Up till three or so years ago the VLA (Very Large Array radio telescope)
was using a PDP 11/70. Most of the workstations were Sun Ultra 1 systems
that were horribly outdated to a point where I had already sent mine to
land fill a few years before. Now they have a spiffy Linux cluster on
modern
Which works very well, but unlike all of the English
thread combinations, you must keep the lathe's half-nuts
engaged to the lead screw ALWAYS. That means when you reach
the end of the thread, you must stop the lathe, and back
it up to the beginning of the thread to make the next cut.
With
On Sat, Dec 17, 2011 at 4:48 AM, Chuck Harris cfhar...@erols.com wrote:
Which works very well, but unlike all of the English
thread combinations, you must keep the lathe's half-nuts
engaged to the lead screw ALWAYS. That means when you reach
the end of the thread, you must stop the lathe, and
I suspect turret lathes are still used for shortish runs of some of the
simpler parts, like bushings and similar parts.
Not every shop looks like a NASA facility.
-John
==
On Sat, Dec 17, 2011 at 4:48 AM, Chuck Harris cfhar...@erols.com wrote:
Which works very well, but unlike
Chris,
You must be kidding! How old are you?
Lee K9WRU
- Original Message -
From: Chris Albertson albertson.ch...@gmail.com
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Saturday, December 17, 2011 11:00 AM
Subject: Re: [time-nuts] metric
On 12/17/11 9:14 AM, J. Forster wrote:
I suspect turret lathes are still used for shortish runs of some of the
simpler parts, like bushings and similar parts.
Not every shop looks like a NASA facility.
Oddly, NASA facilities aren't necessarily the most modern or sophisticated.
It takes an
The manual machines are still in use for limited production runs,
such as are used in prototype manufacture.
Screw machines, and second op lathes see extensive use in
manufacturing because they are quicker than CNC machines...
that and very cheap to use.
I use manual machines because it is
PM
Subject: Re: [time-nuts] metric / English
The manual machines are still in use for limited production runs,
such as are used in prototype manufacture.
Screw machines, and second op lathes see extensive use in
manufacturing because they are quicker than CNC machines...
that and very cheap
Hi Don:
Sure converting lengths is easy and I have metric, English and weird taps and
dies, but how do you turn metric threads?
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/Brooke4Congress.html
Don Couch wrote:
The idea that conversion to metric would
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf
Of Brooke Clarke
Sent: December 16, 2011 11:49
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] metric / English
Hi Don:
Sure converting lengths is easy
With a metric tap die set?
:-)
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Brooke Clarke
Sent: 16 December 2011 16:48
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] metric / English
Hi Don:
Sure
Not that hard, actually. My 1984-vintage lathe has an inch lead screw, but
the quick-change box that drives the leadscrew will do all of the inch and
most metric threads directly. The few weird metric pitches are
accommodated by changing two gears on the input side of the QC box. I
suppose that at
On Fri, Dec 16, 2011 at 8:48 AM, Brooke Clarke bro...@pacific.net wrote:
Hi Don:
Sure converting lengths is easy and I have metric, English and weird taps
and dies, but how do you turn metric threads?
How would you cut 40 tpi or 24 tpi? You put in the correct gears to
drive the lead screw so
You use the change gears in a ratio of 127:50 (254:100)
-John
==
Hi Don:
Sure converting lengths is easy and I have metric, English and weird taps
and dies, but how do you turn metric threads?
Have Fun,
Brooke Clarke
http://www.PRC68.com
There is no error with the change gears. The ratio of inches to
centimeters is exactly 1:2.54 or 100:254 or 50:127. It is often done with
a train of 3 gear pairs to get the center-to-center shaft spacing right.
-John
=
Not that hard, actually. My 1984-vintage lathe has an inch
On Fri, Dec 16, 2011 at 9:45 AM, George Dubovsky n4ua...@gmail.com wrote:
. I
I... suppose that at some very small level, there is some error in the
metric
threads produced (and I've never bothered to calculate it for my lathe) but
it's a VERY small error that has never been an issue for
I have small British lathe (Myford) with a 1/8 inch leadscrew, and a
127 tooth gear is inconveniently large.
By examining the ratio of every gear for every thread required (with
a simple basic program) I found
a solution within 50 parts per million for all metric threads.
The wierdest threads
: Re: [time-nuts] metric / English
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Date: Friday, December 16, 2011, 9:48 AM
Hi Don:
Sure converting lengths is easy and I have metric, English
and weird taps and dies, but how do you turn metric
threads?
Have
Hi Chris:
Yes. In hospitals they are measuring your height in feet and inches, but your weight is in kg (6' 1 120 kg). Sort of
like tire sizes which use inches for the wheel diameter and mm for the section width (P215/65R15 - 215mm section width,
15 rim diameter).
Even more interesting
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