Lee Valley counterbore countersink set

[Mark Rainey]

Got Lee Valley counter bore/ countersink set 6 months ago. They have been working good, but of late, the counterbore/sink collet that goes over the drill bit has been slipping and spinning. I tighten it with the small allen wrench but I am not sure if I am torquing so hard that I am beginning to strip the wrench or screws. A couple of my drill bits have grooves cut into them because of the screws. Is this happening to anyone. I have not been using the depth ( stop ) collets.

[Bill Dufour]

On hole saws the pilot drills come with flats pre-ground on the shanks for the setscrew.
Bill D

[Don Stephan]

Let us know what Lee Valley has to say.

[Edwin Santos]

Let us know what Lee Valley has to say.

Ditto on this because I have the same set and have experienced the same problem.

[Bill Dufour]

Did they come with the drill bits? are you drills pre-ground with one flat for the setscrew or did you do it by hand?
Bill D

[Doug Garson]

+1 on filing or grinding a flat on the drill bit for the set screw, surprised the Lee Valley ones don't come that way. I struggled with that problem for years until someone clued me in.

[Mark Rainey]

Did they come with the drill bits? are you drills pre-ground with one flat for the setscrew or did you do it by hand?
Bill D

The counterbores do come with the drill bits. And I also used the counterbore on a brad point drill bit from LV.

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[Mark Rainey]

+1 on filing or grinding a flat on the drill bit for the set screw, surprised the Lee Valley ones don't come that way. I struggled with that problem for years until someone clued me in.

Thanks Doug, this may be the solution. I will call Lee Valley and follow up.

[Bill Dufour]

like this one.
Bill D.

https://www.grainger.com/product/MILWAUKEE-Pilot-Drill-Bit-3Y083

[Edwin Santos]

The counterbores do come with the drill bits. And I also used the counterbore on a brad point drill bit from LV.

458328458329458330458331

Yes, this is the same set that I have. Today I was looking at it a little more closely in light of this thread. The set comes with tapered bits, a good thing IMO, but I don't personally think they lend themselves to grinding a flat, at least on the tapered portion.
The key I think is to engage both set screws evenly. This may be why they designed the counterbores and depth stops with two set screws instead of one.
When I cinched one down more than the other, it was easier to dislodge, but when I took care to engage them as evenly as I could it was more secure.

[Lloyd McKinlay]

I have what appears to be an earlier version (green box) and never have been happy with the performance.

[Mark Rainey]

like this one.
Bill D.

https://www.grainger.com/product/MILWAUKEE-Pilot-Drill-Bit-3Y083

Bill, those flats on the shaft are nice. As Doug said I may have to grind on myself.

[Mark Rainey]

Yes, this is the same set that I have. Today I was looking at it a little more closely in light of this thread. The set comes with tapered bits, a good thing IMO, but I don't personally think they lend themselves to grinding a flat, at least on the tapered portion.
The key I think is to engage both set screws evenly. This may be why they designed the counterbores and depth stops with two set screws instead of one.
When I cinched one down more than the other, it was easier to dislodge, but when I took care to engage them as evenly as I could it was more secure.

I will try that Edwin. Very frustrating when you have the drill bit tight in the chuck, the hole drilled, but the counterbore standing still not drilling.

[johnny means]

It's an inherently flawed design. I switched to these years ago have never had any problems.

[Mark Rainey]

[QUOTE=johnny means;3122604]It's an inherently flawed design. I switched to these years ago have never had any problems.[/QUOTE

Johnny, who makes these?

[Bill Dufour]

Looked at the design. What is the point of having two collars? seems like a needless complication over a longer cutting bit with two screws in that one piece. The one piece design doubles the torque required to spin the cutter on the drill shank.
I have had that stepped flat drill for decades always wondered why not just a continuous flat. I think I figure it out today, I think. It is for a hole saw and it prevents the drill from pulling out and staying behind in the waste.
Bill D

[Edwin Santos]

Looked at the design. What is the point of having two collars? seems like a needless complication over a longer cutting bit with two screws in that one piece. The one piece design doubles the torque required to spin the cutter on the drill shank.
I have had that stepped flat drill for decades always wondered why not just a continuous flat. I think I figure it out today, I think. It is for a hole saw and it prevents the drill from pulling out and staying behind in the waste.
Bill D

The second collar in the LV set is a depth stop. So you can vary the size and depth of your counterbore. Or if you simply want your counterbores consistent.

[johnny means]

[QUOTE=johnny means;3122604]It's an inherently flawed design. I switched to these years ago have never had any problems.[/QUOTE

Johnny, who makes these?
I buy the Amana versions. They're not cheap, but the carbide is long lasting and can be resharpened many times. They fit any old cheap drill bit.

[Mark Rainey]

I heard back from Lee Valley. They recommend grinding a flat in the drill bit, as Doug & Bill recommend. They said some drill bits have a flat already ground. I will try this approach. The Amana counterbore looks impressive - and the spinning stop collar looks interesting - of course it is expensive.