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Drill Press Chuck Runout

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sean69

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#1
I have a 1980s Busy Bee 18" benchtop drill press, got it at auction for $150 a few years ago. It looks brand new, seldom or very lightly used.

But: I had always had trouble drilling straight holes (usually 11"-14" deep) so I finally got around to checking it for runout.

Turns out the spindle is good, solid, no play and +/- 0.0005 runout... as is the chuck shank (arbour?) about the same runout. measuring a ground shaft in the chuck itself, I get +/- 0.0050 runout (!)
Checked the jaws, no dirt looking clean and clear. so:

Is there a way to correct the existing chuck or am I looking at a new chuck?

-thanks
-sean
 

benmychree

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#2
You will always have trouble drilling holes that deep without the drill wandering to some extent; what material ate you drilling? The only way to drill really deep straight holes is the process of "gun drilling", which requires special tools and equipment.
Bottom line, do not expect a new chuck to equal straight holes when drilling that deep.
 

sean69

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You will always have trouble drilling holes that deep without the drill wandering to some extent; what material ate you drilling? The only way to drill really deep straight holes is the process of "gun drilling", which requires special tools and equipment.
Bottom line, do not expect a new chuck to equal straight holes when drilling that deep.
I have some little processes to compensate for crooked holes - mostly into endgrain in hardwoods. (holes for magazine tubes in rifle fore ends)

But I can see the end of the bits wobbling - it affects other work as well - more distressing are out of round holes in metals. I bought a set of reamers a couple weeks back & completely ruined a ram rod tube trying to ream it out ...
 

mikey

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But I can see the end of the bits wobbling - it affects other work as well - more distressing are out of round holes in metals. I bought a set of reamers a couple weeks back & completely ruined a ram rod tube trying to ream it out ...
Sean, I totally agree with John re the deep holes. Accuracy with an Asian drill press in deep drilling is probably not gonna happen.

If your spindle is accurate, and 0.0005" is pretty good for a drill press, then an increase to 0.005" of run out on a rod in the chuck suggests that a) the arbor is bad, b) the chuck's internal taper is bad, c) that a and b are okay but the chuck was not mounted on the arbor accurately, d) the jaws are damaged or not holding the rod concentric to the chuck body, or e) the chuck is a POS and needs to be changed to a precision chuck.

You sort of need some frame of reference as to how much a properly mounted chuck in good condition will run out on an Asian drill press. There is no such standard, at least to my knowledge, but I have a Craftsman 15" drill press in which I replaced the spindle, spindle and drive sleeve bearings, mounted an Albrecht keyless chuck in pristine condition on a brand new Albrecht arbor with great care paid to how I installed the chuck in the spindle and I have under 0.0005" TIR at the arbor and under 0.001" on a 3/8" dowel pin measured 1/2" beyond the chuck. It is pretty accurate when drilling holes but even I understand that this only handles the driving end of the hole making process.

So, do you need a new chuck? Dunno', maybe. If your chuck is the OEM chuck that came with that drill press then I would say dump it and use an Albrecht, Rohm or Jacobs Super Chuck. The OEM Chinese chucks are worthless other than for drilling holes in wood, in my opinion. I would also dump that OEM arbor and get a decent one from Albrecht, Jacobs, Rohm or some other reputable maker.

The biggest issues when we get out of round holes are chatter and vibration. This has little to do with the drill press directly; it has more to do with the drills and how we use them. About 3-4 years ago, I looked into this subject and am "speaking" off the top of my head about what I recall but chatter is a really big deal. As you might expect, speeds have a lot to do with chatter. If you drill a partial depth hole and you see a sunray pattern, like spokes on a wheel, at the bottom of the hole instead of a smooth surface then you have chatter. Just like on a lathe, the solution is to reduce speed and increase feed. It may surprise you to find that this works rather well, crude as it may seem. This is why I tend to run my drills slower and feed harder nowadays and it works.

The other issue is vibration. As I recall, you can modify your tool web to be thicker and use less relief behind the cutting edge. I may be wrong on this but increasing the contact area at the cutting tip dampens vibration, leading to less out of roundness.

To be honest, I don't modify my drill geometry. Too lazy, I think. What works for me is:
  • Use spotting drills to get my drill started well and I make sure the drill flute ends are buried in the hole before I clear chips the first time. This makes a hole my drill can re-enter accurately.
  • Avoid pilot drills when I can. Pilot drills are thin and will wander, and any drill that follows will follow the same path. Using a main drill works better, for me at least.
  • Use lower speeds and harder feeds. This works better than you might think.
  • Clear chips after going in 2-3 drill diameters.
  • Always use lube.
  • For reamers, spot, then drill with a drill one size smaller than your pre-reamer drill to rough out the hole, then use your pre-reamer drill, then ream. I tried all kinds of things to figure out how to ream an accurate hole and this works best for me. I also run the reamer at about 100 rpm on the mill or the slowest I can on the drill press (about 250 rpm) and make a steady controlled pass on the infeed only, then I shut off the machine and manually withdraw the reamer. This gives me a better finish, a more accurate hole and my reamers stay sharp longer. I use a lot of lubricant, too.
It matters which drills you use before running a reamer in the hole. See the attached file.

It sounds like you're a gun guy and I'm not sure which brand of reamer works best for your needs. For my simple needs, I prefer Alvord Polk, L&I and PTD reamers.
 

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Technical Ted

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#5
It might not be the run out that is causing your issue; most drill especially in smaller diameters will flex and follow a started hole. It might be that the drill press spindle is not perfectly square/perpendicular with the table that your work piece is sitting on. Check this the same way you would tram in a vertical mill head, like a Bridgeport head.

If the work piece is not set perfectly square with the spindle there is no way the drilled hole will be square in the work piece regardless how true a chuck runs.

Just a thought,
Ted
 

Technical Ted

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Sometimes a picture is worth a thousand words. Here's an illustration I drew up in Fusion 360 of a two inch wide block 14 inches long. The bottom right edge is skewed off the horizontal by 0.002" which you would see as 0.002" dial indicator error per side if your arch from center in your drill press spindle was 2 inches (4 inch total swinging diameter).

As you can see, the center line of a vertical line (which would be your spindle) starts at 1" at top but over the 14 inches moves 0.014" (almost a 1/64") off from it's original entry (the two dimensions in ( ).

This demonstrates only a error of 0.002 per side so if your table is off more than this it obviously gets worse. Also, errors like this magnify with the length of the piece, so 14" can show a lot of error where you wouldn't really notice it on a very short piece.

If you drill press table is not trammed in very closely on these long pieces you are going to see this error, just as you would on a milling machine.

Maybe I'm barking up the wrong tree, but this is something that gets overlooked sometimes...

Hope this makes sense,
Ted

Tram error.jpg
 

stupoty

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#7
I have a 1980s Busy Bee 18" benchtop drill press, got it at auction for $150 a few years ago. It looks brand new, seldom or very lightly used.

But: I had always had trouble drilling straight holes (usually 11"-14" deep) so I finally got around to checking it for runout.

Turns out the spindle is good, solid, no play and +/- 0.0005 runout... as is the chuck shank (arbour?) about the same runout. measuring a ground shaft in the chuck itself, I get +/- 0.0050 runout (!)
Checked the jaws, no dirt looking clean and clear. so:

Is there a way to correct the existing chuck or am I looking at a new chuck?

-thanks
-sean

You might try taper shank drills for the holes that require more accuracy.

Although that is a fairly deep hole your drilling.

How off line does it go ?


Stu
 

Tozguy

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Sean69, my suggestion re the question of what gives with the chuck is to take it apart and see. I would expect that it could use a bit of deburring and cleaning. Once you have done that it will be clearer whether the chuck can meet your precision requirement.
As mentioned above, common drill chucks are not considered good for precision work. To get the best results from any drill chuck you need to have the best drill bit for the job. I would even say that the drill bit might be more important than the chuck for quality work. You might not have exhausted all your drilling options yet.
 

pdentrem

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Assuming that you can separate the chuck from the arbour, you can then indicate the arbour for runout. Likely the issue is with the chuck, replacing to a better quality will help.

Deep hole drilling is always a problem, wood or metal makes no difference. There are special drills with a grind for deep holes. Wood with its differing hardness especially in end grain is a problem. I would drill a smaller hole about an inch and follow with the either finish drill or just under would be better. Repeat until done. 1 inch at the time, using the previous hole as a bushing to help guide the drill straighter. Use the finish drill to clean out the hole. Best I can suggest at the moment.
 

sean69

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#10
It might not be the run out that is causing your issue; most drill especially in smaller diameters will flex and follow a started hole. It might be that the drill press spindle is not perfectly square/perpendicular with the table that your work piece is sitting on. Check this the same way you would tram in a vertical mill head, like a Bridgeport head.

If the work piece is not set perfectly square with the spindle there is no way the drilled hole will be square in the work piece regardless how true a chuck runs.

Just a thought,
Ted
magazines are generally somewhere in the 0.660" range, I use a 5/8 brad point (very expensive lee valley HSS) to start & then ream the rest of the way with an adjustable hand reamer and extensions.

I've made up a jig for this purpose and use a laser to line it up parallel with the tool, the jig gets blocked up at the bottom to compensate for any flex in the DP column - I then can drill 1/2 way through, flip it end for end and drill from the other side (on a very meticulously squared piece of material)
Once (and only once) I had a little wooden button drop out where the brad points met perfectly in the middle.

Anyway - if that hole is under 1/16" out then I can compensate a little by reaming it a little larger, but any more than that I have to square up the material again to the bore before doing anything else. A "true" hole would save me a couple hours easy.

20170713_191944.jpg 20170713_193809.jpg 20170713_193835.jpg 20170713_194150.jpg 20170713_194701.jpg
 

sean69

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#11
You might try taper shank drills for the holes that require more accuracy.

Although that is a fairly deep hole your drilling.

How off line does it go ?


Stu
Hum .... interesting thought! It's a specialized operation, I wouldn't mind spending $$ on a bit specialized for that.... certainly takes the runout out of the equation. The trick would be finding one long enough to get at least half way through my material - I generally have to advance the drill bit in the chuck a bit with what I am doing now.

As far as how far off they go - it all depends on how meticulous I am with setup. generally not more than 3/16" over 10"/12' the real problems show up when the holes are out both vertically and horizontally.

those holes are nothing for 'deep' either ... drilling ramrod holes is the real tricky bit. I regularly have to make drill bit extensions 4' long and purpose made D reamers for the entry holes.... a giant pain!
 

sean69

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#12
Sometimes a picture is worth a thousand words. Here's an illustration I drew up in Fusion 360 of a two inch wide block 14 inches long. The bottom right edge is skewed off the horizontal by 0.002" which you would see as 0.002" dial indicator error per side if your arch from center in your drill press spindle was 2 inches (4 inch total swinging diameter).

As you can see, the center line of a vertical line (which would be your spindle) starts at 1" at top but over the 14 inches moves 0.014" (almost a 1/64") off from it's original entry (the two dimensions in ( ).

This demonstrates only a error of 0.002 per side so if your table is off more than this it obviously gets worse. Also, errors like this magnify with the length of the piece, so 14" can show a lot of error where you wouldn't really notice it on a very short piece.

If you drill press table is not trammed in very closely on these long pieces you are going to see this error, just as you would on a milling machine.

Maybe I'm barking up the wrong tree, but this is something that gets overlooked sometimes...

Hope this makes sense,
Ted

Make perfect sense & thanks for taking the time to draw up the illustration :)

For the deep holes my press does not have the overhead room to mount the work and the tool - the table has to be turned 90^ parallel to the tool - I posted a pic in another response. That makes using an indicator pretty much impossible. :( The laser is a bore sighting laser and is very accurate. setup for it is pretty easy- chuck it, turn on the press, if the dot 'wobbles' on the floor then it isn't straight - repeat until the laser is a dot that does not move on the floor while the press is running. then set the table/fixture so the laser line runs all the way along the fixture and doesn't taper off (like the one image I posted)

That's the best I have been able to figure out.
 

sean69

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#13
Assuming that you can separate the chuck from the arbour, you can then indicate the arbour for runout. Likely the issue is with the chuck, replacing to a better quality will help.

Deep hole drilling is always a problem, wood or metal makes no difference. There are special drills with a grind for deep holes. Wood with its differing hardness especially in end grain is a problem. I would drill a smaller hole about an inch and follow with the either finish drill or just under would be better. Repeat until done. 1 inch at the time, using the previous hole as a bushing to help guide the drill straighter. Use the finish drill to clean out the hole. Best I can suggest at the moment.
Gun drills and D bits - yes, I have used them, had to make them, they are slow but work brilliantly.

Problem here with my deep holes is that I am working with wildly figured materials, burls, boles etc. the hardness of the material can vary wildly as can the direction of the grain. Drilling a smaller hole first is usually futile because of that :(

I took a peek at the chuck & don't see an easy way to get it apart. If I replace it (looking like I will) I'll probably replace the arbour at the same time.
 

sean69

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#14
Sean69, my suggestion re the question of what gives with the chuck is to take it apart and see. I would expect that it could use a bit of deburring and cleaning. Once you have done that it will be clearer whether the chuck can meet your precision requirement.
As mentioned above, common drill chucks are not considered good for precision work. To get the best results from any drill chuck you need to have the best drill bit for the job. I would even say that the drill bit might be more important than the chuck for quality work. You might not have exhausted all your drilling options yet.
Drill bits are something I learned quite a while ago to not cheap out on. Canadian Tire is not here you want to buy precision tooling ;)

Brad points for end grain ... you can't sharpen them so you gotta live with their limited lifetime, but even a beefy 5/8" twist drill can wander in an obstinate piece of walnut.
 

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#15
Hi Guys,

The drill itself, how its sharpened can make a big difference to how straight a hole can be.
I used to have to drill a 5/32" inch hole in aluminum 6" inches long to land within a 1/64".
Dormer made me the drills to do this job, and they cost a fortune but they worked.
The grind on the cutting edges and the flute form made the difference, between a hole drilled with a normal long series drill and the ones that Dormer made for me.
 

sean69

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#16
So, do you need a new chuck? Dunno', maybe. If your chuck is the OEM chuck that came with that drill press then I would say dump it and use an Albrecht, Rohm or Jacobs Super Chuck. The OEM Chinese chucks are worthless other than for drilling holes in wood, in my opinion. I would also dump that OEM arbor and get a decent one from Albrecht, Jacobs, Rohm or some other reputable maker.
It's looking like I am leaning towards replacing the chuck, though can't come even close to affording an Albrecht - $400+? ouch! :(
Though ~ speaking of Asian machines - I am also considering (strongly) upgrading to a larger more rigid floor model.


The biggest issues when we get out of round holes are chatter and vibration. This has little to do with the drill press directly; it has more to do with the drills and how we use them. About 3-4 years ago, I looked into this subject and am "speaking" off the top of my head about what I recall but chatter is a really big deal. As you might expect, speeds have a lot to do with chatter. If you drill a partial depth hole and you see a sunray pattern, like spokes on a wheel, at the bottom of the hole instead of a smooth surface then you have chatter. Just like on a lathe, the solution is to reduce speed and increase feed. It may surprise you to find that this works rather well, crude as it may seem. This is why I tend to run my drills slower and feed harder nowadays and it works.
Yes - speeds & feeds are just as important working with wood as they are with metal - even more so since if you cut too fast your work can actually catch fire! :)
That's another reason I am considering a new press - something with a variable speed/gear head where I don't have to futz with belts & can dial in my speed more accurately.


The other issue is vibration. As I recall, you can modify your tool web to be thicker and use less relief behind the cutting edge. I may be wrong on this but increasing the contact area at the cutting tip dampens vibration, leading to less out of roundness.
I have never modified a bit either - nor can you with a brad point (though these lee valley ones do have some relief behind the brad points - they really are very nice, but of course useless for metal)


It sounds like you're a gun guy and I'm not sure which brand of reamer works best for your needs. For my simple needs, I prefer Alvord Polk, L&I and PTD reamers.
Well guns are not the only thing that gets built in the shop - but ~mostly~ :)
Honestly, reaming is not an operation I have to do a lot of, I have not had to do any chamber reaming (super specialized tooling = $$$) mostly hand reaming wood. the other bit would be the ram rod pipes (that I ruined) these are generally rough brass castings that need to be opened up slightly to allow the ram rod to clear them smoothly. (3/8 hole, 3/8 rod ... you know) they have a large tab on them (to secure to the stock) so defy being held in the lathe accurately.... :(
 

sean69

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#17
Hi Guys,

The drill itself, how its sharpened can make a big difference to how straight a hole can be.
I used to have to drill a 5/32" inch hole in aluminum 6" inches long to land within a 1/64".
Dormer made me the drills to do this job, and they cost a fortune but they worked.
The grind on the cutting edges and the flute form made the difference, between a hole drilled with a normal long series drill and the ones that Dormer made for me.
Agreed.
The correct tool geometry for the material... technically for my application into the end grain, a forstner type bit would be ideal, but they just don't make em that long :(
 

Tozguy

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#18
I have a 1980s Busy Bee 18" benchtop drill press, got it at auction for $150 a few years ago. It looks brand new, seldom or very lightly used.

But: I had always had trouble drilling straight holes (usually 11"-14" deep) so I finally got around to checking it for runout.

Turns out the spindle is good, solid, no play and +/- 0.0005 runout... as is the chuck shank (arbour?) about the same runout. measuring a ground shaft in the chuck itself, I get +/- 0.0050 runout (!)
Checked the jaws, no dirt looking clean and clear. so:

Is there a way to correct the existing chuck or am I looking at a new chuck?

-thanks
-sean
Gun drills and D bits - yes, I have used them, had to make them, they are slow but work brilliantly.

Problem here with my deep holes is that I am working with wildly figured materials, burls, boles etc. the hardness of the material can vary wildly as can the direction of the grain. Drilling a smaller hole first is usually futile because of that :(

I took a peek at the chuck & don't see an easy way to get it apart. If I replace it (looking like I will) I'll probably replace the arbour at the same time.
It is not obvious to me that a new precision drill chuck and arbor will help solve your problem.
 
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sean69

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#19
It is not obvious to me that a new precision drill chuck will help solve your problem.
no it won't magically solve the deep hole problem, I agree. But it may solve the reaming problems.

as might a new machine ...... :)
 

Technical Ted

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#20
I've been wrong before and I'm sure I'll be wrong a lot more down the road, but my gut tells me you have more of an alignment issue than a chuck run out problem.

Do you have a dial indicator you can mount either in your chuck or on the spindle? If so, I would suggest mounting it and take a reading against the three sides of that channel in your jig you put your work pieces in. Run it up and down against the sides as far as you can. It needs to be very close. I personally don't think that laser is a good enough way to line things up within a few thousands so your holes will meet in the middle head on.

Again, I could be wrong, but these are the things I would be looking at before buying a new chuck just to possibly find out I have the same problem after doing so.

Ted
 

Tozguy

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#21
Anyway - if that hole is under 1/16" out then I can compensate a little by reaming it a little larger, but any more than that I have to square up the material again to the bore before doing anything else. A "true" hole would save me a couple hours easy.
If you are drilling a stock blank and have to work the blank after drilling anyway why does the hole have to be so good? What is the extra 'couple hours' for if the hole is not 'true'?
 

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#22
I've been wrong before and I'm sure I'll be wrong a lot more down the road, but my gut tells me you have more of an alignment issue than a chuck run out problem.

Do you have a dial indicator you can mount either in your chuck or on the spindle? If so, I would suggest mounting it and take a reading against the three sides of that channel in your jig you put your work pieces in. Run it up and down against the sides as far as you can. It needs to be very close. I personally don't think that laser is a good enough way to line things up within a few thousands so your holes will meet in the middle head on.

Again, I could be wrong, but these are the things I would be looking at before buying a new chuck just to possibly find out I have the same problem after doing so.

Ted

I am using a dial indicator to test for runout - it is there in the chuck body.

It certainly can be a combination of runout and alignment. I've never really been happy with 'the fixture'

I suppose mounting 2 indicators on a bar in the chuck would allow me to mic the whole length of the fixture & not just the top 3" - though it is a plywood and maple jig - sooooo not super smooth, flat or true. But it certainly sounds like a faster setup than futzing with the laser.

though I guess I could also grab a length of aluminum angle stock or use some setup blocks ..... that stock needs to move along the fixture, drill 3" move the stock, drill another - flip, drill 3" move the stock ... Lots of things can be happening there.
 

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#23
If you are drilling a stock blank and have to work the blank after drilling anyway why does the hole have to be so good? What is the extra 'couple hours' for if the hole is not 'true'?
The next operation would be 'roughing' out the barrel channel with a router. The barrel and mag tube need to be absolutely parallel to one another. So I need an edge on the work to be absolutely parallel to the hole center.
 

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#24
Agreed.
The correct tool geometry for the material... technically for my application into the end grain, a forstner type bit would be ideal, but they just don't make em that long :(
Would an auger work ? Apart from the threaded tip it has the same geometry as a forstner bit.
 

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#25
Sean, I looked into how the wood turner guys bore lamp holes and they use a lamp auger, sometimes called a shell auger. Supposedly, it bores a straight hole in wood and might work better for you if you can hold the work piece in the lathe. Here is one such bit: https://www.amazon.com/DEWALT-DW168...&qid=1539030527&sr=8-3&keywords=auger+bit+5/8

This has got to be better than trying it in a drill press. A drill bit will deflect in a deep hole that long, no matter how careful you are. This auger has a shape that will hopefully keep you centered.
 

sean69

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#27
Would an auger work ? Apart from the threaded tip it has the same geometry as a forstner bit.
Yes augers do work & I have used them - mostly in the ramrod holes. the drawback for them is't use power to run them ... :( you also need a starting hole to keep them accurate.
 

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#28
Sean, I looked into how the wood turner guys bore lamp holes and they use a lamp auger, sometimes called a shell auger. Supposedly, it bores a straight hole in wood and might work better for you if you can hold the work piece in the lathe. Here is one such bit: https://www.amazon.com/DEWALT-DW1681-8-Inch-17-Inch-Auger/dp/B00004RGZC/ref=sr_1_3?ie=UTF8&qid=1539030527&sr=8-3&keywords=auger+bit+5/8

This has got to be better than trying it in a drill press. A drill bit will deflect in a deep hole that long, no matter how careful you are. This auger has a shape that will hopefully keep you centered.
Yes - I have delved into the deep hole thing extensively. Lamp turners, pepper mill makers, flute makers all need to make deep holes - but they don't need to be particularly accurate as all they do after is mount the piece between centers after an ~voila~ the hole is centered by accident... :(

What you have there is a ship auger - a shell auger is quite different, no center spur and a very shallow cutting angle - they almost grind. they are specifically designed for cutting into end grain but you don't see them any more since the advent of the forstner ...

The next best option I really have is creating some tooling so I can do this on the lathe.
 

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#29

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#30
Bummer
 
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