How Much Is Too Much?

DanF

DanF

Knifemaker / Craftsman / Service Provider
Joined
Apr 17, 2017
Messages
1,438
The typically available benchtop drill presses we use are not high precision pieces of equipment. Over time I have wondered how much run out is too much on a benchtop drill press, or, should we even worry about it?
In the past 10 years, I have thrown out one because the run out was so bad, and changing out the chuck did not help it. So, are there any other steps we can take to make them a little more precise (other than chucks and squaring up the table)?
 
Mini Mill?

I kid. I see the benchtop drill press as a (ultimately) consumable piece of equipment. I have a mill, so if I need to drill precise holes, I use that. But I fully expect to replace my drill press in a few years.
 
Drilling holes in general is not precise anyhow, so what difference does it make?

Are you requiring more precise hole locations?
maybe make a fixture with drill bushings? Wobble and runout might not matter then, so much.

letting your vise float will allow it to just go along for the ride.

drilling and then reaming on a drillpress floating, is way better (more accurate) than clamped on a mill
 
It may depend on the drill press and the chuck. I have a Grizzly bench top drill press. Plus a fairly nice chuck. I have almost no run out. However I spent a lot of time getting the table and the press squared away with each other. I've had it for about eight years now. Though my use is fairly light.
 
navman said:
Mini Mill?

I kid. I see the benchtop drill press as a (ultimately) consumable piece of equipment. I have a mill, so if I need to drill precise holes, I use that. But I fully expect to replace my drill press in a few years.
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The mini mill ruined me, was perfectly happy with the drill press until I used something considerably better.
If I knew I had another decade of knifemaking ahead I’d go for a second mini mill and be done with it,
I agree, the benchtop drill press is expendable but would like to get the most out of it I can .
 
Crag the Brewer said:
Drilling holes in general is not precise anyhow, so what difference does it make?

Are you requiring more precise hole locations?
maybe make a fixture with drill bushings? Wobble and runout might not matter then, so much.

letting your vise float will allow it to just go along for the ride.

drilling and then reaming on a drillpress floating, is way better (more accurate) than clamped on a mill
Click to expand...
Stainless or nickel bolsters on fixed blades and especially folders require a higher degree of accuracy, and squareness than just scales or scales with g10 bolsters. Sometimes close is not close enough😊
 
DanF said:
Stainless or nickel bolsters on fixed blades and especially folders require a higher degree of accuracy, and squareness than just scales or scales with g10 bolsters. Sometimes close is not close enough😊
Click to expand...
my point was that drill bits are inherently inaccurate. Regardless of them being used in a drill press vs. a mill.
 
I have two bench top drill presses. The one that gets used the most is a cheap Wally World special, the other is really old and should be retired. In my experience, unless the drill press is faulty, worn, or damaged in some way, quality bits make a huge difference. I’m partial to Norseman drill bits. I’m slowly moving my cheapo bits out and replacing them with Norseman.
 
DanF said:
The typically available benchtop drill presses we use are not high precision pieces of equipment. Over time I have wondered how much run out is too much on a benchtop drill press, or, should we even worry about it?
In the past 10 years, I have thrown out one because the run out was so bad, and changing out the chuck did not help it. So, are there any other steps we can take to make them a little more precise (other than chucks and squaring up the table)?
Click to expand...

Hi Dan,

I have drilled thousand of holes on drills ranging from bench and mag drills to 20 ton radial arms and holes from 1mm to 2 1/2 inch, the lines and center punch marks are the biggest causes of error on hole location, with incorrect uneven sharpening or dissimilar angles causing error on hole diameter, a visibly wandering bit due to the spindle or chuck is probably third. The best way to eliminate most error is to use a drill bushing on a tool steel fixture which is only viable, in my opinion, in a repetitive production environment where thousand of holes will be drilled in exactly the same place, in that scenario punching the holes would probably be more cost effective due to speed and tooling costs.

A drill wandering a bit on a pin hole in a full tang knife handle would not even enter my head as a concern, on a pivot pin in a slipjoint folder, for example, is a different matter, where 90 degree x-y-z accuracy is more critical tp the operation than the difference between a H7 and H9 reamer for controlling hole diameter. The first whack with the hammer should sort out any slack in the hole but nothing can be done if the hole is not 90 degrees to the work.

If the workpiece is clamped to the table and the position of the intended hole satisfactorily determined, the accuracy of the grind on the drill is most important for regular holes because as soon as the drill hole is at full diameter it is self centering, a case can be argued that the slacker everything is, shaft wise, the more likely the drill bit to accommodate the precision of the drill bit grind.

Disclaimer, I am not a prolific knifemaker, but my engineering knowledge, skill and experience I would consider transferable knowledge, so make of it what you will.
 
Way-Barney said:
Hi Dan,

I have drilled thousand of holes on drills ranging from bench and mag drills to 20 ton radial arms and holes from 1mm to 2 1/2 inch, the lines and center punch marks are the biggest causes of error on hole location, with incorrect uneven sharpening or dissimilar angles causing error on hole diameter, a visibly wandering bit due to the spindle or chuck is probably third. The best way to eliminate most error is to use a drill bushing on a tool steel fixture which is only viable, in my opinion, in a repetitive production environment where thousand of holes will be drilled in exactly the same place, in that scenario punching the holes would probably be more cost effective due to speed and tooling costs.

A drill wandering a bit on a pin hole in a full tang knife handle would not even enter my head as a concern, on a pivot pin in a slipjoint folder, for example, is a different matter, where 90 degree x-y-z accuracy is more critical tp the operation than the difference between a H7 and H9 reamer for controlling hole diameter. The first whack with the hammer should sort out any slack in the hole but nothing can be done if the hole is not 90 degrees to the work.

If the workpiece is clamped to the table and the position of the intended hole satisfactorily determined, the accuracy of the grind on the drill is most important for regular holes because as soon as the drill hole is at full diameter it is self centering, a case can be argued that the slacker everything is, shaft wise, the more likely the drill bit to accommodate the precision of the drill bit grind.

Disclaimer, I am not a prolific knifemaker, but my engineering knowledge, skill and experience I would consider transferable knowledge, so make of it what you will.
Click to expand...
You said it a little more eloquently than I did.
 
Another reason that I punch out all my holes in the tang prior to heat treat with a step drill.

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Its easier, later to be more accurate on drilling the handle material then it is on drilling the tang. Besides doing this provides a lot of weight saving and glue rivets if ya want.
 
I wasn’t gonna say anything but I have my press set up with two bubble levels so I can check horizontal and vert.
It should be doubly accurate. 🤨
 
My point of humor was that having the drill bit vertical won't guarantee a vertical hole unless you are sure the piece being drilled is at 90° to the bit in all directions.
Be honest, when was the last time most of us trammed out drill press table????
 
Stacy E. Apelt - Bladesmith said:
My point of humor was that having the drill bit vertical won't guarantee a vertical hole unless you are sure the piece being drilled is at 90° to the bit in all directions.
Be honest, when was the last time most of us trammed out drill press table????
Click to expand...

I got a new floor-standing drill press last year, so I indicated my table in perpendicular to a precision ground 1/2" rod in the new chuck after I checked in the new arbor. 😁 Starrett is still pretty good stuff!
 
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