I'll Keep You Alive

A fellow QR modeller asked me the other day about fitting a Stay Alive (or Keep Alive - what's in a name) in a Wuiske brand of QR 2100 loco, in HO scale.

So some research with my loco was in order and then eventually I decided to progress and whack a Stay Alive in my QR 2100 loco.  My plan is to have all my QR locos with stay alives to cater for dirty track and poor trackwork that you sometimes come across on some layouts...  Not that my wheels would EVER be dirty... no, never...  ;-)

Step one was to rip the loco's shell off - carefully. Crikey that bench of mine is getting messy again!  QR locos are so narrow and not too tall either - not much room I'm afraid.  And this loco has two parts of sweet FA space to play with.

Above you see the shell off, but when it sits on the mech, there's not much space free in there.

I proceeded to see where I could plonk a Stay Alive.  It turned out there's no room for a home made one, be it a five or a four cell version.  So I got the measurements for the ESU single cell Stay Alive - they call it a PowerPack, from the ESU website via a google search (careful what you search for...) and I proceeded to see if it would fit.  Bugger - nothing suitable without cutting or grinding the mech.

Don't know what made me look, but I did and found that the google search had given me the OLD measurements for the OLD version of the ESU PowerPack.  So with the new dimensions now on hand for the ESU 54671 PowerPack I recompared the spaces.  Here is the little Stay Alive itself.  There is a circuit board that does circuit type stuff with the electricity and there is a single super capacitor soldered to it.  It is 15.7 mm x 9.7 mm x 13 mm in size.

I found four possible sites or ways to install the Stay Alive - only one needed any filing or cutting.

The above photo shows the Stay Alive sitting in the mech tower.  It is a smidge too big on the circuit board so would not fit down low enough.  But I reckon a small amount of filing or grinding of the tower would allow it to fit nicely.

The above shot shows the rear end of the shell with the decoder, an ESU Micro, double sided taped to the inner roof. This space is suitable. You see, the yellow box I drew, well the decoder and Stay Alive will fit within that and will be below the height limit posed by the shell mounting post - pointed to by the red arrow.  This will be the method I use.

Another option I reckon is to use the mech tower, but modify the Stay Alive.  I haven't modified it in the above shot, but the yellow outline shows where the circuit board would be.  You see, the super capacitor part of the Stay Alive will fit in the tower. Now if we were to cut the heat shrink off the device and bend the circuit board 180 degrees out, it would sit in the space on the left of the tower - voila.

In the above shot you can see the Stay Alive on its side and on an angle sitting between the mech tower and the decoder plug area.  You just need to make sure it doesn't cover the screw hole that the loco shell uses.  Maybe even a piece of sheet styrene to make a plate for it to sit on and keep it from dropping down into the mech.

So I proceeded with installing the Stay Alive in the same area as the  decoder.  Now as per the photo above, this is the area above the loco I have to play with.  The yellow circle marks where I must stay clear to allow the shell screw to come through.

First up we need to solder the three wires from the Stay Alive to the Decoder.  I had to cut a bit of heat shrink carefully off of the Decoder first to expose the three solder pads where the wires will go.  Two pads are currently unused - easy peasy.  The one on the other side though, is used as the common for the circuit.  So there is already a wire soldered there - see the first of the two shots above.  

So careful careful when I solder.

The above two shots show that I needed to add some double sided tape to the Decoder and Stay Alive so I could position them in the shell so they wouldn't get out of position when the shell is put back on.

Above, we can see them now in place - noice one PK, I says to meself.

Above, the shell is loosely in place so I can test the loco to make sure that (1) she still works and that (2) the Stay Alive works.  I fired her up and all was good with the work :-)  She moves and also goes toot toot, and even does it for a few seconds when lifted off the track now.

Above, she is all screwed together and ready to run.

I won't talk about the 15 minutes or so poking around positioning wires and swearing a lot to get it all fitted in.  Maybe a hot glue drop here and there next time to hold wires out of the way might be the go :-)