Sergent coupler experiments


Jared Harper <harper-brown@...>
 

I've been doing some examination of and experimenting with Sergent
couplers. Comparing the coupler head with other scale size couplers
I think the Sergent wins hands down as far as prototype fidelity is
concerned. The major drawback is that it is designed to fit into the
standard HO draftgear box that is too large. The Accumate scale
coupler certainly has the advantage here. As far as uncoupling is
concerned I like uncoupling rod of the Sergent coupler. The other
scale couplers--Kadee and Accumate--both have the curved uncoupling
pin underneath the coupler so they can be magnetically uncoupled from
the bottom, but I feel this is unsightly. The Sergent coupler does
not have the pin and is uncoupled from the top. Several modelers
have asked, "How do you uncouple passenger cars with Sergent couplers
with diaphrams in the way?" That is a problem that I don't have a
solution for. How do Kadee and Accumate users who cut off the
uncoupling pin for more realistic appearance solve this problem?

Recently I have experimented with fitting the Sergent coupler to
Accumate's scale width box (Dennis Storzek, are these boxes available
separately?). I cut off the shank at the point the round hole and
the rectangular slot meet. I then narrowed the remaining shank on
each side of the rectangular slot. Using a round tapered file I
filed a circular hole at the top of the slot (nearest the coupler
head/knuckle) to match the curcular mounting boss in the Accumate
draftgear box. It fits like a charm and swivels fine. There's no
mounting for the Sergent "tension spring," however, but if one is
operating in a situation where you can always reach your cars
coupling without the tension spring present should not be a problem.
Just position the coupler by hand for a coupling of cars like
prototype brakemen do.

Jared Harper
Athens, GA


Rob Kirkham <rdkirkham@...>
 

Jared, this is interesting to me. Could you post a scan or photo of the modified sergent coupler and one of it in the Accumate box, please? I think this option offers a lot of hope - especially for tank car models where the draft gear can be so exposed!

As to the diaghragm issue, here is my completely untested idea: a tiny electro magnet in the diaghragm, above the coupler head is the start of the solution. Finding a way to turn it on and off conveniently is the next part of the problem. I don't know much about DCC, but couldn't one code a tiny curcuit with a separate DCC chanel that would power the elctromagnet with a push of a button?

On a simialr, but freight car theme, as I was coupling cars on a friend's layout today, I was thinking how I miss the sounds of real cars coupling (especially the clank and echoe of empty steel cars). I wonder what it would take to be able to rig an HO coupler to trigger a small sound loop/speaker hidden inside a freight car to react when coupled with the right sort of crash sound. Then again, maybe it would quickly drive everyone in the room round the bend.....

Rob Kirkham


Thomas M. Olsen <tmolsen@...>
 

Rob and Jared,

The couplers operate using a magnetized wand to lift the steel ball out of the lock block in the coupler head by magnetic attraction.. Why can't the ball and the wand be magnetized so that you could put the wand below the coupler head and have them repel rather than attract in the same fashion that placing the same poles of two magnets together cause them to repel?

Tom Olsen
7 boundary Road, West Branch
Newark, Delaware, 19711-7479
(302) 738-4292
tmolsen@udel.edu

Rob Kirkham wrote:

Jared, this is interesting to me. Could you post a scan or photo of the modified sergent coupler and one of it in the Accumate box, please? I think this option offers a lot of hope - especially for tank car models where the draft gear can be so exposed!

As to the diaghragm issue, here is my completely untested idea: a tiny electro magnet in the diaghragm, above the coupler head is the start of the solution. Finding a way to turn it on and off conveniently is the next part of the problem. I don't know much about DCC, but couldn't one code a tiny curcuit with a separate DCC chanel that would power the elctromagnet with a push of a button?

On a simialr, but freight car theme, as I was coupling cars on a friend's layout today, I was thinking how I miss the sounds of real cars coupling (especially the clank and echoe of empty steel cars). I wonder what it would take to be able to rig an HO coupler to trigger a small sound loop/speaker hidden inside a freight car to react when coupled with the right sort of crash sound. Then again, maybe it would quickly drive everyone in the room round the bend.....

Rob Kirkham



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Spen Kellogg <spenkell@...>
 

Thomas M. Olsen wrote:

Rob and Jared,

The couplers operate using a magnetized wand to lift the steel ball out of the lock block in the coupler head by magnetic attraction.. Why can't the ball and the wand be magnetized so that you could put the wand below the coupler head and have them repel rather than attract in the same fashion that placing the same poles of two magnets together cause them to repel?
Tom,

Magnets repel only when the same poles (ie: north or south) are pushed together. Even if you could magnetize the small ball in the coupler, there would be no way to ensure that the correct pole would be up. In fact, if there is enough room for the ball, I suspect that the wrong pole would rotate to the down side so that the magnet would always pull it down. If you were to replace the ball with an elongated shape, so that its orientation could not change, then you probably could do as you suggest, if you could get the internal magnet powerful enough. I doubt that HO couplers are large enough to allow this. O scale might, though. How did Lionel make their couplers work? Was it the repelling or attraction of magnetism?

Regards, Spen Kellogg


Dennis Storzek <dstorzek@...>
 

--- In STMFC@yahoogroups.com, Spen Kellogg <spenkell@o...> wrote:

...If you were to replace the ball with an elongated shape, so
that its orientation could not change, then you probably could do as
you
suggest, if you could get the internal magnet powerful enough. I doubt
that HO couplers are large enough to allow this. O scale might, though.
How did Lionel make their couplers work? Was it the repelling or
attraction of magnetism?

Regards, Spen Kellogg
But that negates the beauty of Sergent's patented ball lock. Other
scale couplers that try to model the actual shape of the lock fail
because there is too much friction for the weight of the lock to
reliably overcome. Sergent's stainless steel ball has maximum weight
with minimum surface area, and therefore minimum friction. Turning the
ball into a cylinder goes in the opposite direction from that design goal.

Lionel couplers (at least the fifties era ones I'm familiar with) are
locked by a rod that is forced upward into the bottom of the coupler
by a spring. The rod is attached to a lever that runs back under the
axles, where it is close to the rails, and thus close to the
uncoupling magnet, but this design requires the coupler be attached to
the truck, not a problem in Lionel's scheme of things. It does add a
lot of extra metal to the bottom of the truck. An extra wide spring
plank, maybe?

Since sergent's coupler locking ball falls by gravity, I wonder if it
couldn't be raised by a mecanical cam, the same as a prototype bottom
operated Type E coupler, but the operating parts would be tiny. No,
smaller than tiny.

Dennis Storzek


Patrick Wider <pwider@...>
 

Why can't an HO-scale operating coupler be made that is perfectly scaled in every way,
with the precision of a multi-jeweled Swiss watch, be available by the gross in every hobby
shop or certain websites, be self-lubricating, be cheaper than the current available
couplers, be pre-weathered, and be available for all important AAR designs: Type D, Type
E, Type H Tight-Lock.........? Once accomplished, what about N-scale?????

BTW: to have strong "N" and "S" "poles", magnets require ends, hence "bar" and
"horseshoe" magnets. Magnetizing a symmetric round ball to have strong opposite poles
and orienting such a thing properly would be virtually impossible. The magnetic wand has
"N" and "S" "Poles". All high school physics.

Pat Wider

--- In STMFC@yahoogroups.com, "Thomas M. Olsen" <tmolsen@U...> wrote:

Rob and Jared,

The couplers operate using a magnetized wand to lift the steel ball out
of the lock block in the coupler head by magnetic attraction.. Why can't
the ball and the wand be magnetized so that you could put the wand below
the coupler head and have them repel rather than attract in the same
fashion that placing the same poles of two magnets together cause them
to repel?

Tom Olsen


Jon Miller <atsf@...>
 

Why can't an HO-scale operating coupler be made that is perfectly scaled in
every way,
with the precision of a multi-jeweled Swiss watch<
Well while not exactly fitting the above does anyone remember the old
MDC coupler (I think it was MDC). It had a working knuckle and a lift pin
very similar to the prototype. I always thought is was very close to scale
but don't have any left. How to make it magnetic might be a problem
however.

Jon Miller
AT&SF
For me time has stopped in 1941
Digitrax, Chief/Zephyr systems, JMRI user
NMRA Life member #2623
Member SFRH&MS


W.R.Dixon
 

Message: 4 Date: Mon, 23 Jan 2006 01:27:53 -0500
From: "Thomas M. Olsen" <tmolsen@UDel.Edu>
Subject: Re: Sergent coupler experiments
Rob and Jared,
The couplers operate using a magnetized wand to lift the steel ball out of the lock block in the coupler head by magnetic attraction.. Why can't the ball and the wand be magnetized so that you could put the wand below the coupler head and have them repel rather than attract in the same fashion that placing the same poles of two magnets together cause them to repel?
You could with a bit of work get the ball polarized on opposite sides but the first time you brought the magnet near it it would flip over so the attractive side was down.

If you used a steel cylinder it would work but there might be too much friction to work properly.

In larger scales you should be able to make the uncoupler lever lift the ball. It is probably possible in HO scale but might not be worth the effort.

Bill Dixon


Patrick Wider <pwider@...>
 

Bill, please describe the precise process to do this. Thanks.

Pat Wider

You could with a bit of work get the ball polarized on opposite sides.......
Bill Dixon


Schuyler Larrabee
 


Thomas M. Olsen wrote:

Rob and Jared,

The couplers operate using a magnetized wand to lift the
steel ball out
of the lock block in the coupler head by magnetic attraction.. Why
can't the ball and the wand be magnetized so that you could put the
wand below the coupler head and have them repel rather than
attract in
the same fashion that placing the same poles of two magnets together
cause them to repel?

Tom,

Magnets repel only when the same poles (ie: north or south)
are pushed together. Even if you could magnetize the small
ball in the coupler, there would be no way to ensure that the
correct pole would be up. In fact, if there is enough room
for the ball, I suspect that the wrong pole would rotate to
the down side so that the magnet would always pull it down.
If you were to replace the ball with an elongated shape, so
that its orientation could not change, then you probably
could do as you suggest, if you could get the internal magnet
powerful enough. I doubt that HO couplers are large enough to
allow this. O scale might, though.
How did Lionel make their couplers work? Was it the repelling
or attraction of magnetism?

Regards, Spen Kellogg
It was attraction. The uncoupler magnet attracted a piece of the coupler so it dropped toward the
track, and released the knuckle via some mechanical connection inside the coupler head. When the
coupler was moved away from the uncoupler, the dropped piece would rise up again, but the knuckle
wouldn't close until either a finger did the job, or two couplers came together to mate.

SGL