How to drill a blind hole?

[Bold & Old]

I personally like using a cheap Harbor Freight milling machine.. after the small hole has been drilled....

plunging a sharp end mill in the same hole position with a end mill will result in a clean precise cut.

also being able to be regulate the speeds........ especially with soft aluminum with a coolant..

a larger drill bit isn't designed for clean cuts with soft metals in the manor you described....

The result may end up ruining the work piece and the tool.

My 2 cents worth....

 

[gkent]

I personally like using a cheap Harbor Freight milling machine.

Well I personally would prefer a CNC mill ... but it doesn't sound like that's in the OP's budget !!!!!

 

[fesser]

If you aren't going very deep, I would try to find a lot shorter shanked cutting tool. A flat faced, carbide router bit will cut aluminum with no problems. The disadvantage is that with fewer flutes it might have a tendancy to want to bite into the material and take the router where you don't want it to go. You might be able to hold it back by hand but I would probably try to cut some sort of a guide to limit where the router can go.

 

[gkent]

From personal experience, that bit will do just fine. The twisted flute is the way to go but make sure the flute will pull the chips UP. They are available with flutes going either way.

 

[sam dupont]

Well I personally would prefer a CNC mill ... but it doesn't sound like that's in the OP's budget !!!!!

My problem is the space for a Mill.

With this end mill, I can plunge cut with my drill press and use the side flutes like a burr? In my side view,

cutaway drawing, I want to square my hole sides and enlarge the diameter. I also would like to thin the base by 1/8".
Is this end mill suitable?

 

[chtampa]

Clamp it down on a drill press and use a 3/4 end mill. Plunge it one time.

 

[gkent]

1) the drill press doesn't run fast enough
2) you won't be able to control the piece by hand
3) due to the height of the side wall a router is pretty much out of the question
4) good luck !!

 

[chtampa]

1) the drill press doesn't run fast enough
2) you won't be able to control the piece by hand
3) due to the height of the side wall a router is pretty much out of the question
4) good luck !!

Most drill presses are variable speed
If you use c-clamp vise-grips there is no control issue
Cast aluminum cuts easy and slow to keep from gumming the bit, so use WD-40
Go slow

 

[Dave P]

Something to keep in mind is that a lot of drill presses have a taper on the chucks
that do not like side loads associated with using them as a mill. They are known to
come loose an inappropriate times!
Edit....I'd use a high speed steel vs. carbide in something as floppy as a drill
press.....less likely to break it

 

[Virg464]

Before you jam an endmill into the material make sure it is a "Center Cut" endmill. Not all endmills are center cut and can be plunged straight into the material. Look at the end of the mill (depending on the number of flutes) at least two of the cutting edges should meet dead center, if not (if there's a void) it won't work, it will walk and/or just a cut a ring onto the material.

 

[sam dupont]

With my caveman mill and this 3/4 end mill, (a 1930's John Deere with a USAF missile site surplus 1/2" Sioux Drill) I plan to drill 1/8" deep holes in 3/8ths flat aluminum.

 

[threewood]

End mill and mount the piece to a rotating base to get the circle.

 

[Bold & Old]

Well I personally would prefer a CNC mill ... but it doesn't sound like that's in the OP's budget !!!!!

Well then I would prefer having you do the deed!

The topic is using a drill press... drill presses are for drilling holes.

i was making the point that a drill press isn't going to work so well and you dont have to spend a lot of money with the cheaper option I suggested.

A drill press the drill bit is going to walk on you even with a pilot hole pre-drilled.

wood is no problem.

 

[Bold & Old]

 

[Virg464]

With my caveman mill and this 3/4 end mill, (a 1930's John Deere with a USAF missile site surplus 1/2" Sioux Drill) I plan to drill 1/8" deep holes in 3/8ths flat aluminum.



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Pre-drill the through hole, run the cutter slow, I would suggest having a can of WD-40 (might keep the alum from sticking to your cutter. Go at it easy and it should work.