Can the DBS-22 Sharpen Spot Drills?

[Dr.Al]

I'm wondering about getting the DBS-22 sometime soon.  I have quite a large collection of spot drills and quite a lot of them are blunt now, so I'd love to be able to sharpen them.  Can the DBS-22 sharpen this sort of thing?

Example of the type of drill I'm talking about: https://www.scribd.com/document/276985270/Nc-Spot-Drills

[Ken S]

Welcome to the forum, Dr.Al.

Good question. I don't have any spot drills, so I forwarded your post to Tormek Support. Unfortunately, they are on vacation until July 31, so response time will probably be slower. We do have several members who are machinists. Hopefully they will reply.

Ken

[RickKrung]

I see no reason why that type of drill could not be sharpened.  The flutes are straight and it looks like there is just the primary facet and a relief.  I think it will be important to get the point well centered as accurate locating is the "point" of this type of drill. 

I don't have any drills like that and have not used them before.  I use centerdrills with the two stepped flutes.  They are on the small side, typically and I've not tried sharpening the points on them, but they do become dull. 

Rick

[Dr.Al]

I see no reason why that type of drill could not be sharpened.  The flutes are straight and it looks like there is just the primary facet and a relief.  I think it will be important to get the point well centered as accurate locating is the "point" of this type of drill. 

I agree that getting a well centred point is essential for these drills.  I've shied away from trying to (hand) sharpen them as I don't think I'd be able to maintain the centre accuracy.  If the DBS-22 can do it then that would definitely tempt me to get one.

I don't have any drills like that and have not used them before.  I use centerdrills with the two stepped flutes.  They are on the small side, typically and I've not tried sharpening the points on them, but they do become dull. 

I also used to use centre drills for this application.  Then I discovered spot drills and I've never gone back (except for drilling centres in the lathe, obviously).  The spot drills are even better at starting in the right point than centre drills and they are a lot more robust.

As a side benefit, they're sharpened at 90°, so I sometimes use an oversize one to start a hole, then drill the through hole with a smaller drill bit - the result is perfectly aligned countersunk hole in two operations.  Of course that only works if you're using sensible metric fasteners with a 90° countersink included angle 

[RickKrung]

...snip...
except for drilling centres in the lathe, obviously).  The spot drills are even better at starting in the right point than centre drills and they are a lot more robust.
...snip...

If the latter statement above is true, why would you not also use them for drilling centers on a lathe? 

Rick

[Dr.Al]

...snip...
except for drilling centres in the lathe, obviously).  The spot drills are even better at starting in the right point than centre drills and they are a lot more robust.
...snip...

If the latter statement above is true, why would you not also use them for drilling centers on a lathe? 

Rick

Because the point is 90°, whereas centres are 60°. Also, the little nib on a centre drill gives oil somewhere to go when you push the dead centre into the hole made by the centre drill.

[RichColvin]

I'm wondering about getting the DBS-22 sometime soon.  I have quite a large collection of spot drills and quite a lot of them are blunt now, so I'd love to be able to sharpen them.  Can the DBS-22 sharpen this sort of thing?

Example of the type of drill I'm talking about: https://www.scribd.com/document/276985270/Nc-Spot-Drills

If you want to send me one, I will try to sharpen it on my DBS-22 and send it back to you. If interested, PM me. 

[Dr.Al]

I'm wondering about getting the DBS-22 sometime soon.  I have quite a large collection of spot drills and quite a lot of them are blunt now, so I'd love to be able to sharpen them.  Can the DBS-22 sharpen this sort of thing?

Example of the type of drill I'm talking about: https://www.scribd.com/document/276985270/Nc-Spot-Drills

If you want to send me one, I will try to sharpen it on my DBS-22 and send it back to you. If interested, PM me.

Thanks for the very kind offer Rich, but your profile suggests you live in Ohio & I suspect that sending a drill bit across the atlantic ocean & back again will cost too much to be worth the hassle.

[cbwx34]

...
As a side benefit, they're sharpened at 90°
...

The DBS-22 manual on page 4 says:

Centering drills usually have a 90° point angle.

Might be a clue that it will?

[Dr.Al]

...
As a side benefit, they're sharpened at 90°
...

The DBS-22 manual on page 4 says:

Centering drills usually have a 90° point angle.

Might be a clue that it will?

Sounds promising, unless it means centre drills (for drilling centres in the lathe). These have a point (I'm not sure of the angle; I can check when I'm next in the workshop) and a short narrow section. They then have a 60° larger section for cutting the centre itself.

Having said all that, centre drills are very short, so I'd be surprised if you can hold them in the jig. Also, I tend to break the fragile tip long before they go blunt, so I probably won't ever need to sharpen a centre drill 

For that matter, spot drills are quite short too: perhaps that's a limiting factor regardless of geometry? My smallest spot drills (3 mm diameter) are about 50 millimetres long I think; when you set the drill protrusion with the stop on the DBS-22, how much sticks out of the clamp?

[Ken S]

Just in from support:

"Hi Ken.
You need the protrusion and at least 1/3 of the length inside the drill holder. 2-2,5" in length is minimum. Do you know the length of the drill bits?
Have a nice day."

Ken

[Dr.Al]

Just in from support:

"Hi Ken.
You need the protrusion and at least 1/3 of the length inside the drill holder. 2-2,5" in length is minimum. Do you know the length of the drill bits?
Have a nice day."

Ken

The shortest drill bit is 50 mm (so about 2"). The bigger sizes are a bit longer.

[Dr.Al]

This is my little collection of spot drills that I'd love to be able to sharpen:

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I probably use them more than any other drill bits as most holes are started with these bits.

This is the best photo I could take (of a 12 mm spot drill) showing the tip geometry:

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Sorry it's blurry: they're hard to photograph!

This photo shows the lengths of all the spot drills (3 mm, 4 mm, 5 mm, 6 mm, 8 mm, 10 mm and 12 mm diameter):

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The grid on the paper is 5 mm squares.

[RichColvin]

I really see no reason why the DBS-22 would not work unless they are made from some metal composite which is extraordinarily hard to grind. 

[Dr.Al]

I really see no reason why the DBS-22 would not work unless they are made from some metal composite which is extraordinarily hard to grind.

They're HSS, so I'm not concerned about the Tormek grinding them.

The stuff I'd seen on the DBS-22 seemed very focused on conventional twist drills & I wasn't sure whether any difference in geometry would be significant (as you can probably tell, I don't know much about drill tip shapes).