LGB 10345 shuttle is short cycling

bmartinpe

Registered
25 Dec 2020
1
0
71
Tennessee
I installed the LGB 10345 shuttle unit and it short cycles. The loco starts up, then reverses before it reaches the break at the first diode. After it passes the diode, it does not reverse, but continues in the same direction to run off the track. Checked to see that the track break sections are on the same rail. Checked to see that the diodes are pointed in the same direction. Double checked the wiring diagram to be sure that the power supply and the track power connections are correct. Please help. Bill Martin, Nashville, Tennessee
 

LVT

Analogue automated LGB Euro on 4 loops
24 Oct 2009
172
10
Near Atlantic City NJ USA
I installed the LGB 10345 shuttle unit and it short cycles. The loco starts up, then reverses before it reaches the break at the first diode. After it passes the diode, it does not reverse, but continues in the same direction to run off the track. Checked to see that the track break sections are on the same rail. Checked to see that the diodes are pointed in the same direction. Double checked the wiring diagram to be sure that the power supply and the track power connections are correct. Please help. Bill Martin, Nashville, Tennessee
Bill,
Try reversing the diode that the engine runs past on its way to running off the track. For the shuttle to work, each diode must cut the power to its respective isolated section, and then restore it when the unit reverses polarity on the main section. A remote possibility could be a faulty diode.

You can check that the diodes are correct by connecting your power supply directly to the main section and then manually use the direction switch to confirm the diodes’ orientation and functionality. Good luck on achieving the reliable and entertaining operation that a shuttle unit can provide.
 

Greg Elmassian

Registered
8 Mar 2014
4,670
687
San Diego
www.elmassian.com
Reversing the diode would explain running past the "break", but what explains it reversing before the first diode?

But the op's post indicates it reverses before the first diode, but next he says it goes past the diode and runs off the track, is this after it prematurely reverses, and heads off to the OTHER end?

Something is not quite clear here.

Greg
 

Dan

Registered
28 Jan 2010
372
33
Eastern MA
The LGB reversing units have a X1 and X10 switch/jumper connection for the timer circuit. I assume yours is set to X1 (times 1) not X10 (times 10).
 

Neil Robinson

Registered
24 Oct 2009
9,423
540
N W Leicestershire
I think some shuttle units are activated by the short circuit that occurs as the rail gap adjacent to a diode is traversed. If this is the case and the loco reverses before it reaches the first diode there may be an intermittent short in the loco. I suggest using a different loco.