My expierience with big locos

[Schraddel]

Hello Bernhard and Wayne,

thank you for your efforts and thoughts you made. Some of your advices i have picked up, so e.g. the enlarging of the bores. But the soldering of the rods fixed onto the head, that will not work.
Sometimes you have to rethink a device, here it was to modify the existing device to make it work. The bend ends of the rods were clearly a failure.
- The ends have to be the shape of a somewhat "knob".
- This knob must be moveable as the angle of the guide rods, in relationship to the diaphragm head, will change whenever the loco begins to negotiate a curve.
- The knob must not slid out to the rear
- The knop must not slid of forward
At least i found a solution:


Here the bend ends of he rods were removed. Instead some pieces of 0,2mm brass sheet were drilled with 0,8mm (the diameter of the rods).
Those pieces were then soldered onto the ends of the rods. Mounting the rods into a drill chuck, take a rasp and make them round, here it is about 2mm. This will be a kind of an knob, a very flat one, but a knob.
Next take a milling cutter, one of this very small face cutter and mill
a) the styrene plate complete thru
b) the brass head end to a countersunk depth of app. 0.8mm.
This will guarantee the knobs have the movability they need and will prevent them to slid out to the rear.






Then make some bucklers out of the 0.5mm black styrene. Glue them with some styrene glue onto the sunks. But beware, that the knobs hav still enough space to take movement action. So the bucklers will not be pressed in flush. The overlaying can later, when the styrene glue is completely dried out, filed flush to the surface.
The use of styrene glue prevents the rods of going sticky or even solid, as the sort of glue does not adhere on brass.





One of the tasks was the repositioning of the coupler bolt, according RP37, to get an optimal loco to tender distance. Here it was simplier to make a new one out of brass stock.





So the modified plate looks like.





Next was test running.





Taking a Atlas #4 switch. This switch is in an industrial spur were such big loco do not belong to.





But she was able to take the #4 switch and the reversed curve. Here the limit is reached and you can see the start of gaping.





Another industrial spur. Here is the very limit. And this limit is determined by the long rigid wheelbase of the four coupled loco with it's 73' drivers.
The nuts on the rear end of the rods were after the test running secured by a little drop of AC.

My opinion, if this works in tight curves of industrial spurs, so it will work on mainline stretches with more gently curvatures too.


Cheers Lutz