless...

http://www.youtube.com/watch?v=W8yOAFVUTTI (I need to tidy it up a bit!)

Jonathan
09-09-2011, 04:47 PM
Nice... is that a PIC? If so it's easy to reduce the number of wires using the method I mentioned.

HankMcSpank
09-09-2011, 04:49 PM
Yes, it is & yes I know - charlieplexing - must sort that out one day & sit down to implement it!

So, to sum up thus far...

1. Gun drill bits (thanks robin - didn't know they existed)

2. You think it's a tall order (me too)

.....but we sent blokes to the moon over 40 years ago ....before I contact NASA, any more ideas here re how to drill a straight/precise hole along a 450mm wood guitar neck using a 4mm bit? (or even how to make a 450mm drill bit snce nobody seems to make one - this is the only (cheap) option I've seen to date http://www.orbitalfasteners.co.uk/details/6mm-HSS-Drill-Bit-400mm-Long-5mm-Shank-Diameter-9354.html ...trouble is, the drill bit @6mm is 2mm too wide)

blackburn mark
09-09-2011, 05:00 PM
Hehe, cheesy, uneccesary...but justifiable nevertheless...

http://www.youtube.com/watch?v=W8yOAFVUTTI (I need to tidy it up a bit!)

hahahahah.... just checked your bubble bath special ..... WINNER !! :)

HankMcSpank
09-09-2011, 05:07 PM
Hehehe, I'd forgot about that one (uploaded a good while ago, and I don't use my youtube account much), for those that are wondering I found an alternate use for a garden leaf blower ....

Ricardoco
09-09-2011, 05:38 PM
could you not slit along the side and come in through the side fret markers (if they have them) it would not be hard to make a good cosmetic job after....

HankMcSpank
09-09-2011, 05:45 PM
No visible wood should be hurt during the making of this drama! (seriously, I'm happy to drill unseen wood, but guitarists in gerneral are very precious when it comes to anyone taking sharp pointy tools towards nice bits of visible wood! Beside my 'cosmetic' repairs would make many projectile vomit)

Ricardoco
09-09-2011, 05:53 PM
No visible wood should be hurt during the making of this drama! (seriously, I'm happy to drill unseen wood, but guitarists in gerneral are very precious when it comes to anyone taking sharp pointy tools towards nice bits of visible wood! Beside my 'cosmetic' repairs would make many projectile vomit)

I do take your point. and my cosmetic repairs may even end with the same result as yours.... more ideas then...

Jonathan
09-09-2011, 06:28 PM
Use a laser!

More seriously the first thing I thought of when reading your first post was use a gun drill. I can't think of anything better.

blackburn mark
09-09-2011, 06:35 PM
projectile vomit

im with you there....
id use my ovation as a chopping board but id build a teleporter and beam the stuff in there before i touched the paint job on my jackson.

if you ever get around to drilling though you have got to video that!
it may seem mean but if you are going to projectile vomit all over that very posh peice of wood i have just got to see it :rofl:

HankMcSpank
09-09-2011, 07:18 PM
Well it look like gun drilling is the answer...the problem is the bit holder, I'm not gonna get one of these down B "do you want decking" &Q...

Jonathan
09-09-2011, 09:56 PM
Kynar wire is where it's at:

http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=m570.l2736&_nkw=kynar+wire

HankMcSpank
13-09-2011, 10:25 AM
Me again, had the chance to mull this a little.

Here's the immediate problem - just about every implementation of gun drilling has the drill static & the workpiece turing - that's fine when your workpiece is circular (gun barrel, kids musical recorder etc)...just lob the workpiece in a collet - it's perfect centred...job done.

But if the workpiece is a guitar neck (ie odd shaped!), then that's not gonna work very well (to much potential for it to be misaligned ...especially at the far end)

Therefore I reckon I need to have the gun drill bit turning & mount the guitar neck on a static table/bed - the problem here is, gun drills always have compressed air squirted down their centre (to expel the chips from the cutting end) ....so how do you supply/maintain compressed air down the centre of a drill bit that is turning? (ie what's the name of the part that allows a static pneumatic hose to connect to something that is spinning)

m_c
13-09-2011, 01:03 PM
A rotary union or swivel joint.

Basic ones only use two o-rings with glide rings, while more complex/higher duty ones will use ball bearings with lip seals. It all depends on speed/pressure/type of fluid.

blackburn mark
13-09-2011, 03:42 PM
im assuming you will be reaching through the spindle bore to get at the opening in the end of the tool ??? might be worth knocking something up for the time being, brass tube with a lose (ish) fit inside the tool coolant bore
if you have a pretty decent compresser it'll keep up with a leaky joint at least till you have proven the concept and start an all out production

Robin Hewitt
13-09-2011, 04:21 PM
Therefore I reckon I need to have the gun drill bit turning & mount the guitar neck on a static table/bed

Not sure that works. You'd think all rotations were relative, but are they? :naughty:

If you spin the workpiece you define a line through it, the axis of rotation.

If you spin the drill you define squat.

If a turning drill goes off line, it's centre is still the slowest moving part of the cut.

If a stationary drill goes off line, it isn't.

Question is, is that how a long gun drill bit keeps itself on target?

They cut and burnish.

BillTodd
13-09-2011, 07:06 PM
Robin has it bang on (saved me a lot of typing :)) gun drills only work because the job is spinning.

That said: I think, with the right technique, you could drill 500mm into a soft-ish material without too much drift.

First, grab yourself some wood of the same type as the neck to practice on.

Use a sequence of drills each a 1/2 mm or so smaller than the last. (you might be able to do it with one drill, but that doesn't give you the option of 'correcting' the path slightly)

Fix (braze or silver solder) the smaller drills into the end of steel rods the diameter of the previous drill. (concentricity is obviously important, as is a correctly sharpened drill).

I've drilled an 8" deep blind hole in steel using this technique with a 4mm jobber bit that was just a press-fit into the end of a silver steel rod ( I pinned it to the rod to stop the drill turning)

The first drill hole is the most important. Make a sequence of sleeves to align the rod in the first hole, so the drill is guided for its whole length.

Drill using lots of pecking (3-6mm in, then pull out and clear the chips) .

If you don't have a long bed lathe handy, then some kind of long sliding rig is essential.

It's a difficult, not an impossible job.

Bill

Robin Hewitt
13-09-2011, 09:50 PM
Robin has it bang on

Blimey, that's a rarity, thanks :smile:

I just took pics of a gun drill. They are a bit odd.

HankMcSpank
14-09-2011, 12:31 AM
Blimey, that's a rarity, thanks :smile:

I just took pics of a gun drill. They are a bit odd.

As you say...odd (thanks for the pic)

Re not being able to keep the workpiece static (& rotate the bit), this page suggests it's one of the methods....

http://www.gundrillingsolutions.com/Pages/basicpr.html

Bill, the method you outlined I'd considered...I have no sliding rail though, so would have to contempate making one...but then I saw the cost of a pair of support rails @1.2mm long - gulp.

BillTodd
14-09-2011, 12:03 PM
Bill, the method you outlined I'd considered...I have no sliding rail though, so would have to contempate making one...but then I saw the cost of a pair of support rails @1.2mm long - gulp.

They don't have to be that strong, they just have to be straight.

HankMcSpank
14-09-2011, 12:47 PM
They don't have to be that strong, they just have to be straight.

Yes I realised that (as there'd not be much deflection force operating downwards), but I'd imagine getting 'straight' at a length of about 1.2m might prove a little difficult (I'm also thinking bass guitars might be an option so now allowing up to 600mm - so 600mm drilling 'travel' + 600mm to retract the neck before/after drilling it = 1.2mm rails needed)...which is why I looked at supported rails...they be straight!

i'm open to siggestions though (I can feel a custom rig coming on!)

Jonathan
14-09-2011, 05:42 PM
which is why I looked at supported rails...they be straight!

i'm open to siggestions though (I can feel a custom rig coming on!)

What about these ones? Maybe not the cheapest, but they are good with lots of wood dust around:

http://uk.rs-online.com/web/p/linear-guides-rails-carriages/4485499/?origin=PSF_346163|cav

Apparently you can get them directly from the igus site in the size you want for a good price. It's probably worth exploring a cheaper option first.
I guess it all depends on how many you're making.

HankMcSpank
14-09-2011, 07:30 PM
What about these ones? Maybe not the cheapest, but they are good with lots of wood dust around:

http://uk.rs-online.com/web/p/linear-guides-rails-carriages/4485499/?origin=PSF_346163|cav

Apparently you can get them directly from the igus site in the size you want for a good price. It's probably worth exploring a cheaper option first.
I guess it all depends on how many you're making.

That's actually quite a nice system, it wasn't clear from the 3d piccie on RS, but this video shows that it could be a good contender...