# A question for DonR???



## Magic (Jan 28, 2014)

I'm thinking of building a small 4x8 HO layout for my great grandson, 7 years old. (I can't be that old.)

I will use an old DCC Bachmann F7 with a Bachmann EZ Command unit.

These have a button for forward and one for reverse.
Question is what will happen if the train is going forward 
and the reverse button is pushed?
Will the train stop before going in reverse or will it try to reverse 
while still going forward? :dunno:

Hope you can answer this but not from experience.   

Magic


----------



## J.Albert1949 (Feb 3, 2018)

I don't have the equipment or loco that you have.

But with dcc, I've found that the engine will first stop, then reverse.
Not "instantaneous reverse" as with dc.

If you have CV 4 (deceleration rate) set, that will govern how quickly it slows to a stop.


----------



## flyboy2610 (Jan 20, 2010)

I've sometimes wondered about that, myself. Particularly in regards to using between-the-rails uncoupling magnets. Imagine backing a car until it's over the magnet, push the direction button, then as soon as the loco moves a bit, push it again to dead-push the car into place. Haven't had the courage to try it yet, though!


----------



## DonR (Oct 18, 2012)

I had both the Bachmann DCC system and
the Bachmann F unit locos with Bachmann
decoders. 

The response of the decoder to a change in
direction is fairly quick, so while it necessarily
will stop it will immediately go in the
opposite direction when the FWD - REV buttons
are pressed. I never had a problem but only
on a few unintended times did I do the fast
reverse. My brother often used the buttons
when switching and had no problems as a
result.

Now if the throttle is wide open (  gasp!)
when the reverse buttons are used, I would
think that the plastic gearing could suffer.

In short, while you can do it...DON'T!

Don


----------



## flyboy2610 (Jan 20, 2010)

DonR said:


> In short, while you can do it...DON'T!
> 
> Don


"Captain, engineering reports 105% on the reactor possible, but not recommended." _The Hunt for Red October_


----------



## CTValleyRR (Jul 26, 2014)

I would say that's pretty much true for any DCC system: better to stop the loco with the throttle before reversing.


----------



## gregc (Apr 25, 2015)

CTValleyRR said:


> I would say that's pretty much true for any DCC system: better to stop the loco with the throttle before reversing.


the TCS T1 decoder with momentum will slow to a stop and then accelerate slowly in the opposite direction.

this is a common technique when decoupling over a magnetic decoupler, trying to time it so that the loco slows, stops and reverses directly over the decoupler.


----------



## Magic (Jan 28, 2014)

Thanks guys, just what I was looking for.
What I was concerned about was a 7 year old doing it at speed.

I'll just make sure he *doesn't* do it.
This is all in the planning stage and don't know if it will really happen.

Magic


----------



## CTValleyRR (Jul 26, 2014)

gregc said:


> the TCS T1 decoder with momentum will slow to a stop and then accelerate slowly in the opposite direction.
> 
> this is a common technique when decoupling over a magnetic decoupler, trying to time it so that the loco slows, stops and reverses directly over the decoupler.


I prefer to do it like a real engineer would.


----------



## gregc (Apr 25, 2015)

CTValleyRR said:


> I prefer to do it like a real engineer would.


we've seen that if you come to a complete stop, probably both the metal coupler and wheels are pulled toward the uncoupler. Quickly changing direction maintains the momentum of the car so that it continues to move away from the uncoupler or at least gives the loco a chance to move away before the coupler closes again.


----------



## flyboy2610 (Jan 20, 2010)

gregc said:


> we've seen that if you come to a complete stop, probably both the metal coupler and wheels are pulled toward the uncoupler. Quickly changing direction maintains the momentum of the car so that it continues to move away from the uncoupler or at least gives the loco a chance to move away before the coupler closes again.


So if you're only going at speed step 1 or 2 you'd be OK?


----------



## gregc (Apr 25, 2015)

flyboy2610 said:


> So if you're only going at speed step 1 or 2 you'd be OK?


if you're over the uncoupler and pull away slowly, the car is pulled toward the coupler and loco. The loco would need to pull away quickly, but momentum prevents that.


----------

