eBay is full of those:

http://shop.ebay.com/?_nkw=%22micro+drill%22+carbide

or similar tiny carbide end mills.

My question is how usable are they on a hobby sized CNC machine like
my Bridgeport Interact, with slow top speed. Is using them totally out
of question, or just frustrating, or perhaps they are handly for small
work?

i

On 9/25/2010 12:19 PM, Ignoramus10035 wrote:
eBay is full of those:

http://shop.ebay.com/?_nkw=%22micro+drill%22+carbide

or similar tiny carbide end mills.

My question is how usable are they on a hobby sized CNC machine like
my Bridgeport Interact, with slow top speed. Is using them totally out
of question, or just frustrating, or perhaps they are handly for small
work?

You need to adjust your feed rate so as not to exceed
a reasonable chip load at lower RPMs but they work great
particularly on nasty stuff like fiberglass.
I milled out a couple double-sided PCBs using the tiny
end mills and the quality was far superior to any of
my previous attempts using other methods.

Try it, you'll like it.

--Winston

--
Corporate executive forgets to commit a felony for 24 hours.
Film at 11.

On Sat, 25 Sep 2010 14:19:20 -0500, Ignoramus10035
wrote:

eBay is full of those:

http://shop.ebay.com/?_nkw=%22micro+drill%22+carbide

or similar tiny carbide end mills.

My question is how usable are they on a hobby sized CNC machine like
my Bridgeport Interact, with slow top speed. Is using them totally out
of question, or just frustrating, or perhaps they are handly for small
work?

i

Ive got about 500 of those.

send me an shipping address and Ill send you some

Gunner


I am the Sword of my Family
and the Shield of my Nation.
If sent, I will crush everything you have built,
burn everything you love,
and kill every one of you.
(Hebrew quote)

On Sep 25, 3:54*pm, Winston wrote:
On 9/25/2010 12:19 PM, Ignoramus10035 wrote:

eBay is full of those:
* * *http://shop.ebay.com/?_nkw=%22micro+drill%22+carbide
or similar tiny carbide end mills.

My question is how usable are they on a hobby sized CNC machine like
my Bridgeport Interact, with slow top speed. ...

You need to adjust your feed rate so as not to exceed
a reasonable chip load at lower RPMs but they work great
particularly on nasty stuff like fiberglass.
....
--Winston

I've used them with a pin vise to make a hand-powered bow drill when
the Dremel at work was broken. I couldn't quite locate the PC board
well enough on the CNC board engraving machine to redrill the holes
larger without breaking bits.

Their main limitations are spindle play and chuck centering. They
worked fine at spin-with-the-fingers speed and a fairly coarse feed
pressure.

There's something odd about making a stone-age tool to solve a CNC
problem in a semiconductor factory. I had some spare round boards for
the flywheel weight and didn't have to grind a hole in a flat pebble.

jsw

On Sat, 25 Sep 2010 13:37:01 -0700, Gunner Asch
wrote:

On Sat, 25 Sep 2010 14:19:20 -0500, Ignoramus10035
wrote:

eBay is full of those:

http://shop.ebay.com/?_nkw=%22micro+drill%22+carbide

or similar tiny carbide end mills.

My question is how usable are they on a hobby sized CNC machine like
my Bridgeport Interact, with slow top speed. Is using them totally out
of question, or just frustrating, or perhaps they are handly for small
work?

i

Ive got about 500 of those.

send me an shipping address and Ill send you some

Gunner

I got a bunch of Gunner's drills a while back. they have served me
well. I know i should install the spindle speeder, but I normally
don't and just use a very low feed. They are easy to break, but very
cheap so not much bother.

Karl

On Sep 25, 12:19*pm, Ignoramus10035 ignoramus10...@NOSPAM.
10035.invalid wrote:
eBay is full of those:

* * *http://shop.ebay.com/?_nkw=%22micro+drill%22+carbide

or similar tiny carbide end mills.

My question is how usable are they on a hobby sized CNC machine like
my Bridgeport Interact, with slow top speed. Is using them totally out
of question, or just frustrating, or perhaps they are handly for small
work?

i

Well, they are used on machines not much different from hobby machines
in both size, but speed is way higher. However, there are both drills
and "burrs" in the machines. Obviously the drills do holes, only! The
burrs are used to mill the outline of the circuit board so as to
completely cut it from a panel of boards, or sometimes just leave
small tabs between boards in a panel. In other cases, a special "V"
shaped burr is used to mill a scoring line between boards so they can
be cut apart after populating them with components.

I have several assorted sets from both Grizzly and from Ebay. All are
1/8" shank. When we have to drill or mill a board, we use a variable
speed drill press, 0-20,000 or 0-39,000 rpm.

Paul

Ignoramus10035 wrote:
eBay is full of those:

http://shop.ebay.com/?_nkw=%22micro+drill%22+carbide

or similar tiny carbide end mills.

My question is how usable are they on a hobby sized CNC machine like
my Bridgeport Interact, with slow top speed. Is using them totally out
of question, or just frustrating, or perhaps they are handly for small
work?

Sure you can use these on your mill. Feed will have to be appropriate
for the spindle
RPM, something like .0001" per revolution, for the smallest ones. That
makes for
pretty slow going, but if you are only doing a few special holes in
something, it will
work fine. These are really designed for drilling composites, but you
can drill copper,
brass and aluminum just fine. Steel will require even more care. If
the point of the drill
enters even a hair off center, the drill will break.

Jon

On 2010-09-26, Jon Elson wrote:
Ignoramus10035 wrote:
eBay is full of those:

http://shop.ebay.com/?_nkw=%22micro+drill%22+carbide

or similar tiny carbide end mills.

My question is how usable are they on a hobby sized CNC machine like
my Bridgeport Interact, with slow top speed. Is using them totally out
of question, or just frustrating, or perhaps they are handly for small
work?

Sure you can use these on your mill. Feed will have to be
appropriate for the spindle RPM, something like .0001" per
revolution, for the smallest ones. That makes for pretty slow
going, but if you are only doing a few special holes in something,
it will work fine. These are really designed for drilling
composites, but you can drill copper, brass and aluminum just fine.
Steel will require even more care. If the point of the drill enters
even a hair off center, the drill will break.

Thanks Jon. I can live with that, this would be for one off things.


i

I've milled pcb's with the mills - and drills. The motor
with chuck ran 12k RPM's - and side loads are death to the drill/mill.

They are carbide - and likely sharp. Often pcb drillers/plating shops
send them to be sharpened, but fail to come for them as the price for
new is close to grind cost.

So if you need tiny holes and are willing to live with short lifetimes -
do it.

I also used them in various materials - being carbide they are capable.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
"Our Republic and the Press will Rise or Fall Together": Joseph Pulitzer
TSRA: Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Originator & Charter Founder
IHMSA and NRA Metallic Silhouette maker & member. http://lufkinced.com/

On 9/25/2010 2:19 PM, Ignoramus10035 wrote:
eBay is full of those:

http://shop.ebay.com/?_nkw=%22micro+drill%22+carbide

or similar tiny carbide end mills.

My question is how usable are they on a hobby sized CNC machine like
my Bridgeport Interact, with slow top speed. Is using them totally out
of question, or just frustrating, or perhaps they are handly for small
work?

i

?
"Jon Elson" wrote in message
...
Ignoramus10035 wrote:
eBay is full of those:

http://shop.ebay.com/?_nkw=%22micro+drill%22+carbide

or similar tiny carbide end mills.

My question is how usable are they on a hobby sized CNC machine like
my Bridgeport Interact, with slow top speed. Is using them totally out
of question, or just frustrating, or perhaps they are handly for small
work?

Sure you can use these on your mill. Feed will have to be appropriate for
the spindle
RPM, something like .0001" per revolution, for the smallest ones. That
makes for
pretty slow going, but if you are only doing a few special holes in
something, it will
work fine. These are really designed for drilling composites, but you can
drill copper,
brass and aluminum just fine. Steel will require even more care. If the
point of the drill
enters even a hair off center, the drill will break.

Jon

PCB drills are generaly C2 carbide, not recomended for drilling steel.

If your gonna buy some on ebay only purchase new ones, used ones
will usually need to be resharpened.

Best Regards
Tom.

"azotic" wrote in message
...
?
snip

PCB drills are generaly C2 carbide, not recomended for drilling steel.

If your gonna buy some on ebay only purchase new ones, used ones
will usually need to be resharpened.

Best Regards
Tom.
the broken drills are almost free, and they provide a great source of
carbide for engravers, etc

On 2010-09-26, azotic wrote:
?
"Jon Elson" wrote in message
...
Ignoramus10035 wrote:
eBay is full of those:

http://shop.ebay.com/?_nkw=%22micro+drill%22+carbide

or similar tiny carbide end mills.

[ ... ]

PCB drills are generaly C2 carbide, not recomended for drilling steel.

Though I have used one for drilling out a broken HSS tap. I was
rather amazed at how well it worked. This was in a sensitive drill
press, with the workpiece firmly clamped and lots of speed.

If your gonna buy some on ebay only purchase new ones, used ones
will usually need to be resharpened.

Actually -- I suspect that a lot of the really cheap ones are
from a resharpening facility which after resharpening discovered that
they were just a little shorter than the minimum length for normal use.
This could explain the batches of them which show up dirt cheap at
hamfests and the like.

Enjoy,
DoN.

--
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Email: | Voice (all times): (703) 938-4564
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