Machining some aluminum help!
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
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, cdelect@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
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--
Dr. Don Latham
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304
Yo cdelect@juno.com!
On Fri, 28 Jul 2017 12:46:30 -0700
cdelect@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.
RGDS
GARY
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
gem@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
Nice!
Do you mind posting some photos?
Thanks.
Edésio
On Fri, Jul 28, 2017 at 12:46:30PM -0700, cdelect@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.