Viktor Kovacs

Nice review! Now we have the XL, L, M and E motors (=could be called the Small motor) and a real servo. My only question would be the difference between the old receiver and the new if there is any. What builders could really use now is a new remote control with dual channel direct pwm mode, similar to what the old radio based RC system used. (the receivers support it, but there is no official remote that outputs this command)

Actually I have a 7715 and upgraded it to power functions with the motor and battery in the locomotive. I've done it before the first pf trains showed up for sale with parts ordered from s@h. This is what got me into bulding train mocs as an adult... www.brickshelf.com/cgi-bin/gallery.cgi?f=432819

The problem is that only 2 wheels pick up the power. Since the track is not smooth, sometimes only 3 wheels touch the rails, like a 4 legged table on a rough surface. Usually this contact problem is avoided by using all wheel pickups, like the 9V train motor. This does require split axles or isolator rings between the axles and the wheels. This complicates pickup but gives the best results and this is what lego used for it's 9V system. For you the best would be the same solution that most home made car lighting systems use in the model railway world. That is using 2 bogies with 4 wheels with each bogie picking up only one side. This means that any 3 wheel combinations out of 4 will give 1 good contact with the selected rail and with 2 bogies this means 2 good contacts regardless of track conditions. This also works for turnouts, but pickup safety there could be improved with larger wheelbase bogies (2 or 3 studs between wheels). just my 2 cents: Viktor ps: i could use a few of those metal wheels myself...

It is possible to do it the lego way: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=4495832 (the connectors on top of the the battery contain the classical 'short' between gnd-C1, 9V-C2) This allows the use of an old 9V battery box with the PF receiver. A little bit cramped but works: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=4495840 (the battery box occupies the space reserved for the train weights) I also use this trick to power bigger locomotives from old 9V AA battery boxes. (this means it is possible to have 5000 mAh of battery capacity in a locomotive and with cheap recharagable AA batteries) just my 2 cents...