Sprung drivers?

[Schraddel]

Kevin,
i understand your question. As far as my experiences are, the electrical pick up will improve definitely better when all wheels have permanently contact to the railhead.
Thanks to Dan M. for the link. This is a very advanced group for running gears and i will tell you how far i went.

European models, especially of German prototype are beautiful looking pieces but sometimes very poor runners because of nasty running gears. As deeeep flanges are common here, which prevent derailing on uneven track, there is no necessity for the manufacturers to develop equalized running gears or anything else in this direction. In fact the rigid running gear of a todays loco model is just the same as it was in the aera of clockwork powered miniature trains. Most Modellbahners are satisfied running their trains in a speeding toy like matter on old and older tracks and even still older worn out tracks.
But not all of them.

This was one of those cases of a beautiful looking 0-6-0 Rangierlok / switcher / shunter but a lousy runner. The motor is good, the gear and gear ratio is good, but main problem was the poor electrical pick up. Speeding yes, but crawling?
To show what i am meaning, a couple of photos:

There i have made a huge dent into the rail for demonstration purposes. The left side wheels of the first an second axle have airtime. Your track on the layout will be far better than this, but even a gap of 0,02mm is a insulator for electric current.



Third axle over the dent, has contact to the rail. But now the the right side wheels of axle 1 and 2 have the airtime ... :wait:
And made your prayers that there is not even the tiniest fluff or gunk between the only wheel which has just contact to the rail on this side.

It will improve the pick up when all six wheel will have permanently contact to the rails .
What i have done here is written in chapter 7 of the principles of loco motive suspension und compounded with a little springing.
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In short terms:
- First axle wil become the rocking one.
- Second axle will be sprung loaded.
- Third axle will stay rigid.



This simple piece of 1,2mm brass wire will become the central bearing for the first axle.



The bearings for axle 1 and 2 will be filed or milled so that:
- 1st axle is able for rocking
- 2nd axle is able to take sprung action
- the botton plate will also be modified to enable rocking or springing



The modified running gear. Flanges were also reduced to NMRA Standards.
The leaf type spring is the "H" shaped piece.


The side rods.
As you see, this is a combination of continous and jonted. Here in this case the bore in the middle has an oval shape vertical! This enables the 2nd axle to travel up and down although the side rods are rigid.


Have a look what takes action now on the same spot:



All wheels are permanently onto the rail.

Now this loco runs as good as it looks like. Even the slowliest crawl is possible and no fear of stalling. Good bye speed switching.
Now it is a Rangierlok / shunter / switcher who can do it's duty in a prototipical manner.


My two Cents

Lutz