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Discussion Starter · #1 ·
Hi All
I finally found my Fleischmann BR614 DMU's to do a DCC conversion to
These were second hand from feeBay

I finished the motorized unit and gave it a run , the wheels needed a good clean to get it running right
But now it runs faster in reverse than in the Forward direction
It also appears to run smoother in the reverse direction.
The motor is the round type there is a conversion on the TCS site for a similar unit

The last time this was run on Analog It did the same thing

I have a couple of Warm white LEDs ( wired to the green )lighting the passenger section these appear to be on consistently when running in either direction
All lighting is powered by the blue wire

Any help would be appreciated

Regards Zmil
 

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Hi zmil,

Never really found the answer to this one - it does seem more common on the 614's than other stock that use's the 3-pole motor - maybe it has been run mostly in the direction it runs better ?
 

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Sometimes trains run badly in one direction if the drive circuit in the DCC decoder has been damaged. However if this happens on DC with no decoder fitted then it is a motor rather than a decoder problem.

With the default decoder settings, lights connected to the green wire should be controlled by one of the function buttons and not depend on direction.
 

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For some unknown reason turning the gear around solved this on a shunter after running in reverse better it settled out and is even as it was intended if the loco has been apart this may have happened.
 

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Many drives show this sort of effect. What you need to look for in the mechanism are assymetries. If this is all spur gear drive then the gear teeth may be very worn on the faces corresponding to the usual direction of operation. On worm gear drives the motor shaft may run more sweetly at one of it's limits of travel, which will be direction dependent.
 

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Discussion Starter · #7 ·
Hi All
Many thanks for the help so far

I'm going to pull the motor apart to investigate a bit further

and at the same time try a "light diffuser" experiment on the internal lighting
The Internal lighting is using a Fleischmann kit with bulbs replaced by LED's
It works OK at present , the light director spreads light up and down the passenger area
but there are still bright spots near the LEDs (which have been modified by filing)

Regards Zmil
 

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Discussion Starter · #8 ·
Hi All

Problem solved

The motor's three commutators , each had a build up , on one part of the contact area
at the start of the gap for about 15 degrees of arc .
So it only effected travel in one direction
Giving poor power transfer between the Carbon brush and the commutator at the start of
a new cycle in one direction but not the other

Cleaned up and The DMU works well in both directions

Regards Zmil
 
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