Extra Pick Ups for your Locos & Tenders. 10/08/19
Many locos have below par electrical pick ups causing intermittent running, stalling on points or stopping at the slightest hint of dirt on the track. More so with steam locos than diesels
To reduce these problems the loco electrical pickup foot print length has to be increased by adding extra pickups.
These power interruptions have become more of an issue with the increasing popularity of sound locos. Power interruptions are nothing new. With non sound locos, the loco would mostly coast through the interruption with only a slight hesitation but with sound locos, this same slight hesitation you now hear this interruption because the sound decoder resets and starts making sounds again from idle, causing a real annoying effect.
For steam engines due to their design less than 50% of their wheels pickup compare to diesels that have most of the 8 or 12 wheels picking up.
For example my 4-6-0 Austrains 36 Class steam engine with a split chassis and a tender with a total of 18 wheels only 6 (33%) pickup power. Effectively this loco has the same pickup as an 0-6-0 tank steam engine and always stalls on my Peco Double Slips and on many other points due to the gaps.
The C36s C38 D50, D53s etc brass locos and DJH brass and white metal kits may be physically long but have less than desirable pickup. Half the main driver wheels pickup on one rail and half the tender wheels pickup on the other rail. The footprint length is really only 2 inches, 5 cms long, that is too short.
One of the first things to do on a poorly performing loco suffering from what seems to be power pickup problems, is check for over lubrication. I found plenty of grease around the axle bearings on the 30T. Cleaned all this away and lightly lubricated with Peco Electrolube oil. This reduced the sound resets somewhat.
Extra Pickups I have installed:
Bergs brass 4-6-0 30T Class.
Attach a thin piece of Veroboard along the insulated drive side and install .4 mm phosphor bronze wire pickups.
Adding a Tomar Shoe 805 from Tomar Industries available in Sydney from the Model Railroad Craftsman, to the tender in between the two rear axles for the insulated R/Hand wheels. Tested What a great improvement. to the tender increased the pickup footprint for the right rail.
Shown above is the Tomar Shoe on the track. With it painted black, it will hardly be noticed.
This loco now performs flawlessly, and negotiates all the layout dead spots and even negotiates a couple of dead frog points that is what I want ultimately on my layout.
Austrains 4-6-0 C36 steam loco.
This loco has a split chassis with power pickups on the locos 6 drivers. Fitting tender pickups, once again extends the footprint and I did this two ways.
I drilled a .4 mm hole through the bogie webbing and fitted .4mm phosphor bronze, soldering the wires to what looks like an ugly joint. I slid the tinned wire under the tinned .4mm P/B pickup and deliberately left it untrimmed and did not curl the wire around the P/B pickup wire, so there is a large flat blob of solder preventing the P/B wire from moving around that secured the P/B pickup in the bolster.
On the other bogie I used Kadee Springs as per Harold Minkwitz’s article. This required more time and 4 springs 10BA nuts and bolts and required much more time, but what looks like more professional installation. Most probably works better too.
As with both installations, you need to adjust the tension of the pickups to allow the wheels to move.
A diesel extra pickup installation that can be done on Main West and AR mechanisms or similar is the one that is described by NMRA member Gerry Hopkins.
On my C30 and a Z26 tank engines that only have 0-6-0 electrical pickup and I cannot add extra pickups to increase the length of the footprint, I will use a Lenz Gold Mini Back EMF decoder with a Power Module. To see more on this see my article Lenzs USP absolutely great for HO 0-6-0 stalls.
Also see my article on Stay Alive for NCE, TCS & Soundtraxx DSD decoders.
Why do steam locos stop more than diesels?
The trick in getting rid of power interruption (and sound resets) is to add pick ups to a loco that extends the length of the pick up foot print to allow for crossing of points. These bad electrical pick up points are compounded by the fact that the loco or tender rocks and rolls as it goes through points as it traverse the gaps in the rail.
Steam engine suffer these problems more as they have half the drivers (one side normally the right hand side) for one pick up and half the tender wheels for the other pick up that only gives a 3 wheel length footprint. In the case of the 30T, this is only 40 to 50 mm long. Diesels on the other hand, many have all wheel pick up that is 4 to 6 wheels (8 or 12 wheel diesels) and their footprint is 125 mm long for a NSW 48 Class and 150 mm for a NSW 45 Class.
When traversing points and this depends on what type, there is a dead spot at the frog. For example the dead spots on y points are as follows:
For the loco like a the 30T with only 3 wheels contacting the track AT BEST with a 40 to 50 mm footprint, there is a good chance that only one is in contact and sometimes, NONE. This results in the annoying sound reset or at worst a STALLED loco at the points.
Looking at the mechanics of all of this when going over the frog gap, the first of the 3 driver wheels falls into the gap and now the loco slightly tips that raises the loco chassis slightly and the rear wheel looses contact with the track, so now the only electrical path is via the centre wheel that in many cases is flangeless and probably not in contact for 50% of the time, so the loco looses power. Remember a break in the circuit of EITHER the left or right hand pick ups, the loco stops. The falling into the gap is can be reduced with a balanced by weight loco and a correctly adjusted pony truck spring that will provide some downward pressure on the pony wheels and reduce de-railing.