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Drilling with the Knee

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ddickey

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#1
Some people prefer to drill on the mill by raising the knee rather than lowering the quill.
What do you do?
Advantages? Disadvantages?
Doesn't the table shift when lowering? I suppose it wouldn't matter..?
 

markba633csi

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#2
Kind of depends on the machine and the material- I used the knee once when milling a hole in brass- I didn't want to risk my bit grabbing and pulling the quill down and ruining the part. Brass is very "tenacious" and grabby
 

Technical Ted

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#3
Quill if the machine has one, knee or saddle if it doesn't (if doing work with a horizontal machine without an overhead, etc.).

Ted
 

Smithdoor

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#4
Some people prefer to drill on the mill by raising the knee rather than lowering the quill.
What do you do?
Advantages? Disadvantages?
Doesn't the table shift when lowering? I suppose it wouldn't matter..?
Some of older mills do not have quill
If using brigport mill has a light duty feed on the quill so drill larger holes need the knee

Dave

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ddickey

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#5
Larger than 1/2"?
 

projectnut

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#7
I use the knee on my Bridgeport for drilling or milling blind holes. The dial on the knee is much more accurate than the scale on the quill. If the hole has to be in a relatively precise location I lock the table in both the X and Y axis. If accuracy is necessary I use an undersize drill and finish with the proper size end mill.

When precise location isn't necessary (+/- .005" or more in depth or location ) use the quill.
 

aliva

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#8
I always use the quill as I have DRO for depth measurement's. If I'm drilling stuff like UHMW I use the fine feed option this way the bit won't get sucked into the part. UHMW is really bad for this.
 

chips&more

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#9
If I'm drilling stuff like UHMW I use the fine feed option this way the bit won't get sucked into the part. UHMW is really bad for this.
VERY GOOD ADVICE!!!!
 

brino

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#10
Some people prefer to drill on the mill by raising the knee rather than lowering the quill.
What do you do?
I have a 102-year old Cincinnati horizontal mill with a vertical head. Early pictures here.
No choice; if I want the benefit of the lead screw feed dials for hole distances than I have to crank the (guessing ~500lb?) knee up and down.

No feedback; I can't feel a thing about the drilling operation especially on smaller diameter drill bits.
Always scared of breaking them.

-brino
 
Last edited:

P. Waller

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#11
Drilling with the knee is about the most laborious, tedious and annoying operations that I can imagine, why would one do such a thing?
 

coffmajt

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#12
I use my quill for drilling but the knee if I have a boring head installed. I added a power feed to the knee a couple of years ago and it does a great job when boring. I also have DRO's on all four axis so holding tolerances and repeatability are made easier== Jack
 

Larry42

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#13
I normally drill with the quill, often with the feed engaged. I don't have a readout on the quill yet so will use the knee when I have to stop at an exact location. I'm just in the process of installing a feed on the Knee. It has been a real PIA. I even contacted the seller to make sure it would fit my Jet 9x49 mill. No problem they said..... Except for the fact that the threads on the shaft they provided were 18TPI and my mill has 16TPI. Strange machine design. On the same shaft there are also 2mm pitch threads & M6-1.0. I made a new shaft but it isn't as good as I had hoped. Works but I don't want anyone to see the behind the scenes view! Had to buy a 3mm carbide end mill for the keyway. Worked but I made a lot of thin passes. Given my past history it was almost a sure bet to get broken, didn't.
 

Janderso

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#14
I never considered drilling with the knee.
I agree about the accuracy being better.
Brass grabs? Is that why the higher speeds for brass and aluminum?
I have lots of dumb questions
 

Larry42

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#15
I have a Jet 9x49 VS. I'd hate to go back to belt changes. Range is 60 to 4200. Low end is often used for tapping, higher end for aluminum and small tools. Back gear is 60-500. Being able to change speed on the fly has helped me a lot. I don't always pick the best speed first, but a few quick spins of the hand wheel and I'm running where I want to be.
My mill is well worn and I had to replace the VS belt a few months ago. Not the easiest trick to pull off. Sure glad I have high ceilings and access to a forklift.
 
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