LGB 20576 and 20577 F7A Santa Fe (grey/blue)

[Wim6467]

Hello from Belgium !

Does anyone have experience with the F7 LGB Santa Fe 20576 and 20577 (grey-blue). These are locomotives from the beginning of Marklin-LGB and I wonder how the quality of these locomotives is? Is this comparable with my LGB 20570 and 20586 Santa Fe? Does it have Bühlermotors ? How is the decoder (LGB 55027?)? Quid the used plastics? Compatible with the grey/red Santa Fe F7A 20570 en B 20582?
I'm thinking about making a A-B-A unit so any help is welcome.

 

[AlanL]

I recently had a problem with my 20576 and 20586 (blue/grey)A-B combination. I also have an older 20570 (red/grey)running solo.

The repair involved swapping the rear panel that contains the power switch and two sockets from the older locomotive and fitting to the newer 20576 version.

I believe that the decoder in the 20576 is a standard LGB two-motor decoder and the motors are also as standard.

So I would say that the powered units are identical apart from some minor differences such as the headlights. On the older locomotive, there are two bright lights and the newer locomotive has one less bright light.

Alan

 

[Wim6467]

Thank you Alan for this very useful information!

Wim

 

[adverse camber]

I too have a blue/grey ABA combination. Despite a lot of effort the speeds of the motors in the two A units seem to be very slightly different (even after trying to play the DCC settings) and between then the B unit regularly derails. In the end I have given up running it in the ABA configuration and just use AB and A separately. It may be possible to get it all running well but I think it would be a lot of effort and you may end up like me not bothering.

 

[Wim6467]

I too have a blue/grey ABA combination. Despite a lot of effort the speeds of the motors in the two A units seem to be very slightly different (even after trying to play the DCC settings) and between then the B unit regularly derails. In the end I have given up running it in the ABA configuration and just use AB and A separately. It may be possible to get it all running well but I think it would be a lot of effort and you may end up like me not bothering.

Ok, this is useful information that I shall keep in mind!

 

[AlanL]

I too have a blue/grey ABA combination. Despite a lot of effort the speeds of the motors in the two A units seem to be very slightly different (even after trying to play the DCC settings) and between then the B unit regularly derails. In the end I have given up running it in the ABA configuration and just use AB and A separately. It may be possible to get it all running well but I think it would be a lot of effort and you may end up like me not bothering.

Your experience with the A-B-A combination is interesting because in theory they are designed to run as a unit. The LGB instructions tell you how to configure the setup and it seems straight forward. I've never ran my F7's as an A-B-A combination but there are some points that I might suggest.

Both of my F7's have suffered with loose connectors to the motor blocks. My red F7 stopped dead recently and I found that both motor connectors were lose. Prior to stopping dead the loco seemed to be running fine. Did both connectors come lose together by coincidence? A slight loss of drive to one set of wheels could cause your problems.

Did you try turning off the back EMF ? Back EMF can be an untamed beast if the locos are not in balance. I've recently set up a pusher loco on the end of a train and after many derailments of the train I found that the back EMF had to be set at a low level. The decoders were not the same, one was an LGB and the other a Massoth so it can be done. I wished that I had started with the back EMF turned off and gradually increased it to enable the train to climb a 2% slope.

The B unit is very light and is the first to derail especially if I've had to press the emergency stop button! If nothing else works, I would suggest removing the speaker from the B unit, it is not used in the A-B-A combination, and filling the area with a bag of something heavy.

Alan

 

[PhilP]

Could there be a new motor in one unit?

I was informed the Buhler motors had undergone a design change, and the latest (identical part) were even more efficient, so different characteristics to older motors..

I tend to run 'bare' motor blocks. - A pair of 'croc-clips' can bridge the pins, about a foot apart on the track, and select 'near-enough' matched-pairs, where I can..
Have sometimes swapped a new motor into a single-motor loco, to get two similar performance motors for a bigger loco..

PhilP.

 

[AlanL]

That's a good tip about the matching of motors. If ever I have a motor fail I should replace them as pairs in my big twin motor locos. My F7A Santa-Fe red is my oldest loco and is the most 'miles on the clock' with wheels that show it's use but the motors are still going strong, touch wood.

Alan