Re: [time-nuts] Machining some aluminum help!

[Charles Steinmetz]

Joseph wrote:


For _forming_, one needs something very viscous, something that
lubricates at very high pressures, at the yield strength of the
material being formed.


I've had excellent results with STP oil treatment, by itself or with 
added Tungsten disulfide.  I frequently tap under power at 20-150 rpm, 
using Tapmatic self-reversing tapping heads.


Best regards,

Charles


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[jimlux]

On 8/7/17 7:36 AM, Joseph Gwinn wrote:

On Sat, 29 Jul 2017 22:49:10 -0400, time-nuts-requ...@febo.com wrote:


--

Message: 2
Date: Sat, 29 Jul 2017 20:57:56 -0400
From: Scott McGrath <scmcgr...@gmail.com>
To: Discussion of precise time and frequency measurement
<time-nuts@febo.com>
Subject: Re: [time-nuts] Machining some aluminum help!
Message-ID: <f4dd2bec-d51d-43b2-93f3-28a57cd6e...@gmail.com>
Content-Type: text/plain;   charset=us-ascii

Kerosine is a better tap lube for Aluminum as it is more persistent
and less flammable


NO.  Kerosene is *not* a good lubricant for _forming_ taps.

Kerosene (WD-40) and alcohol are good lubricants for _cutting_.

For _forming_, one needs something very viscous, something that
lubricates at very high pressures, at the yield strength of the
material being formed.



Like Molybdenum Disulfide or STP?


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Scott McGrath]

I dont want to start a flame war here but I tend to take the recommendations in 
Machinery's Handbook as the basis for process decisions.

for the last 75 years Machinerys Handbook recommend Kerosene as a tapping fluid 
for Aluminum even for forming taps

Btw if anyone here has a machinists tool box that odd rectangular drawer is for 
your copy of Machinery's Handbook

http://new.industrialpress.com/machinery-s-handbook-30th-edition-toolbox.html

WD40 should not be used in any machining operation  

it was initially created for the USAF to remove water (WATER DISPLACER formula 
40) from missile parts which had gotten wet and to leave behind a dry lubricant 
to prevent corrosion and force out water via capillary action

Thats why it works on seized fasteners the capillary action gets the lube into 
the corrosion cells allowing fasteners to move





Content by Scott
Typos by Siri
> On Aug 7, 2017, at 10:36 AM, Joseph Gwinn <joegw...@comcast.net> wrote:
> 
>> On Sat, 29 Jul 2017 22:49:10 -0400, time-nuts-requ...@febo.com wrote:
>> 
>> --
>> 
>> Message: 2
>> Date: Sat, 29 Jul 2017 20:57:56 -0400
>> From: Scott McGrath <scmcgr...@gmail.com>
>> To: Discussion of precise time and frequency measurement
>><time-nuts@febo.com>
>> Subject: Re: [time-nuts] Machining some aluminum help!
>> Message-ID: <f4dd2bec-d51d-43b2-93f3-28a57cd6e...@gmail.com>
>> Content-Type: text/plain;charset=us-ascii
>> 
>> Kerosine is a better tap lube for Aluminum as it is more persistent 
>> and less flammable
> 
> NO.  Kerosene is *not* a good lubricant for _forming_ taps.
> 
> Kerosene (WD-40) and alcohol are good lubricants for _cutting_.
> 
> For _forming_, one needs something very viscous, something that 
> lubricates at very high pressures, at the yield strength of the 
> material being formed.
> 
> Joe Gwinn
> 
> 
> 
>> Content by Scott
>> Typos by Siri
>> 
>>>> On Jul 29, 2017, at 6:41 PM, Joseph Gwinn <joegw...@comcast.net> wrote:
>>>> 
>>>> On Sat, 29 Jul 2017 12:00:02 -0400, time-nuts-requ...@febo.com wrote:
>>>> Send time-nuts mailing list submissions to
>>>>   time-nuts@febo.com
>>>> 
>>>> Message: 7
>>>> Date: Fri, 28 Jul 2017 14:11:09 -0700
>>>> From: "Gary E. Miller" <g...@rellim.com>
>>>> To: Discussion of precise time and frequency measurement
>>>>   <time-nuts@febo.com>
>>>> Subject: Re: [time-nuts] Machining some aluminum help!
>>>> Message-ID: <20170728141109.71aad...@spidey.rellim.com>
>>>> Content-Type: text/plain; charset="utf-8"
>>>> 
>>>> Yo cdel...@juno.com!
>>>> 
>>>> On Fri, 28 Jul 2017 12:46:30 -0700
>>>> <cdel...@juno.com> wrote:
>>>> 
>>>>> After mounting the tap in the drill
>>>>> press and putting a dab of Crisco on the tap I was able to tap each
>>>>> hole to a depth of 7/16" as fast as I could turn the handwheel!
>>>> 
>>>> 
>>>> Cool!
>>>> 
>>>> I suggest you get some real cutting fluid.  The threads will be smoother.
>>> 
>>> I second that.  What I use is a lubricant wax made by Lenox, the saw 
>>> maker.  It's intended for metal-cutting band saws, but works just 
>>> splendid for form taps.  There are many equivalents.
>>> 
>>> By the way, when drilling aluminum, use denatured alcohol as the 
>>> cutting fluid.  This will prevent aluminum gumming up the cutting edge 
>>> of the drill.
>>> 
>>> And, as others have mentioned, one does not use the same size drill for 
>>> forming taps as for cutting taps.  The diameter accuracy required can 
>>> only be achieved by using the correct number (versus fractional) drill 
>>> bit size.  Do not use Chinese drill bits - steel not good enough.  US, 
>>> Japan, Germany et al are OK.
>>> 
>>> Joe Gwinn
>>> 
>>> 
>>>> RGDS
>>>> GARY
>>>> 
> ---
> 
>> 
>> End of time-nuts Digest, Vol 156, Issue 38
>> **
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Joseph Gwinn]

On Sat, 29 Jul 2017 22:49:10 -0400, time-nuts-requ...@febo.com wrote:
> 
> --
> 
> Message: 2
> Date: Sat, 29 Jul 2017 20:57:56 -0400
> From: Scott McGrath <scmcgr...@gmail.com>
> To: Discussion of precise time and frequency measurement
>   <time-nuts@febo.com>
> Subject: Re: [time-nuts] Machining some aluminum help!
> Message-ID: <f4dd2bec-d51d-43b2-93f3-28a57cd6e...@gmail.com>
> Content-Type: text/plain; charset=us-ascii
> 
> Kerosine is a better tap lube for Aluminum as it is more persistent 
> and less flammable

NO.  Kerosene is *not* a good lubricant for _forming_ taps.

Kerosene (WD-40) and alcohol are good lubricants for _cutting_.

For _forming_, one needs something very viscous, something that 
lubricates at very high pressures, at the yield strength of the 
material being formed.

Joe Gwinn


 
> Content by Scott
> Typos by Siri
> 
>> On Jul 29, 2017, at 6:41 PM, Joseph Gwinn <joegw...@comcast.net> wrote:
>> 
>>> On Sat, 29 Jul 2017 12:00:02 -0400, time-nuts-requ...@febo.com wrote:
>>> Send time-nuts mailing list submissions to
>>>time-nuts@febo.com
>>> 
>>> Message: 7
>>> Date: Fri, 28 Jul 2017 14:11:09 -0700
>>> From: "Gary E. Miller" <g...@rellim.com>
>>> To: Discussion of precise time and frequency measurement
>>><time-nuts@febo.com>
>>> Subject: Re: [time-nuts] Machining some aluminum help!
>>> Message-ID: <20170728141109.71aad...@spidey.rellim.com>
>>> Content-Type: text/plain; charset="utf-8"
>>> 
>>> Yo cdel...@juno.com!
>>> 
>>> On Fri, 28 Jul 2017 12:46:30 -0700
>>> <cdel...@juno.com> wrote:
>>> 
>>>> After mounting the tap in the drill
>>>> press and putting a dab of Crisco on the tap I was able to tap each
>>>> hole to a depth of 7/16" as fast as I could turn the handwheel!
>>> 
>>> 
>>> Cool!
>>> 
>>> I suggest you get some real cutting fluid.  The threads will be smoother.
>> 
>> I second that.  What I use is a lubricant wax made by Lenox, the saw 
>> maker.  It's intended for metal-cutting band saws, but works just 
>> splendid for form taps.  There are many equivalents.
>> 
>> By the way, when drilling aluminum, use denatured alcohol as the 
>> cutting fluid.  This will prevent aluminum gumming up the cutting edge 
>> of the drill.
>> 
>> And, as others have mentioned, one does not use the same size drill for 
>> forming taps as for cutting taps.  The diameter accuracy required can 
>> only be achieved by using the correct number (versus fractional) drill 
>> bit size.  Do not use Chinese drill bits - steel not good enough.  US, 
>> Japan, Germany et al are OK.
>> 
>> Joe Gwinn
>> 
>> 
>>> RGDS
>>> GARY
>>> 
---

> 
> End of time-nuts Digest, Vol 156, Issue 38
> **
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Clay Autery]

Kerosene as the cutting fluid and use Acetone to clean up the kerosene
afterwards.

__
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389

On 7/29/2017 7:57 PM, Scott McGrath wrote:
> Kerosine is a better tap lube for Aluminum as it is more persistent and less 
> flammable
>
> Content by Scott
> Typos by Siri
>

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Scott McGrath]

Kerosine is a better tap lube for Aluminum as it is more persistent and less 
flammable

Content by Scott
Typos by Siri

> On Jul 29, 2017, at 6:41 PM, Joseph Gwinn <joegw...@comcast.net> wrote:
> 
>> On Sat, 29 Jul 2017 12:00:02 -0400, time-nuts-requ...@febo.com wrote:
>> Send time-nuts mailing list submissions to
>>time-nuts@febo.com
>> 
>> Message: 7
>> Date: Fri, 28 Jul 2017 14:11:09 -0700
>> From: "Gary E. Miller" <g...@rellim.com>
>> To: Discussion of precise time and frequency measurement
>><time-nuts@febo.com>
>> Subject: Re: [time-nuts] Machining some aluminum help!
>> Message-ID: <20170728141109.71aad...@spidey.rellim.com>
>> Content-Type: text/plain; charset="utf-8"
>> 
>> Yo cdel...@juno.com!
>> 
>> On Fri, 28 Jul 2017 12:46:30 -0700
>> <cdel...@juno.com> wrote:
>> 
>>> After mounting the tap in the drill
>>> press and putting a dab of Crisco on the tap I was able to tap each
>>> hole to a depth of 7/16" as fast as I could turn the handwheel!
>> 
>> 
>> Cool!
>> 
>> I suggest you get some real cutting fluid.  The threads will be smoother.
> 
> I second that.  What I use is a lubricant wax made by Lenox, the saw 
> maker.  It's intended for metal-cutting band saws, but works just 
> splendid for form taps.  There are many equivalents.
> 
> By the way, when drilling aluminum, use denatured alcohol as the 
> cutting fluid.  This will prevent aluminum gumming up the cutting edge 
> of the drill.
> 
> And, as others have mentioned, one does not use the same size drill for 
> forming taps as for cutting taps.  The diameter accuracy required can 
> only be achieved by using the correct number (versus fractional) drill 
> bit size.  Do not use Chinese drill bits - steel not good enough.  US, 
> Japan, Germany et al are OK.
> 
> Joe Gwinn
> 
> 
>> RGDS
>> GARY
>> ---
>> 
>> End of time-nuts Digest, Vol 156, Issue 36
>> **
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Joseph Gwinn]

On Sat, 29 Jul 2017 12:00:02 -0400, time-nuts-requ...@febo.com wrote:
> Send time-nuts mailing list submissions to
>   time-nuts@febo.com
> 
> Message: 7
> Date: Fri, 28 Jul 2017 14:11:09 -0700
> From: "Gary E. Miller" <g...@rellim.com>
> To: Discussion of precise time and frequency measurement
>   <time-nuts@febo.com>
> Subject: Re: [time-nuts] Machining some aluminum help!
> Message-ID: <20170728141109.71aad...@spidey.rellim.com>
> Content-Type: text/plain; charset="utf-8"
> 
> Yo cdel...@juno.com!
> 
> On Fri, 28 Jul 2017 12:46:30 -0700
> <cdel...@juno.com> wrote:
> 
>> After mounting the tap in the drill
>> press and putting a dab of Crisco on the tap I was able to tap each
>> hole to a depth of 7/16" as fast as I could turn the handwheel!
> 
> 
> Cool!
> 
> I suggest you get some real cutting fluid.  The threads will be smoother.

I second that.  What I use is a lubricant wax made by Lenox, the saw 
maker.  It's intended for metal-cutting band saws, but works just 
splendid for form taps.  There are many equivalents.

By the way, when drilling aluminum, use denatured alcohol as the 
cutting fluid.  This will prevent aluminum gumming up the cutting edge 
of the drill.

And, as others have mentioned, one does not use the same size drill for 
forming taps as for cutting taps.  The diameter accuracy required can 
only be achieved by using the correct number (versus fractional) drill 
bit size.  Do not use Chinese drill bits - steel not good enough.  US, 
Japan, Germany et al are OK.

Joe Gwinn

 
> RGDS
> GARY
> ---
> 
> End of time-nuts Digest, Vol 156, Issue 36
> **
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Edesio Costa e Silva]

Nice!

Do you mind posting some photos?

Thanks.

Edésio

On Fri, Jul 28, 2017 at 12:46:30PM -0700, cdel...@juno.com wrote:
> Well I did some research and found my new best friend!
>
> If you remember I needed:  "I have a square aluminum tube 5" X 5" with a
> .25" wall it's 8 1/2" long.
>
> I need 20 holes in each end tapped for 4/40 and 1/2" deep."
>
> This for a Rubidium standard I am working on.
>
> I found all about self forming taps!
>
> I drilled the 20 1/2" deep holes and then made a handwheel to attach to
> the pulley on my drill press. After mounting the tap in the drill press
> and putting a dab of Crisco on the tap I was able to tap each hole to a
> depth of 7/16" as fast as I could turn the handwheel!
>
> I then got another 8-32 self forming tap to do the holes for 15 feedthru
> capacitors, again as fast as I could turn the handwheel.
>
> I'm very happy to discover these taps
>
> Cheers,
>
> Corby
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Gary E. Miller]

Yo cdel...@juno.com!

On Fri, 28 Jul 2017 12:46:30 -0700
 wrote:

> After mounting the tap in the drill
> press and putting a dab of Crisco on the tap I was able to tap each
> hole to a depth of 7/16" as fast as I could turn the handwheel!


Cool!

I suggest you get some real cutting fluid.  The threads will be smoother.

RGDS
GARY
---
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
g...@rellim.com  Tel:+1 541 382 8588

Veritas liberabit vos. -- Quid est veritas?
"If you can’t measure it, you can’t improve it." - Lord Kelvin


pgpn3ISOcp_1P.pgp
Description: OpenPGP digital signature
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[djl]

Good even for mild steel too. Best is your good advice to use the drill 
press to keep the tap aligned.  softer aluminum alloys are very "sticky" 
and demand backing off a turn for almost every turn forward for cutting 
taps to break the chip. I've found that the 6/32 tap is the most easily 
broken. sigh.
Pay attention, the tap drill is not the same for the forming tap as it 
is for the cutting tap.

Don


On 2017-07-28 13:46, cdel...@juno.com wrote:

Well I did some research and found my new best friend!

If you remember I needed:  "I have a square aluminum tube 5" X 5" with 
a

.25" wall it's 8 1/2" long.

I need 20 holes in each end tapped for 4/40 and 1/2" deep."

This for a Rubidium standard I am working on.

I found all about self forming taps!

I drilled the 20 1/2" deep holes and then made a handwheel to attach to
the pulley on my drill press. After mounting the tap in the drill press
and putting a dab of Crisco on the tap I was able to tap each hole to a
depth of 7/16" as fast as I could turn the handwheel!

I then got another 8-32 self forming tap to do the holes for 15 
feedthru

capacitors, again as fast as I could turn the handwheel.

I'm very happy to discover these taps

Cheers,

Corby
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

and follow the instructions there.


--
Dr. Don Latham
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] Machining some aluminum help!

[cdelect]

Well I did some research and found my new best friend!

If you remember I needed:  "I have a square aluminum tube 5" X 5" with a
.25" wall it's 8 1/2" long.

I need 20 holes in each end tapped for 4/40 and 1/2" deep."

This for a Rubidium standard I am working on.

I found all about self forming taps!

I drilled the 20 1/2" deep holes and then made a handwheel to attach to
the pulley on my drill press. After mounting the tap in the drill press
and putting a dab of Crisco on the tap I was able to tap each hole to a
depth of 7/16" as fast as I could turn the handwheel!

I then got another 8-32 self forming tap to do the holes for 15 feedthru
capacitors, again as fast as I could turn the handwheel.

I'm very happy to discover these taps

Cheers,

Corby
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Van Horn, David]

For popping off the lid, a few threaded holes in the lid would be nice.  Insert 
screws and let them push against the body and push the lid off.


-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of ed breya
Sent: Thursday, May 25, 2017 3:08 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] Machining some aluminum help!

This is the first time I've looked at time-nuts in about a month, and I noticed 
the run about this project. I'm very late to the party, but have a few 
suggestions that may help - if it's not too late. I quickly scanned many of the 
posts, and agree with many of the ideas. Please forgive if my suggestions are 
redundant to what's already been said.

First, I assume that the aluminum box is a simple extrusion, so it will likely 
be a soft alloy that will tend to gall horribly with machining - especially bad 
for anything that needs high precision. With these kinds of material, go big, 
starting with bigger fasteners. With 1/4" walls, you can easily up it to 6-32 
or 8-32, as long as the holes are fairly shallow, and you can jig it up for 
good centering and plumbness. With
4-40 and blind holes, you're just asking for trouble - especially taking a 
chance 40 times. The tap drill will be quite skinny, and prone to deform and 
wander as it goes in, and can easily be snapped off when it stalls due to the 
galling - and that's just the drilling stage - the tapping will be worse.

Bigger threads give you a chance to get it done with fewer fasteners and holes, 
and much less grief. The thread depth should allow for at least one 
pitch-diameter of penetration for strength, but preferably two or more, so you 
don't have to worry about finding exact right screw lengths that won't bottom 
out. Depending on the thickness of the end plates, you could get down to two or 
three fasteners per side to hold the small pressure needed.

If you're using a drill press, punch mark the hole centers, then use a center 
drill to make the pilot holes for the tap drill. If you're freehand drilling, 
put the piece on the floor and drill downward, keeping it as plumb as possible. 
Definitely use an oil or other lubricant for all the drilling and tapping 
operations.

For sealing, I'd recommend against fancy o-ring features and such - these are 
also harder to machine cleanly in soft aluminum, and add unnecessary 
complexity. If the end caps need regular remove and replace operations, then go 
with a pliable gasket, have more fasteners to get more uniform compression, and 
make the threads deeper so they'll last longer. If the sealing is one-time, or 
seldom needs to be broken, I'd recommend using a gasket sealing goop that will 
work fine with few fasteners and even rough surface finish. My favorite is 
Permatex #2 "Form-A-Gasket Sealant," which I've used for all sorts of stuff 
over fifty years (back then it was Radiator Specialties brand). Don't use a 
silicone goop unless you want to spend a lot of time scraping off the old stuff 
if it needs to be opened. If you do use a goop, it's a good idea to machine in 
features for prying the lids off, such as gasket-plane screwdriver slots, or 
extra tapped through-holes in line with the mounting holes on of the l
 id.

Ed
___
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Chris Albertson]

That is one reason people have been recommending heilicoils.   The
drill an tap size is about 30% larger than for #4 screws without the
inserts.  It is easier to do and when you are done there are stainless
female threads that are much stronger.

On Thu, May 25, 2017 at 3:57 PM, ed breya  wrote:
> ..., you can save a lot of grief by using a slightly larger bit than the
> standard tap drill. You're not really too concerned with optimal fit and
> strength here - it's more about being able to make a whole lot of usable
> screw holes without losing too many bits and taps,
-- 

Chris Albertson
Redondo Beach, California
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[ed breya]

One thing I forgot to add - if you must use the 4-40 screw size for some 
reason, you can save a lot of grief by using a slightly larger bit than 
the standard tap drill. You're not really too concerned with optimal fit 
and strength here - it's more about being able to make a whole lot of 
usable screw holes without losing too many bits and taps, or reworking. 
You can experiment and see what size makes the best tradeoffs.


It's amazing sometimes how a little more root clearance can makes things 
so much nicer - a shallower cut, so less torque on that tiny tap, more 
room for chip clearing, and better lubing. You can also get deeper 
threads to compensate for less meat in the thread root. Even the drill 
bit will have a better chance of survival, since it will be slightly 
bigger and stronger.


Of course, if you go too far, there won't be enough thread - but then 
you'll have reason to jump to the next size up.


Ed
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Chris Albertson]

Why not make the enclosure with a round, not square cross section then
the end plate can screw in.  Only one hole to thread that way.  Of
course there is plumbing pipe but also stainless steel water bottles,
fly rod cases and all kinds of ready  made metal enclosures with
thread caps that can hold pressure.A stanley wide mouth thermos
would be excellent for making a temperature controlled metal
enclosure.  The vacuum insolation is pretty good, and of course they
already hold pressure.

On Thu, May 25, 2017 at 2:08 PM, ed breya  wrote:
> This is the first time I've looked at time-nuts in about a month, and I
> noticed the run about this project. I'm very late to the party, but have a
> few suggestions that may help - if it's not too late. I quickly scanned many
> of the posts, and agree with many of the ideas. Please forgive if my
> suggestions are redundant to what's already been said.
>
> First, I assume that the aluminum box is a simple extrusion, so it will
> likely be a soft alloy that will tend to gall horribly with machining -
> especially bad for anything that needs high precision. With these kinds of
> material, go big, starting with bigger fasteners. With 1/4" walls, you can
> easily up it to 6-32 or 8-32, as long as the holes are fairly shallow, and
> you can jig it up for good centering and plumbness. With 4-40 and blind
> holes, you're just asking for trouble - especially taking a chance 40 times.
> The tap drill will be quite skinny, and prone to deform and wander as it
> goes in, and can easily be snapped off when it stalls due to the galling -
> and that's just the drilling stage - the tapping will be worse.
>
> Bigger threads give you a chance to get it done with fewer fasteners and
> holes, and much less grief. The thread depth should allow for at least one
> pitch-diameter of penetration for strength, but preferably two or more, so
> you don't have to worry about finding exact right screw lengths that won't
> bottom out. Depending on the thickness of the end plates, you could get down
> to two or three fasteners per side to hold the small pressure needed.
>
> If you're using a drill press, punch mark the hole centers, then use a
> center drill to make the pilot holes for the tap drill. If you're freehand
> drilling, put the piece on the floor and drill downward, keeping it as plumb
> as possible. Definitely use an oil or other lubricant for all the drilling
> and tapping operations.
>
> For sealing, I'd recommend against fancy o-ring features and such - these
> are also harder to machine cleanly in soft aluminum, and add unnecessary
> complexity. If the end caps need regular remove and replace operations, then
> go with a pliable gasket, have more fasteners to get more uniform
> compression, and make the threads deeper so they'll last longer. If the
> sealing is one-time, or seldom needs to be broken, I'd recommend using a
> gasket sealing goop that will work fine with few fasteners and even rough
> surface finish. My favorite is Permatex #2 "Form-A-Gasket Sealant," which
> I've used for all sorts of stuff over fifty years (back then it was Radiator
> Specialties brand). Don't use a silicone goop unless you want to spend a lot
> of time scraping off the old stuff if it needs to be opened. If you do use a
> goop, it's a good idea to machine in features for prying the lids off, such
> as gasket-plane screwdriver slots, or extra tapped through-holes in line
> with the mounting holes on of the lid.
>
> Ed
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



-- 

Chris Albertson
Redondo Beach, California
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[ed breya]

This is the first time I've looked at time-nuts in about a month, and I 
noticed the run about this project. I'm very late to the party, but have 
a few suggestions that may help - if it's not too late. I quickly 
scanned many of the posts, and agree with many of the ideas. Please 
forgive if my suggestions are redundant to what's already been said.


First, I assume that the aluminum box is a simple extrusion, so it will 
likely be a soft alloy that will tend to gall horribly with machining - 
especially bad for anything that needs high precision. With these kinds 
of material, go big, starting with bigger fasteners. With 1/4" walls, 
you can easily up it to 6-32 or 8-32, as long as the holes are fairly 
shallow, and you can jig it up for good centering and plumbness. With 
4-40 and blind holes, you're just asking for trouble - especially taking 
a chance 40 times. The tap drill will be quite skinny, and prone to 
deform and wander as it goes in, and can easily be snapped off when it 
stalls due to the galling - and that's just the drilling stage - the 
tapping will be worse.


Bigger threads give you a chance to get it done with fewer fasteners and 
holes, and much less grief. The thread depth should allow for at least 
one pitch-diameter of penetration for strength, but preferably two or 
more, so you don't have to worry about finding exact right screw lengths 
that won't bottom out. Depending on the thickness of the end plates, you 
could get down to two or three fasteners per side to hold the small 
pressure needed.


If you're using a drill press, punch mark the hole centers, then use a 
center drill to make the pilot holes for the tap drill. If you're 
freehand drilling, put the piece on the floor and drill downward, 
keeping it as plumb as possible. Definitely use an oil or other 
lubricant for all the drilling and tapping operations.


For sealing, I'd recommend against fancy o-ring features and such - 
these are also harder to machine cleanly in soft aluminum, and add 
unnecessary complexity. If the end caps need regular remove and replace 
operations, then go with a pliable gasket, have more fasteners to get 
more uniform compression, and make the threads deeper so they'll last 
longer. If the sealing is one-time, or seldom needs to be broken, I'd 
recommend using a gasket sealing goop that will work fine with few 
fasteners and even rough surface finish. My favorite is Permatex #2 
"Form-A-Gasket Sealant," which I've used for all sorts of stuff over 
fifty years (back then it was Radiator Specialties brand). Don't use a 
silicone goop unless you want to spend a lot of time scraping off the 
old stuff if it needs to be opened. If you do use a goop, it's a good 
idea to machine in features for prying the lids off, such as 
gasket-plane screwdriver slots, or extra tapped through-holes in line 
with the mounting holes on of the lid.


Ed
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Bob kb8tq]

Hi


> On May 19, 2017, at 5:35 PM, Chris Albertson  
> wrote:
> 
> Yes, threaded inserts.  There are many kinds but they are used almost
> universally for cases where the material to be threaded is soft, like
> aluminum.   They also eliminate or reduce galvanic corrosion which is an
> issue with steel screws in aluminum.  (that said, as long as you keep water
> away you are OK.)

There are some interesting internal studies out of places like Boeing that 
suggest the “keep moisture
away” includes some pretty modest levels of humidity …. It then becomes a 
question of if you do
or do not accept their methods. 

Bob


> Still these inserts are the "class" way to go and will
> save some broken taps.
> 
> As for a seal, it is hard to beat o-rings.  A proper designed o-ring seal
> does not need much clamping pressure as it depends on the pressure inside
> to force the ring in place and hold it there.
> 
> On Fri, May 19, 2017 at 12:51 PM, Lincoln  wrote:
> 
>> 
>>> 
>>> There are a lot of variables involved. Run the screws in and out of the
>> aluminum a number of times and
>>> the holes will fail first ….There are other gotchas as well.
>>> 
>>> Bob
>>> 
>> 
>> This is where helicoils come in to play. They are used a lot on the CVD
>> furnaces that I used to make parts for. They are not just for un-buggering
>> a thread. They would be installed form the get go and could be replaced
>> should something gall.
>> 
>> Link
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/
>> mailman/listinfo/time-nuts
>> and follow the instructions there.
>> 
> 
> 
> 
> -- 
> 
> Chris Albertson
> Redondo Beach, California
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Chris Albertson]

I worked on a project like this once.  No screws at all.  Rather then a 0.1
PSI over pressure. the interior was flush with dry gas then pumped out with
to  a crude vacuum with a hand pump.  Air pressure alone force the cover
plate on.  OK a couple screws where there just to aid in assembly but the
cheap $12 hand pump was good enough.

"high vacuum" requires expensive equipment and is a black art but "crude
vacuum" is easy, easier then holding a pressure because the forces are
pushing the seal together for you.

On Thu, May 18, 2017 at 2:46 PM, jimlux  wrote:

> On 5/18/17 1:34 PM, cdel...@juno.com wrote:
>
>> Well that generated a lot of advice and thanks for it!
>> I think I might do it myself and go with a 1/2" hole depth and 1/4"
>> threaded depth.
>> I'll get some of that Aluminum Tap magic, some new taps and new drill
>> bits.
>> Good idea about drilling the end plates first and drilling thru to match.
>> Between the end plate and the tube is a gasket that needs to seal
>> pressure and moisture tight. That's why I used 5 per side.
>>
>
> I would make the end plate "real thick",with a machined groove for the
> o-ring, and use some sort of latches to hold it in place, rather than "lots
> 'o screws".  Unless you've got a real tight space constraint. How much
> pressure do you have to hold? That will determine the clamping force needed
> on your gasket (and potentially, on your fasteners).  Do you need the full
> 4.5x4.5" inside clear space? A 1/4-20 bolt in the corner might be a good
> way to go.
>
> There's also inexpensive surplus vacuum equipment around, as well as run
> of the mill plumbing. Unless Steel (stainless or not) isn't an option.
>
>
>
>
>
>
>> Will let you know how it turns out.
>>
>> Cheers,
>>
>> Corby
>>
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/m
>> ailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> ailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 

Chris Albertson
Redondo Beach, California
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Chris Albertson]

Yes, threaded inserts.  There are many kinds but they are used almost
universally for cases where the material to be threaded is soft, like
aluminum.   They also eliminate or reduce galvanic corrosion which is an
issue with steel screws in aluminum.  (that said, as long as you keep water
away you are OK.)Still these inserts are the "class" way to go and will
save some broken taps.

As for a seal, it is hard to beat o-rings.  A proper designed o-ring seal
does not need much clamping pressure as it depends on the pressure inside
to force the ring in place and hold it there.

On Fri, May 19, 2017 at 12:51 PM, Lincoln  wrote:

>
> >
> > There are a lot of variables involved. Run the screws in and out of the
> aluminum a number of times and
> > the holes will fail first ….There are other gotchas as well.
> >
> > Bob
> >
>
> This is where helicoils come in to play. They are used a lot on the CVD
> furnaces that I used to make parts for. They are not just for un-buggering
> a thread. They would be installed form the get go and could be replaced
> should something gall.
>
> Link
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 

Chris Albertson
Redondo Beach, California
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Bob Bownes]

We also used helicoils in titanium frames of the supercomputer I used to work 
with. Meant we could use relatively standard fasteners without fear of falling. 

On a time nuts related note, I have a u blox GPS-1E that seems to be stuck 
spewing out in ublox format. With no development sw available (that runs on my 
Mac), I'm looking for the correct string to send its way to change it back to 
NMEA. Anyone point me at some docs or know the appropriate string?

Thanks!
Bob

> On May 19, 2017, at 15:51, Lincoln  wrote:
> 
> 
>> 
>> There are a lot of variables involved. Run the screws in and out of the 
>> aluminum a number of times and 
>> the holes will fail first ….There are other gotchas as well.
>> 
>> Bob
>> 
> 
> This is where helicoils come in to play. They are used a lot on the CVD 
> furnaces that I used to make parts for. They are not just for un-buggering a 
> thread. They would be installed form the get go and could be replaced should 
> something gall. 
> 
> Link
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Scott McGrath]

Corby

Unless you have the tubing and plates machined flat they will leak as the 
tubing sides are not guaranteed to be flat and parallel wrt each side and 
aluminum plate stock is not flat unless you purchase 'tooling plate' which is 
ground parallel on both sides

So creating a seal is problematic at best

Content by Scott
Typos by Siri

> On May 19, 2017, at 4:23 PM,   wrote:
> 
> Thanks everyone.
> 
> Not looking for a redesign, just figuring out how to get the holes
> drilled and tapped.
> 
> I have come up with a scheme that looks promising and will let you know
> how it goes.
> 
> The enclosure only has to hold +.1PSI of dry nitrogen without leaking.
> 
> It will have a pressure sensor inside to allow long term monitoring.
> 
> From the feedback and some research I will be reducing the depth of the
> threaded portion.
> 
> Cheers, 
> 
> Corby
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] Machining some aluminum help!

[cdelect]

Thanks everyone.

Not looking for a redesign, just figuring out how to get the holes
drilled and tapped.

I have come up with a scheme that looks promising and will let you know
how it goes.

The enclosure only has to hold +.1PSI of dry nitrogen without leaking.

It will have a pressure sensor inside to allow long term monitoring.

>From the feedback and some research I will be reducing the depth of the
threaded portion.

Cheers, 

Corby

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Lincoln]

> 
> There are a lot of variables involved. Run the screws in and out of the 
> aluminum a number of times and 
> the holes will fail first ….There are other gotchas as well.
> 
> Bob
> 

This is where helicoils come in to play. They are used a lot on the CVD 
furnaces that I used to make parts for. They are not just for un-buggering a 
thread. They would be installed form the get go and could be replaced should 
something gall. 

Link
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Chris Albertson]

To tell the truth I had not worked this out.But I wonder of the screws
fail first on
they are in aluminum holes with only 1/4 of thread.

Which fails depends on the material and the number of engaged threads,

But if what you say is right for this case.  It strengthens my case for
using self threading screws.  I try and use these when I can.

What you do is center punch the screw location around the end plate.  Then
glue the end plat in place using blue lock tight. (or even two tiny daps of
"Super Glue")  then go to the drip pressed drill through the endplate into
the edge of the wall and insert one screw.  The right size the type screw
will cut its own thread as you screw it in.  Then drill neither hole and
put in another screw.   It is imported to place the screw as you drill to
keep alignment, even when using the glue.   Later take out the screw and
break the glue, reassemble.



On Thu, May 18, 2017 at 5:13 PM, jimlux  wrote:

> On 5/18/17 2:36 PM, Chris Albertson wrote:
>
>> It would be easy to re-design the job for cheaper machining..  Do you
>> really need to tap the holes?  You might use self taping screws.  Id the
>> would work then you can do the work yourself with just a hand drill.
>>
>> OK it you must use machine threads and they must be #4 size try "rivets"
>> these work like pop rivets but leave a hollow thread insert in the hole
>> that will take screws.  Takes all of 5 seconds to install a thread hole.
>>
>> Think again about threading aluminum.  It is not very strong, it would be
>> easy for an end user to strip the #4 threads.  Better to use the rivet or
>> other steel thread insert.Even native nuts  installed with flush
>> rivets
>> is better
>>
>
> Interestingly enough, for 4-40 hardware, the screws fail before the
> aluminum does.  The area of the thread engagement is quite a bit larger
> than the cross section of the fastener that is not thread.
>
> For large fasteners, where the thread depth is a smaller fraction of the
> fastener diameter, this may not be the case (as anyone who has stripped the
> threads on an aluminum cylinder head with a steel sparkplug will know, in a
> deep and visceral way).
>
>
>
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> ailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 

Chris Albertson
Redondo Beach, California
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Joseph Gwinn]

On Fri, 19 May 2017 12:00:01 -0400, time-nuts-requ...@febo.com wrote:
> Re: [time-nuts] Machining some aluminum help!

It's much easier to use thread-forming taps in aluminum than thread 
cutting, and the threads are far stronger.  Blind holes are not as 
large a problem.  Lubricate with soft wax, not Tap-Magic.  Also, why 
4-40 in a 0.25" thick wall?  A larger screw will actually be easier and 
again, stronger.

.<https://www.mcmaster.com/#thread-forming-taps/=17p2qoh>

.<https://www.mcmaster.com/#lubricant-stick-wax/=17p2rpl>

Joe Gwinn
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Bill Hawkins]

These threads where there is not enough information to define the
problem can grow forever, because they are based on speculation, not
facts.

Corby, you have decided what you need based on what you know, but the
rest of us need a more general statement of the problem.

Unless, of course, that is something you do not choose to reveal.

Bill Hawkins


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Bob kb8tq]

> On May 18, 2017, at 8:13 PM, jimlux  wrote:
> 
> On 5/18/17 2:36 PM, Chris Albertson wrote:
>> It would be easy to re-design the job for cheaper machining..  Do you
>> really need to tap the holes?  You might use self taping screws.  Id the
>> would work then you can do the work yourself with just a hand drill.
>> 
>> OK it you must use machine threads and they must be #4 size try "rivets"
>> these work like pop rivets but leave a hollow thread insert in the hole
>> that will take screws.  Takes all of 5 seconds to install a thread hole.
>> 
>> Think again about threading aluminum.  It is not very strong, it would be
>> easy for an end user to strip the #4 threads.  Better to use the rivet or
>> other steel thread insert.Even native nuts  installed with flush rivets
>> is better
> 
> Interestingly enough, for 4-40 hardware, the screws fail before the aluminum 
> does.  The area of the thread engagement is quite a bit larger than the cross 
> section of the fastener that is not thread.

There are a lot of variables involved. Run the screws in and out of the 
aluminum a number of times and 
the holes will fail first ….There are other gotchas as well.

Bob


> 
> For large fasteners, where the thread depth is a smaller fraction of the 
> fastener diameter, this may not be the case (as anyone who has stripped the 
> threads on an aluminum cylinder head with a steel sparkplug will know, in a 
> deep and visceral way).
> 
> 
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[jimlux]

On 5/18/17 2:36 PM, Chris Albertson wrote:

It would be easy to re-design the job for cheaper machining..  Do you
really need to tap the holes?  You might use self taping screws.  Id the
would work then you can do the work yourself with just a hand drill.

OK it you must use machine threads and they must be #4 size try "rivets"
these work like pop rivets but leave a hollow thread insert in the hole
that will take screws.  Takes all of 5 seconds to install a thread hole.

Think again about threading aluminum.  It is not very strong, it would be
easy for an end user to strip the #4 threads.  Better to use the rivet or
other steel thread insert.Even native nuts  installed with flush rivets
is better


Interestingly enough, for 4-40 hardware, the screws fail before the 
aluminum does.  The area of the thread engagement is quite a bit larger 
than the cross section of the fastener that is not thread.


For large fasteners, where the thread depth is a smaller fraction of the 
fastener diameter, this may not be the case (as anyone who has stripped 
the threads on an aluminum cylinder head with a steel sparkplug will 
know, in a deep and visceral way).




___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[J. L. Trantham]

Corby,

Is it a 'pressure' seal or a 'vacuum' seal?

Vacuum should be much easier to achieve.

Joe

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of 
cdel...@juno.com
Sent: Thursday, May 18, 2017 3:34 PM
To: time-nuts@febo.com
Subject: [time-nuts] Machining some aluminum help!

Well that generated a lot of advice and thanks for it!
I think I might do it myself and go with a 1/2" hole depth and 1/4"
threaded depth.
I'll get some of that Aluminum Tap magic, some new taps and new drill bits.
Good idea about drilling the end plates first and drilling thru to match.
Between the end plate and the tube is a gasket that needs to seal pressure and 
moisture tight. That's why I used 5 per side.

Will let you know how it turns out.

Cheers,

Corby

___
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Chris Albertson]

So the goal is not to attach end plates, that is the solution. The real
goal is a sealed container that can be re-opened.I suggest a trip to
the plumbing supply store.Why not just use screw-on end caps

It you need it sealed 4-40 screw are not able to provide any reasonable
clamping force.   The weak link is the aluminum threads.  You need enough
force to deform the gasket material and those little screws are not going
to do it.

If you need a gas tight chamber, look at plumbing parts.  They make
screw-on end caps with both make and female threads.

There is also a system for brazing alumni that work almost as well as
celiac welding and you can do it with a propane lumber's torch.   They sell
the rods at Harbor Freight.

Why not post a specification (enclose with x,y,z inside dimension,
water/gas tight/ ends on one end,) and ask people for ideas on the
lowest cost way to make that using simple tools.

There are SO MANY solutions, one is double sided, coper clad PCB material.
You can cut it with a wood saw and then solder the panels together to make
a box.   I find that I can solder brass screws to copy PCB material and
make thread posts or studs.

On Thu, May 18, 2017 at 4:13 PM, Andy ZL3AG via time-nuts <
time-nuts@febo.com> wrote:

>
> Why are my eyes watering?
>
> On 19/05/2017, at 5:03 AM, Bob Darlington wrote:
>
> >  I had
> > to soak my cavity ring in nitric acid for a month to get the tap out.
> >
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 

Chris Albertson
Redondo Beach, California
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Ken Winterling]

Andy,

Although this is a hydraulic cylinder, this is along the lines of what you
described.




On Thu, May 18, 2017 at 19:18 Andy ZL3AG via time-nuts 
wrote:

>
>
> Or go for thicker wall aluminium tube, oversized endplates and long bolts
> or threaded rods running the entire length down the outside of the tube so
> you're clamping both ends in one operation. No tapping required. Simples!
>
>
>
>
> On 19/05/2017, at 6:16 AM, Tim Shoppa wrote:
>
> > I bet you went to 0.25" wall square tubing only because you want to tap
> the
> > walls for 4-40. Alternative designs can let you use much thinner material
> > and a very different flange on the ends, but the costs will likely move
> > towards welding/brazing rather than machining.
> >
> > Tim N3QE
> >
> > On Thu, May 18, 2017 at 12:54 PM,  wrote:
> >
> >> Hi,
> >>
> >> I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long.
> >>
> >> I need 20 holes in each end tapped for 4/40 and 1/2" deep.
> >>
> >> This is for a Rubidium project.
> >>
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
-- 

Ken
WA2LBI

Sent from one of my mobile devices
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Andy ZL3AG via time-nuts]

Or go for thicker wall aluminium tube, oversized endplates and long bolts or 
threaded rods running the entire length down the outside of the tube so you're 
clamping both ends in one operation. No tapping required. Simples!




On 19/05/2017, at 6:16 AM, Tim Shoppa wrote:

> I bet you went to 0.25" wall square tubing only because you want to tap the
> walls for 4-40. Alternative designs can let you use much thinner material
> and a very different flange on the ends, but the costs will likely move
> towards welding/brazing rather than machining.
> 
> Tim N3QE
> 
> On Thu, May 18, 2017 at 12:54 PM,  wrote:
> 
>> Hi,
>> 
>> I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long.
>> 
>> I need 20 holes in each end tapped for 4/40 and 1/2" deep.
>> 
>> This is for a Rubidium project.
>> 

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Andy ZL3AG via time-nuts]

Why are my eyes watering?

On 19/05/2017, at 5:03 AM, Bob Darlington wrote:

>  I had
> to soak my cavity ring in nitric acid for a month to get the tap out.
> 

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Chris Albertson]

It would be easy to re-design the job for cheaper machining..  Do you
really need to tap the holes?  You might use self taping screws.  Id the
would work then you can do the work yourself with just a hand drill.

OK it you must use machine threads and they must be #4 size try "rivets"
these work like pop rivets but leave a hollow thread insert in the hole
that will take screws.  Takes all of 5 seconds to install a thread hole.

Think again about threading aluminum.  It is not very strong, it would be
easy for an end user to strip the #4 threads.  Better to use the rivet or
other steel thread insert.Even native nuts  installed with flush rivets
is better

So try self threading screws first them go to threaded inserts, you could
install 100 4-40 inserts in one hour using just hand tools.


On Thu, May 18, 2017 at 9:54 AM,  wrote:

> Hi,
>
> I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long.
>
> I need 20 holes in each end tapped for 4/40 and 1/2" deep.
>
> This is for a Rubidium project.
>
> The local machine shop want's $360.00
>
> Anyone have a machining setup that could do the work a bit cheaper?
>
> If not I'll give it a try myself.
>
> Please contact me off list.
>
> Thanks!
>
> Corby Dawson
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 

Chris Albertson
Redondo Beach, California
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[jimlux]

On 5/18/17 1:34 PM, cdel...@juno.com wrote:

Well that generated a lot of advice and thanks for it!
I think I might do it myself and go with a 1/2" hole depth and 1/4"
threaded depth.
I'll get some of that Aluminum Tap magic, some new taps and new drill
bits.
Good idea about drilling the end plates first and drilling thru to match.
Between the end plate and the tube is a gasket that needs to seal
pressure and moisture tight. That's why I used 5 per side.


I would make the end plate "real thick",with a machined groove for the 
o-ring, and use some sort of latches to hold it in place, rather than 
"lots 'o screws".  Unless you've got a real tight space constraint. How 
much pressure do you have to hold? That will determine the clamping 
force needed on your gasket (and potentially, on your fasteners).  Do 
you need the full 4.5x4.5" inside clear space? A 1/4-20 bolt in the 
corner might be a good way to go.


There's also inexpensive surplus vacuum equipment around, as well as run 
of the mill plumbing. Unless Steel (stainless or not) isn't an option.








Will let you know how it turns out.

Cheers,

Corby

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Scott McGrath]

Content by Scott
Typos by Siri

> On May 18, 2017, at 4:34 PM,   wrote:
> 
> Well that generated a lot of advice and thanks for it!
> I think I might do it myself and go with a 1/2" hole depth and 1/4"
> threaded depth.
> I'll get some of that Aluminum Tap magic, some new taps and new drill
> bits.
> Good idea about drilling the end plates first and drilling thru to match.
> Between the end plate and the tube is a gasket that needs to seal
> pressure and moisture tight. That's why I used 5 per side.
> 
> Will let you know how it turns out.
> 
> Cheers,
> 
> Corby
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Chris Albertson]

Yes, generally when something is expensive to manufacture it is because the
designer was not thinking about costs.  A design with 40 size "tiny" thread
holes in just not cost-effective.  A redesign could save hours work.

On Thu, May 18, 2017 at 11:16 AM, Tim Shoppa  wrote:

> I'm very dubious that you need a tapped 4-40 hole to be threaded any deeper
> than 0.25". If you work with the machinist I'm sure you can come up with
> some reasonable spec that does not require a bottoming tap and will save
> you a lot of money.
>
> I bet you went to 0.25" wall square tubing only because you want to tap the
> walls for 4-40. Alternative designs can let you use much thinner material
> and a very different flange on the ends, but the costs will likely move
> towards welding/brazing rather than machining.
>
> Tim N3QE
>
> On Thu, May 18, 2017 at 12:54 PM,  wrote:
>
> > Hi,
> >
> > I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long.
> >
> > I need 20 holes in each end tapped for 4/40 and 1/2" deep.
> >
> > This is for a Rubidium project.
> >
> > The local machine shop want's $360.00
> >
> > Anyone have a machining setup that could do the work a bit cheaper?
> >
> > If not I'll give it a try myself.
> >
> > Please contact me off list.
> >
> > Thanks!
> >
> > Corby Dawson
> >
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/
> > mailman/listinfo/time-nuts
> > and follow the instructions there.
> >
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 

Chris Albertson
Redondo Beach, California
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Scott McGrath]

If you need pressure moisture tightness you are going to want to have machinist 
mill tube ends and plates flat if you take off say 075-100 thousands deep and 
.225 thousanths around edge of plate and have machinist predrill holes in cover 
plate you will have both a tight seal and drill guide for the tube drilling and 
tapping.


Content by Scott
Typos by Siri

> On May 18, 2017, at 4:34 PM,   wrote:
> 
> Well that generated a lot of advice and thanks for it!
> I think I might do it myself and go with a 1/2" hole depth and 1/4"
> threaded depth.
> I'll get some of that Aluminum Tap magic, some new taps and new drill
> bits.
> Good idea about drilling the end plates first and drilling thru to match.
> Between the end plate and the tube is a gasket that needs to seal
> pressure and moisture tight. That's why I used 5 per side.
> 
> Will let you know how it turns out.
> 
> Cheers,
> 
> Corby
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[MLewis]

On 18/05/2017 4:34 PM, cdel...@juno.com wrote:
I think I might do it myself and go with a 1/2" hole depth and 1/4"
threaded depth.

Or go back to the shop and get a new quote with them knowing it's not 
bottom tapping, only 1/4" threaded depth.


Michael

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] Machining some aluminum help!

[cdelect]

Well that generated a lot of advice and thanks for it!
I think I might do it myself and go with a 1/2" hole depth and 1/4"
threaded depth.
I'll get some of that Aluminum Tap magic, some new taps and new drill
bits.
Good idea about drilling the end plates first and drilling thru to match.
Between the end plate and the tube is a gasket that needs to seal
pressure and moisture tight. That's why I used 5 per side.

Will let you know how it turns out.

Cheers,

Corby

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[jimlux]

On 5/18/17 11:53 AM, jimlux wrote:

On 5/18/17 11:16 AM, Tim Shoppa wrote:

I'm very dubious that you need a tapped 4-40 hole to be threaded any
deeper
than 0.25". If you work with the machinist I'm sure you can come up with
some reasonable spec that does not require a bottoming tap and will save
you a lot of money.


Fixing the table formatting


ThreadsFastener
Engaged Length0.125 in
TPI  40
Diameter  0.112 in
mean Diam0.0995 in Root Diam0.087 in
Engaged area 0.0391 sq in  Area   0.00594 sq in
Load200 lb
Shear stress  5,119 psiStress  33,644 psi
Ultimate strength42 ksiultimate74 ksi
Shear Strength   24,249 psiproof   55,000 psi
Safety factor  4.74Safety factor 1.63

AluminumSteel



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Lincoln]

I agree, tapping that depth in aluminum is just asking to gall the threads. If 
you have a decent alloy (6061 7075) you only need 1/8” to hold what ever is 
save to hold with a #4. If you need more strength then it would be best to use 
helicoil inserts. 

Where are you located? There are a number of hacker spaces across the country / 
globe. If you are in the US, there is also "The Tech Shop”. If you are in the 
SF Bay Area I would take a look.

Link


> On May 18, 2017, at 11:16 AM, Tim Shoppa  wrote:
> 
> I'm very dubious that you need a tapped 4-40 hole to be threaded any deeper
> than 0.25". If you work with the machinist I'm sure you can come up with
> some reasonable spec that does not require a bottoming tap and will save
> you a lot of money.
> 
> I bet you went to 0.25" wall square tubing only because you want to tap the
> walls for 4-40. Alternative designs can let you use much thinner material
> and a very different flange on the ends, but the costs will likely move
> towards welding/brazing rather than machining.
> 
> Tim N3QE
> 
> On Thu, May 18, 2017 at 12:54 PM,  wrote:
> 
>> Hi,
>> 
>> I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long.
>> 
>> I need 20 holes in each end tapped for 4/40 and 1/2" deep.
>> 
>> This is for a Rubidium project.
>> 
>> The local machine shop want's $360.00
>> 
>> Anyone have a machining setup that could do the work a bit cheaper?
>> 
>> If not I'll give it a try myself.
>> 
>> Please contact me off list.
>> 
>> Thanks!
>> 
>> Corby Dawson
>> 
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/
>> mailman/listinfo/time-nuts
>> and follow the instructions there.
>> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Tim Shoppa]

I'm very dubious that you need a tapped 4-40 hole to be threaded any deeper
than 0.25". If you work with the machinist I'm sure you can come up with
some reasonable spec that does not require a bottoming tap and will save
you a lot of money.

I bet you went to 0.25" wall square tubing only because you want to tap the
walls for 4-40. Alternative designs can let you use much thinner material
and a very different flange on the ends, but the costs will likely move
towards welding/brazing rather than machining.

Tim N3QE

On Thu, May 18, 2017 at 12:54 PM,  wrote:

> Hi,
>
> I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long.
>
> I need 20 holes in each end tapped for 4/40 and 1/2" deep.
>
> This is for a Rubidium project.
>
> The local machine shop want's $360.00
>
> Anyone have a machining setup that could do the work a bit cheaper?
>
> If not I'll give it a try myself.
>
> Please contact me off list.
>
> Thanks!
>
> Corby Dawson
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Brent]

People's (mis)perception of machine shop costs always amazes me.  All too
often they equate the fact that they could do it themselves (inaccurately)
on an old drill press and then hand tap with what a real shop will do - all
while that real shop has a $100k - $500k investment in a single machine.

Yes it can be done cheaper, but not profitably.  Its why people end up with
25k pounds of machinery in their garage (nothing wrong with that).  Its
really no different than what you would expect if you took your rubidium
standard into a small, profitable RF shop and asked them to characterize it
- they would charge you going rate.  Which is why many of us end up with
1000's of sounds of test equipment in the basement or back bedroom - in
addition to the machine shop in the garage.

Brent


On Thu, May 18, 2017 at 1:27 PM, Todd Caldwell  wrote:

> Tap Magic for Aluminum will be your best friend for this operation.
>
> I've been using it on some extrusion for a 3D printer project. It makes an
> amazing amount of difference.
>
> Good luck with you project.
>
> Todd
>
>
>
> On 05/18/17 12:18, Pete Lancashire wrote:
>
>> Price sounds reasonable to me.
>>
>> Tapping 40 each 4-40's that deep in to a closed hole is the killer. If I
>> still had my old Bridgeport J and was NC'ed Your looking at say 1 hour to
>> program, 10 minutes to mount in a vice and get aligned, drill 40 each #44
>> or #43 holes would be easy, but then slow things down, cross fingers and
>> start tapping.
>>
>> Doing it by hand, at 1/2 deep those holes better be close to "perfectly"
>> aligned.
>>
>>
>> On Thu, May 18, 2017 at 9:54 AM,  wrote:
>>
>> Hi,
>>>
>>> I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long.
>>>
>>> I need 20 holes in each end tapped for 4/40 and 1/2" deep.
>>>
>>> This is for a Rubidium project.
>>>
>>> The local machine shop want's $360.00
>>>
>>> Anyone have a machining setup that could do the work a bit cheaper?
>>>
>>> If not I'll give it a try myself.
>>>
>>> Please contact me off list.
>>>
>>> Thanks!
>>>
>>> Corby Dawson
>>>
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/
>>> mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/m
>> ailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> ailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Todd Caldwell]

Tap Magic for Aluminum will be your best friend for this operation.

I've been using it on some extrusion for a 3D printer project. It makes 
an amazing amount of difference.


Good luck with you project.

Todd


On 05/18/17 12:18, Pete Lancashire wrote:

Price sounds reasonable to me.

Tapping 40 each 4-40's that deep in to a closed hole is the killer. If I
still had my old Bridgeport J and was NC'ed Your looking at say 1 hour to
program, 10 minutes to mount in a vice and get aligned, drill 40 each #44
or #43 holes would be easy, but then slow things down, cross fingers and
start tapping.

Doing it by hand, at 1/2 deep those holes better be close to "perfectly"
aligned.


On Thu, May 18, 2017 at 9:54 AM,  wrote:


Hi,

I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long.

I need 20 holes in each end tapped for 4/40 and 1/2" deep.

This is for a Rubidium project.

The local machine shop want's $360.00

Anyone have a machining setup that could do the work a bit cheaper?

If not I'll give it a try myself.

Please contact me off list.

Thanks!

Corby Dawson

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
and follow the instructions there.


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Pete Lancashire]

Price sounds reasonable to me.

Tapping 40 each 4-40's that deep in to a closed hole is the killer. If I
still had my old Bridgeport J and was NC'ed Your looking at say 1 hour to
program, 10 minutes to mount in a vice and get aligned, drill 40 each #44
or #43 holes would be easy, but then slow things down, cross fingers and
start tapping.

Doing it by hand, at 1/2 deep those holes better be close to "perfectly"
aligned.


On Thu, May 18, 2017 at 9:54 AM,  wrote:

> Hi,
>
> I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long.
>
> I need 20 holes in each end tapped for 4/40 and 1/2" deep.
>
> This is for a Rubidium project.
>
> The local machine shop want's $360.00
>
> Anyone have a machining setup that could do the work a bit cheaper?
>
> If not I'll give it a try myself.
>
> Please contact me off list.
>
> Thanks!
>
> Corby Dawson
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[jimlux]

On 5/18/17 10:03 AM, Bob Darlington wrote:

Ask them what they'd do it for without the tapping.  Normally I'd do
something like this for free but 40 tapped 4-40 holes in heavy wall
aluminum is a pain.  It would be a miracle if I didn't break the tap off at
least once.


Very much so.. 40 tapped holes is a lot of holes


 Last time was for a resonant cavity amp (23cm band) and I had

to soak my cavity ring in nitric acid for a month to get the tap out.

At least it's not steel.


Or copper(!)

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Dave Daniel]

This is fairly easy to do on a vertical mill, but it can be done using a 
drill press.


I would machine and drill the end plates first. Then I would use 
hot-glue or double-sided tape to attach one of the end plates to the 
tube ends and use the end plate as a drilling guide to drill and tap the 
holes in the tube. The critical aspect of drilling the tube holes is 
that the end of the tube that is being drilled has to be absolutely 
perpendicular to the drill bit.


The drill press can also be used to tap the holes - with the drill press 
power off, install the tap and hand turn the spindle while using the 
lever arm to gently follow the tap in as it cuts. Since it is aluminum, 
hand-tapping the holes without using the drill press should be fairly 
easy also.


DaveD

On 5/18/2017 10:54 AM, cdel...@juno.com wrote:

Hi,

I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long.

I need 20 holes in each end tapped for 4/40 and 1/2" deep.

This is for a Rubidium project.

The local machine shop want's $360.00

Anyone have a machining setup that could do the work a bit cheaper?

If not I'll give it a try myself.

Please contact me off list.

Thanks!

Corby Dawson

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[Bob Darlington]

Ask them what they'd do it for without the tapping.  Normally I'd do
something like this for free but 40 tapped 4-40 holes in heavy wall
aluminum is a pain.  It would be a miracle if I didn't break the tap off at
least once.  Last time was for a resonant cavity amp (23cm band) and I had
to soak my cavity ring in nitric acid for a month to get the tap out.

At least it's not steel.

-Bob

On Thu, May 18, 2017 at 10:54 AM,  wrote:

> Hi,
>
> I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long.
>
> I need 20 holes in each end tapped for 4/40 and 1/2" deep.
>
> This is for a Rubidium project.
>
> The local machine shop want's $360.00
>
> Anyone have a machining setup that could do the work a bit cheaper?
>
> If not I'll give it a try myself.
>
> Please contact me off list.
>
> Thanks!
>
> Corby Dawson
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Machining some aluminum help!

[jimlux]

On 5/18/17 9:54 AM, cdel...@juno.com wrote:

Hi,

I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long.

I need 20 holes in each end tapped for 4/40 and 1/2" deep.



So you're putting 5 holes in each side? in the ends? (i.e. the long axis 
of the screw is within the wall?


That's a fairly tricky operation, especially if the tube is standard 
extruded tube, because the sides might not be perfectly flat or at right 
angles. You're drilling a 0.112 hole in a 0.25" wall, so you've got some 
clearance, but I assume you've got a matching cover plate you want to 
attach?


How critical is the spacing of the holes?

A good drill press (or vertical mill), and a really good clamping setup, 
and "match drill" the cover plate and the tube at the same time.




This is for a Rubidium project.

The local machine shop want's $360.00

Anyone have a machining setup that could do the work a bit cheaper?

If not I'll give it a try myself.

Please contact me off list.

Thanks!

Corby Dawson

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] Machining some aluminum help!

[cdelect]

Hi,

I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long.

I need 20 holes in each end tapped for 4/40 and 1/2" deep.

This is for a Rubidium project.

The local machine shop want's $360.00

Anyone have a machining setup that could do the work a bit cheaper?

If not I'll give it a try myself.

Please contact me off list.

Thanks!

Corby Dawson

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.