I have MANY (hundreds) of holes to drill in brass of my choice. (making
perf-plates for a pasta extruder).

I'd like some input on what will give me the best surface finish inside the
holes.

The life of the drill bit is important, but not critical. I will swap a
bit every hundred holes if the surface finish is perfect. Also, I could
use carbide drills, and drill 10,000 holes with one, but if that won't give
as good a surface as (say) HSS, then I'll go with the HSS bits.

Any input?

Thanks,
Lloyd

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in
. 3.70:

I have MANY (hundreds) of holes to drill in brass of my choice.
(making perf-plates for a pasta extruder).

I'd like some input on what will give me the best surface finish
inside the holes.

The life of the drill bit is important, but not critical. I will swap
a bit every hundred holes if the surface finish is perfect. Also, I
could use carbide drills, and drill 10,000 holes with one, but if that
won't give as good a surface as (say) HSS, then I'll go with the HSS
bits.

Any input?

I've had very good luck with "slow twist" drill bits. I bought a set
years ago, and they are wonderful for brass & plastic. The ones I have
were made by Chicago Latrobe.

One size went missing (25/64ths?) a while back, and I tried to replace
it. I ordered a slow twist drill bit from McMaster Carr, and received a
C-L drill bit, but the twist rate is about half way between normal drills
& the ones in my set. I originally thought they had sent me a regular
bit by mistake, but they checked their stock, and I compared to both
drill types. It's slow, but not that slow.

I don't know if C-L has decided to change the design or what. MSC also
sells slow twists, and the next time I place an order, I will probably
see what theirs look like.

Doug White

On 12/23/2011 3:25 PM, Lloyd E. Sponenburgh wrote:
I have MANY (hundreds) of holes to drill in brass of my choice. (making
perf-plates for a pasta extruder).

I'd like some input on what will give me the best surface finish inside the
holes.

The life of the drill bit is important, but not critical. I will swap a
bit every hundred holes if the surface finish is perfect. Also, I could
use carbide drills, and drill 10,000 holes with one, but if that won't give
as good a surface as (say) HSS, then I'll go with the HSS bits.

Any input?

Thanks,
Lloyd



I needed to make some clean holes in brass and happened to mention it to
my retired tool and die maker dad. He asked if I knew how to make a
scraping edge on a bit. I'm hoping someone else here can give you more
technical terms. In essence take a whet stone and flatten the lead edge
of each cutting flute so that the bit is scraping chips rather than
cutting curls. It hurt my soul to "dull" a brand new bit, but the
project worked well. I also modify bits the same way for plexiglass and
aluminum. It seems to radically reduce the tendency to grab/lift the
material and the burr on the back side.

I wasn't expecting to find much about it, but google "modify drill bit"
and "brass drill bit" and there are many articles:
here is one with pictures:
http://www.homemodelenginemachinist....p?topic=8618.0

another from the dropbox:
http://www.metalworking.com/DropBox/brass1.jpg
http://www.metalworking.com/DropBox/brass2.jpg

http://www.hawkfish.org/snailman/acrdrill.htm

http://www.practicalmachinist.com/vb...l-chuck-76515/


--


___________________________________

Keep the whole world singing . . .
Dan G

On 2011-12-23, Doug White wrote:

[ ... ]

I've had very good luck with "slow twist" drill bits. I bought a set
years ago, and they are wonderful for brass & plastic. The ones I have
were made by Chicago Latrobe.

Probably even better with the straight flute drill bits like
were made for Yankee push drills.

One size went missing (25/64ths?) a while back, and I tried to replace
it. I ordered a slow twist drill bit from McMaster Carr, and received a
C-L drill bit, but the twist rate is about half way between normal drills
& the ones in my set. I originally thought they had sent me a regular
bit by mistake, but they checked their stock, and I compared to both
drill types. It's slow, but not that slow.

I don't know if C-L has decided to change the design or what. MSC also
sells slow twists, and the next time I place an order, I will probably
see what theirs look like.

You know how to "dub" the cutting edge on a drill bit? This
does the same thing that the slow twist does for you -- it minimized the
rake where the cutting is happening. Take your "sorta slow" bit, or a
regular twist bit, and dub it (grind the first 1/16" or so of the rake
to a surface parallel to the drill bit's axis.

Check this out and scroll down to the first non-atavar photo.
(It is large enough to get your attention anyway. :-)

Enjoy,
DoN.

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Email: | Voice (all times): (703) 938-4564
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--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" fired this volley in
:

Check this out and scroll down to the first non-atavar photo.
(It is large enough to get your attention anyway. :-)

No binaries get through, Don. Can you just list a link?
Lloyd

On 23-Dec-2011 16:25, Lloyd E. Sponenburgh wrote:

cutter for highly machinable brass
making perf-plates for a pasta extruder


Most machinable brasses will have lead in them.
I hope you're not in California.
__________________________________________________ __________________
Gardner Buchanan gbuchana(a)teksavvy(dot)com
FreeBSD: Where you want to go. Today.

On Sat, 24 Dec 2011 07:45:38 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

"DoN. Nichols" fired this volley in
:

Check this out and scroll down to the first non-atavar photo.
(It is large enough to get your attention anyway. :-)

No binaries get through, Don. Can you just list a link?
Lloyd

You probably have the idea by now that you want to avoid positive
rake. That may not be a problem anyway, drilling in thin plate, but
the idea behind purpose-made cutters for brass is to avoid any
significant positive rake that would make the cutter dig in. In the
case of a drill bit, a positive-rake cutter can start self-feeding,
tear up the hole, and possibly break the bit.

Someone described stoning the lip so the cutting rake is zero --
parallel to the axis of the bit. That's what I do. It only requires a
very small flat. If I had to cut a lot of holes, I'd just buy a
purpose-made bit for the job. But you really don't need it for brass.

If you want a better finish and you're going to make a lot of holes,
consider a drill/reamer combination tool, and nub off the drill-lip
rake with a small slipstone.

--
Ed Huntress

On 2011-12-24, Ed Huntress wrote:
On Sat, 24 Dec 2011 07:45:38 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

"DoN. Nichols" fired this volley in
:

Check this out and scroll down to the first non-atavar photo.
(It is large enough to get your attention anyway. :-)

No binaries get through, Don. Can you just list a link?

I didn't see Lloyd's posting for some reason -- perhaps in the
killfile in part if not the whole name?

I didn't post a binary, so of course it did not get through. :-)

I thought that I had posted a link, but apparently forgot to cut
and paste it into the article.

Here is the URL which I had found befo

http://www.practicalmachinist.com/vb/general/dubbing-drill-bits-183967/

Lloyd

You probably have the idea by now that you want to avoid positive
rake. That may not be a problem anyway, drilling in thin plate, but
the idea behind purpose-made cutters for brass is to avoid any
significant positive rake that would make the cutter dig in. In the
case of a drill bit, a positive-rake cutter can start self-feeding,
tear up the hole, and possibly break the bit.

Indeed so.

Someone described stoning the lip so the cutting rake is zero --
parallel to the axis of the bit. That's what I do. It only requires a
very small flat. If I had to cut a lot of holes, I'd just buy a
purpose-made bit for the job. But you really don't need it for brass.

Indeed so.

If you want a better finish and you're going to make a lot of holes,
consider a drill/reamer combination tool, and nub off the drill-lip
rake with a small slipstone.

Hmm ... an interesting product. I don't have any of those,
though I do have the combination drill bit and tap which work nicely in
a tapping head in the drill press. (Not tried on brass, yet. :-)

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Sat, 24 Dec 2011 17:19:42 -0500, Gardner
78436578346587364578364578@kjhgfjkerhfjksdhfjkdfh kjhjkgfsdhfjdhfjkhfjkgfh.com
wrote:

On 23-Dec-2011 16:25, Lloyd E. Sponenburgh wrote:

cutter for highly machinable brass
making perf-plates for a pasta extruder


Most machinable brasses will have lead in them.
I hope you're not in California.
______________________________

I would choose a lead free brass alloy for food service!

1. drill then ream
2. Dreamer ( a totally useless tool unless you already have one, I
inquired once and it was several hundred bucks and an 8 week wait to
get one.)


Remove 333 to reply.
Randy

On Mon, 26 Dec 2011 09:07:02 -0500, the renowned Randy333
wrote:

On Sat, 24 Dec 2011 17:19:42 -0500, Gardner
78436578346587364578364578@kjhgfjkerhfjksdhfjkdf hkjhjkgfsdhfjdhfjkhfjkgfh.com
wrote:

On 23-Dec-2011 16:25, Lloyd E. Sponenburgh wrote:

cutter for highly machinable brass
making perf-plates for a pasta extruder


Most machinable brasses will have lead in them.
I hope you're not in California.
______________________________

I would choose a lead free brass alloy for food service!

From a brief investigation.. under what looks like the relevant NSF
rule-- 4.2.3.2 (FE-2009-12), leaded brass is only permitted in food
zone applications when tea, coffee or water are involved, and then
only to a maximum of 8% Pb content. No arsenic, cadmium or mercury
content is permissible.


1. drill then ream
2. Dreamer ( a totally useless tool unless you already have one, I
inquired once and it was several hundred bucks and an 8 week wait to
get one.)


Remove 333 to reply.
Randy


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Most machinable brasses will have lead in them.
I hope you're not in California.


You guys presume WAY too much, and are being didactic while not helping.

I have a contract which clearly spells out using freely-machinable brass
for the perf-plate. The customer has already spoken on the issue of
lead. HE specified brass, waived the lead content issue, and I have it
in writing.

So, why would you tell me not to do it? _I_ am not making food with
leaded brass -- I am building a machine to the customer's specs, and have
made sure he's educated on it. There's no more I need to do.

I cannot predict what he'll do with the device or even if "pasta" is what
he's extruding. HE called it a "pasta extruder", and after suitable
warnings, that's where my responsibility ends.

Lloyd

On Dec 26, 11:47*am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

I cannot predict what he'll do with the device or even if "pasta" is what
he's extruding. *HE called it a "pasta extruder", and after suitable
warnings, that's where my responsibility ends.

Lloyd

In a drag race shop I used to deal with, my buddy Sparky had a sign
over his bench that read, "Give the customer what he wants, even if it
kills him."

OTOH, you want to make sure it's spelled out very carefully that there
is lead in the material, and have him sign something that says that he
has read the specs (even if they are his specs).

I usually deliver my electronic and electro-mechanical prototypes and
designs with a disclaimer that says that we have tried our best to
adhere to the customer's specifications, but we make no warrantee that
the device delivered is suitable for any purpose. During our warrantee
period (10, 30, 60 90 [or sometimes longer] days, depending on the
complexity of the job), it is up to the customer to demonstrate that
what we built is not what he asked for. In writing.

HTH

On Mon, 26 Dec 2011 10:47:59 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Most machinable brasses will have lead in them.
I hope you're not in California.


You guys presume WAY too much, and are being didactic while not helping.

I have a contract which clearly spells out using freely-machinable brass
for the perf-plate. The customer has already spoken on the issue of
lead. HE specified brass, waived the lead content issue, and I have it
in writing.

So, why would you tell me not to do it? _I_ am not making food with
leaded brass -- I am building a machine to the customer's specs, and have
made sure he's educated on it. There's no more I need to do.

I cannot predict what he'll do with the device or even if "pasta" is what
he's extruding. HE called it a "pasta extruder", and after suitable
warnings, that's where my responsibility ends.

If it were my contract, I'd want to check with them damn revenuers to
make sure they wouldn't come after me for doing precisely what the
customer wanted, especially concerning lead. In Govspeak, that's the L
word.

--
[Television is] the triumph of machine over people.
-- Fred Allen

On 2011-12-26, Randy333 wrote:

[ ... ]

2. Dreamer ( a totally useless tool unless you already have one, I
inquired once and it was several hundred bucks and an 8 week wait to
get one.)

What size and what material? Looking on MSC's web site, I find
a bunch of them in different sizes, mostly HSS.

In HSS ranging between

1/8" $38.05

and

5/8" $129.97

And one which came up in the search in solid carbide.

10mm $116.35 Shank size is given, but not ream diameter.

Enjoy,
DoN.

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Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
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--- Black Holes are where God is dividing by zero ---