Above photo is my Gosford complete with the Overhead. Click on the photo to see the Main North Album at Flickr

Tuesday, August 31, 2021


Over the years for uncoupling locos and rolling stock I’ve used In Track Magnets, under track Electomagnets from Kadee and Bob Olde, Toothpicks, Satay Sticks (skewers) Rix Dual Magnet Uncouplers etc. Due to the extra effort and getting the location correct when using Electromagnets, I've only installed a few. 

Now days I use Yellow Piksters purchased from Coles, Woolies etc. 

I have fitted Yellow Piksters to all of my Throttles so everyone has an "on hand" easy to use Uncoupler. 

Shown left, is a Pikster fitted to a Cab06, complete with the Operating Card and an external "White" Direction Button on the L/H side that allows easy one fingered operation of the Knob and changing the direction, leaving the Operator free to use the Pikster. 

For details of the Cab04/06 Direction Button see my web page.

Drill a hole in the Top of the Throttle making sure the Pikster will clear the Throttle circuit boards inside, shown right in a Radio Procab.

Install a piece of 3 mm Heat Shrink for a Guide then at the bottom, glue the Sleeve that comes with the Pikster to the back housing, making sure just enough of the Pikster sticks out of the Top, to be able to grab and not too much that can fowl the layout. 

Sliding the Pikster inside until the Handle fits tightly in the Sleeve, keeps the Pikster secure and leaves the "hairs" of the Pikster Head protected and not being squashed out of shape. 

I’ve accumulated lots of the Kadee 321 In Track Magnets but all of us know they cause unintentional uncoupling of the rolling stock on slow moving trains, certainly a problem on a mainline but okay on a Siding like into my Gosford Goods Shed and at the Sulphide Works. I'll replace this with an Electromagnet, one day.

One of my mates Ray P uses the large under track O scale permanent magnets in some places on his layout with a fascia lever/knob that rotates the magnet through 90 degrees, UP to under the rails to uncouple and DOWN to eliminate unwanted uncoupling. I was going to try these but as usual didn't get around to getting one. 

Uncoupling for my "Rear End Banking" operations: Banker Locos, 5069 and 5229 at Murrurundi Loco, 5063 at Fassifern and 4801 at Willow Tree, have their Front Couplers "Locked Open" using Blu Tac or a piece of .010" Phosphor Bronze wire. The Second Operator has to vigilant to keep his Banker pushing hard up against the Van, you don't want a gap, not very pretty. When necessary, the Banker Operator just slows down his loco to a stop and it "uncouples", while the train continues on. The Banker Operator then returns the Banker to it's original location.  

If I ever I get to install the Overhead at Gosford, using the Pikster will be difficult, I’ve been experimenting with Electromagnets at Gosford, having purchased a few of the Bob Olde’s Electromagnets, see December 1991 AMRM for details, at an exhibitions, some years ago. Shown below with a Relay for the Timer including the Diode "across" the relay's Coil at the terminals.

Recently I’ve acquired more Bob Olde Electromagnets so I need to get them into Gosford, Broadmeadow etc.

Uncoupling using a Pikster at Werris Ck’s Rear Platform where the track is 600 – 700 mm from the fascia and 1400 mm off the floor, is very difficult for this short arse Operator.

To fit the Up North West Mail at Werris Ck’s Rear Platform, I needed to uncouple on a curve. I knew uncoupling was a “no-no” on a “curve” but I didn’t want to drill another hole 2 inches away and secondly, I was “testing” uncoupling here.

I removed the Point Motor and fitted an Electromagnet. Tested okay, I fitted another Electromagnet at the other end for down trains.

To make the uncoupling procedure easier and to eliminate the chance of burning out the Electromagnets, you need to use a Momentary Switch and a Timer. I made a 20 second Timer and buried them in the wiring mess at Werris Ck’s Control Panel.

I fitted LED Platform Lights adjacent to where the Electromagnets to help Operators positioning the 48s for uncoupling. They’re illuminated when the electromagnet is energized.

Uncoupling the 48 worked most of the time for me, but when I gave a Mate my “new” Operating Card for the Up North West Mail to test out the new Electromagnets and my Instructions, he was having trouble uncoupling the 48 at the L/H end.

Discussing this issue with another mate and asking what they’re doing on their club layout, he told me they were trying the Rapido Uncouplers and had tested them on a “double curve” providing the worst alignment of loco/rolling and they worked 100% of the time. I need one at Werris Ck.

Rapido "Rail Crew" Uncouplers.

About 2 years ago I saw the new Rapido Uncouplers a mate was installing on his layout and was suitably impressed. Being slack I did not chase up with getting some of the Uncouplers.  

I was lucky to be able to borrow a Rapido “Rail Crew” Uncoupler to test it at my problem Double Curved turnout to see if I could get better uncoupling.

As per the Instructions, you need a 44 mm hole. Guess what size hole I use for my Peco Point Motors – 44 mm.

Replaced the Electromagnet with the Rapido, it could not be easier, it was a snug fit, how lucky was I. I’ll fit the supplied securing plates later.  

 Wired up as per the Instructions using the supplied momentary DPDT Switch, initially connected to a "local" 12.0 Volt D.C. Supply and I connected my LED Lamp Post as my "panel" indicator, illuminated with the Uncoupler in the "energized" position. 

Shown mounted under the Double Curve Peco Points, with the "Alignment" black line showing correct orientation with the Internal Blue LED Indicator illuminated, indicating the uncoupler is "energized". 


Uncoupling works EVERYTIME on this curved turnout.

The Kadee Trip Pins move further with the Rapidos when compared to my Electromagnets indicating why these Rapidos work so well and without the time constraints on uncoupling when using a Timer,

I’d thoroughly recommend using the Rapidos and they come with everything to get 100% uncoupling.

I have a lot of the Bob Olde Electromagnet Uncouplers, that I’ll continue using as I have to use what I’ve already got stashed under the layout, with the backup of installing a Rapido, if necessary.

If you don’t have a stash of Uncouplers, then I’d recommend the Rapido as the “go to” Uncoupler.

For more details on these Rapido Rail Crew Uncouplers, click here.  

Now I’ve got a second unit, I checked out how they work. 

Top removed, the Magnets and the Plate are in the "OFF" position with the Plate and Magnets “in line” with the rails.

The Coil is just visible through the hole below the L/H magnet & the Micro Switch Striker is shown above the R/H magnet.

Momentarily operating the Panel Switch to the ON, powers the Coil for a second with the polarity of the voltage to make Coil have the same magnetic field as the L/H magnet - Like "poles" (magnetic fields), REPEL, causing the Plate to rotate 90 degrees. The opposite magnetic fields between the lower magnet and the Coil, helps with this movement. 
The  Magnets and the Plate are now in the “ON” position, now "across" the rails, contacting the Striker and illuminating the Internal Blue LED.
When done, the Operator momentarily presses the Panel Switch to OFF. This again powers the Coil with the polarity of the voltage reversed, causing the Plate and Magnets to move back to the original position, with the Magnets "in line" with the rails that disable uncoupling.

The other side of the Rapido, showing the Coil, Internal LED, Micro Switch for the LED and associated electronics.

Pins 4 & 5 power the Coil, while Pins 1, 2 & 3 are for the LED. 

Note: The Coil is energized for about 1 second irrespective of how long the Operator presses the switch.

When looking at Rapido Uncoupler reviews on the Internet, at:

Dale said he wanted to power them from his existing 12 Volt D.C. supply but found they caused so much electrical noise when operating, that it adversely affected other electronic devices on that 12 Volt supply so he wired them into a separate 12 Volt supply. 

A few days after installing the Rapido, my Control Panels at Werris Ck and Port Waratah were dead. I found there was a short on the 12.0 Volts D.C Power supply, Fault traced to a burnt out 555 Timer chip for the Electromagnet Uncoupler; Rectified the Timer and both Controls Panels, okay.

Remembering what I had read above and what's good "electronics practice" is when using Coils/Relays, there should be a Diode "across" the Relay Coil, to suppress the Spike caused by a collapsing magnetic field inside the Relay, when coil power is removed. I fit these Diodes on all my relay installations. There was no diode for the Rapido Coil, as this would be difficult due to the reversing polarity during normal operation of the Rapido.

In my haste to get 12 Volts for my Rapido installation, I connected my Rapido to the 12.0 Volts supply at Pin 8 of the burnt out 555, I suspect a “spike” let the smoke out of my 555. 

I installed a separate 15.0 Volt D.C. Power Pack for the Rapido.

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